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RNGY 7767 ZE OG D URNA hu 张舒 on lind on llva ce ec 44 raazhe obon duazho rsch on ceon aznd of nd eeanon acts ccrrceanha nd ou ceze ud nd eess hazvendnd rson nv rs bo 40 od rs on ° ss nv rs ouacrs aze haze eaeacaoadab oaeefss a ze ha nu5506 87ze fell on ceaeli caonss av oa ss bu on once ze ce onae cazece ce du li cafa ce nd eaze eanv eagy ec e20 ccon ze un 38 duovboun nd ce ecnvrsouNG Sh acrreazha aend rrun

O FOG TR NSFORM T ON DUR NG A ONG A NG V S B L TY …dqwl.nuist.edu.cn/TeacherFiles/file/20160910/... · s tarted o b e tr nsformed from haz e to fog. Th i s s udy ca l l s f o

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Vol . 22S IJOURNALOFTROPICALMETEOROLOGYJul y20 1 6

Arti c leID :1 006-

87 75 (20 1 6 )S I

0 067-

11

HAZE-TO-FOGTRANSFORMATIONDURINGALONGLASTING,LOW

VISIBILITYEPISODEINNANJING

ZHANGShu-

ting(张舒婷 ) ,

NIUSheng-

jie(牛生杰 )

(Key

Labo ra tory of Meteo ro logi calD isas ter

,M inis tryo fEdu cat io n/ J oint Interna t iona lRes earch Labo rato r

yo f C limate

and E nv ironmen tCh ange/Co l labora ti veInn ovat ionCen teronForecast andEva luat ionofMe teo ro log icalDis aster s

Nanj ingUn i

v ers i tyof In fo rmat

i onSc ienceandTec hno logy,Nanj ing2 1 0044China

Abstract :Haze -

to-

fog tran sfo rmat io nduri

ng

a lon

g la sting , l

owvisib i l i

tyep i

sodewasexam inedus ingtheobs ervat

i on s

fromacomprehens iv efie ldcampaigncon duct

ed inNanj i ng ,Chi naduring4

9Decemb er20 1 3 . Inth isep i sode,haze

wastrans formed intofogand the fog

lastedfo rdozensofhour s.Theimpac t sofme teorolog icalfac torssuchas w ind

t emperat

ur e(T

) andrel at i

veh umid ity (RH

) onhaze , tran sit i onandfogduring thisepi

sodewere inves t igated .Resul tsr e?

vea led s i

gn i fi cant di fferencesbetween hazeandfo

gdays ,dueto the ird ifferen tfo rmationm echani sms .Compari sonwas

madefo rbou ndary

layer cond it ionsduringhazydays ,haze

to-

fog

day sand foggydays .D ist ribu ti onsofw indspeed

and w ind di re ct ionaswe ll as syno

pticweathercondi ti ons aroundNanj in

ghadde term inati veimpactsontheoccur rences

and charac terist icso f hazeandfog

. Weakeneds ou ther l

yw ind insou thern Nanj i ng

resu lted inhi

ghconcentrat

ionofpo l

lutan ts,andh azeeventsoccurred f

requ ent lyduring thestudyperiod .Th ew

inds

peedwas les sthan 1m s

in thehaze

event,wh ichresu l tedi na stab leatmo s

phericcond i tionand we akd ispersiono fth e

pol lu tan ts .Thehe i

gh tof th etem

per

atureinvers ionwasabout400mduri ng

theperiod

.Th e invers ionin tens itywasweakandthetempe rature

d ifference

w as4°

Ckm'

orle ss inhaze ,wh i lethe i

nvers ionwass tronger,andtemperature

differencewasabout6^ 1kin*

,ap?

proach in

g th einvers ionl a

yerin tensi

y i nth e fogevent .Hazeeventi sstrong lyin fluenced by

amb ien tRH .RHval ues in?

creased, wh ich res ul ted inhazeda

ysev ident ly increased

,sugges ti ng

that ani ncreasi ng

frac t ionof haze eventsbecaus ed

byhygros cop ic

grow th ofaeros ol s,ra th er th ansimp

l yby h i gha eroso ll oading

.When RHwasab ove9 0% ,hazeaero so ls

startedtobetrans fo rm edfromhazetofog

.Th isstudy

ca ll sfo rmoreefforts to contro lem i ss ionstop

reventhazeevents

inthereg

ion .

Keyw

o rds :h aze;fog ;

tran sformat ion;met eorol og

ica le lement s

CLC number :P427 .2Documentcode :A

do i :

1 0. 1 6 5 55 /j.1 00 6

-8 77 5 .2 0 1 6 . S1 .007

1INTRODUCTIONYangtzeR iverDel ta (

YRD)ha ssufferedfromseve re

po llution scausedb yh i ghconcen trationsofaerosol

par-

Low vis ibi li t

ycau sedby

fogorsevere hazecanbe tide s re sul tedfromem i s sions fromfo ss i l fueland

aheavyburdenfora ir transpor

tand roadtraffic .Po llu-biomas sburning ,transportationandoth ercombu stion

tantpar tic leconcentra tionsdur inghazeorfogeventssource s (

Cheneta l .

[5

).Conc entration sofaerosol

par ti-

canb es everal times,orevenadozentimes

,highe rthan

c lesgreatlyexceeded therecent lyrevisedambi enta ir

those dur ingnorma lweathe rs,and

po l lu tantpar tic les inqua

l itys

tandardofChinaforPMZ5 andwereatleas t1 0

thea irthreatenthehea lthofhumansandotherl iv ing t imesthosemeasuredinea ste rnUS .Thema incauseof

things in manyregionsintheworld

(Jacquel ineetal .

;hazei satmospheri cae roso lpartic le s

,andfogcouldde-

Poschl[2

).Duetofa stdeve lopment inChin ainrecentcreasePM

2.

5andPM 1 0ne artheground(

Fane tal .

E6

).

years ,China'

sregiona lhaze i nurb anare ashas in-Aeroso lsin theenvi ronmentaredecidedbypar

ti cle

c rea seds i

gni ficantl

y ,wh i lethe re isadec re as ing

trend s ize,

shapeandchem ica lcompos i t ion(

Okadae tal.

[7]

).

of foggydaysinCh i na(

T iee ta l.

3]

;Fueta l .

4J

).TheAtmo spher icfinepart icul atesplayama

jorrol eina ir

pollut ion (Heeta l .

[8]

).

Recei ved2 0 1 5-

0 7-

2 8;Revi sed20 16

03-

1 5;Accep

tedTheformationofhazei sc losel

yl inkedtome teoro-

20 1 6-07 -

1 5logica landatmosp

he ri ccondi t ions(La iandS eque ira

[9]

Foundationi tem :Nat iona lNatu ra lScienceFoun dati onof Ch i

-L ieta l.

[l 0

).Atmo spher ichazeisma in lygatheredin the

na(4 1 275 1 5 1,4 1 3 75 1 38 ) ;Gr aduateS tudentInnovat ionP lanbounda r

ylayer

,sow ind, temperatureandhumidi t

ybe-

for theUni vers iti eso f J ian

gsuProv ince (CXZZ 1 3

0 5 1 4 ) ;apro -

l〇w850hPaa re themos timportantfactors .Whenthe re

je ctfundedby thePrio r

ity Academ icPr ogramDeve lopm

en tofisaninver siolllaye r inthei〇w ertroposphe re ,thea tmo-

J iang suH igherEducat ion In st itut ion s,

?.

^^A,?

,,,.

^j.

j?

,sphe re ismas tables tate,whi chwouldl imi tvert i ca l

B iography :ZHANGShu-

ting,Ph .D .cand idate

,p rimari

yun

. .

^ tr , n^,,mi 、

dertak i ng

res earchon atmosphericenvironment .d lSPerS 10nof

Pol lutants(P lheeta l

[U

;Roa cheta l -

[' 2

)-

Correspondingauthor:ZHANGShu-

t ing,e

-ma il :va ri ationofhazedays isma in l

yre lat edto

zhangst1 0@nuis t .edu . cnaeroso lpo l lutioncondi tionandtochange sofsurround

6 8JournalofTrop i calM eteo ro logyVo l. 22

ingenvi ronmen t .Ca lmcond idonmwinte r isop

t imal

2DATAANDMETHODSforhazeto oc cur .High

pressuresys temi s thema insyn

opt icsys teminwhichha zec anoccur(Wange tal .

1 31

).2 . 1Dataands iteinfo

rmat ion

Themainrea soni sthatatmosphe ricstratif

ication issta

-TheYRDh adbe enundergoingrapiddevelopment

bleand theinversionlayer

i smuchth i cke rinwinte r;a sduringthela stthreedec ades .Nan

jing

i same gaci ty

i n

are sul t,po llu tantsaremuche as iertogather .Incon- theYRDwi thhi

ghpopu

l at iondensi ty andawel

l-deve l

tra st, inwe athersys tem sofcyc loneandea ste r lyb el t

,opede conomy.Urbanizationh asbrought

grea tstres sto

hazedays occurrarely .l oca lenvironmentan dhaze-

rel ateddi sastersh appened

SixChine semegac it i es su fferedfromcon tinuous-frequently .Thefie ldstudy

focusingonphys

i cscharac-

lydecreas ing vi s ib il i ty inthepas t30

years(Change t ter is tic s infogan

dhazew asc arriedoutinDec .20 1 3 .

a l .

[14

).Thevis ib i li ty trendcou ldbeattributedtotheThesampl ings itewasloc ateda t(

1 1 8 .7°

E,3 2 .2

°

N;22

increaseinsul furdioxideem i s sionoraeroso lconcen -

mabo vethesea leve l)

inNUIST(Nan

jingUn ive rsit

yof

tra tion

;however

,nocausa li tycou

ldbees tabl i shedsoInforma tionandSc ienc eT echno logy),whi chi snorthof

far .Many in-

s itumea surementshaveal readybeenc ar -theY ang

tzeRiverandsur roundedbyvari ouspol lution

r ie dout tos tudyhazeandfo gunderdi ffe rentrela tivesourc es,suchas

petrochem ic a lfac tori es,as tee l

p lant,a

hum id ity(

RH)

.Re sultssh owedthatlowvi sibi li tytherma l

powe rs tation,

ani trog enou sferti li ze rp

lan t,and

eventsunder lowRHcondi tionweremost l

yinducedh i

ghw ay

s(Lueta l .

[2 ,

).

byhe avyaerosol loading,

wh il ethoseunderh i

ghRH2 .2Ins trume nts

c ondi t ionwe reduetotheinf luenc eofaeroso lhygro-Theme asu rementscol le cteddur ingt

hefi eldexper-

sc opicgr

owthbecom ings

tron ge r

,whi chcouldlead toimentincludevi sib i li ty,boundary-

l ayerprofi lesand

lowv i s ib i l ityev ents evenunderm ode ra teaeroso lpo

l-CCNnumberconc entration

,amon gothe rs .Vi s ib i l ity

lu tants .Animportan tsou rceofaeroso lpart icl e si slo-

andreal-

t imeweatherw ere automat i cal lymea suredand

ca lemi ss ion (Ch anandYao

, 5]

).Someauthor sana -

recordedeve ry30sw ithaVPF-730AutomatedPre sent

yzedthehighe stleve lofatmosp

he ri ce nv i ronmentWe atherObse rv ingSy stem(B iral

,Bris tol

,UK ).The in?

po l lutantsinw inte rre su ltedfromveh ic leexhau stands trumentha sanoptical transm it ter,a forwardsca tterre

coa l/cokeem i ssions,andconcludedequal l y

impo rtan tc eiverandaback-

sc atterrec eive r,whichrecordfog

c ontri butionsof loc a lem i ss ionandregional transpor tdens i ty ,prec ip i ta t ionident ity,

rainra te,andsnowfal l

inN orthChina,unde rtheme teoro logi ca lcond i

tion so fra te.Thevi sua lrangeoftheinst rument isfrom 1 0 mto

lowtemp erature

, lowRH,we akradi ation

,andlow75km . There la t iveer rorofthe ins trumen ti s± 1 0% for

bou nda ry-

layerhe i gh t(Chenetal .

[1 6

;Che neta l .

[1 7

;v i s ibi l ityl e ssthan1 6km,and±20%forvi si bi l itybe

Da ie ta l .

[ , K J

).tween1 6and30km .

Ex is t ingresul tsabouttheeffectofhazeaeroso lsonDe tect ionofboundary layerw asdon eus i ng

foga reno tc ons i s tent.Som es tu d iesshow ed tha tthein -TPAWP-

3000m ic rowaverad iometer(Rad iome trics

c reaseofh azeaeroso l scouldstrengthenfogforma tionU SA

) ,wh ichdete cts tempera tureand liqu idwate r-vapor

anddevelopm ent(JiaandG uo

1 9]

) , andothersshowedprofi le sfromtheearth'

ssurfac eto10km.I thasfive

tha ttheradiat ioneffec t inducedbyhazeaerosolsc ouldoxygenchannel s andsev enwater

-vaporc hanne l,

le adtoreduct ionoffogoc cur renceinfrequency(Gau -TPAWP-

3000recordeddataeverym inu te .Br ightne ss

tame tal .

201

). Inrec en t

yea rs

,fogandhazeeventsoc -

temperaturerange is0-400K .Surfac etemperaturede-

curredfrequently intheYRDregionofChina;however

,tec tionandrelat iv ehum idit

ypre ci s ionsa re2%.

thetransi t ionofhazetofogi snotw e llunders tood .InTheab i li t

yofModel33 2 1Aerodynam i cPartic le

thi ss tudy ,weana l

yzedhaze -

to-fogtransform at i ondur-S izerSpec tromete r(APS

)tomakeaccu rate

inga long la st ing ,lowvi s ibi l ityepi sod einNan

jing

andm as s-we i ghteds i zedis tribut ionmeasurementwa seva lu

cha ra cter is tic sofboundary layerus ingi n-

s i tum ea sure -

a ted .Sampl ingfrequencywas 1min,an

dmeasurement

mentsofmac ro-

andmicro-

phys

ic sonhaze-

to-

fogday spa rti cl esc aleswe re0 . 3 7

-20|

xm .Asaresult,theAPS

inwinter20 1 3 .Th egoa lofthi ss tudyi stoanalyze3 32 1systemdetec tedpart icl e sthatwe re le ssthan0 .3

xm

h aze-to-

fo gtransformationmechani smi nordertopro-inaerodynam icdiame te rus ing

the lowes tsize bin .

v id em orescientifi cevidencefo ridentifi ca tionandpre

-Acont inuou s-

flowdu alCCNcounter (CCN-200

dictionofhazeandfogevents .The

pap er iso rgan

izedm anufac turedbyDrople tMe asureme tnTechno logie s

a sfo l low s .Se ction2de scribe s the in-

s i tufo gandhaze(DMT

,USA)wa suti li zed tomeasureCCNconcentra-

mea surements,introducing theobserva t ionper iod

,s i tet i onsa tdi fferentsupe rsaturationvalues(Robertsand

andda ta .Inse ction3 . 1,gene ra l informa tiononhazetoNenes[

221

;Lanc ee ta l .

[23

).F ivesupersa tu rat ionva lue s

fogevent s isdescribed .Se ction s3 .2to3 .4addre ss the( nom ina ll

y0 . 1

,0 .2

,0 .4

,0 .8

,and 1 .0%

)madeup

acycl e

m eteoro logica le lementsofwind

,tempera

tureandRHo fh al fanhour,ta

k ing10m info r0 . 1%and5m infor

inonehaze-to-

fogevent.Aeroso lsandc loudconcentra -

theo thersupersatura tionva lues .C loudroomto tala ir-

tionnumber(CCN

)concen trat ionduringhaze-

to-

fogf low ratewa s500cm3

min" 1

,ratioofbes tsh eathflow

transi tionareana l

yze dinse ction3 . 5 .

Summ aryandandsamp linga irfl ow ratewas1 0

:1

,sampling

frequency

conc lu sionaregiven i nsection4 .was1Hz

,andmeasurementparticl esca le sw ere0 . 75 -

S IZHANGShu- t

ing (张舒婷 )and N 1 USh eng

j i e(牛生 杰)69

1 0 .0 0

xm(L ie ta l .

[24

).pen

dedwa terdrople tsand/o ric ec rys tal s(

N a t iona lO -

Su rfacem ete oro logi ca lcond it ionsandsynopt

i ccean i ca ndA tmosphe ri cAdm in i s trat i on,1 995

).Haze

weatherdatawereobta in edfrom theCh inaM eteor olog- regim eoccursas atrans i t ionbe tw eenc l ear

sky

a nd fog

ic a lAdm in ist rat i on'

scompre h ens i veo bse rvat i onnet-reg imes

,andv is ib i l i tyi sh igh l

yvar iab l e inhazereg ime ,

work .Wate r-va

pord iv erge ncewa sobta ine dus ing

theHazeregimei sdefineda sv i s i b i l i t

ylowe r than5000m

Fina lAn al

ys isDa ta(FN L

)from th eNati ona lCen ter sunt i l

fogoccurs(E l ia seta l

[26

).Hazetrans i t ion

phasei s

forEnv ironm en ta lPred i ct i on(NCEP

)oftheUS .defin edbythesta rtofanaeroso lact ivat ionproc es

s .

Compu

ta t ionforhazeisdoneforv i s ib i l i tylow erthan

2000m,asdrop

letsappe ara tv i s ib i l itybetween1400

3 .

1Ge ne ral

info rmat ionon hazetofogtramform ationand2000m .Thev i s ib il i tyval ueso f40 0and8 8 0m

A tm osphe ri ccond i t i on sm aybec la s si fi edi n tocha rac ter izethetra ns i t ionphasebetweenfogandhaze

th reereg im esacc ord ingtov i s ib i l ity :cl ea rsky ,fogandregim es,wh i c his cons i sten tw i ththe500 - 10 00mv i s i

haze .Cl as s i fic a t ioni susua l lydonebasedonabs o lutebi l ity

i n te rva lcorrected .I nou rs tudy ,weuseR Ha nd

va lue sofv i sib il ityrange (Ta rd ifandRa smussen1

251

).v i s ib i li ty (

V is)

todefin efogandhaze ( Fi g . l

): it is fog if

C le ar-

shyregime isdefineda rb itrar i lyforvi s ib i l i tybet

-V i s< 1kmandRH> 90%;iti shaze , ifV is<5kmand

te rt han5000m, i ncontra sttohazyandfoggyc ond i

-RH<8 0%; iti sthetran s i ti onp

hase,i fVi s< lkmand

tionswhenv i s i b i l i tycanreachdram at ic al lylow er va l

-80%<RH<90%;an

di tiscl ea r-

skyreg imeifvi sibi li ty

ues .T he in ternat i ona ldefin it i onoffogi s anob servedval uei sbe tter tha n5000m .Thehaze -

to-

fogtra n s i t ion

horizon ta lv i s ib i l itybe low1kini n thep re senceofsu s-dur ingoursu rveycanberough l ydiv i dedin t

ofour

3 .

<a >

IA . !—— I

g Haze| |to fo

g II Fog| |Fog

2 01 3 / 1 2/4 | ||2 01 3 / 1 2/6| 1

2 01 3 /1 2 /8

t:; f !K :

ll i l JTii 1 -

〇 . 〇_

._yIt 1

RH(%

20 1 3/ 1 2/4I II20 1 */ 1 2 / 6I I 20 1 3/ 1 2/8

II I I

以I IIII

(C

)i

/i,iHMf LIHIHHHi 1! ■20 0

_ 0 .8 fr1

\\ g i i

ji 丨置 丨f■> 4^

吞 ij i : ij i i . i'HW i!_以

TO0 .4 - II IIII iij

flf I>

,MUS

至 。 .2 .U I !. I t 1M !J|'

0 .0 I^I . I .TA I.1

T(t :)

20

1 3/12/42 01 3 /1 2/620

1 3 /1 2 /8

T ime

Figu re1 .Tempo ra

lvaria

tionsof

(a

)v

is

ib i l ity , ( b)RHand (

c)

tempe

ratu re .B la ck l i

neisRH= 90% ,

an dgrayl i

n eisRH=80% .

Ta bl e1 .Start ing

time ,en di n

gtime

,d ur atio n,me an san ds tan dardd ev ia t

ion s( inparent hes is )ofkeyp

ropert

iesu nderdi fferen t

w eather co nd it

ion sin20

1 3 .

4Ac cumu lat ionCo arseparti c le

Ave rag eAv erage

Av e rag e .

,,

?」T i me_‘

part ic lenumb ern umber

Re gimeT ime pe r io d,Temp.KHV i s

du rat ion心 、,

n / 、 ,,、 concent rat ioncon cen tr at

i on

⑴ (%

)( km

)(cm

- -

)(cm

- '

S tart ing t imeEnd ing t ime

H aze20 1 3/ 1 2/32 3 : 4020 1 3 / 12 /4 1 0 :47l

l h5 . 673 .90 .7348 .2- 1 548 9 . 2534 .4-46 34 . 1

(2 . 0

)(4 . 9

)(0 .

1 )

H azetofog2 0 1 3/ 1 2 /42 3 :2 120 1 3 / 1 2 /51 0 : 26l l h6 . 684 . 50 . 527 4. 6

2 1528 . 945 9 . 4-

8 52 3 8 .7

(1

. 8 )(5

)(0 .2)

Fog

I2 0 1 3 / 1 2/52 3 :442 0 1 3/ 1 2 /68 : 2 09h5 . 8 339 1 . 90 . 722 5 . 7

1 1 1 86 .6 12 5 .9-

13 1 4 . 7

(0 . 5

)( 5 . 4)(

0 . 1)

Fog

II2 0 1 3/ 1 2/71 7 :

1 02 0 1 3/ 1 2 /99 : 3 233 h5 . 8 799 4.30 . 32 7 0 . 7-

1 52 45 9 .81 53 . 4-

94 1 42 .3

( 1. 6

)(6 .9 )(

0 . 2)

70J ou rnalof Trop ica lM e teo rologyVo l.2 2

stages(

Table1

): hazes tage(

2340LS丁(LST

UTC+8h)

_

广 . 二W3D ecem be rto1 047LST4Dec em ber

) ,haze -

to -

fog各知 、

s tage (232 1LST4Dec emberto 1 026LST5D ec ern -/

be r) ,fogstageI

(2344LST 5De cember to08 2 0LST6^283

L* .

De c ember) ,andfo gstageI I (

2 1 25LST6De cem bertoG%^

093 2LST9Dec embe r)

3 .2Impac tofsurfacewi

ndonhaze

to-

fogtramfor rna

?/0

non

W indspeedandboundary-

l ayerstra tif

ic at io np ro-

卜’7

▽\)

v i dethewea ther b ackgroundforhazeorfogevents.A t

°

^r^r

surfac e,theweakpre ss uresy

s temc on tro l ledmos tar eas

ofcen tra lande as ternCh ina,andthedom inantflows\。

wer efromth esou thwe standwe s t,w i

thw i ndspee

dles s /

?T'

l〇

^^

\ ,/

tha n3ms

,wh i chcou l dre su lti nahaze- fogep isode ;

(Yangeta l .

2 7]

.Ea r l

ystud ie soffo

rm at i ona ndevo lu t ion'

mechanism sofhazeevents inB ei

jing

foundthatthe卜 :

s\

p rima ryreasonsw eres tab l eant i

c yc lon icc i rcu l a ti onat^^y

* 79

t |.

? 4

^surfac e

, l ow er ing

thep lane ta rybounda ry-

l ayerhe igh t

(Denget al .

2 8]

).Wang e

tal .foundthattheco l da irbe-

\一"

longed to thehori zonta lthroughturn ingto longi tud in a l ^ ^S

,rTIt

s ty l e,

thegrou ndw ascon tro l ledbythe

pre- h igha n t icy

c lon eandthegroundfron tzone hadbeen

pre s sedtothe .一

J iangnanreg

io n |

l 41

.Zhangeta lshowe dtha ttheE as t.

,A ,

Y i

^

A s ianw i nte rm on soonwa swe ak inJ anua ry20 1 3 ,an’

^.

abnorma l lyh ighpre ssurecen te rocc urredat42 . 5°

N,

p\

1 20 . 0°

E,andtheco l da irof

p ostthroughw asd i ffi cu l t

to i nvadeeas te rnCh ina a sare su lt[29

.F ig .2i s theweath -,M

erpat ternove re as ternCh i nafrom0 800LST4Decern-為二

t3

ber to093 2LST9De cember20 1 3 .Athigha lt i tud e,a

7 \

T?

troughi nt

henorthmovede a stwa rdon3Decembe r,: A

andm ovedaw ayfi om J i angsuProv inc ea t

2000LST4j*

丄咖

Dec embe r.On5Dec em b er,theE as tAs i anma

jor二

troughmovedea stwa rd,wh il e them i d-

lat i tud ege opo-f *

^ }|||||^&Ajt^===s^-c= ::^

ten t i alhe i

gh tfie ldappe ar e

d tobezonal l

yor ie n ted . Un-j ̄

(bV .

t i l2 000LST8De cem be r,anupper

layer troug

hcom-’

^v

b i nedw iththem id-

lowe rl aye rco ldai rshe armoved'

^eas tw ard

,br ingingco lda irsou thw ardneart hesurfac e,\

.f

wh ic h im pac ted thewe ath er i nNa nj

i ng.A cco rd i ngto

-?

,\

thesu rfaceobserva t ion, t

henorthw es ter l

yp reva i l ed i n—

H?

Na nj

ingon3Decembe r,s inc ethec i tywasinfro n to fa

wea kh i gh-

pre ssuresys temtha twa sc en te redinNorth

C h i na .On4D ec embe r,t

hew ea kc o ld ai rmovedsou th-

^wa rda ndc aus ed

pres sure

grad i en ttodec re ase .Na nj

i ng1

wa sunder thecon tro lofhomoge neouspre s sure,a ndth e

windspe edw asre duced .Seve reco l da ir i ntrudedsou th-

t/"

wa rdsincethen i

gh tof 8De cembe r

,wh i chcau sed

pre s-

suregrad i enttoinc re ase,andw indspe

edin cr ea se dto'

^r

97

^

6-

8ms

_ l

.Thev i s ib i l i tyobv iou s lyim proveda t1 700

LST9Dec ember,and th el arge

sca l eh aze-

to- fo g

ePi S

T!;

e t〇 an end '

n ,fnW i ndd i rec t ionc anin

flue n cethetra n spor to f

po

l lu-4

—tr

ta n ts,w h

i l ew ind speedgre at

yinf luenc esatmosp

he r ic*

?iJ〇fc

d ispe rs ionc apab i l i ty .Lowwi ndspeed

inthehor izo nt al

d ire ct i on imp

l i es th attheatmosphe re isra ther stab le,an dF ig

u re2 .A ve ragesyn op ticweath e rdu r

ingt hehaze

to-

fo g

tha tthed i sper sionofl oca lem i ss ions i s l im i ted .A ir

-ma s sproces sof 4 -9D ecember20 1 3 . (

a)Su rfac ew i

ndfie ld; (

b)

transport canb ri ng inpo l lu tan ts o rc le ana ir from d is tan t,g

eopot en ti a lh e i

gh tfi e l d at8 50hPa

;(c

)geop otentia lh e i

ght

inf luenci ngloc alconc ent rat ionsof

pa rt i c l e s.fie lda t500h Pa .

S IZHANGS hu-

ting(张舒婷 )and N IUShen

g-

j ie(牛生杰 )7 1

F igure3shows thew indspeedwa s les sthan1mwec ou l dconc lud ethepo llu te da ir m as sesfrom we stern

sl

inthehazeevent,w h ichhel

ped toma in tai nthesta

-a rea scon tribu tedto thea cc umul at i onofpar t ic l esi n

b leboundarylaye rne art

hesurfac e .

Surfa ceroughnessNan

jing (

Fig .4)

.When thew indspe edsl ow eddown ,the

a l so inf luenc e sw indspe ed.C i t ie sw ithdense lyd i s

-hazebegan totran sform in tofog .Loca lem i ss iona c-

t r ibu tedta llbu i ld i ngshaveh i ghsurfa ceroughn es s,compan i edb

yregi onal transportfrom we stw as re spon

w h ichs low sd ownnear -surfacew in d .Loww indspeeds i ble fo rthepa rt ic l es inhaze-to-

fog trans i t ion .F ig .5 a

ind i ca tes tha td i spe rs ionhadb eenweakenedove rtheshowsthespa ti a ld i str ibu t io no fsu rfacew in dd i re ct ion

obs erva t ionreg ion . I nF ig .3,i nthenorthwes ttosou th-dur ingthehazeeve nt .Thes i tewascon tro l ledbyt h e

w es tbyw es t (

NW-WSW) thew in dsp eed(

W S)wasnorthea s terl

yw i nd ,wh ic ht ransp orted thepo l l u tant s

h i

ghb eforehazetra n sform edtofog,andtheconc en t ra

-fromtheno r th tothe s ite,w h i l ethesouthw es tpa rtof

t i onof ae roso landCCNshowedare l ati ve l

yh igh leve l.theobservat ions itewa sdomi na te dbyw i ndfromthe

A ccord ingtoHYSP LITbackt rajectori e sandfi reho tnorthwe st inthehazeevent .An inver sere lat ionshipbe

spo tsfo rthehaze -

fogpe ri odsdur ingtheobservat ion .tw eenconc en t rationandw indspeedsugge sts thep re-

Zha ngXiangz

h i,thedepu

tyd i re ctorofTe st i ng

ce n te rofdom ina nceofloca lsourc es,be c ausest rongw indsent

Depar tmento fEnv i ronmen talProtec tion,said

Thepo l lu tantsou tof thes tudyareawhe rea swe akw i nda l

conc en tra t ionsofpo tas s i umi onandb la ckc a rbon inthelowedpo l l uta ntstoac cumul ateove rt ime .Apa rtfrom

a i rwe rei nc reas ed .The setwocompos it ionsw er e0 . 5lo ca lemi ss ion

,reg i ona ltransp ortwa sreportedasan

t ime sh i

gher thann ormal .Th i s isca used b

ys trawb um-impor tan tcau seforpa rt icl econc en t rat ionintheatm o-

ing !Th esek i ndsofpar t ic le sm ain l ycam efromthespher icenv ironmen t(Pe tere tal .

[3 0

).Thewe aknorther ly

northofJiangsuprov i nce . Thewindsfrom the se d ire c-w ind l edto th eac cum u l at io nof aeroso l sa ndt he i r

pre-

t i on sb rought inpo l lu tan t sfrom strawcom bu s ti on;so

,cur sor saround thes ite (X ueta l .

[3 l

;Gaoe tal .

[32

).

0 . 00 043 . 758 7 . 501 31 . 31 75 . 02 1 8 . 82 62 . 53 06 . 33 50 .0

2^

#W i nd d i re ct i on

* I

(0

旦 .??J!

卜A4Aj^ tlii \ \U

20 1 3/ 1 2 /42 01 3 /1 2 /52 01 3 /1 2/62 0 1 3/ 1 2/ 720 1 3/ 1 2/ 82 0 1 3 /1 2 /9

T im e

F igure3.T emp o ra lv a r ia t io nso f w in dspeed andw in dd i rec t ion .

Fogformationre qu i resafavorab lewe at

hercond i

po rtorea c hNanj

ing .Ac cum u l at ionofwate rvaporin

t ion,sayasa tu ra tedwa ter

- vaporenv i ronm en t .Duri ngthe con ve rgen ce zoneh el pedfogfonnat i on i n th isare a ,

thehaz e-

to -

fog trans i t i on,su rfac ew indspe edwa sl ow

,W i ndspe ed in thefoge ventwasgrea te rthantha t

t hesamea sin th ehazeeven t,w h ichi sc onduc ive toa c- inhazeandhaze

to -fog tran sit ion .When fogwa s ind e?

c um u la tio no f

pa rt icu latem at ter sandt he ir i nte ract ionve l opmentandmatures tage s

,m ic rophys ic a lproce sse s

wi thwatervapor .Lowsurfac e-windspeeda lsoprovid-suc hasconde nsa t i ona ndevapora ti ondeve lopedwe l

l ,

edthec ond it i onforthe t ra nsfo rmat ion .Fo rw inddi re c-Whenthea irb ecamesa tura ted ,sma l lpe rtu rbat i on s

t ion ,F i g . 5bshowsthesurfacew inda l lcamefromthecou ldcauseo therphysi c al

quan t i t ie s(e .g .

,wa te rvapor,

southa ndconvergeda t the s i te,wh ic htran sportedwam itu rbu lenc e

,ortem pe ra tu re)tom akecorre spond ingad

andhum idai rtothes i te .The rew asaconve rgen ce l i nejus tmen tstoach i evean ewequ i l ib ri ums tate .Inth i s

near1 1 8°

E .Toth ewes toftheconve rgenc el ine,theba l ance ds ta te

,tu rbu lencecou lddeve lop ;so,var ia b il i ty

near -su rfacew i ndwasdom i na tedbyt heso u thwe s te rl y ;o fw i ndsp eedwou l dbela rger thanin thehazeeven t ,

totheea s ttotheconvergence

l ine,thenea r

sur fac eF i

gu re5 cshowsthew indf ie ldi nthefi rstfog

w i ndwa sthesou theas ter ly .T hesouth e as te r lyandeven t .Th i sfogl as tedn i neho urs .Tothenor thof the

sou thwes te rlyar e themos ttypi ca lc arrie rsforwate rva-s i te,thene ar -surfa cew indw asthenorthea ste rl y ;to the

7 2 Jo urn a lof Tro

pica l M e teo rologyV ol

. 22

C l uste rmea ns-

Stan da rd

33backwardt rajecto r ies

GDASMeteo ro log ical Data

?SHGE. '咖135

慧.

mmam,:

〇-3 000

< ‘'

、?2500

co

)2 000

① —- -———

^****^ ——1 500

a;1 000 「■^

▼^ 1 000

^ ̄

500

244872

F igure4.B ack trajec tor

ytoNa n

jing

72 ha ndfi rehotspot sonYR Ddu r

ng 1

1 5D ecemb e r20 1 3,

t he in t e rva lbe tw eentwop

oi

n ts

i s1 2h ,andt he starp

oin t i sNan

j i

ng

southofthes ite,

thew indwa sdom i na tedbythenorth-temp eratu rew as inthefogeve nt .Lowtem pe ra tureis

wes te rly .Low -

pre ssu rer eara i rflowincreasedc onve r-

genera l lyfavora b leformo is turecondensat i on,bec au s e

gence

,sowa terv apo rconden seda ndforme dfo g .The i tw i l lmakemorepa rt ic l eshygro scop icfora ct i va t ion

secondfogeventl asted60hour s,but no tcon tinuous l

y.andg

rowth .Thehaze -

to-fogt ransi ti onhappen edbas i

I twa sdom ina te dbythesouthe rl yw ind(F ig . 5d

).Ne arca l l y inth e i nvers i onl aye r.Thehe igh tof the tem pe ra

theob servations ite,therewastheconve rgenc ezone,

turei nvers i onwa sabo ut 400m .Whentherewa satem-

andthesou thea ste rl

ywindbroughtwarma ndhum i dp

era tu reinvers ioninhaze,the inver s io nin ten s i tywas

a ir,w h ichp rov idedmo i sture forthefog

top

er s is t .weakandthetem perature-

d ifferencewa s4X.knr1

o r

3 .3Impact of

temperatureonhaze -to

fogtra jisfo rinal ionl es s .Inthehazeeven tthetemperatu rewash ig herth an

T he rewa san inver s ionlaye rne arthesurfa cebe-thatd ur ingthetr ans i t ionan d thefogd aysatsurface,

foreth efo rmat i onoffog(N i uetal .

[3 3

) ,andthefogtherewa sl es swa te rvapo r

,aeroso lc onden sat ionwas

form ed inthe inve rs i onl ayer.After t

he form at i onof theweak,re

l eas el aten theat w assma l l ,

fog , theinve r si on laye rgrad ua l lymovedtoth etopo

fInthehaze -

to -

fogtrans i t i on

,the in ten s i tyo fthein

thefog . Inthedeve lopm en tstageo f thefog , tempe ra-ver s ionwa ss trong er

,andtemperatu re-d i fferenc ewa s

turedecrea sedatth em o is tad iaba t ic l aps erate .A tem-abou t6X.knr1

,approach ingtheinve rs io nlayer

i ntens ity

peratureinversioni sas tablestratificationandwi l lac

- inthefogeve n t .Du ri ngtheha ze- to

-fogtra n s i t i on , th e

c umu l atemo i s ture ande nergy i nthe inver s ionl ayer ;so

,th ic knes softhei nver s ion layerinc rea sed

,thebounda ry

tempe rature inver s ionprov idesaco nd it i onforch ang ing la

yerwa ss tab leandthewa te rva

poraccum u la tedat

s i zea nd chem ica lreact ionofpar

ti c les .n i gh t .

Fi

gure6s how s theprofi

le sof temperaturedur ingFogdeve l ope dinth ein ver s ionlayer

.The intens i ty

theha ze-to -

fog t ra nsforma t ion .Theh ighes tsurfac etem-ofi nvers i onwa sal sothemax im um inthefogeven t,

pe ratu reapp ear edd ur i ngthehazeeven t

,fo l l ow edbythoug hthetem pera tureinver si ond isappe aredsomet ime s

th ati nthehaze-

to - fogtrans it i on

,andth e lowes t surface inthefog even t.T h issugges

tsthatfogeven

tco u ldoc-

S IZHANGSh u-

ting(张舒婷)

an dN IUS heng-

j i e (牛 生杰 )73

37N-

—^

—一  ̄ 37N

r—

r—

湖■

(迁)'

? ,、 ,

,、 、 、 v 、

/36N.

(b

\,一

广

7V7/

35N 、 ,」 .

、、 G.

v 、 、 、 、35N 、 .

34N*

34N-\\

^33N

. ,J\33N*J

^32N

? '

132N' '+ ■

31 N'

;. 1 3 1 N

Z\

::: ,.

^: ::

) /^2 7

H 2 E1 HE11 6E1 1 8E1 20£ 1 22E1 24EJ2 6E 1 28E

2 ?

n 2 E 1 1 4E1 1 6E1 1 8E1 20£ 1 22 E 1 24E_

1 26E 1 28E

3 7N t—

3 7NT i

3 6N.(C

^/

’?? ?

Wh\、36N

-d

j^ y\>

yV\V

r麵2 7

1 1 2E 11 4E 1 1 6E1 1 8E1 20E 1 22 E 1 24E1 26E1 28E

2 ? ,

1 1 2E1 1 4E1 1 6 E 1 1 8E 1 20E1 22 E

T24E_

1 26E 1 28Eit

Fi gure5

.Vap orf l

uxd ive r

g ence(g/ (h

Pa ?

cm2 ?

s) )and

win dfie ld(

ni/s)on the

ground :(a

)0 0 00LST4Decemb e r20 1 3 ,(b ) 0 00 0

LST5Decembe r20 1 3, (

c) 00 00LST6Decembe r20 1 3

,an d(d) 0

000LST8De cemb er20 1 3 .Th e star i sth e ob se rvat io nsit e .

1-4Vx

<\'

n.N.\.—

*^

haze-

fog

wW f〇g

r ̄

1 .0■ /

■★

暑丨 : \\〕\

I :\U-

0 .5 -\1l

丨 丨 j■

0 .0_>

..

051 01 5

Tem pe rature(

°

C )

Fi

gu re 6.T emp

e raturepro fi

lesdu r

ing

th ehaze-

t o-

fog

tran s fo rmat

io np roces s.

c urinuns tab l e temperaturestra tific at i on .Thetw ofogTemper atureatthe inve rs i onlayerto

pw ass i

gnif

ic an t l

e ventsw eres l igh t lyd i fferen t . Inthefirstfogeven t,higherinthefoge vent t

han inthehazeevent;th iswas

s i nc e th erewa s thenorthe rl

ywind

,ani so the rma ll ayerduetothefactthatthefogi nthedeve lopmen ts tagere

began toappea rbe tw ee n100a nd200m

,a ndthenfogl easedla tenthea t

,inve rsera d ia t ionh ind eredlongwa ve

e xtendedtothegroundatth is lo cat ion .I nt hesecondrad ia t ivecoo l i ngnea rthesurface,a ndwa rmadvec t ion

fogeven t,wa te r

vap or t ransportfromthe sou thwa sonewa sa l soan importan tr ea sonfortheinver s ionat the

oftheimp or tantfac tor sfortran s i t ionfromh a zetofog .fogtop .

74Journ a l of Tro

picalMe teo rol ogyV o

l. 22

3 .4Impac

t of

RH o nhaze-

to-

fog transfo rmat ione rfractionofhazeev entswa scausedby

hygroscop ic

Ambi en tRHc an in fluen cehazeorfogformat ion,growthofa eroso l s .Thereduction in

pr imaryae roso le

developm en tanddi ss ipat i onbyaffecting

hygroscop

icm i s sionfu rtherampl if

i edthi seffect,an

dRHa lsohad

grow thofa tm osphe ri c ae roso ls .Underthesamep art i c l eobv i ousandimportan te ffectonthesc a le

,s i zeand

concentrat i on,theh ighe rt heRHi s

,the lowe r thev is i

-numberofa i rpo l l u tants .

bil i ty

be com es .Dur ing

t hehazeevent,

thema infeatures3 .5Haz eae ro so lcharacter is t ic sandac t iva tionratiodur-

wer eaccumu lationofaerosol s,

lowRHnear th esurfac e ing thehaz c -to

fogtransformation

andloww indspe ed .M ixtureandtrans it i onofpart i c l e sTab l e1showsth em in im umvalue sofac cumu la

andwa te rvaporusua l l

yhapp

enunderh igherhumidityt i onpani c l enumberconcentrat ionw eresma l le rtha n

thanhazeevent .Whenth eai rwassaturated,hazec oarse -

pa rt ic lenumbe rconcentration innon-

fogdays,

aerosolscouldb eac tiva tedtoformCCN,andth e andv i c ever sa .Them a x imumva luesofaccumu la t ion

ae roso lp art ic le s th atw erecon t inuous lyac cumu l atedpa rt i c l enumberconcentr at ionwe real llarge rtha n

cou l dmixandcoex is tw i thfogdrop le t s,thereb

ypro-coar se-

pa rt ic l enumberconc entra t ion,exc ep tdur ingthe

mo t inganexp

los ivedeve l opmentoffogevent . t rans i tionfromhazetofog .Thecoagu lationofhaze

F igure6show sthewater-

vapo rd i ve rgenc ein theaeroso lshappenedats izebe low0 .5

jl iti(Husa randHo l

groundlayer .Dur ingthehazeevent,thes itewa sina low a

M,

);

inpart i cu l a r,thereduct

i onofae roso l

part i c l es

regionof wa te r

vapo rdive rge nce(ne ga t i vecente r

),sug

- le ssthan0 .2|

xmdu ringthe trans it i onfromha /etofog

ge s t ingtha tmoi s tureconve rgedi nNanj

ingarea .Part i

-wasc ausedpr imar i l y

byc oagu l at io n (Ja cque l i n e

M l

) . I n

cl esbeganhygroscop i cgrowth

;bu tduetoh i

ghconc en - thehazc-to - fog

trans i t ionduringwh ic ha irwassa tura t

trat i onofhyg roscop i cpart i c le sandweakwa te r-

vapored ,somea e ro so lsi nac cumulat i onmodecou ldbeacti-

dive rgenc e

,part i c le sc ouldnotgrowin tofogdrop l e ts .vatedasCCNandconve rtedtofogdrop

letsthrough

Howeve r, th i scou ldserveas

preparat ion

periodoffog,condensa t iongr

ow th.Tab le2show sthat tempor a lva ri

naine ly ,con tinu edmo i s tureconvergencean

dwater-va-at io nsofaero so lnumb erco nce n trat

i on,ac cumu l at ion

por transportcouldturnha ze intofog .Lackofm o is tur e

,num bercon cen tra t ion,coarse -

par t ic l enumberconc en -

hazewou ldrema inas haze;wi thcoldai rcom ingdown, tra tion

,a ndCCNco ncent ra tion .Nc cn(CCNnumbe r

hazewou ldd i ss i

pa te .conc en trat

i on)va luedependeds trongl

yonwe athersys

Dur ingth eha ze- to-fogtran s i

tion

,al thou ghthe retern sduringt

hem ea suremen tpe rio d .H i

ghNc cnva lues

wasnoo bvi ousmo is tu reconve rgencene artheobserva-wereobse rveddur ingpe riod sofheavyae roso lpo llu?

t ionsi te,thedom inan tw indd irect i onsou thof thes i tet ion .Nc cnwa sfo undtobea sh i

ghas3 8 1 98 .4 cm

at

wou l dbringwarmandhum ida irfromthesouth,in

-0 .99%supe r sa turati on .Norma l l

y ,Nc cnwa sabou t 5929 . 1

cr ea s inga irhum id ity .Hygroscop icgrowthcont i nued,and9967 . 9cm

atsupe rsa turat iono f0 . 1 98%and

andthehaze cou l dtransfo rmintofog .Ano therpos s ib le0 . 397%

, re spe ct i ve ly ,a ndm orethan30000 . 0cm

at

re asonwa s thata i rpo l lut ionhadb ecomemorecomplexsurp ersa turat i onabove0 . 5% .Unde rdi ffe ren twea ther s ,

ove r theyea rs,andseconda ryaeroso lhygro scop icwasCCNconcen trat ion swe red ifferen t .Onthehaz e-to -fog

stro nge randmorei nc li nedtomoi stureabsorpt i onanddays,theCCNconcen trat i onwas theh i ghe st

,fo l lowed

growth lead i ngtoreducedv is ib i li ty .Th i smean sah igh

-bythaton thefog

days .

Tab le2.S ta t i st icso f CCNN umberCo ncen trat io n .TheN ccn (

cm3

)a

t fi vesupersaturat ion sarepre sented .Them i

nimum ,max

mum,m eanva l ueand thecorresp

on di ng

standardd ev ia tio na re presented .The l astl i

neis then umbero f samp

l es .

SS0 . 1 98%0 .3 9 7%0 . 5 96%0 . 79%0 . 99%

M in 1 . 6 1 5 3 . 846 9 2 . 351 73 . 5530 4 . 1

M ax1177 0.42554 63379 7 . 43 65 33 . 33 81 98 . 4

M ean592 9. 1996 7 . 91 138 7 . 6 1 21 87 . 61 22 62 . 8

S td195 8 . 9395 3 . 1470 3 . 251 04 .451 33 . 4

N43 15025 035 014 1 5

Inanattempttoanal

yzea ct i va tionofae roso lstole s s than1 5

jumw eretoosm a l ltoa ct ivateunder the

CCNandtheconve rs ionofCCNtofogdrop

l e ts,

thera - threesurper sa turat i onva lues

,wh i lep ar t icl e sof3 5

xm

tiosofact i va tionbased on the obse rvednumberc onc en -had thea ct ivat ionra t ioof 0 . 9a ta llthreesupersatura-

tra t ionofaeroso lsandCCN(N cn

(aeroso lnumbercon-t ionva lues .Mos t

pani c les of25

jimw ere activated,be -

c en tration)andN ccn

)arecal cu lated .Therat ioforcausesma l lsolub lefi actionwa sunab le tobeac t ivated ,

aeroso lact ivation toCCN is deno te dbyac t

iva tionra tio :Theac ti vati on rat ios trong lydependsonpart i cl es ize :

Activat ionrat io=Nccn/Ncnx l00%, (

1)thea ct i va tionra t ioin cre aseswi th inc re as ingdi ameter .

Fi

gure7show sthea ct iva t ionratiosa tsup

e rsatura-WhenRHwa sabove90%,hazeaerosol sstar tedtob e

tionof0 .5 96%,0 .79%and0 .99% .A eroso lsw ithsi zetran sformedfromhazetofog

.There l easeof latentheat

S IZHANGSh u-

ting(张舒婷

)andN IUS he ng

j i e(牛生杰 )75

producedh i

ghn umbe rconcen trat i ono fhazepa

rt i cl e sonDe cembe r6 .Rel ativehum id itywash i

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Anunusualhaze-to- fogtransi t ionoc curredduringdeve lopedofhaze and fog .

4-9D ecem ber20 1 3 .Thelowvi sibi li ty(

<l km

)la stedREFERENCES *

fivedays,whi chwa scapturedbyaf ie ldcampa ign .The

measurementsincluded vis ib i li ty ,commonmeteoro logi

-[1

]JACQUEL INEDC ,ANDREWJG,JAMESMS ,eta l.

c alvariab les,pa rt ic l enumberconc entra t ion

,andpl ane-Cy tok in eprodu c ti onb

y humanai

rwayep

i th e l ialcell sa fte r

taryboundary-

layers tructure .Thi spape r

focusedonth eexpo su reto anairpol l

ut ionp

ar tic leis metal-de

penden t [

J]

majorprop ertie sof thehaze-to-

fog trans ition,andth eTox ico lA

pplPharmac

,199 7

,146

(1 99 7

).1 80

1 88 .

- .,

1^ tjrr

2 1PO SCHLU .Atm os ph ericaeroso l s :compo si t ion,t rans for

relat . onshipbe tw eenhazeandfog .

ma t ion ,c l imateandhea ltheffec ts [J

],A

genwandt eChem ie

Ou rconclus ions a reasfo llows :

In tEd,200 5

, 44 (

46 ) : 7520-

7540 .

(1)Ath igha lti tude

, theE astAsian troughmoved[

3]TIEXue

x i,BRA SSEURGP

,ZHAOC hun-

she ng,eta l .

ea stwa rdandwa scontrol l edbym id-

la ti tud egeo

poten-

Ch em icalcharac t

erizationof air

po ll uti on i

nEasternCh ina

t ia lhe i

gh tf

ie ld thatappe aredzonal ly overtheYRDre

andtheEas ternUni tedSta tes[J

].Atmo sEnvi ron ,20 06,

g ion .Anupper-

layertroughandthem id-

lowerlayer40 :26 07-262 5 .

colda irshea rmo vedeas tward,caus ingcolda irtoi n-[

4]FUQi

ng-

yan,ZHUANGGuo-

shun ,WANGJing

,eta l.

trudesou thw ardne arthesurfac e .A ccord ing to thesur-Mechani smofformat ionof theheavies tp

o l l ut ionep isod e

fac eobservat ions,Nan

jingwasi nfron tofawe akeverreco rded in theY ang

tzeR iverDe lta

,Ch i na[J]

At-

high-

pressuresys temtha twa sce n tered inNorthCh in arao sE nv

iron ,2008 ,4

2:2023

20 36 .

j . ,

ut[

5]CHENJ ,ZHAOC S,MAN,etal

.Aparame ter

izat

ion ofandwascontrol ledbyhomoge neouspre ssure

;a sare- L 」F

..

,j」jt i?

」Alowv is i bil

iti esfor h azyd ay s inth eNo rthCh inaP la in[J l.

suit, thewmdspeedwa sreduc ed .Thisweahersystem

Atmo sChemPh ys ,20 1 2

, 1 2 : 49 35-

4 95 0 .

l edtoa lowe rsurfac ew indsp eedand stabl

ys trat

ifi ed[

6]FANSX ,HUANGHL,FANT,e ta l

.S ized ist ribut ion

atm osphe re .

charac teri st icso fpo l

ycy cl icaromatich

ydro carbonso f

(2

)Win dspeedw asl es sthan1 m s in th ehazePM 1 0 infoggydays int

heno rthsuburbofNanj ing [

J]

even t,andthes i tewasunderthenor ther lywind

,whi chEn v

iro nSc i ,2009 ,30 (9 ) :2707

27 15 .

transportedpo l l utantsfromthenorthtothe si te .Dur ing[7

]OKADAKM,IKEGAM I ,ZA IZENY.Th em ixturest at e

thehaze- to- fogtrans it ion,thesurfacewinda l lc ameof i

nd iv

idualae ro so lpart ic lesi

nthe1 99 7In dones ianhaze

fromthesouthandconvergedatth eobserva tions i te,ep

isode[ J] .JAero so lSc i,200 1 ,3 2

(1 1

) :

12 69-

127 9 .

wh i chtransp ortedwa rma ndhum ida irtothes ite .The[8

]HEJ ia-

bao,FANS hu

xi an ,MENGQ ing-

zi ,eta l

.Pol y-

var iabil i tyofwind spe e

dduringthefogeven twa sla rg

-cyc l i caromat ic hyd ro carbon s(

PAHs)ass oc ia tedw ithfin e

丄x t_ Aj?

x 1_it Tpart icu latema tte rs inNanj

ing ,Ch in a :Di stri bu t

io ns ,

er thantha tdur in g theha zeevent.Low-

pressurerearK , ,

.i,r i n4^

. _

,_

so urc e san dme t eoro log i ca lin f luences[J l

Atmos Env i ron,

ai rfl owin cre asedconvergence of w ater vapor .

2〇 丨 489(20 1 4 )

20 72 15

(3)Theh ighe stsurfac etempe ratur eappeared inthe

[9

]LA ILY ,SEQU E IRAYR .V i s ibi l ityd eg

radat ionac ros s

hazeeven t,fo l lowedby

thati nthehaze- to- fogtrans i-

HongKong:i t scom

ponents and th e i rre lat

iveco ntr ibut

i on s

t ion, andthelowes tsurfac etempe ratureappeare

dinthe[J]

,A tmo sEn vi ron , 200 1 , 35 ( 34) :586 1-

5872 .

fogevent . In theha zeevent,

the inver sionintens ity wa s[

1 0]L IZQ ,

GuX,WANGL

,e tal .Aero so lphy sica land

we ak .Inthefogeven t,the invers ion intens itywasthechem ic a lp ropert iesre tri ev edfromg

ro und-

bas edremo te

s trongest

,butthetempera tureinver siondi sappea redsen singmeas urem en tsdur in

g h eav y

hazeda ys inBe ij in

somet ime sdur ingthefogevent .Th i ssugge ststhatfog

win ter[

J]

.Atmos ChemPhysD i scu ss

,2 0 1 3,1 3(2) :5

even tcanoccurunde run stable temperatures trat ifica-09 1

-51 22 .

t ion .The tem peratureoftheinv ers ion l ayer topwa ss i

g-[

1 HP IL IERJ

,MACKEJ

,KOCMONDW C ,e ta l

.Thel ife

..

..

^tc yc leofval l eyfog .Part 1 :M icrometeoro log ica lcharac -

m ficant l

yh

. gherm thefog

even t than inthehazeeven t .

terist i cs[ J] ,JAp p

lM eteo ro l,1 9 75

, 1 4 (

197 5 ) :347-

364 .

Thedeve lopmentoffogmaybeexp

lainedbysurface

[, 2

]ROACHWT,BROWNR ,CAUGHEYSJ ,e

t al .Re ad-

rad i at io ncoo l ingandassoc ia tedlaten t- heat relea se.

ing s.Thephy

sicsofrad i

at io nfo g:I

-afi eldstudy[

J]

(4)Theminimumvalue sofac cumul at ionpartic leQuart JRoyM eteoro lS oc , 1 9 76 ,1 02 : 3 1 3

3 33 .

numberc onc entra t ionwere smal l erthancoarse-partic le[13

]WANGH ong-

le i ,ANJ un-

l in ,SHENLi

juan ,e ta l

numberconcentra t ioninnon-fogd ays

,andv icev ersa.Mechani smfor thefo rmat ionand m icro

physica lcharac -

Themax imumva lue sof accumula tionpartic lenumber terist i csof subm ic ron aero so ldu ringheav yhazepol l ut io n

c oncentrationwerea ll la rgerthancoarse-

partic l enum-ep

isodeintheYangtzeRiverDe lta

,Chin a [J

].Sc iTot al

be rc oncen trationexc eptinthetransi tio nfromhazetoEnv iron,2 0

14,490

(20 14

):50 1

-5 08 .

fog .Nc cndep ended stronglyonwe athe r sys temdur ing[1 4

]CHANGDi,SONGYu

,L IUB

ing

. Visi b i l itytrendsin six

u,

??o t junno /megac it ies i

nCh ina19 73

- 2007 [J]

.AtmosRes,2009,94 :

themea surementp eriod .WhenRHwa sabove90%,

1 6 11 Wha zeaeroso l sstarted tobe transformedfromhazeton c irruA

. .

[1 5

]CHANCK

,YaoX iaohon

g.A

irp

o l l ut ioni nmegaci ti es

fog.Therel easeofl atenthea t causedthes i zeof i nCh ina[

J]

, A tmo sEnviron,2 00 8 ,42(

1)

:1-

42 .

ae roso lstosh iftfromsma ll ers izetol arge rone ,an

d [1 6

]CHENXu n-

la i,FENGYe

rong ,WANG An-

yu,et a l. N u

prov ided appropri ate s izeaerosolsthatc anbee ffec tive -

m erica lex

per imen t res earchonai

rpo llu tan tsdu ri nga t

lya ctivated toCCN .Unders trongcoo lingandh ighhu

S IZHANGShu-

ting (张舒婷) andNIUSheng

j ie(牛 生杰)77

mospherich azeover themulti

cit iesofPearlRiverDelta t ion,ha

ze,and fog[J ]

, AtmosRes ,2009,9 2 : 443 -45 4.

regi on[J ].Ac taSc iNatUni

vSunyats en i,2007,46 (4 ):[2

7]YANGXin

,CHENYi

zhen ,LIUHou-feng ,etal

.Char-

1 03-

1 07 ( inCh inese).ac teris ti csandformat ionm echanism o f awin terhaze-fo

[1 7

]CHENY,ZHAOC ,

ZHANGQ,e ta l .Aircraftstudyofe

pis odeinT ian

jin

,Chi na [

J]

.Atm osEnv iron20 14,98

mounta inch imneyeffect of Beij ing,Ch ina[ J]

.JGeophys(20 1 4) :3 2 3-

33 0 .

Res,2 009,

11 4 :D083 06 .[

28 ]DENGZ Z

,ZHAOCS,MAN

,etal

.Anexam inat

ionof

[1 8

]DAI Yong-

l i,TAOJun

,L INZe-

j ian,e tal

.Characteri st icsparameterizat ion sfor theCCNnumbe rconcentration

ofhazeand its impact fac tors infour me

gac i ties i

nCh inabasedonin situmeasurementsof aero so lac t iva tionp

rop-

during 2006

2 009 [J

].E nv ironSc i

,20 1 3 ,34 (8) :292 5

2ertiesintheNorthChinaP la in [J

].AtmosCh emPhys ,

93 3.20 1 3

, 1 3 :

622 7-

6 23 7 .

[1 9

]J IAX ing

can,GUOXue

lian

g.Impactsof an throp

ogen ic[

29]ZHANGJ K

,SUNY,L IU ZR

,et al.Charac terizat ionof

a tmo spheri c

pollu

tan tonformat ionaadd ev e lopmentofasubmicrona ero sol sduringaserious

po l lut ionmon th in

wi nter heavyfoge vent[ J]. Ch inaJ A tmo sSc i ,20 1 2

,3 6:Be ij ing(20 13 )usinganaerodyneh igh

re so lutionaeroso l

99 5-

1008( inChinese).masss

pectrometer [

J]

. A tmo sChemPhysD iscuss,2 0 1 3

[20

]GAUTAMR,H SUNC

,KAFATOSM,etal

.Influ ences 1 3 (7) :19 009-

1 9049 .

ofwi nterhazeonfog /l owc l oudover th e Indo-Gange tic[ 30 ]PETERKK, JOHNGW

,JUDITHCC,etal.Al eis .

[J]

. JGeophysRes,2007 , 1 1 2 : 207

2 1 8 .Seasona lcharac teri st icsandreg ional tran spo rtofPM2 . 5

[2 1

]LUChun

song ,NIUShen

jie

,TANGL i

li, et al

.Chemi

- inHongKong[J].AtomsEnv iron ,20 05,39(2 005) :1

ca lcomposi ti onoffog

wateri nNanj ingareaofCh ina695

17 1 0 .

andits relatedfogmicrophysics [ J] .A tmo sRes

,20 1 0

,97[3 1

]XU Feng,

N IU Sheng

jie ,2MANGYu

,e tal .Analy seson

(201 0 ) :47 -

69 .chemicalcharac ter ist icofspringseafogwat eronDong

[22

]ROBERTSGC ,NENESA .Acon tinuou s-

fl owstream-ha i Is landinZhanj

i ang ,Ch ina [J

].Ch inaEnvi

ronSci,

wi setherma l

gradi entCCNchamb erfo ratmos

pheric20 1 1 ,3 1 (3 ) :3 53

3 60 .

measurements [ J].Aero so lSciTech

,2005 ,39: 206 -

22 1 .[32]GAOJ ian ,WANGTao

,ZHOUXue-hua

,etal.Measure

[2 3

]LANCES ,SM ITHJ ,NENESA.Mapp in gtheope rati onment of

aero so lnumbers izedistribut ions in theY angtze

of th eDMTcont inuousflowCCNcount er[J]

.AerosolRiverd e lta inCh ina :fo rmati onandgrowthofpart icl es

S c iTe ch ,2006,40: 2 42

2 54.underpoll

utedcond itions[J]

.Atmo sEnv iro n

,2009

,43 :

[24

]L ILi

,Y INYan

, GUXue-

s ong ,eta l

.Observat ionals tudy829-

83 6.

ofc loudcondensat ionnu c leip ropert iesa tvariousa l ti-[33 ]NIUS heng

j ie ,LUChun-s ong ,YuHua-

ying

,eta l.Fog

t udesofHuangshanMounta in s[

J]

. Ch inJAtmo sSc i

,researchinCh ina :anoverv iew[J]

.AdvAtmo sSc i,

20 14

,3 8(3) :4 1 0-42 0.20 1 0 , 2

7(3 ) :639

6 62 .

[2 5

]TARD IFR ,RASMUSSENRM.Event

basedc l imato logy[

34]HUSARRB ,HOLLOWAYJM .The

properti esandc l i

andtypologyo ffogi ntheNewYo rkc i tyregion [

J]

. Jmateofatmospheri chaz e[

J]

.Hygros copi cAero so ls,

App

IMeteorC l imato l ,2007

,46 : 1 1 4 1

1 1 6 8 .HamptonV irg in ia ,AD ee

pakPub l ish in

g.1 984 :1 2 9

1 70 .

[2 6

]ELIAST,HAEF FEL INM

,DROB INSKIP

, e t a l .Part icu?

la

tecontribu t ion toext

inctio no fv

is

iblerad ia

tio n :Pol lu

Ci tation :ZHANGSh u-

tin ean dN IUShenff- j

ie .H az e- to-

fo e tran sforma tion durin g

:a l

ong l

as ti ne,lowv isi bil it ye pisod e i

nNa njine

[J]

. J TrapMet eoro l ,20 1 6,2 2

(S 1

): 67

77 .