Michael D. King NASA Goddard Space Flight Center

The Role of Aerosols in Cloud Growth, The Role of Aerosols in Cloud Growth, Suppression, and Precipitation:Suppression, and Precipitation:

Yoram Kaufman and his ContributionsYoram Kaufman and his Contributions

Aerosol optical & microphysical Aerosol optical & microphysical propertiesproperties– Ground-based sunphotometer Ground-based sunphotometer

measurementsmeasurements Optical thicknessOptical thickness Size distribution & absorption propertiesSize distribution & absorption properties

– Aircraft remote sensingAircraft remote sensing SCAR-B and field validation/prototypingSCAR-B and field validation/prototyping

– Satellite remote sensingSatellite remote sensing Dense dark vegetationDense dark vegetation Spectral surface albedo characterizationSpectral surface albedo characterization MODIS aerosol over landMODIS aerosol over land

Cloud-aerosol interactionCloud-aerosol interaction– Relationship between absorbing and Relationship between absorbing and

nonabsorbing aerosol & cloud formation, nonabsorbing aerosol & cloud formation, cloud cover, and optical propertiescloud cover, and optical properties

Michael D. KingMichael D. KingNASA Goddard Space Flight CenterNASA Goddard Space Flight Center

Surface Measurements of Sun/Sky RadiationSurface Measurements of Sun/Sky Radiation (B. N. Holben, T. F. Eck, I. Slutsker et al. – NASA GSFC)(B. N. Holben, T. F. Eck, I. Slutsker et al. – NASA GSFC)

AERONETAERONET Automatic recording and transmitting sun/sky photometersAutomatic recording and transmitting sun/sky photometers Data Base: Aerosol optical thickness, size distribution, phase function, Data Base: Aerosol optical thickness, size distribution, phase function,

optical properties, and precipitable wateroptical properties, and precipitable water Collaborative:Collaborative: NASA – instruments/sites and centralized calibration & NASA – instruments/sites and centralized calibration &

databasedatabaseNon-NASA – instruments/sitesNon-NASA – instruments/sites

Holben et al. (1998)Holben et al. (1998) 589 citations589 citations

Holben et al. (1998)Holben et al. (1998)

AERONET-An Internationally Federated Network AERONET-An Internationally Federated Network (B. N. Holben, T. F. Eck, O. Dubovik, A. Smirnov et al. – NASA (B. N. Holben, T. F. Eck, O. Dubovik, A. Smirnov et al. – NASA

GSFC)GSFC) Characterization of aerosol optical propertiesCharacterization of aerosol optical properties Validation of satellite aerosol retrievals and model predictionsValidation of satellite aerosol retrievals and model predictions Near real-time acquisition; long term measurementsNear real-time acquisition; long term measurements

– aeronet.gsfc.nasa.govaeronet.gsfc.nasa.gov

589 citations589 citations

256 citations256 citationsDubovik et al. (2002)Dubovik et al. (2002)

Aerosol Climatology from AERONETAerosol Climatology from AERONET((O. Dubovik, B. N. Holben, T. F. Eck, A. Smirnov et al. - GSFC)O. Dubovik, B. N. Holben, T. F. Eck, A. Smirnov et al. - GSFC)

Coolin

gC

oolin

gH

eatin

gH

eatin

g

Han

sen e

t al.

Han

sen e

t al.

(199

7)

(199

7)

Difference between the Reflection Function and Difference between the Reflection Function and Surface Reflectance as a function of ASurface Reflectance as a function of Agg and and 00

(Y. J. Kaufman and R. S. Fraser – NASA GSFC)(Y. J. Kaufman and R. S. Fraser – NASA GSFC)

Fraser and Kaufman (1985)Fraser and Kaufman (1985) 83 citations83 citations

Retrieval of Retrieval of aa

Optical thickness Optical thickness increases with increases with aa for for dark surfacesdark surfaces

Optical thickness Optical thickness decreases with decreases with aa for for bright surfacesbright surfaces

There is a critical AThere is a critical Agg where reflection where reflection function is insensitive function is insensitive to to aa

– depends on single depends on single scattering albedoscattering albedo

Aerosol Effects on Reflected Radiation over Land Aerosol Effects on Reflected Radiation over Land (M. D. King, Y. J. Kaufman, D. Tanr(M. D. King, Y. J. Kaufman, D. Tanré, T. Nakajimaé, T. Nakajima – GSFC, Lille, – GSFC, Lille,

Tokyo)Tokyo)Biomass burningBiomass burning

Cuiabá, Brazil (August 25, 1995)Cuiabá, Brazil (August 25, 1995)

20

km

20

km

12 km12 km

R = 0.66 µmR = 0.66 µm

G = 0.55 µmG = 0.55 µm

B = 0.47 µmB = 0.47 µm

R = 1.6 µmR = 1.6 µm

G = 1.2 µmG = 1.2 µm

B = 2.1 µmB = 2.1 µm

King et al. (1999)King et al. (1999) 155 citations155 citations

AAgg (2.1 µm) < 0.10 (2.1 µm) < 0.10

0.10 < A0.10 < Agg (2.1 µm) < 0.15 (2.1 µm) < 0.1500 = 36° = 36°

Surface reflectance is high Surface reflectance is high at 2.2 µm, moderate at 0.66 at 2.2 µm, moderate at 0.66 µm, and low at 0.49 µmµm, and low at 0.49 µm

The aerosol effect on The aerosol effect on reflected solar radiation is reflected solar radiation is small at 2.2 µm and large at small at 2.2 µm and large at 0.49 µm0.49 µm

MODIS operational algorithm MODIS operational algorithm over land assumesover land assumes

Surface Reflectance at Near-Infrared WavelengthsSurface Reflectance at Near-Infrared Wavelengths (Y. J. Kaufman, A. Wald, L. A. Remer et al. – NASA GSFC, U. Lille)(Y. J. Kaufman, A. Wald, L. A. Remer et al. – NASA GSFC, U. Lille)

Surface Reflectance at Near-Infrared WavelengthsSurface Reflectance at Near-Infrared Wavelengths (Y. J. Kaufman, A. Wald, L. A. Remer et al. – NASA GSFC, U. Lille)(Y. J. Kaufman, A. Wald, L. A. Remer et al. – NASA GSFC, U. Lille)

AAgg(0.47 µm) (0.47 µm) = = 0.5A0.5Agg(0.66 µm)(0.66 µm)

= 0.25A= 0.25Agg(2.1 (2.1 µm)µm)

Kaufman et al. (1997)Kaufman et al. (1997) 82 citations82 citations

Dynamic Aerosol ModelsDynamic Aerosol Models (L. A. Remer, Y. J. Kaufman and B. N. Holben – NASA GSFC)(L. A. Remer, Y. J. Kaufman and B. N. Holben – NASA GSFC)

Dynamic Aerosol ModelsDynamic Aerosol Models (L. A. Remer, Y. J. Kaufman and B. N. Holben – NASA GSFC)(L. A. Remer, Y. J. Kaufman and B. N. Holben – NASA GSFC)

Accumulation mode particles (Accumulation mode particles (rr < 0.3 < 0.3 µm)µm)– mostly organic smoke particles or mostly organic smoke particles or

sulfatessulfates– depend on optical thicknessdepend on optical thickness

Aerosol-free troposphere plus Aerosol-free troposphere plus stratospheric aerosol (0.3 µm < stratospheric aerosol (0.3 µm < rr < 0.8 < 0.8 µm)µm)

Maritime salt particles in the mid-Maritime salt particles in the mid-Atlantic region (0.8 µm < Atlantic region (0.8 µm < rr < 2.5 µm) < 2.5 µm)

Coarse particles (Coarse particles (rr > 2.5 µm) > 2.5 µm)

King et al. (1999)King et al. (1999) 155 citations155 citations

Chu et al. (1998)Chu et al. (1998)

Remote Sensing of Aerosol over LandRemote Sensing of Aerosol over Land: SCAR-B: SCAR-B (D. A. Chu(D. A. Chu, , Y. J. Kaufman, L. A. Remer, B. N. Holben – NASA Y. J. Kaufman, L. A. Remer, B. N. Holben – NASA

GSFC)GSFC)

Remote Sensing of Aerosol over LandRemote Sensing of Aerosol over Land: SCAR-B: SCAR-B (D. A. Chu(D. A. Chu, , Y. J. Kaufman, L. A. Remer, B. N. Holben – NASA Y. J. Kaufman, L. A. Remer, B. N. Holben – NASA

GSFC)GSFC)

Spectral optical thickness derived from MASSpectral optical thickness derived from MAS Intercomparison with ground-based Intercomparison with ground-based

AERONETAERONET Dot-dashed lines are the retrieval error (Dot-dashed lines are the retrieval error (aa

= 0.05 ± 0.2= 0.05 ± 0.2aa) anticipated using the MODIS ) anticipated using the MODIS aerosol optical thickness retrieval algorithmaerosol optical thickness retrieval algorithm24 citations24 citations

Brazil (August-September 1995)Brazil (August-September 1995)

Spectral Variability of Urban EcosystemSpectral Variability of Urban Ecosystem(E. G. Moody, M. D. King, C. B. Schaaf, S. Platnick - GSFC, Boston (E. G. Moody, M. D. King, C. B. Schaaf, S. Platnick - GSFC, Boston

U.)U.)

Moody et al. (2005)Moody et al. (2005)

January - JuneJanuary - June

TanrTanréé et al. (1999) et al. (1999)

Remote Sensing of Aerosol over Ocean: TARFOXRemote Sensing of Aerosol over Ocean: TARFOX (D. Tanr(D. Tanré, é, L. A. Remer, Y. J. Kaufman et al. – U. Lille, NASA L. A. Remer, Y. J. Kaufman et al. – U. Lille, NASA

GSFC)GSFC)

Remote Sensing of Aerosol over Ocean: TARFOXRemote Sensing of Aerosol over Ocean: TARFOX (D. Tanr(D. Tanré, é, L. A. Remer, Y. J. Kaufman et al. – U. Lille, NASA L. A. Remer, Y. J. Kaufman et al. – U. Lille, NASA

GSFC)GSFC)

Spectral optical thickness derived from MAS Spectral optical thickness derived from MAS using the MODIS at-launch algorithmusing the MODIS at-launch algorithm

Aerosol optical thickness measured by the Aerosol optical thickness measured by the sunphotometer (AATS-6) aboard the University sunphotometer (AATS-6) aboard the University of Washington C-131A aircraftof Washington C-131A aircraft


Atlantic Ocean (July 1996)Atlantic Ocean (July 1996)

Validation of Aerosol Retrievals over Ocean: Validation of Aerosol Retrievals over Ocean: TARFOXTARFOX

(D. Tanr(D. Tanré, é, L. A. Remer, Y. J. Kaufman et al. – U. Lille, NASA L. A. Remer, Y. J. Kaufman et al. – U. Lille, NASA GSFC)GSFC)

Retrieval of Retrieval of aa

Spectral optical Spectral optical thickness derived thickness derived from MAS using from MAS using MODIS at-launch MODIS at-launch algorithmalgorithm

Aerosol optical Aerosol optical thickness measured thickness measured by the by the sunphotometer sunphotometer (AATS-6) aboard the (AATS-6) aboard the University of University of Washington C-131A Washington C-131A aircraftaircraft

King et al. (1999)King et al. (1999) 155 citations155 citationsTanrTanréé et al. (1999) et al. (1999) 38 citations38 citations

How well does Terra Represent the Daily How well does Terra Represent the Daily Average?Average?

(Y. J. Kaufman, B. N. Holben, D. Tanré et al. - NASA GSFC, Univ. (Y. J. Kaufman, B. N. Holben, D. Tanré et al. - NASA GSFC, Univ. Lille)Lille)


AERONET analysis of AERONET analysis of aa

Scatter plot of the Scatter plot of the daily ratio of daily ratio of aa during during Terra overpass time Terra overpass time to the daily averageto the daily average– no systematic biasno systematic bias

No diurnal bias No diurnal bias observed in Ångstrobserved in Ångström öm exponent or column exponent or column water vaporwater vapor

0.010.01 110.10.1 10100.000.0011

1.51.5

0.50.5

1.01.0

0.50.5

Rati

o o

f para

mete

r fo

r Terr

a/w

hole

day

Rati

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f para

mete

r fo

r Terr

a/w

hole

day

Terra aerosol optical thickness (550 nm)Terra aerosol optical thickness (550 nm)

1.01.0

0.50.5

1.01.0

0.00.00.50.5 1.01.0 1.51.5

MODIS Aerosol ProductMODIS Aerosol Product(Y. J. Kaufman, L. A. Remer, D. Tanré - NASA GSFC, Univ. Lille)(Y. J. Kaufman, L. A. Remer, D. Tanré - NASA GSFC, Univ. Lille)

Seven MODIS bands are utilized to derive aerosol propertiesSeven MODIS bands are utilized to derive aerosol properties – 0.47, 0.55, 0.65, 0.86, 1.24, 1.64, and 2.13 µm0.47, 0.55, 0.65, 0.86, 1.24, 1.64, and 2.13 µm– OceanOcean

reflectance contrast between cloud-free atmosphere and ocean reflectance contrast between cloud-free atmosphere and ocean reflectance (dark)reflectance (dark)

aerosol optical thickness (0.55-2.13 µm)aerosol optical thickness (0.55-2.13 µm) size distribution characteristics (fraction of aerosol optical thickness in the size distribution characteristics (fraction of aerosol optical thickness in the

fine particle mode; effective radius)fine particle mode; effective radius)– LandLand

dense dark vegetation and semi-arid regions determined where aerosol is dense dark vegetation and semi-arid regions determined where aerosol is most transparent (2.13 µm)most transparent (2.13 µm)

contrast between Earth-atmosphere reflectance and that for dense dark contrast between Earth-atmosphere reflectance and that for dense dark vegetation surface (0.47 and 0.66 µm)vegetation surface (0.47 and 0.66 µm)

aerosol optical thickness (0.47 and 0.66 µm)aerosol optical thickness (0.47 and 0.66 µm) fraction of aerosol optical thickness in the fine particle modefraction of aerosol optical thickness in the fine particle mode

Kaufman et al. (1997)Kaufman et al. (1997) 179 citations179 citationsTanrTanréé et al. (1997) et al. (1997) 190 citations190 citations

King et al. (2003)King et al. (2003)

Terra/MODIS Aerosol Optical Thickness Terra/MODIS Aerosol Optical Thickness (Y. J. Kaufman, L. A. Remer, D. Tanré - NASA GSFC, Univ. Lille)(Y. J. Kaufman, L. A. Remer, D. Tanré - NASA GSFC, Univ. Lille)

True Color Composite (0.65, 0.56, 0.47)True Color Composite (0.65, 0.56, 0.47)

May 4, 2001May 4, 2001

Aerosol Optical ThicknessAerosol Optical Thickness

0.40.4 0.80.80.00.0 0.20.2 0.60.6 1.01.0

aa (0.56 µm) (0.56 µm)

sunglintsunglint


MODIS Monthly Mean Aerosol Optical ThicknessMODIS Monthly Mean Aerosol Optical Thickness(Y. J. Kaufman, D. Tanré, O. Boucher – NASA GSFC, U. Lille)(Y. J. Kaufman, D. Tanré, O. Boucher – NASA GSFC, U. Lille)

TerraTerraSeptember 2000September 2000

Fine ModeFine Mode– Industrial pollutionIndustrial pollution

US, Europe, China, IndiaUS, Europe, China, India– Smoke from biomass burningSmoke from biomass burning

South America (Brazil, Bolivia)South America (Brazil, Bolivia) Southern Africa (Angola, Southern Africa (Angola,

Zambia)Zambia) Australia, BorneoAustralia, Borneo

Coarse ModeCoarse Mode– Desert dustDesert dust

Sahara, Arabian SeaSahara, Arabian Sea– Sea saltSea salt

Southern oceanSouthern ocean


Terra/MODIS Global Aerosol Optical Properties Terra/MODIS Global Aerosol Optical Properties (Y. J. Kaufman, L. A. Remer, and D. Tanré – NASA GSFC, U. Lille)(Y. J. Kaufman, L. A. Remer, and D. Tanré – NASA GSFC, U. Lille)

Aerosol Optical Thickness

August 30, 2001August 30, 2001Fine Mode vs Coarse Mode AerosolFine Mode vs Coarse Mode Aerosol9090

-90-90

Lati

tud

eLa

titu

de

00

-45-45

4545

LongitudeLongitude00

1.01.0

0.00.00.00.0 0.250.25 0.50.5

Aerosol Optical ThicknessAerosol Optical ThicknessFin

e A

ero

sol

Fin

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Fra

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Monthly Mean Aerosol Optical PropertiesMonthly Mean Aerosol Optical Properties(L. A. Remer, Y. J. Kaufman, and D. Tanr(L. A. Remer, Y. J. Kaufman, and D. Tanréé et al. – GSFC, U. Lille) et al. – GSFC, U. Lille)

April 2005 (April 2005 (Collection 5Collection 5))AquaAqua

Zonal Mean Aerosol Optical ThicknessZonal Mean Aerosol Optical Thickness(L. A. Remer, Y. J. Kaufman, and D. Tanr(L. A. Remer, Y. J. Kaufman, and D. Tanréé et al. – GSFC, U. Lille) et al. – GSFC, U. Lille)

April 2005 (April 2005 (Collection 5 Collection 5 vsvs Collection 4 Collection 4)) AquaAqua

Zonal Mean Aerosol Fine Mode FractionZonal Mean Aerosol Fine Mode Fraction(L. A. Remer, Y. J. Kaufman, and D. Tanr(L. A. Remer, Y. J. Kaufman, and D. Tanréé et al. – GSFC, U. Lille) et al. – GSFC, U. Lille)

April 2005 (April 2005 (Collection 5Collection 5)) AquaAqua

Effect of Smoke and Dust on Shallow CloudsEffect of Smoke and Dust on Shallow Clouds (Y. J. Kaufman, I. Koren, L. A. Remer, D. Rosenfeld, Y. Rudich –(Y. J. Kaufman, I. Koren, L. A. Remer, D. Rosenfeld, Y. Rudich –

GSFC, Hebrew U., Weizmann Inst.)GSFC, Hebrew U., Weizmann Inst.)


GSFC, Hebrew U., Weizmann Inst.)GSFC, Hebrew U., Weizmann Inst.) AerosolsAerosols


dustdust

smokesmoke

pollutionpollution

sea saltsea salt

stratiformstratiform

mixedmixed

convectiveconvective

Dust and sea saltDust and sea salt

aa(fine mode)/(fine mode)/aa(total) < 0.50(total) < 0.50

Pollution and smokePollution and smoke

aa(fine mode)/(fine mode)/aa(total) > 0.50(total) > 0.50

CloudsCloudsDeep convective cloudsDeep convective clouds

ppcc < 300 hPa < 300 hPa

MixedMixed

640 hPa < p640 hPa < pcc < 300 hPa < 300 hPa

Low-level stratiform cloudsLow-level stratiform clouds

ppcc > 640 hPa > 640 hPa


GSFC, Hebrew U., Weizmann Inst.)GSFC, Hebrew U., Weizmann Inst.)June - August 2002June - August 2002

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12

14

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18

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22

-100 -80 -60 -40 -20 0

5-30N June-Aug 2002

0<AOT<0.10.1<AOT<0.20.2<AOT<0.30.3<AOT<0.4

Longitude

0

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-100 -80 -60 -40 -20 0

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0<AOT<0.10.1<AOT<0.20.2<AOT<0.30.3<AOT<0.4

Longitude

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-50 -40 -30 -20 -10 0 10 20

Longitude

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-50 -40 -30 -20 -10 0 10 20

0<AOT<0.10.1<AOT<0.20.2<AOT<0.30.3<AOT<0.4

Longitude

Kaufman et al. (2005)Kaufman et al. (2005)

Aerosol indirect effectsAerosol indirect effects Increase in stratiform cloud Increase in stratiform cloud

cover with an increase in cover with an increase in aerosol concentrationaerosol concentration

Lower concentration of Lower concentration of aerosols associated with aerosols associated with larger effective radiuslarger effective radius– Assessed the impact of Assessed the impact of

meteorology and how it meteorology and how it varies as opposed to varies as opposed to aerosol propertiesaerosol properties

The aerosol forcing The aerosol forcing corresponding to the corresponding to the increase in cloud cover is ~ 6 increase in cloud cover is ~ 6 W/mW/m22 in the June-Aug period in the June-Aug period over the Atlantic Oceanover the Atlantic Ocean


5°-30°N5°-30°N

20°S-5°N20°S-5°N

5°-30°N5°-30°N

20°S-5°N20°S-5°N

Publications on ‘MODIS’ AND ‘Aerosol’Publications on ‘MODIS’ AND ‘Aerosol’ (Y. J. Kaufman – NASA GSFC)(Y. J. Kaufman – NASA GSFC)

YearYear

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Aerosol properties & their impact on climate pioneered by Yoram Aerosol properties & their impact on climate pioneered by Yoram KaufmanKaufman– Atmospheric correction and calibration of satellite sensorsAtmospheric correction and calibration of satellite sensors– Dense dark vegetation and retrievals of aerosol optical properties over land Dense dark vegetation and retrievals of aerosol optical properties over land – Visionary in establishing a multiyear spectral aerosol climatology, later Visionary in establishing a multiyear spectral aerosol climatology, later

supplanted by worldwide AERONET ground-based sun/sky radiometerssupplanted by worldwide AERONET ground-based sun/sky radiometers– Aerosol effect on negating influence of COAerosol effect on negating influence of CO22 increases in Earth’s atmosphere increases in Earth’s atmosphere

– Satellite algorithms for aerosol optical thickness and fine mode fractionSatellite algorithms for aerosol optical thickness and fine mode fraction– Effects of aerosols on cloud suppression, optical properties, and precipitationEffects of aerosols on cloud suppression, optical properties, and precipitation

KKey publications that have had a long and influential role in aerosol scienceey publications that have had a long and influential role in aerosol science– Holben, B. N. et al., 1998: AERONET—A federated network. Holben, B. N. et al., 1998: AERONET—A federated network. Remote Sens. Remote Sens.

EnvironEnviron., ., 6666, 1-16, 1-16. [591 citations][591 citations]– King, M. D., Y. J. Kaufman, King, M. D., Y. J. Kaufman, W. P. Menzel, andW. P. Menzel, and D. Tanr D. Tanréé, 1992: Remote , 1992: Remote

sensing of cloud, aerosol, and water vapor properties from MODIS. sensing of cloud, aerosol, and water vapor properties from MODIS. IEEE IEEE Trans. Geosci. Remote SensTrans. Geosci. Remote Sens., ., 3030, 2-27, 2-27. [245 citations][245 citations]

– Kaufman, Y. J., D. TanrKaufman, Y. J., D. Tanré, and O. Boucheré, and O. Boucher, 1978: A satellite view of aerosols , 1978: A satellite view of aerosols in the climate system. in the climate system. NatureNature, , 419419, 16971-16988, 16971-16988. [192 citations][192 citations]

Published over 200 papers with over 7500 citationsPublished over 200 papers with over 7500 citations 412 different co-authors412 different co-authors

Summary and ConclusionsSummary and Conclusions

Dr. Yoram J. KaufmanDr. Yoram J. KaufmanRadiative transfer, aerosol remote sensing, aerosol-cloud Radiative transfer, aerosol remote sensing, aerosol-cloud

interactions, colleague and friend interactions, colleague and friend

Documents

Michael D. King NASA Goddard Space Flight Center