Aerosol optical thickness retrieval over land and water using SCIAMACHY/GOME data

TNO Physics and Electronics Laboratory

J. Kusmierczyk-MichulecG. de Leeuw

7 December 2004Aerosol optical thickness retrieval

•launched in March 2002

•high-resolution (0.2-0.4 nm) spectrometer

•wavelength range: 240--2380 nm

•Swath Dim.: 960 km (cross track) by 25 km (along track at nadir) •Nadir scan: 4 pixels of 240 km (cross track)

by 25 km (along track) •Limb scan: 960 km (cross track) vertical tangential step size 3.0 km

The SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) on board the ESA Envisat satellite

http://envisat.esa.int/


The Global Ozone Monitoring Experiment (GOME)

GOME aboard ERS-2 (courtesy of ESA)

•Launched in April 1995

•4-channel grating spectrometer

•Spectral resolution 0.2-0.4 nm

•Wavelength range: 240 -790 nm

•One across-track : 3 ground pixels: 40 km x 320 km


Aerosol retrieval algorithm for SCIAMACHY/GOME

s

ss

atmsgssTOA

STT

termsurf

termsurfT

1)()(

_

_),(),,(

where atm = R + a + aR

s is the zenith solar angle

is the zenith observation angle

s - is the relative azimuth between the incident and observation vertical planes


3 0 0 4 0 0 5 0 0 6 0 0 7 0 0w a v e len g th [n m ]

0 .0 0

0 .0 5

0 .1 0

0 .1 5

0 .2 0

0 .2 5

refle

ctan

ce [r

el. u

nits

]

I sp ra , 0 3 .0 6 .9 8

R a

R ay l

su rf_ te rm

R to a G O M E

•Ra is based on the sunphotometer

measurements in Ispra (03.06.98)

(Holben et al. 1998)

•Rtoa - GOME data

TOA reflectance - example


3 8 0 4 8 0 5 8 0 6 8 0 7 8 0w a v e le n g th [n m ]

0 .0

0 .1

0 .2

0 .3

0 .4

LER

of s

urfa

ce [r

el. u

nits

]

la n d (F ra n c e )

w a te r (In d ia n O c ea n )

LER-Lambertian Equivalent Reflectance derived from reflectances measured by GOME

(R. Koelemeijer et al., 2003)

Spectral reflectances of natural surfaces -examples


Approach over land/water for GOME

Reflectances at TOA measured by GOME

(380, 440, 463, 495, 555, 670 nm)

Cloud screeningFRESCO algorithm

(Koelemijer et al., 2001,2002)

Correction for ozoneabsorption

Surface correction GOME surface reflectances database

LUT of aerosol/atmospheric/Rayleigh reflectancesfor a given satellite and solar geometry3 predominantly aerosol types-“maritime”, <-0.1, 0.65>- “continental”, <0.65, 1,32>- “urban”, <1.32, 2.8>

The best fit with aerosol model

AOD


January-December 1997

y = 0.9728x + 0.0048R2 = 0.9529

N=102

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

AOD(440) AERONET

AO

D(4

40) G

OM

E


January-December 1997

y = 1.0706x - 0.0279R2 = 0.9395

N=48

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

AOD(670) AERONET

AO

D(6

70) G

OM

E


0 2 4 6 8 1 0 1 2seq u en ce n u m b er

0 .0

0 .4

0 .8

1 .2

1 .6

AO

D(4

40)

B id i B ah n

A E R O N E T

G O M E

13-J

an

9-A

pr

15-A

pr

14-M

ay

30-M

ay

12-J

un

18-J

un

4-Ju

l

10-J

ul

11-A

ug

27-A

ug

15-S

ep


0 4 8 1 2 1 6 2 0 2 4 2 8seq u en ce n u m b er

0 .0

0 .4

0 .8

1 .2A

OD

(440

)B o n d o u k o u i

A E R O N E T

G O M E4-

Jan

13-J

an23

-Jan

29-J

an8-

Feb

11-F

eb20

-Feb

4-M

ay14

-May

18-J

un2-

Aug

14-A

ug21

-Aug

12-S

ep15

-Sep

20-O

ct26

-Oct

30-O

ct5-

Nov

11-N

ov21

-Nov

24-N

ov27

-Nov

4-D

ec10

-Dec

20-D

ec29

-Dec


0 2 4 6 8 1 0 1 2 1 4seq u en ce n u m b er

0 .0

0 .2

0 .4

0 .6

0 .8

1 .0A

OD

(670

)B o n d o u k o u i

A E R O N E T

G O M E14

-May

1-Ju

l

13-J

ul

8-A

ug

14-A

ug

21-A

ug

12-S

ep

15-S

ep

20-O

ct

26-O

ct

5-N

ov

11-N

ov

21-N

ov

24-N

ov


3 0 0 4 0 0 5 0 0 6 0 0 7 0 0w av e le n g th [n m ]

0 .0 0

0 .0 4

0 .0 8

0 .1 2

0 .1 6

0 .2 0

aero

sol o

ptic

al th

ickn

ess

C ap o V erd e , 2 1 -1 0 -1 9 9 7

A E R O N E T

G O M E


0 2 4 6 8seq u en ce n u m b er

0 .0

0 .2

0 .4

0 .6

0 .8

AO

D(4

40)

17-J

an

10-A

pr

24-J

ul

12-A

ug

21-O

ct 22-N

ov

1-D

ec

17-D

ec

C ap o V erd e

A E R O N E T

G O M E


0 2 4 6 8seq u en ce n u m b er

0 .0

0 .2

0 .4

0 .6

0 .8

AO

D(6

70)

C ap o V erd e

A E R O N E T

G O M E

10-A

pr

24-J

ul

12-A

ug

21-O

ct

22-N

ov

1-D

ec

17-D

ec


3 0 0 4 0 0 5 0 0 6 0 0 7 0 0w a v e le n g th [n m ]

0 .1

1 .0

aero

sol o

ptic

al th

ickn

ess

V e n ise , 2 0 0 0

2 6 M a y , A E R O N E T

2 6 M a y , G O M E

1 4 A u g u s t, A E R O N E T

1 4 A u g u s t, G O M E


Outline


• We thank the PI investigators: Didier Tanré, Brent Holben, Philippe Goloub and Giuseppe Zibordi, and their staff for establishing and maintaining the AERONET sites used in this investigation.

• We acknowledge Piet Stammes and Martin de Graaf for kindly providing us GOME data and the results from FRESCO algorithm.

• The algorithm was developed as part of the EO-037 project of the National Data User Support Program of the Netherlands Space Research Organization (SRON).


Illustration of the retrieval process- example 1

3 0 0 4 0 0 5 0 0 6 0 0 7 0 0w a v e len g th [n m ]

0 .1

1 .0

1 0 .0

aero

sol o

ptic

al th

ickn

ess

A E R O N E T (0 .2 1 )

m aritim e (0 .2 3 )

co n tin en ta l (0 .2 9 )

u rb an

C a p e V e rd e , 1 2 -0 8 -9 7


Illustration of the retrieval process – example 2

3 0 0 4 0 0 5 0 0 6 0 0 7 0 0w a v e len g th [n m ]

0 .1

1 .0

1 0 .0

aero

sol o

ptic

al th

ickn

ess

D ak a r, 2 5 -0 5 -9 7

A E R O N E T (0 .0 1 )

m aritim e (0 .0 9 )

co n tin en ta l

u rb an


Illustration of the retrieval process – example 3

3 0 0 4 0 0 5 0 0 6 0 0 7 0 0w av e len g th [n m ]

0 .0 0 0

0 .0 0 1

0 .0 1 0

0 .1 0 0

1 .0 0 0

aero

sol o

ptic

al th

ickn

ess

A v ig n o n , 2 5 -1 0 -2 0 0 0

A E R O N E T (1 .4 5 )

u rb an (1 .3 3 )

m aritim e

c o n tin e n ta l


3 0 0 4 0 0 5 0 0 6 0 0 7 0 0 8 0 0w av e len g th [n m ]

0 .0

0 .2

0 .4

0 .6

0 .8

1 .0

cont

ribut

ion

of th

e su

rfac

e to

TO

A re

flect

ance

I

II

III

IV

V

V I

V II

V III

IX

X

X I

X II

P o la n d (5 0 N , 2 0 E )sc a t. a n g le 1 2 0 d e gA O D (5 5 5 )= 0 .4c o n tin e n t. a e ro so l ty p e

Aerosol optical thickness retrieval over land and water using SCIAMACHY/GOME data

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