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J. Ku smierczyk-Michulec G. de Leeuw. Aerosol optical thickness retrieval over land and water using SCIAMACHY/GOME data. The SC anning I maging A bsorption Spectro M eter for A tmospheric CH artograph Y ( SCIAMACHY ) on board the ESA Envisat satellite. launched in March 2002 - PowerPoint PPT Presentation
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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/
7 December 2004Aerosol optical thickness retrieval
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
7 December 2004Aerosol optical thickness retrieval
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
7 December 2004Aerosol optical thickness retrieval
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
7 December 2004Aerosol optical thickness retrieval
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
7 December 2004Aerosol optical thickness retrieval
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
7 December 2004Aerosol optical thickness retrieval
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
7 December 2004Aerosol optical thickness retrieval
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
7 December 2004Aerosol optical thickness retrieval
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
7 December 2004Aerosol optical thickness retrieval
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
7 December 2004Aerosol optical thickness retrieval
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
7 December 2004Aerosol optical thickness retrieval
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
7 December 2004Aerosol optical thickness retrieval
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
7 December 2004Aerosol optical thickness retrieval
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
7 December 2004Aerosol optical thickness retrieval
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
7 December 2004Aerosol optical thickness retrieval
Outline
7 December 2004Aerosol optical thickness retrieval
7 December 2004Aerosol optical thickness retrieval
7 December 2004Aerosol optical thickness retrieval
7 December 2004Aerosol optical thickness retrieval
7 December 2004Aerosol optical thickness retrieval
7 December 2004Aerosol optical thickness retrieval
• 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).
7 December 2004Aerosol optical thickness retrieval
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
7 December 2004Aerosol optical thickness retrieval
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
7 December 2004Aerosol optical thickness retrieval
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
7 December 2004Aerosol optical thickness retrieval
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