Research ArticleObservation Study on the Size Distribution ofSand Dust Aerosol Particles over Yinchuan China

Jiandong Mao Hongjiang Sheng Hu Zhao and Chunyan Zhou

School of Electrical and Information Engineering Beifang University of Nationalities Yinchuan 750021 China

Correspondence should be addressed to Jiandong Mao mao-jiandong163com

Received 25 November 2013 Revised 24 January 2014 Accepted 28 January 2014 Published 5 March 2014

Academic Editor Gwo-Fong Lin

Copyright copy 2014 Jiandong Mao et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

The Yinchuan area which lies in the eastern part of Northwest China is one of the main transportation paths and origins ofsand dust in China In order to investigate the aerosol number size distribution and its temporal-spatial evolution over this areadirect solar radiation data taken from September 2012 to October 2013 by a sun photometer CE-318 located at Beifang Universityof Nationalities (106∘291015840E 38∘131015840N) were analyzed The particle number size distributions were retrieved from the aerosol opticaldepth (AOD) by use of the extinction inversion method The experiment results show that although the averaged size distributionsatisfies basically the Junge function there are two obvious peaks at the particle radius of 06 120583m and 14120583m respectively Becausesand-dust weather occurs frequently the particle size distribution in Spring is obviously larger than that in other seasons whichcoincides with AOD variation tendency Moreover in sand-dust weather the particles number concentration is larger than that ofbackground weather with one order of magnitude especially for the number of concentration of large particles and giant particlesThe research results have very important reference value for quantitative study of the influence of aerosol on atmosphere physicsand chemistry process and monitoring of sand-dust weather and air pollution of this area

1 Introduction

Sand dust aerosol originated from arid and semiarid regionof China is the main component of aerosol in troposphereatmosphere of East Asia which produces extensive influenceon the ecosystem atmosphere environment and atmospherechemistry through intensive sand dust stormweather process[1] In order to study quantitatively the influence of aerosol onatmosphere physics and chemistry process researchers haveto analyze physics and chemistry characters of atmosphericaerosol in detail including the number concentration phasestate size distribution and chemistry component Thereforethe observation of sand dust aerosol of typical region isvery important for us to study the physics and chemistryproperties of aerosol [2]

In the past several decades some research teams havecarried out many observation experiments to investigate theoptical microphysics and chemical properties of sand dustaerosol by using some instruments such as sun photome-ter aerodynamic particle size spectrometer optical particle

counter Andersen sampler and lidar In 1991 DrsquoAlmeida et alresearched the global aerosol optical character includingdeserts area [3] In 1997 Porter and Clarkepresented anaerosol size distribution model summarizing measurementsof sulfate sea salt and dust aerosol obtained in the marineboundary layer and marine free troposphere [4] In 1999Karyampudi et al performed a detailed synoptic analysis of16 September to 19 September 1994 Saharan dust outbreakover the eastern Atlantic and of its origin at over West Africaduring the September 12 to 15 periods [5] In the west andnorth region of China some observations on particle sizedistribution were also conducted For example in 1995 Li etal used the dust counter and solar spectrometer measure andanalyzed the atmospheric AOD and particle size distributionin three places of North China Inner Mongolia Beijing andXinxiang region respectively [6] During April to May of1996 to 1999 Niu et al employed the APS-3310A to measureand analyze the sand aerosol particle size distribution in thedesert areas on both sides of the Helan Mountains underdifferent weather conditions including the background dust

Hindawi Publishing CorporationAdvances in MeteorologyVolume 2014 Article ID 157645 7 pageshttpdxdoiorg1011552014157645

2 Advances in Meteorology

BadanjilinDesert

TenggeliDesert Yinchuan

MaorusuDesert

Wulanbuhe

Desert

Huangtu Plateau

Figure 1 Map of the part of the northwest of China

sand blowing and sandstorm [2] In2006 Liu and Niu useda CE-318 sun photometer to retrieve the AOD and sizedistribution by extinction method in Inner Mongolia andthe results show that there were significant variations intemporal special distributions of AOD [1] In 2010 Mao etal used a compact Mie scattering lidar system for the firsttime to measure the optical properties and temporal-spatialdistribution of atmospheric aerosol particles from 1 to 10April over Yinchuan area [7]

The Yinchuan area lies in the eastern region of North-west China It belongs to the typical temperate continentalclimate and has some special features such as drought littlerain enough sunshine strong evaporation and big windsand Deserts such as Badanjilin desert Wulanbuhe desertTenggeli desert and Maowuso desert are located in thenorthwest west and east of Yinchuan area These deserts areone of themain sand dust sources of East Asia Figure 1 showsthe map of the part of the northwest of China ThereforeYingchuan area is one of the main transportation path andoriginal source of sand dust The observations and analyseson aerosol properties over this area have very importantreference value for quantitative study of the influence ofaerosol on atmosphere physics and chemistry process andmonitoring of sand-dust weather and air pollution

For investigation of the aerosol number size distributionand its temporal-spatial evolution over this area a series ofsystematically observation experiments were carried out bymeans of a sun photometer and many direct solar radiationdata were obtained By use of the extinction inversionmethod the particle size distribution is retrieved from theAOD In Section 2 the retrieval method of size distributionbased on extinctionmethod is discussed in detail in Section 3some experiments were carried out and the results areanalyzed in detail Finally a conclusion is given in Section 4

2 The Retrieval Method

The sun photometer CE-318 can acquire the AOD valuesimply In fact through the inversion of AOD the particlesize distribution can be obtained [8 9] Assuming that theparticulates in the atmosphere can be accurately modeled

by equivalent spheres whose refractive index is knownaccording to extinction method the relationship between theAOD and particle size distribution can be given by [6 10]

120591 (120582) = int

infin

0

1205871199032

119876119890(119903 120582119898) 119899 (119903) 119889119903 (1)

where 120591(120582) is the AOD passing through the whole atmo-sphere 119899(119903) is the aerosol size distribution of vertical columnthrough the whole atmosphere 119903 is particle radius 119898 iscomplex refractive index of aerosol particles and 119876

119890(119903 120582 119898)

is the extinction efficiency factor according Miersquos theory It isclear that this equation is the first kind of Fredholm integralequations

The aerosol size distribution 119899(119903) can be described as aproduct form by two functions namely 119899(119903) = 119891(119903)ℎ(119903)where 119891(119903) and ℎ(119903) are the slowly varying function andthe rapidly varying function respectively According to thePhillips-Twomey constraint inversion equation [11] one canobtain [6 10]

119891 = (119860119879

119860 + 120574119867)minus1

119860119879

120591 (2)

where 119860 is the coefficient matrix 119860119879 is transpose of 119860 and120574is the nonnegative Lagrange multiplier 119867 = 119870

119879

119870 is thesmoothing matrix and119870 can be defined as [12]

119870 =

[[[[[[[[[[[[[[

[

0 0 0 0 0 sdot sdot 0 0 0

minus1 2 minus1 0 0 sdot sdot 0 0 0

0 minus1 2 minus1 0 sdot sdot 0 0 0

0 0 minus1 2 minus1 sdot sdot sdot sdot sdot

0 0 0 minus1 2 sdot sdot sdot sdot sdot

sdot sdot sdot sdot sdot sdot minus1 0 0 0

sdot sdot sdot sdot sdot minus1 2 minus1 0 0

0 0 0 sdot sdot 0 minus1 2 minus1 0

0 0 0 sdot sdot 0 0 minus1 2 minus1

0 0 0 sdot sdot 0 0 0 0 0

]]]]]]]]]]]]]]

]

(3)

And also 119891 and 120591 are both the column vectors By usingthe iterative procedure (2) can be solved as follows [6]

119891(119899+1)

= (119860(119899)119879

119860(119899)

+ 120574(119899)

119867)minus1

119860(119899)119879

120591

119860(119899)

119894119895

= int

119903119895+1

119903119895

119870119894(119903 119898) ℎ

(119899)

119895

(119903) 119889119903

119894 = 1 2 119873 (wavelength numbers)

119895 = 1 2 119872 (size interval numbers)

(4)

where

119870119894(119903 119898) = 120587119903

2

119870119890(119903 120582119894 119898)

ℎ(119899)

119895

(119903) = ℎ(119899minus1)

119895

(119903) 119891(119899minus1)

119895

(119903)

120574(119899)

= 119887sum

(119860(119899)119879

119860(119899)

)119894119894

119873

(5)

Advances in Meteorology 3

Gobi

Three-North Shelterbelt

Beifang University ofNationalities

Figure 2 The campus location in Yinchuan

The convergence criterion can be defined as [6]

(sum(119891(119899)

119894

minus 1)2

119872)

12

lt 120575 (6)

For typical continent climate the Junge function is wellselected and it is in agreement with continent aerosol sizedistribution in the range of less than 2 120583m which can bewritten as

119899 (119903) = 119862119903minus(V+1)

(7)

where 119862 is coefficient and V is the distribution constant andits range is from 20 to 40

In this paper the Junge function is selected as initialrapidly varying function ℎ

(0)

119895

(119903) and the slowly varying func-tion 119891

(119899)

119895

(119903) can be solved by interpolating linearly 119899 orderssolution vector After some iterative procedures the stablesolution of ℎ(119899)

119895

(119903) is the unknown aerosol size distribution119899(119903) [6]

3 The Observation Experiments andResults Analysis

For investigation of the aerosol number size distribution andits temporal-spatial evolution over the Yinchuan area manyobservational experiments were carried out from September2012 to October 2013 at Beifang University of Nationali-ties (106∘E 38∘131015840291015840N) Yinchuan Ningxia China Figure 2shows the campus location in Yinchuan Yinchuan city is amedium sized city which is about 20 kilometers long fromeast to west and about several kilometers wide from south tonorth From the east to the west Yinchuan city can be dividedinto three districts namely Xingqing district Jinfeng districtand Xixia district The population is mainly concentrated inJinfeng district and Xingqing district Beifang University ofNationalities is located at thewest of XixiaDistrict namely inthewest of Yinchuan city In thewest and north of the campusthere are the famous Three-North Shelterbelt and the Gobidesert that is in the eastern foot ofmountain helan and hencethe population is very small

1013

1012

1011

1010

109

108

107

106

105

104

103

102

101

100

10minus1

10minus2

120574 = 2

120574 = 3

120574 = 4

Particle radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

Figure 3 The determination of parameters V of Junge function

A sun photometer CE-318 which is installed at teachingbuilding no 17 is employed to record the direct solarradiation data Every day the sun photometer works fromabout 800 to 1700 Beijing time and automatically recordsthe data except on the days when the sun was obscured byclouds and the rain or when snow or sand dust occur Up tonow a total of 14235 measurements were carried out In thispaper the seasons corresponding to the months are definedas follows Autumn is from September to November Winteris from December to February Spring is fromMarch to Mayand Summer is from June toAugust Considering that aerosoltype of this area mainly belongs to sand dust particles ininversion process the complex refractive index 119898 is assumedto be 15-001119894 [13] Moreover according to their sizes andproduction mechanisms the atmospheric aerosol can gen-erally be divided into three types namely nucleation mode(0001 120583m lt 119903 lt 01 120583m) accumulation mode (01 120583m lt

119903 lt 10 120583m) and coarse mode (119903 gt 10 120583m)In 1963 Junger used power function to describe the

relation between logarithm of particle number concentrationand logarithmof the particle radius In the extinctionmethodmentioned above the Junge distribution function is selectedas the initial rapidly varying function The selection ofparameter V value in (7) is given special attention in inver-sion process For determination of reasonable value of theparameter V some comparisons were made Figure 3 showsthat the size distribution curves under different parametersV of initial Junge function It can be seen that when V = 40

or 30 the retrieved size distribution curve is nonsmoothingnoncontinuous and retrieval process is instable but whenV = 20 the retrieval process is convergent Because extinctionfactor is not sensitive to extinction effect of large diametergiant particle the extinction method only is used to inversethe particle size distribution with diameter from 01 to 5 120583mand especially for the large particle with diameter from 01 to1 120583m the inversion results are more stable Extinctionmethod

4 Advances in Meteorology

01 1

1010

109

108

107

106

105

104

103

102

101

Particle radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

Figure 4 The averaged size distribution of the whole observationperiod

is less sensitive to the selection of initial function in theproper range and in a certain error range the selection ofinitial function is allowed to exist with a certain differenceNevertheless in order to make inversion result closer tothe true result choosing the more ideal initial functionand more reasonable smooth constraints will be required[14] Therefore when Junge function is selected as initialrapidly varying function the computed size distributioncannot always be in good agreementwith the real distributionin the whole size range that is in some size range theretrieval discrepancy is small but in other size range thelarge discrepancy may exist Reasonable selection of initialfunction is also very important in stabilizing the inversionprocess In this paper the particle diameter is within 01 to5 120583m and hence the retrieved size distribution can be in goodagreement with the real distribution in the whole size range

Figure 4 shows the averaged number size distributionduring the whole observation period It is obvious thatthe averaged size distribution basically satisfies the Jungefunction However there are two obvious peaks in therange from 001 to 2120583m which located at 06 120583m of theaccumulation mode and 14 120583m of coarse mode respectivelyAs can be seen from Figure 4 in Yinchuan area the aerosolparticle number size distribution is bimodal structure withtwo peaks located at the accumulation mode and coarseparticles respectively As mentioned above Yinchuan arealocated at the arid region surrounded by three deserts is animportant transportation path and origin of sand dust thatlies in the north of China Under such natural conditionsand atmosphere environment the first aerosol source inYinchuan area is very strong and hence sand dust particleswith larger size are dominant in atmosphere aerosol and theconcentration of aerosol particles in the accumulation modeand coarse mode is much higher than that of many cities ofdeveloped countries Also the number size distribution ofYinchuan area has some similar features with the other citieslocated at dust source area in the north of China such as EjinBanner and Dongsheng [6]

Figure 5 shows the monthly averaged AOD and seasonalaveraged number size distribution from September 2012 toOctober 2013 In Figure 4(a) the averaged AOD value inSpring is the largest and that in Autumn is the smallest Inthe Spring over the Yinchuan area and its surrounding areathe climate is very dry soil is naked and big wind blowsthe sand dust into the air easily therefore sand-dust weatheris frequent In fact in Spring 2013 several serious sand-dust storm processes occurred But in Autumn of Yinchuanrainfall is obviously more than other seasons thereforethe atmosphere is relatively clean In Figure 5(b) it can beseen that the seasonal variation tendency of size distributioncoincides with AOD value but the number concentrationin Spring is larger than that in Autumn with one order ofmagnitude

In Winter the heating needs of human beings increasethe concentration of soot aerosol particles in the atmospheretherefore the influence of soot aerosol on particle sizedistribution should be considered However as mentionedabove the resident population around the campus is verysmall and in Winter the strong northwest wind from Siberiacan easily blow the soot aerosol particles near the schoolto the downwind area Therefore the geographical locationand climate environment determine that the compositionof atmospheric aerosol of Yinchuan area is composed bysand dust particles and that the complex refractive indexis assumed to be 15-001119894 in previous calculations which isbasically reasonable

Figure 6 shows the AOD and number size distributiontaken on 19 September of 2012 a sunny and cloudless dayAs seen in Figure 6(a) the AOD values of all wavelengthbands increase from morning to afternoon In the morningthe AOD value is lower therefore this kind of weather canbe defined as the background weather in contrast in theafternoon the AOD value became higher This is becauseon that day there was no wind and the aerosol particlessuspending in the air could not be dispersed thereforethe atmospheric deposition action was relatively low theaerosol particles were accumulated gradually and finally theAOD value reached the maximum in the afternoon In factaccording to the observational results of Liu and Niu [1]the proportion of this type of AOD daily variation is 36percent in the total observation period of one year in InnerMongolia region which is a north neighbor of the Yinchuanarea In Figure 6(b) the size distributions are all conformedwith the Junge distribution basically and also at 06120583m and14 120583m there exist two peaks which basically conformed tothe averaged size distribution shown in Figure 4 Moreoverfrom the morning to the afternoon when the AOD valueincreased the corresponding particles number concentrationalso became larger

Figure 7 shows theAODand the number size distributionon 1 November 2012 As shown in Figure 7(a) from 8 to49 Beijing time the AOD values of all wavelength bandsincreased suddenly when a strong wind rolled up the sand-dust of earth surface into the atmosphere At 928 Beijing timea peak value of AOD appeared when the standard of sand-dust weather was reached After the peak the value decreasedgradually at 1109 the value returned to the normal level

Advances in Meteorology 5

Oct-12 Dec-12 Feb-13 Apr-13 Jun-13 Aug-13 Oct-1301

02

03

04

05

06

07

08

09AO

T

Month

1020nm870nm

670nm440nm

(a)

01 1

AutumnWinter

SpringSummer

1010

109

108

107

106

105

104

103

102

Radius (120583m)

dNdl

og(r)(120583

mminus1

cmminus2)

(b)

Figure 5 The monthly averaged AOD value and seasonal averaged size distribution of every month

825 853 949 1034 1149 1249 1449 1549 180900

01

02

03

04

05

AOD

Beijing time

1020nm870nm

670nm440nm

(a)

01 1

08191234

1605

1010

109

108

107

106

105

104

103

102

Particle radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

(b)

Figure 6 The AOD and size distribution of a sunny day taken on September 19 2012

the whole sand dust process only lasted about 2 hours andthe AOD varied from 03 to 115 Compared with Figure 6(b)the maximum number concentration at 928 Beijing timein sand dust weather is larger than that of backgroundweather with one order of magnitude and especially thenumber of concentration of large particles and giant particleswhose radius is larger than 02 120583m and 1 120583m respectivelyis obviously larger than that of background weather Whenthe sand dust weather comes concentration of coarse modeparticles in the atmosphere will increase dramatically andwill be greater than that of clear background weather In factwith respect to producing extinction action for solar the largeparticles and giant particles are the main factors which resultin the increase of extinction coefficient and optical thickness

therefore in sand dust weather the visibility is very low butAOD is very high [1]

At present because of the limits of technical means anddetection instruments there are no very good methods todirectly verify the atmospheric column particle size distri-bution retrieved from data of sun photometer In fact someareas which also belong to the main transportation path andorigins of sand dust that lies in the north of China havesimilar particle size distribution with Yinchuan area whichindirectly verify the feasibility of this study such as EjinBanner and Dongsheng Tenggeli Desert [6 14] Moreoverwe use the synchronous measurement data taken by anaerodynamic particle size spectrometer APS-3321 in the samemeasuring place to indirectly verify the feasibility of this

6 Advances in Meteorology

928 1124 1259 1455 1539 1559 165800

02

04

06

08

10

12

14AO

D

Beijing time

1020nm870nm

670nm440nm

(a)

01 1

849905928

105511091124

1010

109

108

107

106

105

104

103

102

Particle radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

(b)

Figure 7 The AOD and size distribution of sand dust weather taken on November 1 2012

1 2

01

1

10

Case 1Case 2Case 3

Case 4Case 5

Radius (120583m)

dNdl

og(r)(cm

minus3)

(a)

101

Case 1Case 2Case 3

Case 4Case 5

Radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

108

107

106

105

104

103

(b)

Figure 8 Some particle number size distributions obtained synchronously by sun photometer and APS-3321 respectively during theobservation period

study Figure 8 shows some particle number size distributionsobtained synchronously by sun photometer and APS-3321respectively during the observation period

In Figure 8 the number size distributions taken by APS-3321 and sun photometer all basically satisfy the Jungerdistribution but in Figure 8(a) there are two obvious peaksat the radius of about 035 and 075 120583m respectively and inFigure 8(b) the peaks appear at the radius of about 06 and14 120583m respectively It is clear that the shape of two typesof size distributions is similar which indirectly verify theresults of this study but the location of peaks is different

This is because the measuring result of APS-3321 is grounddata but the particle size distribution retrieved by sunphotometer is integral data through the whole atmosphereThe ground-air interface is one of important compositions ofwhole atmosphere and the ground data measured by APS-3321 represent the particle size distribution of ground-airinterface [15] The research of Li and Mao has shown that ifthe vertical atmospheric transportation is very enough andvertical mixing is also uniform the size distribution of wholeatmosphere aerosol column will be similar to that of ground[16] In our observational data there are some similar size

Advances in Meteorology 7

distributions between APS-3321 and sun photometer but noidentical size distributions This shows that in observationalperiod when the aerosol vertical mixing is relative stronga lot of aerosol particles suspended in the atmosphere willoriginate from the ground-air interface which can producesimilar results as shown in Figure 8 The case between APS-3321 and sun photometer in this study is similar to that of Liand Mao [16]

4 Conclusion

A sun photometer CE-318 is employed to measure systemat-ically the direct solar radiation data from September 2012 toOctober 2013 over the Yinchuan regionThe particle size dis-tributions were retrieved from the AOD by use of extinctionmethod The experimental results were analyzed and someconclusions are obtained as follows (1) The averaged sizedistribution of this area satisfies the Junge function basicallyhowever there are two obvious peaks in the range from 001to 2 120583m which are located at 06 120583m 14 120583m respectively(2) Because sand-dust weather occurs frequently the particlenumber concentration in Spring is the largest and that inAutumn is the smallest which coincides with AOD variationtendency (3)Theparticle number concentration in sand dustday is larger than that of background weather with one orderof magnitude especially for the number concentration oflarge particles and giant particles

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This work was supported by the National Natural ScienceFoundation of China (NSFC) (no 61168004) the Key Projectof Chinese Ministry of Education (no 211209) the Uni-versities Science and Technology Project of Ningxia (no2011JY007) the Natural Science Foundation of Ningxia (noNZ13094) and The West Light Talent Plan of the ChineseAcademy of Sciences

References

[1] F Liu and SNiu ldquoOptical thickness and size distribution of dustaerosol particles in InnerMongoliardquo Journal of Nanjing Instituteof Meteorology vol 29 no 6 pp 775ndash781 2006

[2] S Niu C Zhang and J Sun ldquoObservational research on thesize distribution of sand aerosol particles in theHelanMountainAreardquoChinese Journal of Atmospheric Sciences vol 25 no 2 pp243ndash252 2001

[3] G A DrsquoAlmeida P Koepke and E P Shettle AtmosphericAerosols Global Climatology and Radiative Characteristics ADeepak Hampton Va USA 1991

[4] J N Porter and A D Clarke ldquoAerosol size distribution modelsbased on in situmeasurementsrdquo Journal of Geophysical ResearchD Atmospheres vol 102 no 5 pp 6035ndash6045 1997

[5] V M Karyampudi S P Palm J A Reagen et al ldquoValidation ofthe Saharan dust plume conceptualmodel using lidarMeteosatand ECMWF datardquo Bulletin of the American MeteorologicalSociety vol 80 no 6 pp 1045ndash1075 1999

[6] F Li J Liu and D Lv ldquoAnalyses of composite observation ofoptical properties of atmospheric aerosols in the late summerover some areas of North Chinardquo Scientia Atmospherica Sinicavol 19 no 2 pp 235ndash242 1995

[7] J-D Mao D-X Hua T-Y He and M Wang ldquoLidar observa-tions of atmospheric aerosol optical properties over Yinchuanareardquo Spectroscopy and Spectral Analysis vol 30 no 7 pp 2006ndash2010 2010

[8] V Vitale C Tomasi A Lupi A Cacciari and S MaranildquoRetrieval of columnar aerosol size distributions and radiative-forcing evaluations from sun-photometricmeasurements takenduring the CLEARCOLUMN (ACE 2) experimentrdquo Atmo-spheric Environment vol 34 no 29-30 pp 5095ndash5105 2000

[9] J Heintzenberg H Muller H Quenzel and E ThomallaldquoInformation content of optical data with respect to aerosolproperties numerical studies with a randomizedminimization-search-technique inversion algorithmrdquo Applied Optics vol 20no 8 pp 1308ndash1315 1981

[10] M D King D M Byrne B M Herman and J A ReaganldquoAerosol size distribution obtained by inversion of spectral opti-cal depth measurementrdquo Journal of the Atmospheric Sciencesvol 35 no 11 pp 2153ndash2167 1978

[11] S Twomey Introduction to the Mathematics of Inversion inRemote Sensing and Indirect Measurements Dover New YorkNY USA 1977

[12] Y Zhang Study of Laser Granulometric Analysis Algorithm [Themaster paper of Xirsquoan] Technological University 2010

[13] K T Whitby R B Husar and B Y H Liu ldquoThe aerosolsize distribution of Los Angeles smogrdquo Journal of Colloid andInterface Science vol 39 no 1 pp 177ndash204 1972

[14] J Xin W Zhang J Yuan and L Liu ldquoThe spectrum distribu-tions of dust aerosol over TenggerDesert retrieved by extinctionmethodrdquo Plateau Meteorology vol 23 no 5 pp 654ndash659 2004

[15] F Li J Liu and D Lu ldquoAnalyses of composite observation ofoptical properties of atmospheric aerosol in the late summerover some area of North Chinardquo Scientia Atmospherica Sinicavol 19 no 2 pp 235ndash242 1995

[16] J Li and J Mao ldquoInversion of the property of atmosphericaerosol by pptical remote sensingrdquo Acta Meteorologica Sinicavol 47 no 4 pp 450ndash456 1989

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Geology Advances in

2 Advances in Meteorology

BadanjilinDesert

TenggeliDesert Yinchuan

MaorusuDesert

Wulanbuhe

Desert

Huangtu Plateau

Figure 1 Map of the part of the northwest of China

sand blowing and sandstorm [2] In2006 Liu and Niu useda CE-318 sun photometer to retrieve the AOD and sizedistribution by extinction method in Inner Mongolia andthe results show that there were significant variations intemporal special distributions of AOD [1] In 2010 Mao etal used a compact Mie scattering lidar system for the firsttime to measure the optical properties and temporal-spatialdistribution of atmospheric aerosol particles from 1 to 10April over Yinchuan area [7]

The Yinchuan area lies in the eastern region of North-west China It belongs to the typical temperate continentalclimate and has some special features such as drought littlerain enough sunshine strong evaporation and big windsand Deserts such as Badanjilin desert Wulanbuhe desertTenggeli desert and Maowuso desert are located in thenorthwest west and east of Yinchuan area These deserts areone of themain sand dust sources of East Asia Figure 1 showsthe map of the part of the northwest of China ThereforeYingchuan area is one of the main transportation path andoriginal source of sand dust The observations and analyseson aerosol properties over this area have very importantreference value for quantitative study of the influence ofaerosol on atmosphere physics and chemistry process andmonitoring of sand-dust weather and air pollution

For investigation of the aerosol number size distributionand its temporal-spatial evolution over this area a series ofsystematically observation experiments were carried out bymeans of a sun photometer and many direct solar radiationdata were obtained By use of the extinction inversionmethod the particle size distribution is retrieved from theAOD In Section 2 the retrieval method of size distributionbased on extinctionmethod is discussed in detail in Section 3some experiments were carried out and the results areanalyzed in detail Finally a conclusion is given in Section 4

2 The Retrieval Method

The sun photometer CE-318 can acquire the AOD valuesimply In fact through the inversion of AOD the particlesize distribution can be obtained [8 9] Assuming that theparticulates in the atmosphere can be accurately modeled

by equivalent spheres whose refractive index is knownaccording to extinction method the relationship between theAOD and particle size distribution can be given by [6 10]

120591 (120582) = int

infin

0

1205871199032

119876119890(119903 120582119898) 119899 (119903) 119889119903 (1)

where 120591(120582) is the AOD passing through the whole atmo-sphere 119899(119903) is the aerosol size distribution of vertical columnthrough the whole atmosphere 119903 is particle radius 119898 iscomplex refractive index of aerosol particles and 119876

119890(119903 120582 119898)

is the extinction efficiency factor according Miersquos theory It isclear that this equation is the first kind of Fredholm integralequations

The aerosol size distribution 119899(119903) can be described as aproduct form by two functions namely 119899(119903) = 119891(119903)ℎ(119903)where 119891(119903) and ℎ(119903) are the slowly varying function andthe rapidly varying function respectively According to thePhillips-Twomey constraint inversion equation [11] one canobtain [6 10]

119891 = (119860119879

119860 + 120574119867)minus1

119860119879

120591 (2)

where 119860 is the coefficient matrix 119860119879 is transpose of 119860 and120574is the nonnegative Lagrange multiplier 119867 = 119870

119879

119870 is thesmoothing matrix and119870 can be defined as [12]

119870 =

[[[[[[[[[[[[[[

[

0 0 0 0 0 sdot sdot 0 0 0

minus1 2 minus1 0 0 sdot sdot 0 0 0

0 minus1 2 minus1 0 sdot sdot 0 0 0

0 0 minus1 2 minus1 sdot sdot sdot sdot sdot

0 0 0 minus1 2 sdot sdot sdot sdot sdot

sdot sdot sdot sdot sdot sdot minus1 0 0 0

sdot sdot sdot sdot sdot minus1 2 minus1 0 0

0 0 0 sdot sdot 0 minus1 2 minus1 0

0 0 0 sdot sdot 0 0 minus1 2 minus1

0 0 0 sdot sdot 0 0 0 0 0

]]]]]]]]]]]]]]

]

(3)

And also 119891 and 120591 are both the column vectors By usingthe iterative procedure (2) can be solved as follows [6]

119891(119899+1)

= (119860(119899)119879

119860(119899)

+ 120574(119899)

119867)minus1

119860(119899)119879

120591

119860(119899)

119894119895

= int

119903119895+1

119903119895

119870119894(119903 119898) ℎ

(119899)

119895

(119903) 119889119903

119894 = 1 2 119873 (wavelength numbers)

119895 = 1 2 119872 (size interval numbers)

(4)

where

119870119894(119903 119898) = 120587119903

2

119870119890(119903 120582119894 119898)

ℎ(119899)

119895

(119903) = ℎ(119899minus1)

119895

(119903) 119891(119899minus1)

119895

(119903)

120574(119899)

= 119887sum

(119860(119899)119879

119860(119899)

)119894119894

119873

(5)

Advances in Meteorology 3

Gobi

Three-North Shelterbelt

Beifang University ofNationalities

Figure 2 The campus location in Yinchuan

The convergence criterion can be defined as [6]

(sum(119891(119899)

119894

minus 1)2

119872)

12

lt 120575 (6)

For typical continent climate the Junge function is wellselected and it is in agreement with continent aerosol sizedistribution in the range of less than 2 120583m which can bewritten as

119899 (119903) = 119862119903minus(V+1)

(7)

where 119862 is coefficient and V is the distribution constant andits range is from 20 to 40

In this paper the Junge function is selected as initialrapidly varying function ℎ

(0)

119895

(119903) and the slowly varying func-tion 119891

(119899)

119895

(119903) can be solved by interpolating linearly 119899 orderssolution vector After some iterative procedures the stablesolution of ℎ(119899)

119895

(119903) is the unknown aerosol size distribution119899(119903) [6]

3 The Observation Experiments andResults Analysis

For investigation of the aerosol number size distribution andits temporal-spatial evolution over the Yinchuan area manyobservational experiments were carried out from September2012 to October 2013 at Beifang University of Nationali-ties (106∘E 38∘131015840291015840N) Yinchuan Ningxia China Figure 2shows the campus location in Yinchuan Yinchuan city is amedium sized city which is about 20 kilometers long fromeast to west and about several kilometers wide from south tonorth From the east to the west Yinchuan city can be dividedinto three districts namely Xingqing district Jinfeng districtand Xixia district The population is mainly concentrated inJinfeng district and Xingqing district Beifang University ofNationalities is located at thewest of XixiaDistrict namely inthewest of Yinchuan city In thewest and north of the campusthere are the famous Three-North Shelterbelt and the Gobidesert that is in the eastern foot ofmountain helan and hencethe population is very small

1013

1012

1011

1010

109

108

107

106

105

104

103

102

101

100

10minus1

10minus2

120574 = 2

120574 = 3

120574 = 4

Particle radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

Figure 3 The determination of parameters V of Junge function

A sun photometer CE-318 which is installed at teachingbuilding no 17 is employed to record the direct solarradiation data Every day the sun photometer works fromabout 800 to 1700 Beijing time and automatically recordsthe data except on the days when the sun was obscured byclouds and the rain or when snow or sand dust occur Up tonow a total of 14235 measurements were carried out In thispaper the seasons corresponding to the months are definedas follows Autumn is from September to November Winteris from December to February Spring is fromMarch to Mayand Summer is from June toAugust Considering that aerosoltype of this area mainly belongs to sand dust particles ininversion process the complex refractive index 119898 is assumedto be 15-001119894 [13] Moreover according to their sizes andproduction mechanisms the atmospheric aerosol can gen-erally be divided into three types namely nucleation mode(0001 120583m lt 119903 lt 01 120583m) accumulation mode (01 120583m lt

119903 lt 10 120583m) and coarse mode (119903 gt 10 120583m)In 1963 Junger used power function to describe the

relation between logarithm of particle number concentrationand logarithmof the particle radius In the extinctionmethodmentioned above the Junge distribution function is selectedas the initial rapidly varying function The selection ofparameter V value in (7) is given special attention in inver-sion process For determination of reasonable value of theparameter V some comparisons were made Figure 3 showsthat the size distribution curves under different parametersV of initial Junge function It can be seen that when V = 40

or 30 the retrieved size distribution curve is nonsmoothingnoncontinuous and retrieval process is instable but whenV = 20 the retrieval process is convergent Because extinctionfactor is not sensitive to extinction effect of large diametergiant particle the extinction method only is used to inversethe particle size distribution with diameter from 01 to 5 120583mand especially for the large particle with diameter from 01 to1 120583m the inversion results are more stable Extinctionmethod

4 Advances in Meteorology

01 1

1010

109

108

107

106

105

104

103

102

101

Particle radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

Figure 4 The averaged size distribution of the whole observationperiod

is less sensitive to the selection of initial function in theproper range and in a certain error range the selection ofinitial function is allowed to exist with a certain differenceNevertheless in order to make inversion result closer tothe true result choosing the more ideal initial functionand more reasonable smooth constraints will be required[14] Therefore when Junge function is selected as initialrapidly varying function the computed size distributioncannot always be in good agreementwith the real distributionin the whole size range that is in some size range theretrieval discrepancy is small but in other size range thelarge discrepancy may exist Reasonable selection of initialfunction is also very important in stabilizing the inversionprocess In this paper the particle diameter is within 01 to5 120583m and hence the retrieved size distribution can be in goodagreement with the real distribution in the whole size range

Figure 4 shows the averaged number size distributionduring the whole observation period It is obvious thatthe averaged size distribution basically satisfies the Jungefunction However there are two obvious peaks in therange from 001 to 2120583m which located at 06 120583m of theaccumulation mode and 14 120583m of coarse mode respectivelyAs can be seen from Figure 4 in Yinchuan area the aerosolparticle number size distribution is bimodal structure withtwo peaks located at the accumulation mode and coarseparticles respectively As mentioned above Yinchuan arealocated at the arid region surrounded by three deserts is animportant transportation path and origin of sand dust thatlies in the north of China Under such natural conditionsand atmosphere environment the first aerosol source inYinchuan area is very strong and hence sand dust particleswith larger size are dominant in atmosphere aerosol and theconcentration of aerosol particles in the accumulation modeand coarse mode is much higher than that of many cities ofdeveloped countries Also the number size distribution ofYinchuan area has some similar features with the other citieslocated at dust source area in the north of China such as EjinBanner and Dongsheng [6]

Figure 5 shows the monthly averaged AOD and seasonalaveraged number size distribution from September 2012 toOctober 2013 In Figure 4(a) the averaged AOD value inSpring is the largest and that in Autumn is the smallest Inthe Spring over the Yinchuan area and its surrounding areathe climate is very dry soil is naked and big wind blowsthe sand dust into the air easily therefore sand-dust weatheris frequent In fact in Spring 2013 several serious sand-dust storm processes occurred But in Autumn of Yinchuanrainfall is obviously more than other seasons thereforethe atmosphere is relatively clean In Figure 5(b) it can beseen that the seasonal variation tendency of size distributioncoincides with AOD value but the number concentrationin Spring is larger than that in Autumn with one order ofmagnitude

In Winter the heating needs of human beings increasethe concentration of soot aerosol particles in the atmospheretherefore the influence of soot aerosol on particle sizedistribution should be considered However as mentionedabove the resident population around the campus is verysmall and in Winter the strong northwest wind from Siberiacan easily blow the soot aerosol particles near the schoolto the downwind area Therefore the geographical locationand climate environment determine that the compositionof atmospheric aerosol of Yinchuan area is composed bysand dust particles and that the complex refractive indexis assumed to be 15-001119894 in previous calculations which isbasically reasonable

Figure 6 shows the AOD and number size distributiontaken on 19 September of 2012 a sunny and cloudless dayAs seen in Figure 6(a) the AOD values of all wavelengthbands increase from morning to afternoon In the morningthe AOD value is lower therefore this kind of weather canbe defined as the background weather in contrast in theafternoon the AOD value became higher This is becauseon that day there was no wind and the aerosol particlessuspending in the air could not be dispersed thereforethe atmospheric deposition action was relatively low theaerosol particles were accumulated gradually and finally theAOD value reached the maximum in the afternoon In factaccording to the observational results of Liu and Niu [1]the proportion of this type of AOD daily variation is 36percent in the total observation period of one year in InnerMongolia region which is a north neighbor of the Yinchuanarea In Figure 6(b) the size distributions are all conformedwith the Junge distribution basically and also at 06120583m and14 120583m there exist two peaks which basically conformed tothe averaged size distribution shown in Figure 4 Moreoverfrom the morning to the afternoon when the AOD valueincreased the corresponding particles number concentrationalso became larger

Figure 7 shows theAODand the number size distributionon 1 November 2012 As shown in Figure 7(a) from 8 to49 Beijing time the AOD values of all wavelength bandsincreased suddenly when a strong wind rolled up the sand-dust of earth surface into the atmosphere At 928 Beijing timea peak value of AOD appeared when the standard of sand-dust weather was reached After the peak the value decreasedgradually at 1109 the value returned to the normal level

Advances in Meteorology 5

Oct-12 Dec-12 Feb-13 Apr-13 Jun-13 Aug-13 Oct-1301

02

03

04

05

06

07

08

09AO

T

Month

1020nm870nm

670nm440nm

(a)

01 1

AutumnWinter

SpringSummer

1010

109

108

107

106

105

104

103

102

Radius (120583m)

dNdl

og(r)(120583

mminus1

cmminus2)

(b)

Figure 5 The monthly averaged AOD value and seasonal averaged size distribution of every month

825 853 949 1034 1149 1249 1449 1549 180900

01

02

03

04

05

AOD

Beijing time

1020nm870nm

670nm440nm

(a)

01 1

08191234

1605

1010

109

108

107

106

105

104

103

102

Particle radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

(b)

Figure 6 The AOD and size distribution of a sunny day taken on September 19 2012

the whole sand dust process only lasted about 2 hours andthe AOD varied from 03 to 115 Compared with Figure 6(b)the maximum number concentration at 928 Beijing timein sand dust weather is larger than that of backgroundweather with one order of magnitude and especially thenumber of concentration of large particles and giant particleswhose radius is larger than 02 120583m and 1 120583m respectivelyis obviously larger than that of background weather Whenthe sand dust weather comes concentration of coarse modeparticles in the atmosphere will increase dramatically andwill be greater than that of clear background weather In factwith respect to producing extinction action for solar the largeparticles and giant particles are the main factors which resultin the increase of extinction coefficient and optical thickness

therefore in sand dust weather the visibility is very low butAOD is very high [1]

At present because of the limits of technical means anddetection instruments there are no very good methods todirectly verify the atmospheric column particle size distri-bution retrieved from data of sun photometer In fact someareas which also belong to the main transportation path andorigins of sand dust that lies in the north of China havesimilar particle size distribution with Yinchuan area whichindirectly verify the feasibility of this study such as EjinBanner and Dongsheng Tenggeli Desert [6 14] Moreoverwe use the synchronous measurement data taken by anaerodynamic particle size spectrometer APS-3321 in the samemeasuring place to indirectly verify the feasibility of this

6 Advances in Meteorology

928 1124 1259 1455 1539 1559 165800

02

04

06

08

10

12

14AO

D

Beijing time

1020nm870nm

670nm440nm

(a)

01 1

849905928

105511091124

1010

109

108

107

106

105

104

103

102

Particle radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

(b)

Figure 7 The AOD and size distribution of sand dust weather taken on November 1 2012

1 2

01

1

10

Case 1Case 2Case 3

Case 4Case 5

Radius (120583m)

dNdl

og(r)(cm

minus3)

(a)

101

Case 1Case 2Case 3

Case 4Case 5

Radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

108

107

106

105

104

103

(b)

Figure 8 Some particle number size distributions obtained synchronously by sun photometer and APS-3321 respectively during theobservation period

study Figure 8 shows some particle number size distributionsobtained synchronously by sun photometer and APS-3321respectively during the observation period

In Figure 8 the number size distributions taken by APS-3321 and sun photometer all basically satisfy the Jungerdistribution but in Figure 8(a) there are two obvious peaksat the radius of about 035 and 075 120583m respectively and inFigure 8(b) the peaks appear at the radius of about 06 and14 120583m respectively It is clear that the shape of two typesof size distributions is similar which indirectly verify theresults of this study but the location of peaks is different

This is because the measuring result of APS-3321 is grounddata but the particle size distribution retrieved by sunphotometer is integral data through the whole atmosphereThe ground-air interface is one of important compositions ofwhole atmosphere and the ground data measured by APS-3321 represent the particle size distribution of ground-airinterface [15] The research of Li and Mao has shown that ifthe vertical atmospheric transportation is very enough andvertical mixing is also uniform the size distribution of wholeatmosphere aerosol column will be similar to that of ground[16] In our observational data there are some similar size

Advances in Meteorology 7

distributions between APS-3321 and sun photometer but noidentical size distributions This shows that in observationalperiod when the aerosol vertical mixing is relative stronga lot of aerosol particles suspended in the atmosphere willoriginate from the ground-air interface which can producesimilar results as shown in Figure 8 The case between APS-3321 and sun photometer in this study is similar to that of Liand Mao [16]

4 Conclusion

A sun photometer CE-318 is employed to measure systemat-ically the direct solar radiation data from September 2012 toOctober 2013 over the Yinchuan regionThe particle size dis-tributions were retrieved from the AOD by use of extinctionmethod The experimental results were analyzed and someconclusions are obtained as follows (1) The averaged sizedistribution of this area satisfies the Junge function basicallyhowever there are two obvious peaks in the range from 001to 2 120583m which are located at 06 120583m 14 120583m respectively(2) Because sand-dust weather occurs frequently the particlenumber concentration in Spring is the largest and that inAutumn is the smallest which coincides with AOD variationtendency (3)Theparticle number concentration in sand dustday is larger than that of background weather with one orderof magnitude especially for the number concentration oflarge particles and giant particles

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This work was supported by the National Natural ScienceFoundation of China (NSFC) (no 61168004) the Key Projectof Chinese Ministry of Education (no 211209) the Uni-versities Science and Technology Project of Ningxia (no2011JY007) the Natural Science Foundation of Ningxia (noNZ13094) and The West Light Talent Plan of the ChineseAcademy of Sciences

References

[1] F Liu and SNiu ldquoOptical thickness and size distribution of dustaerosol particles in InnerMongoliardquo Journal of Nanjing Instituteof Meteorology vol 29 no 6 pp 775ndash781 2006

[2] S Niu C Zhang and J Sun ldquoObservational research on thesize distribution of sand aerosol particles in theHelanMountainAreardquoChinese Journal of Atmospheric Sciences vol 25 no 2 pp243ndash252 2001

[3] G A DrsquoAlmeida P Koepke and E P Shettle AtmosphericAerosols Global Climatology and Radiative Characteristics ADeepak Hampton Va USA 1991

[4] J N Porter and A D Clarke ldquoAerosol size distribution modelsbased on in situmeasurementsrdquo Journal of Geophysical ResearchD Atmospheres vol 102 no 5 pp 6035ndash6045 1997

[5] V M Karyampudi S P Palm J A Reagen et al ldquoValidation ofthe Saharan dust plume conceptualmodel using lidarMeteosatand ECMWF datardquo Bulletin of the American MeteorologicalSociety vol 80 no 6 pp 1045ndash1075 1999

[6] F Li J Liu and D Lv ldquoAnalyses of composite observation ofoptical properties of atmospheric aerosols in the late summerover some areas of North Chinardquo Scientia Atmospherica Sinicavol 19 no 2 pp 235ndash242 1995

[7] J-D Mao D-X Hua T-Y He and M Wang ldquoLidar observa-tions of atmospheric aerosol optical properties over Yinchuanareardquo Spectroscopy and Spectral Analysis vol 30 no 7 pp 2006ndash2010 2010

[8] V Vitale C Tomasi A Lupi A Cacciari and S MaranildquoRetrieval of columnar aerosol size distributions and radiative-forcing evaluations from sun-photometricmeasurements takenduring the CLEARCOLUMN (ACE 2) experimentrdquo Atmo-spheric Environment vol 34 no 29-30 pp 5095ndash5105 2000

[9] J Heintzenberg H Muller H Quenzel and E ThomallaldquoInformation content of optical data with respect to aerosolproperties numerical studies with a randomizedminimization-search-technique inversion algorithmrdquo Applied Optics vol 20no 8 pp 1308ndash1315 1981

[10] M D King D M Byrne B M Herman and J A ReaganldquoAerosol size distribution obtained by inversion of spectral opti-cal depth measurementrdquo Journal of the Atmospheric Sciencesvol 35 no 11 pp 2153ndash2167 1978

[11] S Twomey Introduction to the Mathematics of Inversion inRemote Sensing and Indirect Measurements Dover New YorkNY USA 1977

[12] Y Zhang Study of Laser Granulometric Analysis Algorithm [Themaster paper of Xirsquoan] Technological University 2010

[13] K T Whitby R B Husar and B Y H Liu ldquoThe aerosolsize distribution of Los Angeles smogrdquo Journal of Colloid andInterface Science vol 39 no 1 pp 177ndash204 1972

[14] J Xin W Zhang J Yuan and L Liu ldquoThe spectrum distribu-tions of dust aerosol over TenggerDesert retrieved by extinctionmethodrdquo Plateau Meteorology vol 23 no 5 pp 654ndash659 2004

[15] F Li J Liu and D Lu ldquoAnalyses of composite observation ofoptical properties of atmospheric aerosol in the late summerover some area of North Chinardquo Scientia Atmospherica Sinicavol 19 no 2 pp 235ndash242 1995

[16] J Li and J Mao ldquoInversion of the property of atmosphericaerosol by pptical remote sensingrdquo Acta Meteorologica Sinicavol 47 no 4 pp 450ndash456 1989

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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GeochemistryHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Atmospheric SciencesInternational Journal of

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Advances in

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Geological ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Geology Advances in

Advances in Meteorology 3

Gobi

Three-North Shelterbelt

Beifang University ofNationalities

Figure 2 The campus location in Yinchuan

The convergence criterion can be defined as [6]

(sum(119891(119899)

119894

minus 1)2

119872)

12

lt 120575 (6)

For typical continent climate the Junge function is wellselected and it is in agreement with continent aerosol sizedistribution in the range of less than 2 120583m which can bewritten as

119899 (119903) = 119862119903minus(V+1)

(7)

where 119862 is coefficient and V is the distribution constant andits range is from 20 to 40

In this paper the Junge function is selected as initialrapidly varying function ℎ

(0)

119895

(119903) and the slowly varying func-tion 119891

(119899)

119895

(119903) can be solved by interpolating linearly 119899 orderssolution vector After some iterative procedures the stablesolution of ℎ(119899)

119895

(119903) is the unknown aerosol size distribution119899(119903) [6]

3 The Observation Experiments andResults Analysis

For investigation of the aerosol number size distribution andits temporal-spatial evolution over the Yinchuan area manyobservational experiments were carried out from September2012 to October 2013 at Beifang University of Nationali-ties (106∘E 38∘131015840291015840N) Yinchuan Ningxia China Figure 2shows the campus location in Yinchuan Yinchuan city is amedium sized city which is about 20 kilometers long fromeast to west and about several kilometers wide from south tonorth From the east to the west Yinchuan city can be dividedinto three districts namely Xingqing district Jinfeng districtand Xixia district The population is mainly concentrated inJinfeng district and Xingqing district Beifang University ofNationalities is located at thewest of XixiaDistrict namely inthewest of Yinchuan city In thewest and north of the campusthere are the famous Three-North Shelterbelt and the Gobidesert that is in the eastern foot ofmountain helan and hencethe population is very small

1013

1012

1011

1010

109

108

107

106

105

104

103

102

101

100

10minus1

10minus2

120574 = 2

120574 = 3

120574 = 4

Particle radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

Figure 3 The determination of parameters V of Junge function

A sun photometer CE-318 which is installed at teachingbuilding no 17 is employed to record the direct solarradiation data Every day the sun photometer works fromabout 800 to 1700 Beijing time and automatically recordsthe data except on the days when the sun was obscured byclouds and the rain or when snow or sand dust occur Up tonow a total of 14235 measurements were carried out In thispaper the seasons corresponding to the months are definedas follows Autumn is from September to November Winteris from December to February Spring is fromMarch to Mayand Summer is from June toAugust Considering that aerosoltype of this area mainly belongs to sand dust particles ininversion process the complex refractive index 119898 is assumedto be 15-001119894 [13] Moreover according to their sizes andproduction mechanisms the atmospheric aerosol can gen-erally be divided into three types namely nucleation mode(0001 120583m lt 119903 lt 01 120583m) accumulation mode (01 120583m lt

119903 lt 10 120583m) and coarse mode (119903 gt 10 120583m)In 1963 Junger used power function to describe the

relation between logarithm of particle number concentrationand logarithmof the particle radius In the extinctionmethodmentioned above the Junge distribution function is selectedas the initial rapidly varying function The selection ofparameter V value in (7) is given special attention in inver-sion process For determination of reasonable value of theparameter V some comparisons were made Figure 3 showsthat the size distribution curves under different parametersV of initial Junge function It can be seen that when V = 40

or 30 the retrieved size distribution curve is nonsmoothingnoncontinuous and retrieval process is instable but whenV = 20 the retrieval process is convergent Because extinctionfactor is not sensitive to extinction effect of large diametergiant particle the extinction method only is used to inversethe particle size distribution with diameter from 01 to 5 120583mand especially for the large particle with diameter from 01 to1 120583m the inversion results are more stable Extinctionmethod

4 Advances in Meteorology

01 1

1010

109

108

107

106

105

104

103

102

101

Particle radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

Figure 4 The averaged size distribution of the whole observationperiod

is less sensitive to the selection of initial function in theproper range and in a certain error range the selection ofinitial function is allowed to exist with a certain differenceNevertheless in order to make inversion result closer tothe true result choosing the more ideal initial functionand more reasonable smooth constraints will be required[14] Therefore when Junge function is selected as initialrapidly varying function the computed size distributioncannot always be in good agreementwith the real distributionin the whole size range that is in some size range theretrieval discrepancy is small but in other size range thelarge discrepancy may exist Reasonable selection of initialfunction is also very important in stabilizing the inversionprocess In this paper the particle diameter is within 01 to5 120583m and hence the retrieved size distribution can be in goodagreement with the real distribution in the whole size range

Figure 4 shows the averaged number size distributionduring the whole observation period It is obvious thatthe averaged size distribution basically satisfies the Jungefunction However there are two obvious peaks in therange from 001 to 2120583m which located at 06 120583m of theaccumulation mode and 14 120583m of coarse mode respectivelyAs can be seen from Figure 4 in Yinchuan area the aerosolparticle number size distribution is bimodal structure withtwo peaks located at the accumulation mode and coarseparticles respectively As mentioned above Yinchuan arealocated at the arid region surrounded by three deserts is animportant transportation path and origin of sand dust thatlies in the north of China Under such natural conditionsand atmosphere environment the first aerosol source inYinchuan area is very strong and hence sand dust particleswith larger size are dominant in atmosphere aerosol and theconcentration of aerosol particles in the accumulation modeand coarse mode is much higher than that of many cities ofdeveloped countries Also the number size distribution ofYinchuan area has some similar features with the other citieslocated at dust source area in the north of China such as EjinBanner and Dongsheng [6]

Figure 5 shows the monthly averaged AOD and seasonalaveraged number size distribution from September 2012 toOctober 2013 In Figure 4(a) the averaged AOD value inSpring is the largest and that in Autumn is the smallest Inthe Spring over the Yinchuan area and its surrounding areathe climate is very dry soil is naked and big wind blowsthe sand dust into the air easily therefore sand-dust weatheris frequent In fact in Spring 2013 several serious sand-dust storm processes occurred But in Autumn of Yinchuanrainfall is obviously more than other seasons thereforethe atmosphere is relatively clean In Figure 5(b) it can beseen that the seasonal variation tendency of size distributioncoincides with AOD value but the number concentrationin Spring is larger than that in Autumn with one order ofmagnitude

In Winter the heating needs of human beings increasethe concentration of soot aerosol particles in the atmospheretherefore the influence of soot aerosol on particle sizedistribution should be considered However as mentionedabove the resident population around the campus is verysmall and in Winter the strong northwest wind from Siberiacan easily blow the soot aerosol particles near the schoolto the downwind area Therefore the geographical locationand climate environment determine that the compositionof atmospheric aerosol of Yinchuan area is composed bysand dust particles and that the complex refractive indexis assumed to be 15-001119894 in previous calculations which isbasically reasonable

Figure 6 shows the AOD and number size distributiontaken on 19 September of 2012 a sunny and cloudless dayAs seen in Figure 6(a) the AOD values of all wavelengthbands increase from morning to afternoon In the morningthe AOD value is lower therefore this kind of weather canbe defined as the background weather in contrast in theafternoon the AOD value became higher This is becauseon that day there was no wind and the aerosol particlessuspending in the air could not be dispersed thereforethe atmospheric deposition action was relatively low theaerosol particles were accumulated gradually and finally theAOD value reached the maximum in the afternoon In factaccording to the observational results of Liu and Niu [1]the proportion of this type of AOD daily variation is 36percent in the total observation period of one year in InnerMongolia region which is a north neighbor of the Yinchuanarea In Figure 6(b) the size distributions are all conformedwith the Junge distribution basically and also at 06120583m and14 120583m there exist two peaks which basically conformed tothe averaged size distribution shown in Figure 4 Moreoverfrom the morning to the afternoon when the AOD valueincreased the corresponding particles number concentrationalso became larger

Figure 7 shows theAODand the number size distributionon 1 November 2012 As shown in Figure 7(a) from 8 to49 Beijing time the AOD values of all wavelength bandsincreased suddenly when a strong wind rolled up the sand-dust of earth surface into the atmosphere At 928 Beijing timea peak value of AOD appeared when the standard of sand-dust weather was reached After the peak the value decreasedgradually at 1109 the value returned to the normal level

Advances in Meteorology 5

Oct-12 Dec-12 Feb-13 Apr-13 Jun-13 Aug-13 Oct-1301

02

03

04

05

06

07

08

09AO

T

Month

1020nm870nm

670nm440nm

(a)

01 1

AutumnWinter

SpringSummer

1010

109

108

107

106

105

104

103

102

Radius (120583m)

dNdl

og(r)(120583

mminus1

cmminus2)

(b)

Figure 5 The monthly averaged AOD value and seasonal averaged size distribution of every month

825 853 949 1034 1149 1249 1449 1549 180900

01

02

03

04

05

AOD

Beijing time

1020nm870nm

670nm440nm

(a)

01 1

08191234

1605

1010

109

108

107

106

105

104

103

102

Particle radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

(b)

Figure 6 The AOD and size distribution of a sunny day taken on September 19 2012

the whole sand dust process only lasted about 2 hours andthe AOD varied from 03 to 115 Compared with Figure 6(b)the maximum number concentration at 928 Beijing timein sand dust weather is larger than that of backgroundweather with one order of magnitude and especially thenumber of concentration of large particles and giant particleswhose radius is larger than 02 120583m and 1 120583m respectivelyis obviously larger than that of background weather Whenthe sand dust weather comes concentration of coarse modeparticles in the atmosphere will increase dramatically andwill be greater than that of clear background weather In factwith respect to producing extinction action for solar the largeparticles and giant particles are the main factors which resultin the increase of extinction coefficient and optical thickness

therefore in sand dust weather the visibility is very low butAOD is very high [1]

At present because of the limits of technical means anddetection instruments there are no very good methods todirectly verify the atmospheric column particle size distri-bution retrieved from data of sun photometer In fact someareas which also belong to the main transportation path andorigins of sand dust that lies in the north of China havesimilar particle size distribution with Yinchuan area whichindirectly verify the feasibility of this study such as EjinBanner and Dongsheng Tenggeli Desert [6 14] Moreoverwe use the synchronous measurement data taken by anaerodynamic particle size spectrometer APS-3321 in the samemeasuring place to indirectly verify the feasibility of this

6 Advances in Meteorology

928 1124 1259 1455 1539 1559 165800

02

04

06

08

10

12

14AO

D

Beijing time

1020nm870nm

670nm440nm

(a)

01 1

849905928

105511091124

1010

109

108

107

106

105

104

103

102

Particle radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

(b)

Figure 7 The AOD and size distribution of sand dust weather taken on November 1 2012

1 2

01

1

10

Case 1Case 2Case 3

Case 4Case 5

Radius (120583m)

dNdl

og(r)(cm

minus3)

(a)

101

Case 1Case 2Case 3

Case 4Case 5

Radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

108

107

106

105

104

103

(b)

Figure 8 Some particle number size distributions obtained synchronously by sun photometer and APS-3321 respectively during theobservation period

study Figure 8 shows some particle number size distributionsobtained synchronously by sun photometer and APS-3321respectively during the observation period

In Figure 8 the number size distributions taken by APS-3321 and sun photometer all basically satisfy the Jungerdistribution but in Figure 8(a) there are two obvious peaksat the radius of about 035 and 075 120583m respectively and inFigure 8(b) the peaks appear at the radius of about 06 and14 120583m respectively It is clear that the shape of two typesof size distributions is similar which indirectly verify theresults of this study but the location of peaks is different

This is because the measuring result of APS-3321 is grounddata but the particle size distribution retrieved by sunphotometer is integral data through the whole atmosphereThe ground-air interface is one of important compositions ofwhole atmosphere and the ground data measured by APS-3321 represent the particle size distribution of ground-airinterface [15] The research of Li and Mao has shown that ifthe vertical atmospheric transportation is very enough andvertical mixing is also uniform the size distribution of wholeatmosphere aerosol column will be similar to that of ground[16] In our observational data there are some similar size

Advances in Meteorology 7

distributions between APS-3321 and sun photometer but noidentical size distributions This shows that in observationalperiod when the aerosol vertical mixing is relative stronga lot of aerosol particles suspended in the atmosphere willoriginate from the ground-air interface which can producesimilar results as shown in Figure 8 The case between APS-3321 and sun photometer in this study is similar to that of Liand Mao [16]

4 Conclusion

A sun photometer CE-318 is employed to measure systemat-ically the direct solar radiation data from September 2012 toOctober 2013 over the Yinchuan regionThe particle size dis-tributions were retrieved from the AOD by use of extinctionmethod The experimental results were analyzed and someconclusions are obtained as follows (1) The averaged sizedistribution of this area satisfies the Junge function basicallyhowever there are two obvious peaks in the range from 001to 2 120583m which are located at 06 120583m 14 120583m respectively(2) Because sand-dust weather occurs frequently the particlenumber concentration in Spring is the largest and that inAutumn is the smallest which coincides with AOD variationtendency (3)Theparticle number concentration in sand dustday is larger than that of background weather with one orderof magnitude especially for the number concentration oflarge particles and giant particles

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This work was supported by the National Natural ScienceFoundation of China (NSFC) (no 61168004) the Key Projectof Chinese Ministry of Education (no 211209) the Uni-versities Science and Technology Project of Ningxia (no2011JY007) the Natural Science Foundation of Ningxia (noNZ13094) and The West Light Talent Plan of the ChineseAcademy of Sciences

References

[1] F Liu and SNiu ldquoOptical thickness and size distribution of dustaerosol particles in InnerMongoliardquo Journal of Nanjing Instituteof Meteorology vol 29 no 6 pp 775ndash781 2006

[2] S Niu C Zhang and J Sun ldquoObservational research on thesize distribution of sand aerosol particles in theHelanMountainAreardquoChinese Journal of Atmospheric Sciences vol 25 no 2 pp243ndash252 2001

[3] G A DrsquoAlmeida P Koepke and E P Shettle AtmosphericAerosols Global Climatology and Radiative Characteristics ADeepak Hampton Va USA 1991

[4] J N Porter and A D Clarke ldquoAerosol size distribution modelsbased on in situmeasurementsrdquo Journal of Geophysical ResearchD Atmospheres vol 102 no 5 pp 6035ndash6045 1997

[5] V M Karyampudi S P Palm J A Reagen et al ldquoValidation ofthe Saharan dust plume conceptualmodel using lidarMeteosatand ECMWF datardquo Bulletin of the American MeteorologicalSociety vol 80 no 6 pp 1045ndash1075 1999

[6] F Li J Liu and D Lv ldquoAnalyses of composite observation ofoptical properties of atmospheric aerosols in the late summerover some areas of North Chinardquo Scientia Atmospherica Sinicavol 19 no 2 pp 235ndash242 1995

[7] J-D Mao D-X Hua T-Y He and M Wang ldquoLidar observa-tions of atmospheric aerosol optical properties over Yinchuanareardquo Spectroscopy and Spectral Analysis vol 30 no 7 pp 2006ndash2010 2010

[8] V Vitale C Tomasi A Lupi A Cacciari and S MaranildquoRetrieval of columnar aerosol size distributions and radiative-forcing evaluations from sun-photometricmeasurements takenduring the CLEARCOLUMN (ACE 2) experimentrdquo Atmo-spheric Environment vol 34 no 29-30 pp 5095ndash5105 2000

[9] J Heintzenberg H Muller H Quenzel and E ThomallaldquoInformation content of optical data with respect to aerosolproperties numerical studies with a randomizedminimization-search-technique inversion algorithmrdquo Applied Optics vol 20no 8 pp 1308ndash1315 1981

[10] M D King D M Byrne B M Herman and J A ReaganldquoAerosol size distribution obtained by inversion of spectral opti-cal depth measurementrdquo Journal of the Atmospheric Sciencesvol 35 no 11 pp 2153ndash2167 1978

[11] S Twomey Introduction to the Mathematics of Inversion inRemote Sensing and Indirect Measurements Dover New YorkNY USA 1977

[12] Y Zhang Study of Laser Granulometric Analysis Algorithm [Themaster paper of Xirsquoan] Technological University 2010

[13] K T Whitby R B Husar and B Y H Liu ldquoThe aerosolsize distribution of Los Angeles smogrdquo Journal of Colloid andInterface Science vol 39 no 1 pp 177ndash204 1972

[14] J Xin W Zhang J Yuan and L Liu ldquoThe spectrum distribu-tions of dust aerosol over TenggerDesert retrieved by extinctionmethodrdquo Plateau Meteorology vol 23 no 5 pp 654ndash659 2004

[15] F Li J Liu and D Lu ldquoAnalyses of composite observation ofoptical properties of atmospheric aerosol in the late summerover some area of North Chinardquo Scientia Atmospherica Sinicavol 19 no 2 pp 235ndash242 1995

[16] J Li and J Mao ldquoInversion of the property of atmosphericaerosol by pptical remote sensingrdquo Acta Meteorologica Sinicavol 47 no 4 pp 450ndash456 1989

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

ClimatologyJournal of

EcologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

EarthquakesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom

Applied ampEnvironmentalSoil Science

Volume 2014

Mining

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal of

Geophysics

OceanographyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofPetroleum Engineering

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

GeochemistryHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Atmospheric SciencesInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

OceanographyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MineralogyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MeteorologyAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Paleontology JournalHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Geological ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Geology Advances in

4 Advances in Meteorology

01 1

1010

109

108

107

106

105

104

103

102

101

Particle radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

Figure 4 The averaged size distribution of the whole observationperiod

is less sensitive to the selection of initial function in theproper range and in a certain error range the selection ofinitial function is allowed to exist with a certain differenceNevertheless in order to make inversion result closer tothe true result choosing the more ideal initial functionand more reasonable smooth constraints will be required[14] Therefore when Junge function is selected as initialrapidly varying function the computed size distributioncannot always be in good agreementwith the real distributionin the whole size range that is in some size range theretrieval discrepancy is small but in other size range thelarge discrepancy may exist Reasonable selection of initialfunction is also very important in stabilizing the inversionprocess In this paper the particle diameter is within 01 to5 120583m and hence the retrieved size distribution can be in goodagreement with the real distribution in the whole size range

Figure 4 shows the averaged number size distributionduring the whole observation period It is obvious thatthe averaged size distribution basically satisfies the Jungefunction However there are two obvious peaks in therange from 001 to 2120583m which located at 06 120583m of theaccumulation mode and 14 120583m of coarse mode respectivelyAs can be seen from Figure 4 in Yinchuan area the aerosolparticle number size distribution is bimodal structure withtwo peaks located at the accumulation mode and coarseparticles respectively As mentioned above Yinchuan arealocated at the arid region surrounded by three deserts is animportant transportation path and origin of sand dust thatlies in the north of China Under such natural conditionsand atmosphere environment the first aerosol source inYinchuan area is very strong and hence sand dust particleswith larger size are dominant in atmosphere aerosol and theconcentration of aerosol particles in the accumulation modeand coarse mode is much higher than that of many cities ofdeveloped countries Also the number size distribution ofYinchuan area has some similar features with the other citieslocated at dust source area in the north of China such as EjinBanner and Dongsheng [6]

Figure 5 shows the monthly averaged AOD and seasonalaveraged number size distribution from September 2012 toOctober 2013 In Figure 4(a) the averaged AOD value inSpring is the largest and that in Autumn is the smallest Inthe Spring over the Yinchuan area and its surrounding areathe climate is very dry soil is naked and big wind blowsthe sand dust into the air easily therefore sand-dust weatheris frequent In fact in Spring 2013 several serious sand-dust storm processes occurred But in Autumn of Yinchuanrainfall is obviously more than other seasons thereforethe atmosphere is relatively clean In Figure 5(b) it can beseen that the seasonal variation tendency of size distributioncoincides with AOD value but the number concentrationin Spring is larger than that in Autumn with one order ofmagnitude

In Winter the heating needs of human beings increasethe concentration of soot aerosol particles in the atmospheretherefore the influence of soot aerosol on particle sizedistribution should be considered However as mentionedabove the resident population around the campus is verysmall and in Winter the strong northwest wind from Siberiacan easily blow the soot aerosol particles near the schoolto the downwind area Therefore the geographical locationand climate environment determine that the compositionof atmospheric aerosol of Yinchuan area is composed bysand dust particles and that the complex refractive indexis assumed to be 15-001119894 in previous calculations which isbasically reasonable

Figure 6 shows the AOD and number size distributiontaken on 19 September of 2012 a sunny and cloudless dayAs seen in Figure 6(a) the AOD values of all wavelengthbands increase from morning to afternoon In the morningthe AOD value is lower therefore this kind of weather canbe defined as the background weather in contrast in theafternoon the AOD value became higher This is becauseon that day there was no wind and the aerosol particlessuspending in the air could not be dispersed thereforethe atmospheric deposition action was relatively low theaerosol particles were accumulated gradually and finally theAOD value reached the maximum in the afternoon In factaccording to the observational results of Liu and Niu [1]the proportion of this type of AOD daily variation is 36percent in the total observation period of one year in InnerMongolia region which is a north neighbor of the Yinchuanarea In Figure 6(b) the size distributions are all conformedwith the Junge distribution basically and also at 06120583m and14 120583m there exist two peaks which basically conformed tothe averaged size distribution shown in Figure 4 Moreoverfrom the morning to the afternoon when the AOD valueincreased the corresponding particles number concentrationalso became larger

Figure 7 shows theAODand the number size distributionon 1 November 2012 As shown in Figure 7(a) from 8 to49 Beijing time the AOD values of all wavelength bandsincreased suddenly when a strong wind rolled up the sand-dust of earth surface into the atmosphere At 928 Beijing timea peak value of AOD appeared when the standard of sand-dust weather was reached After the peak the value decreasedgradually at 1109 the value returned to the normal level

Advances in Meteorology 5

Oct-12 Dec-12 Feb-13 Apr-13 Jun-13 Aug-13 Oct-1301

02

03

04

05

06

07

08

09AO

T

Month

1020nm870nm

670nm440nm

(a)

01 1

AutumnWinter

SpringSummer

1010

109

108

107

106

105

104

103

102

Radius (120583m)

dNdl

og(r)(120583

mminus1

cmminus2)

(b)

Figure 5 The monthly averaged AOD value and seasonal averaged size distribution of every month

825 853 949 1034 1149 1249 1449 1549 180900

01

02

03

04

05

AOD

Beijing time

1020nm870nm

670nm440nm

(a)

01 1

08191234

1605

1010

109

108

107

106

105

104

103

102

Particle radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

(b)

Figure 6 The AOD and size distribution of a sunny day taken on September 19 2012

the whole sand dust process only lasted about 2 hours andthe AOD varied from 03 to 115 Compared with Figure 6(b)the maximum number concentration at 928 Beijing timein sand dust weather is larger than that of backgroundweather with one order of magnitude and especially thenumber of concentration of large particles and giant particleswhose radius is larger than 02 120583m and 1 120583m respectivelyis obviously larger than that of background weather Whenthe sand dust weather comes concentration of coarse modeparticles in the atmosphere will increase dramatically andwill be greater than that of clear background weather In factwith respect to producing extinction action for solar the largeparticles and giant particles are the main factors which resultin the increase of extinction coefficient and optical thickness

therefore in sand dust weather the visibility is very low butAOD is very high [1]

At present because of the limits of technical means anddetection instruments there are no very good methods todirectly verify the atmospheric column particle size distri-bution retrieved from data of sun photometer In fact someareas which also belong to the main transportation path andorigins of sand dust that lies in the north of China havesimilar particle size distribution with Yinchuan area whichindirectly verify the feasibility of this study such as EjinBanner and Dongsheng Tenggeli Desert [6 14] Moreoverwe use the synchronous measurement data taken by anaerodynamic particle size spectrometer APS-3321 in the samemeasuring place to indirectly verify the feasibility of this

6 Advances in Meteorology

928 1124 1259 1455 1539 1559 165800

02

04

06

08

10

12

14AO

D

Beijing time

1020nm870nm

670nm440nm

(a)

01 1

849905928

105511091124

1010

109

108

107

106

105

104

103

102

Particle radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

(b)

Figure 7 The AOD and size distribution of sand dust weather taken on November 1 2012

1 2

01

1

10

Case 1Case 2Case 3

Case 4Case 5

Radius (120583m)

dNdl

og(r)(cm

minus3)

(a)

101

Case 1Case 2Case 3

Case 4Case 5

Radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

108

107

106

105

104

103

(b)

Figure 8 Some particle number size distributions obtained synchronously by sun photometer and APS-3321 respectively during theobservation period

study Figure 8 shows some particle number size distributionsobtained synchronously by sun photometer and APS-3321respectively during the observation period

In Figure 8 the number size distributions taken by APS-3321 and sun photometer all basically satisfy the Jungerdistribution but in Figure 8(a) there are two obvious peaksat the radius of about 035 and 075 120583m respectively and inFigure 8(b) the peaks appear at the radius of about 06 and14 120583m respectively It is clear that the shape of two typesof size distributions is similar which indirectly verify theresults of this study but the location of peaks is different

This is because the measuring result of APS-3321 is grounddata but the particle size distribution retrieved by sunphotometer is integral data through the whole atmosphereThe ground-air interface is one of important compositions ofwhole atmosphere and the ground data measured by APS-3321 represent the particle size distribution of ground-airinterface [15] The research of Li and Mao has shown that ifthe vertical atmospheric transportation is very enough andvertical mixing is also uniform the size distribution of wholeatmosphere aerosol column will be similar to that of ground[16] In our observational data there are some similar size

Advances in Meteorology 7

distributions between APS-3321 and sun photometer but noidentical size distributions This shows that in observationalperiod when the aerosol vertical mixing is relative stronga lot of aerosol particles suspended in the atmosphere willoriginate from the ground-air interface which can producesimilar results as shown in Figure 8 The case between APS-3321 and sun photometer in this study is similar to that of Liand Mao [16]

4 Conclusion

A sun photometer CE-318 is employed to measure systemat-ically the direct solar radiation data from September 2012 toOctober 2013 over the Yinchuan regionThe particle size dis-tributions were retrieved from the AOD by use of extinctionmethod The experimental results were analyzed and someconclusions are obtained as follows (1) The averaged sizedistribution of this area satisfies the Junge function basicallyhowever there are two obvious peaks in the range from 001to 2 120583m which are located at 06 120583m 14 120583m respectively(2) Because sand-dust weather occurs frequently the particlenumber concentration in Spring is the largest and that inAutumn is the smallest which coincides with AOD variationtendency (3)Theparticle number concentration in sand dustday is larger than that of background weather with one orderof magnitude especially for the number concentration oflarge particles and giant particles

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This work was supported by the National Natural ScienceFoundation of China (NSFC) (no 61168004) the Key Projectof Chinese Ministry of Education (no 211209) the Uni-versities Science and Technology Project of Ningxia (no2011JY007) the Natural Science Foundation of Ningxia (noNZ13094) and The West Light Talent Plan of the ChineseAcademy of Sciences

References

[1] F Liu and SNiu ldquoOptical thickness and size distribution of dustaerosol particles in InnerMongoliardquo Journal of Nanjing Instituteof Meteorology vol 29 no 6 pp 775ndash781 2006

[2] S Niu C Zhang and J Sun ldquoObservational research on thesize distribution of sand aerosol particles in theHelanMountainAreardquoChinese Journal of Atmospheric Sciences vol 25 no 2 pp243ndash252 2001

[3] G A DrsquoAlmeida P Koepke and E P Shettle AtmosphericAerosols Global Climatology and Radiative Characteristics ADeepak Hampton Va USA 1991

[4] J N Porter and A D Clarke ldquoAerosol size distribution modelsbased on in situmeasurementsrdquo Journal of Geophysical ResearchD Atmospheres vol 102 no 5 pp 6035ndash6045 1997

[5] V M Karyampudi S P Palm J A Reagen et al ldquoValidation ofthe Saharan dust plume conceptualmodel using lidarMeteosatand ECMWF datardquo Bulletin of the American MeteorologicalSociety vol 80 no 6 pp 1045ndash1075 1999

[6] F Li J Liu and D Lv ldquoAnalyses of composite observation ofoptical properties of atmospheric aerosols in the late summerover some areas of North Chinardquo Scientia Atmospherica Sinicavol 19 no 2 pp 235ndash242 1995

[7] J-D Mao D-X Hua T-Y He and M Wang ldquoLidar observa-tions of atmospheric aerosol optical properties over Yinchuanareardquo Spectroscopy and Spectral Analysis vol 30 no 7 pp 2006ndash2010 2010

[8] V Vitale C Tomasi A Lupi A Cacciari and S MaranildquoRetrieval of columnar aerosol size distributions and radiative-forcing evaluations from sun-photometricmeasurements takenduring the CLEARCOLUMN (ACE 2) experimentrdquo Atmo-spheric Environment vol 34 no 29-30 pp 5095ndash5105 2000

[9] J Heintzenberg H Muller H Quenzel and E ThomallaldquoInformation content of optical data with respect to aerosolproperties numerical studies with a randomizedminimization-search-technique inversion algorithmrdquo Applied Optics vol 20no 8 pp 1308ndash1315 1981

[10] M D King D M Byrne B M Herman and J A ReaganldquoAerosol size distribution obtained by inversion of spectral opti-cal depth measurementrdquo Journal of the Atmospheric Sciencesvol 35 no 11 pp 2153ndash2167 1978

[11] S Twomey Introduction to the Mathematics of Inversion inRemote Sensing and Indirect Measurements Dover New YorkNY USA 1977

[12] Y Zhang Study of Laser Granulometric Analysis Algorithm [Themaster paper of Xirsquoan] Technological University 2010

[13] K T Whitby R B Husar and B Y H Liu ldquoThe aerosolsize distribution of Los Angeles smogrdquo Journal of Colloid andInterface Science vol 39 no 1 pp 177ndash204 1972

[14] J Xin W Zhang J Yuan and L Liu ldquoThe spectrum distribu-tions of dust aerosol over TenggerDesert retrieved by extinctionmethodrdquo Plateau Meteorology vol 23 no 5 pp 654ndash659 2004

[15] F Li J Liu and D Lu ldquoAnalyses of composite observation ofoptical properties of atmospheric aerosol in the late summerover some area of North Chinardquo Scientia Atmospherica Sinicavol 19 no 2 pp 235ndash242 1995

[16] J Li and J Mao ldquoInversion of the property of atmosphericaerosol by pptical remote sensingrdquo Acta Meteorologica Sinicavol 47 no 4 pp 450ndash456 1989

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

ClimatologyJournal of

EcologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

EarthquakesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom

Applied ampEnvironmentalSoil Science

Volume 2014

Mining

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal of

Geophysics

OceanographyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofPetroleum Engineering

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

GeochemistryHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Atmospheric SciencesInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

OceanographyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MineralogyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MeteorologyAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Paleontology JournalHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Geological ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Geology Advances in

Advances in Meteorology 5

Oct-12 Dec-12 Feb-13 Apr-13 Jun-13 Aug-13 Oct-1301

02

03

04

05

06

07

08

09AO

T

Month

1020nm870nm

670nm440nm

(a)

01 1

AutumnWinter

SpringSummer

1010

109

108

107

106

105

104

103

102

Radius (120583m)

dNdl

og(r)(120583

mminus1

cmminus2)

(b)

Figure 5 The monthly averaged AOD value and seasonal averaged size distribution of every month

825 853 949 1034 1149 1249 1449 1549 180900

01

02

03

04

05

AOD

Beijing time

1020nm870nm

670nm440nm

(a)

01 1

08191234

1605

1010

109

108

107

106

105

104

103

102

Particle radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

(b)

Figure 6 The AOD and size distribution of a sunny day taken on September 19 2012

the whole sand dust process only lasted about 2 hours andthe AOD varied from 03 to 115 Compared with Figure 6(b)the maximum number concentration at 928 Beijing timein sand dust weather is larger than that of backgroundweather with one order of magnitude and especially thenumber of concentration of large particles and giant particleswhose radius is larger than 02 120583m and 1 120583m respectivelyis obviously larger than that of background weather Whenthe sand dust weather comes concentration of coarse modeparticles in the atmosphere will increase dramatically andwill be greater than that of clear background weather In factwith respect to producing extinction action for solar the largeparticles and giant particles are the main factors which resultin the increase of extinction coefficient and optical thickness

therefore in sand dust weather the visibility is very low butAOD is very high [1]

At present because of the limits of technical means anddetection instruments there are no very good methods todirectly verify the atmospheric column particle size distri-bution retrieved from data of sun photometer In fact someareas which also belong to the main transportation path andorigins of sand dust that lies in the north of China havesimilar particle size distribution with Yinchuan area whichindirectly verify the feasibility of this study such as EjinBanner and Dongsheng Tenggeli Desert [6 14] Moreoverwe use the synchronous measurement data taken by anaerodynamic particle size spectrometer APS-3321 in the samemeasuring place to indirectly verify the feasibility of this

6 Advances in Meteorology

928 1124 1259 1455 1539 1559 165800

02

04

06

08

10

12

14AO

D

Beijing time

1020nm870nm

670nm440nm

(a)

01 1

849905928

105511091124

1010

109

108

107

106

105

104

103

102

Particle radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

(b)

Figure 7 The AOD and size distribution of sand dust weather taken on November 1 2012

1 2

01

1

10

Case 1Case 2Case 3

Case 4Case 5

Radius (120583m)

dNdl

og(r)(cm

minus3)

(a)

101

Case 1Case 2Case 3

Case 4Case 5

Radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

108

107

106

105

104

103

(b)

Figure 8 Some particle number size distributions obtained synchronously by sun photometer and APS-3321 respectively during theobservation period

study Figure 8 shows some particle number size distributionsobtained synchronously by sun photometer and APS-3321respectively during the observation period

In Figure 8 the number size distributions taken by APS-3321 and sun photometer all basically satisfy the Jungerdistribution but in Figure 8(a) there are two obvious peaksat the radius of about 035 and 075 120583m respectively and inFigure 8(b) the peaks appear at the radius of about 06 and14 120583m respectively It is clear that the shape of two typesof size distributions is similar which indirectly verify theresults of this study but the location of peaks is different

This is because the measuring result of APS-3321 is grounddata but the particle size distribution retrieved by sunphotometer is integral data through the whole atmosphereThe ground-air interface is one of important compositions ofwhole atmosphere and the ground data measured by APS-3321 represent the particle size distribution of ground-airinterface [15] The research of Li and Mao has shown that ifthe vertical atmospheric transportation is very enough andvertical mixing is also uniform the size distribution of wholeatmosphere aerosol column will be similar to that of ground[16] In our observational data there are some similar size

Advances in Meteorology 7

distributions between APS-3321 and sun photometer but noidentical size distributions This shows that in observationalperiod when the aerosol vertical mixing is relative stronga lot of aerosol particles suspended in the atmosphere willoriginate from the ground-air interface which can producesimilar results as shown in Figure 8 The case between APS-3321 and sun photometer in this study is similar to that of Liand Mao [16]

4 Conclusion

A sun photometer CE-318 is employed to measure systemat-ically the direct solar radiation data from September 2012 toOctober 2013 over the Yinchuan regionThe particle size dis-tributions were retrieved from the AOD by use of extinctionmethod The experimental results were analyzed and someconclusions are obtained as follows (1) The averaged sizedistribution of this area satisfies the Junge function basicallyhowever there are two obvious peaks in the range from 001to 2 120583m which are located at 06 120583m 14 120583m respectively(2) Because sand-dust weather occurs frequently the particlenumber concentration in Spring is the largest and that inAutumn is the smallest which coincides with AOD variationtendency (3)Theparticle number concentration in sand dustday is larger than that of background weather with one orderof magnitude especially for the number concentration oflarge particles and giant particles

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This work was supported by the National Natural ScienceFoundation of China (NSFC) (no 61168004) the Key Projectof Chinese Ministry of Education (no 211209) the Uni-versities Science and Technology Project of Ningxia (no2011JY007) the Natural Science Foundation of Ningxia (noNZ13094) and The West Light Talent Plan of the ChineseAcademy of Sciences

References

[1] F Liu and SNiu ldquoOptical thickness and size distribution of dustaerosol particles in InnerMongoliardquo Journal of Nanjing Instituteof Meteorology vol 29 no 6 pp 775ndash781 2006

[2] S Niu C Zhang and J Sun ldquoObservational research on thesize distribution of sand aerosol particles in theHelanMountainAreardquoChinese Journal of Atmospheric Sciences vol 25 no 2 pp243ndash252 2001

[3] G A DrsquoAlmeida P Koepke and E P Shettle AtmosphericAerosols Global Climatology and Radiative Characteristics ADeepak Hampton Va USA 1991

[4] J N Porter and A D Clarke ldquoAerosol size distribution modelsbased on in situmeasurementsrdquo Journal of Geophysical ResearchD Atmospheres vol 102 no 5 pp 6035ndash6045 1997

[5] V M Karyampudi S P Palm J A Reagen et al ldquoValidation ofthe Saharan dust plume conceptualmodel using lidarMeteosatand ECMWF datardquo Bulletin of the American MeteorologicalSociety vol 80 no 6 pp 1045ndash1075 1999

[6] F Li J Liu and D Lv ldquoAnalyses of composite observation ofoptical properties of atmospheric aerosols in the late summerover some areas of North Chinardquo Scientia Atmospherica Sinicavol 19 no 2 pp 235ndash242 1995

[7] J-D Mao D-X Hua T-Y He and M Wang ldquoLidar observa-tions of atmospheric aerosol optical properties over Yinchuanareardquo Spectroscopy and Spectral Analysis vol 30 no 7 pp 2006ndash2010 2010

[8] V Vitale C Tomasi A Lupi A Cacciari and S MaranildquoRetrieval of columnar aerosol size distributions and radiative-forcing evaluations from sun-photometricmeasurements takenduring the CLEARCOLUMN (ACE 2) experimentrdquo Atmo-spheric Environment vol 34 no 29-30 pp 5095ndash5105 2000

[9] J Heintzenberg H Muller H Quenzel and E ThomallaldquoInformation content of optical data with respect to aerosolproperties numerical studies with a randomizedminimization-search-technique inversion algorithmrdquo Applied Optics vol 20no 8 pp 1308ndash1315 1981

[10] M D King D M Byrne B M Herman and J A ReaganldquoAerosol size distribution obtained by inversion of spectral opti-cal depth measurementrdquo Journal of the Atmospheric Sciencesvol 35 no 11 pp 2153ndash2167 1978

[11] S Twomey Introduction to the Mathematics of Inversion inRemote Sensing and Indirect Measurements Dover New YorkNY USA 1977

[12] Y Zhang Study of Laser Granulometric Analysis Algorithm [Themaster paper of Xirsquoan] Technological University 2010

[13] K T Whitby R B Husar and B Y H Liu ldquoThe aerosolsize distribution of Los Angeles smogrdquo Journal of Colloid andInterface Science vol 39 no 1 pp 177ndash204 1972

[14] J Xin W Zhang J Yuan and L Liu ldquoThe spectrum distribu-tions of dust aerosol over TenggerDesert retrieved by extinctionmethodrdquo Plateau Meteorology vol 23 no 5 pp 654ndash659 2004

[15] F Li J Liu and D Lu ldquoAnalyses of composite observation ofoptical properties of atmospheric aerosol in the late summerover some area of North Chinardquo Scientia Atmospherica Sinicavol 19 no 2 pp 235ndash242 1995

[16] J Li and J Mao ldquoInversion of the property of atmosphericaerosol by pptical remote sensingrdquo Acta Meteorologica Sinicavol 47 no 4 pp 450ndash456 1989

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

ClimatologyJournal of

EcologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

EarthquakesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom

Applied ampEnvironmentalSoil Science

Volume 2014

Mining

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal of

Geophysics

OceanographyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofPetroleum Engineering

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

GeochemistryHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Atmospheric SciencesInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

OceanographyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MineralogyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MeteorologyAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Paleontology JournalHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Geological ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Geology Advances in

6 Advances in Meteorology

928 1124 1259 1455 1539 1559 165800

02

04

06

08

10

12

14AO

D

Beijing time

1020nm870nm

670nm440nm

(a)

01 1

849905928

105511091124

1010

109

108

107

106

105

104

103

102

Particle radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

(b)

Figure 7 The AOD and size distribution of sand dust weather taken on November 1 2012

1 2

01

1

10

Case 1Case 2Case 3

Case 4Case 5

Radius (120583m)

dNdl

og(r)(cm

minus3)

(a)

101

Case 1Case 2Case 3

Case 4Case 5

Radius (120583m)

dNdl

og(r)(cm

minus2120583

mminus1)

108

107

106

105

104

103

(b)

Figure 8 Some particle number size distributions obtained synchronously by sun photometer and APS-3321 respectively during theobservation period

study Figure 8 shows some particle number size distributionsobtained synchronously by sun photometer and APS-3321respectively during the observation period

In Figure 8 the number size distributions taken by APS-3321 and sun photometer all basically satisfy the Jungerdistribution but in Figure 8(a) there are two obvious peaksat the radius of about 035 and 075 120583m respectively and inFigure 8(b) the peaks appear at the radius of about 06 and14 120583m respectively It is clear that the shape of two typesof size distributions is similar which indirectly verify theresults of this study but the location of peaks is different

This is because the measuring result of APS-3321 is grounddata but the particle size distribution retrieved by sunphotometer is integral data through the whole atmosphereThe ground-air interface is one of important compositions ofwhole atmosphere and the ground data measured by APS-3321 represent the particle size distribution of ground-airinterface [15] The research of Li and Mao has shown that ifthe vertical atmospheric transportation is very enough andvertical mixing is also uniform the size distribution of wholeatmosphere aerosol column will be similar to that of ground[16] In our observational data there are some similar size

Advances in Meteorology 7

distributions between APS-3321 and sun photometer but noidentical size distributions This shows that in observationalperiod when the aerosol vertical mixing is relative stronga lot of aerosol particles suspended in the atmosphere willoriginate from the ground-air interface which can producesimilar results as shown in Figure 8 The case between APS-3321 and sun photometer in this study is similar to that of Liand Mao [16]

4 Conclusion

A sun photometer CE-318 is employed to measure systemat-ically the direct solar radiation data from September 2012 toOctober 2013 over the Yinchuan regionThe particle size dis-tributions were retrieved from the AOD by use of extinctionmethod The experimental results were analyzed and someconclusions are obtained as follows (1) The averaged sizedistribution of this area satisfies the Junge function basicallyhowever there are two obvious peaks in the range from 001to 2 120583m which are located at 06 120583m 14 120583m respectively(2) Because sand-dust weather occurs frequently the particlenumber concentration in Spring is the largest and that inAutumn is the smallest which coincides with AOD variationtendency (3)Theparticle number concentration in sand dustday is larger than that of background weather with one orderof magnitude especially for the number concentration oflarge particles and giant particles

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This work was supported by the National Natural ScienceFoundation of China (NSFC) (no 61168004) the Key Projectof Chinese Ministry of Education (no 211209) the Uni-versities Science and Technology Project of Ningxia (no2011JY007) the Natural Science Foundation of Ningxia (noNZ13094) and The West Light Talent Plan of the ChineseAcademy of Sciences

References

[1] F Liu and SNiu ldquoOptical thickness and size distribution of dustaerosol particles in InnerMongoliardquo Journal of Nanjing Instituteof Meteorology vol 29 no 6 pp 775ndash781 2006

[2] S Niu C Zhang and J Sun ldquoObservational research on thesize distribution of sand aerosol particles in theHelanMountainAreardquoChinese Journal of Atmospheric Sciences vol 25 no 2 pp243ndash252 2001

[3] G A DrsquoAlmeida P Koepke and E P Shettle AtmosphericAerosols Global Climatology and Radiative Characteristics ADeepak Hampton Va USA 1991

[4] J N Porter and A D Clarke ldquoAerosol size distribution modelsbased on in situmeasurementsrdquo Journal of Geophysical ResearchD Atmospheres vol 102 no 5 pp 6035ndash6045 1997

[5] V M Karyampudi S P Palm J A Reagen et al ldquoValidation ofthe Saharan dust plume conceptualmodel using lidarMeteosatand ECMWF datardquo Bulletin of the American MeteorologicalSociety vol 80 no 6 pp 1045ndash1075 1999

[6] F Li J Liu and D Lv ldquoAnalyses of composite observation ofoptical properties of atmospheric aerosols in the late summerover some areas of North Chinardquo Scientia Atmospherica Sinicavol 19 no 2 pp 235ndash242 1995

[7] J-D Mao D-X Hua T-Y He and M Wang ldquoLidar observa-tions of atmospheric aerosol optical properties over Yinchuanareardquo Spectroscopy and Spectral Analysis vol 30 no 7 pp 2006ndash2010 2010

[8] V Vitale C Tomasi A Lupi A Cacciari and S MaranildquoRetrieval of columnar aerosol size distributions and radiative-forcing evaluations from sun-photometricmeasurements takenduring the CLEARCOLUMN (ACE 2) experimentrdquo Atmo-spheric Environment vol 34 no 29-30 pp 5095ndash5105 2000

[9] J Heintzenberg H Muller H Quenzel and E ThomallaldquoInformation content of optical data with respect to aerosolproperties numerical studies with a randomizedminimization-search-technique inversion algorithmrdquo Applied Optics vol 20no 8 pp 1308ndash1315 1981

[10] M D King D M Byrne B M Herman and J A ReaganldquoAerosol size distribution obtained by inversion of spectral opti-cal depth measurementrdquo Journal of the Atmospheric Sciencesvol 35 no 11 pp 2153ndash2167 1978

[11] S Twomey Introduction to the Mathematics of Inversion inRemote Sensing and Indirect Measurements Dover New YorkNY USA 1977

[12] Y Zhang Study of Laser Granulometric Analysis Algorithm [Themaster paper of Xirsquoan] Technological University 2010

[13] K T Whitby R B Husar and B Y H Liu ldquoThe aerosolsize distribution of Los Angeles smogrdquo Journal of Colloid andInterface Science vol 39 no 1 pp 177ndash204 1972

[14] J Xin W Zhang J Yuan and L Liu ldquoThe spectrum distribu-tions of dust aerosol over TenggerDesert retrieved by extinctionmethodrdquo Plateau Meteorology vol 23 no 5 pp 654ndash659 2004

[15] F Li J Liu and D Lu ldquoAnalyses of composite observation ofoptical properties of atmospheric aerosol in the late summerover some area of North Chinardquo Scientia Atmospherica Sinicavol 19 no 2 pp 235ndash242 1995

[16] J Li and J Mao ldquoInversion of the property of atmosphericaerosol by pptical remote sensingrdquo Acta Meteorologica Sinicavol 47 no 4 pp 450ndash456 1989

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

ClimatologyJournal of

EcologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

EarthquakesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom

Applied ampEnvironmentalSoil Science

Volume 2014

Mining

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal of

Geophysics

OceanographyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofPetroleum Engineering

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

GeochemistryHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Atmospheric SciencesInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

OceanographyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MineralogyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MeteorologyAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Paleontology JournalHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Geological ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Geology Advances in

Advances in Meteorology 7

distributions between APS-3321 and sun photometer but noidentical size distributions This shows that in observationalperiod when the aerosol vertical mixing is relative stronga lot of aerosol particles suspended in the atmosphere willoriginate from the ground-air interface which can producesimilar results as shown in Figure 8 The case between APS-3321 and sun photometer in this study is similar to that of Liand Mao [16]

4 Conclusion

A sun photometer CE-318 is employed to measure systemat-ically the direct solar radiation data from September 2012 toOctober 2013 over the Yinchuan regionThe particle size dis-tributions were retrieved from the AOD by use of extinctionmethod The experimental results were analyzed and someconclusions are obtained as follows (1) The averaged sizedistribution of this area satisfies the Junge function basicallyhowever there are two obvious peaks in the range from 001to 2 120583m which are located at 06 120583m 14 120583m respectively(2) Because sand-dust weather occurs frequently the particlenumber concentration in Spring is the largest and that inAutumn is the smallest which coincides with AOD variationtendency (3)Theparticle number concentration in sand dustday is larger than that of background weather with one orderof magnitude especially for the number concentration oflarge particles and giant particles

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This work was supported by the National Natural ScienceFoundation of China (NSFC) (no 61168004) the Key Projectof Chinese Ministry of Education (no 211209) the Uni-versities Science and Technology Project of Ningxia (no2011JY007) the Natural Science Foundation of Ningxia (noNZ13094) and The West Light Talent Plan of the ChineseAcademy of Sciences

References

[1] F Liu and SNiu ldquoOptical thickness and size distribution of dustaerosol particles in InnerMongoliardquo Journal of Nanjing Instituteof Meteorology vol 29 no 6 pp 775ndash781 2006

[2] S Niu C Zhang and J Sun ldquoObservational research on thesize distribution of sand aerosol particles in theHelanMountainAreardquoChinese Journal of Atmospheric Sciences vol 25 no 2 pp243ndash252 2001

[3] G A DrsquoAlmeida P Koepke and E P Shettle AtmosphericAerosols Global Climatology and Radiative Characteristics ADeepak Hampton Va USA 1991

[4] J N Porter and A D Clarke ldquoAerosol size distribution modelsbased on in situmeasurementsrdquo Journal of Geophysical ResearchD Atmospheres vol 102 no 5 pp 6035ndash6045 1997

[5] V M Karyampudi S P Palm J A Reagen et al ldquoValidation ofthe Saharan dust plume conceptualmodel using lidarMeteosatand ECMWF datardquo Bulletin of the American MeteorologicalSociety vol 80 no 6 pp 1045ndash1075 1999

[6] F Li J Liu and D Lv ldquoAnalyses of composite observation ofoptical properties of atmospheric aerosols in the late summerover some areas of North Chinardquo Scientia Atmospherica Sinicavol 19 no 2 pp 235ndash242 1995

[7] J-D Mao D-X Hua T-Y He and M Wang ldquoLidar observa-tions of atmospheric aerosol optical properties over Yinchuanareardquo Spectroscopy and Spectral Analysis vol 30 no 7 pp 2006ndash2010 2010

[8] V Vitale C Tomasi A Lupi A Cacciari and S MaranildquoRetrieval of columnar aerosol size distributions and radiative-forcing evaluations from sun-photometricmeasurements takenduring the CLEARCOLUMN (ACE 2) experimentrdquo Atmo-spheric Environment vol 34 no 29-30 pp 5095ndash5105 2000

[9] J Heintzenberg H Muller H Quenzel and E ThomallaldquoInformation content of optical data with respect to aerosolproperties numerical studies with a randomizedminimization-search-technique inversion algorithmrdquo Applied Optics vol 20no 8 pp 1308ndash1315 1981

[10] M D King D M Byrne B M Herman and J A ReaganldquoAerosol size distribution obtained by inversion of spectral opti-cal depth measurementrdquo Journal of the Atmospheric Sciencesvol 35 no 11 pp 2153ndash2167 1978

[11] S Twomey Introduction to the Mathematics of Inversion inRemote Sensing and Indirect Measurements Dover New YorkNY USA 1977

[12] Y Zhang Study of Laser Granulometric Analysis Algorithm [Themaster paper of Xirsquoan] Technological University 2010

[13] K T Whitby R B Husar and B Y H Liu ldquoThe aerosolsize distribution of Los Angeles smogrdquo Journal of Colloid andInterface Science vol 39 no 1 pp 177ndash204 1972

[14] J Xin W Zhang J Yuan and L Liu ldquoThe spectrum distribu-tions of dust aerosol over TenggerDesert retrieved by extinctionmethodrdquo Plateau Meteorology vol 23 no 5 pp 654ndash659 2004

[15] F Li J Liu and D Lu ldquoAnalyses of composite observation ofoptical properties of atmospheric aerosol in the late summerover some area of North Chinardquo Scientia Atmospherica Sinicavol 19 no 2 pp 235ndash242 1995

[16] J Li and J Mao ldquoInversion of the property of atmosphericaerosol by pptical remote sensingrdquo Acta Meteorologica Sinicavol 47 no 4 pp 450ndash456 1989

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

ClimatologyJournal of

EcologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

EarthquakesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom

Applied ampEnvironmentalSoil Science

Volume 2014

Mining

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal of

Geophysics

OceanographyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofPetroleum Engineering

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

GeochemistryHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Atmospheric SciencesInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

OceanographyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MineralogyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MeteorologyAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Paleontology JournalHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Geological ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Geology Advances in

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

ClimatologyJournal of

EcologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

EarthquakesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom

Applied ampEnvironmentalSoil Science

Volume 2014

Mining

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal of

Geophysics

OceanographyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofPetroleum Engineering

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

GeochemistryHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Atmospheric SciencesInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

OceanographyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MineralogyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MeteorologyAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Paleontology JournalHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Geological ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Geology Advances in