Title: Global satellite validation of SCIAMACHY O3 and NO2 columns with GOME WFDOAS/3.0
1Global satellite validation of SCIAMACHY O3 and
NO2 columns with GOME WFDOAS/3.0
Astrid Bracher, M. Weber, K. Bramstedt,M.
Coldewey-Egbers, L. N. Lamsal, John
Burrows Institute of Environmental Physics
(IUP/IFE), University of Bremen (part of it to
be submitted to ACP special issue in December
2004) SCIAMACHY Validation Workshop, Bremen,
Germany, 7 Dec 2003
bracher_at_uni-bremen.de
2 SCIAMACHY total O3 validation with GOME WFDOAS
All SCIAMACHY 5.01/5.04 from Jan - June 2003
compared to GOME WFDOAS V1.0 (to be submitted
to ACP SCIAMACHY special issue II)
- SCIAMACHY reprocessed data of 2003
- mixture of v5.01/5.04
- only differences in processing settings,
- wrong season index in 5.01 for Jan-Mar 2003
- equivalent to GOME GDP 2.4
- no efficient temperature correction
- AMF calculations
- -with ozone climatology based on 2 dim CTM
- -no iterations to match tO3 a priori with meas.
- limited treatment of atmos. profile shape effect
- partly unsuitable spectral analysis when atmos-
- phere becomes optically thick.
- UV fit window 325-335 nm
- GOME GDP 2.4 known for
- strong dependencies to sza, tO3, seasons, latitude
- GOME WFDOAS
- by Coldewey-Egbers et al. (ACPD, 2004)
- Improved Raman correction ( to account for
- O3-depend. contribution to Ring effect)
- ozone temperature correction
- Cloud cover and effective scene height from
- oxygen A-band absorption (Koellemeijer et
- al. 2001) incl. ghost vertical column
correction - Effective UV albedo (surface reflect.) from 377nm
- Spectral fitting window 326.6-335nm
3GOME WFD global validation with ground-based
- Comparison of WFDOAS with groundbased data 56
stations Brewer/Dobson/SAOZ/M124 - mid-latitudes and tropics agreement to within 1
little seasonal variation (cosine amplitudes
below 0.5 in general) - polar latitudes differences of up to 4 to 8 in
winter (dependent on individual stations) - little seasonal variation (cosine amplitudes
below 0.5 in general)
NH Polar
mid-lat tropics
SH Polar
coincidence criteria 300 km same day
from Weber et al., ACPD 2004
4SCIAMACHY total O3 with GOME WFDOAS
GOME WFDOAS V1.0
SCIAMACHY v5.01
All O3 data of one day (16 Apr 2003) in 2.5
latitudinal X 2.5 longitudinal grids, only
SCIAMACHY data lt90 SZA comparison of SCIAMACHY
and GOME within the same grid
5SCIAMACHY total O3 with GOME WFDOAS
(SCIAMACHY v5.01-GOME-WFD)/GOME-WFD at 16 Apr 2004
70S-23N 1.5 to 3 (1-2) 23N-60N 1.5 to
3 (2-3)
6tO3 (SCIA v5.01/5.04-GOME WFD/GOME WFD)
Polar Latitudes North South
SCIAMACHY to GOME winter 7.5 to 2.5
(3-5) summer 1.5 to 0 (2)
spring-summer 1.5 to 4 (3) fall-winter
3 to 1 (2-4) no. of bins lt 300 strong
increase in scatter of mean relative deviation
and of RMS
7tO3 (SCIA v5.01/5.04-GOME WFD/GOME WFD)
Mid Latitudes North South
SCIAMACHY to GOME winter 2 to 3
(2-3) summer-fall 2 to 0.5 (1-1.5)
spring-summer 2 to 1 (1.5-2) early
winter within 1 (2-3)
8tO3 (SCIA v5.01/5.04-GOME WFD/GOME WFD)
Tropics Global
SCIAMACHY to GOME 2.5 to 0.5 (1) 2 to
0.5 (2)
9tO3 (SCIA v5.01/5.04-GOME WFD/GOME WFD)
comparison as a function of solar zenith angle
(SZA) one day Jan to June 2003
SCIA to GOME mean relative deviation 20 to 60
increase of mean relative deviation with SZA,
gt60to 85 decrease, gt85 increase again
RMS gt85 SZA RMS much higher than below no
dependence to number of bins
10tO3 (SCIA v5.01/5.04-GOME WFD/GOME WFD)
comparison as a function of total ozone one
day Jan to June 2003
SCIAMACHY to GOME mean relative deviation
increase with total ozone to lt390 DU gt390 DU
small decrease with total ozone
RMS dependence to no. of bins only for half
year mean
11NO2 VCD (SCIAMACHY-GOME 3.0)/GOME W3.0
Verification orbits 2508 2510 23 Aug
2002 SCIAMACHY to GOME 3.0
V4.0 V5.0-old 70S-80N -600
70S-80N -600 (/-2-15)
(/-2-15)
error
error
50 0 50
latitude
50 0 latitude
Status March 2004 no latitudinal dependence!
error
Case1 from 5.0-verif. 65S-80N -715
(/-2-15)
50 0 50
latitude
12NO2 VCD (SCIAMACHY-GOME 3.0)/GOME 3.0
Daily comparisons as function of
latitude from Jan-June 2003 v5.01/5.04
10 Jan v5.04
12 May v5.01
error
error
2 Mar v5.04
20 Jun v5.04
error
error
50 0 50
latitude
50 0 50
latitude
13NO2 SCD (SCIAMACHY-GOME 3.0)/GOME W3.0
Daily comparisons as function of
latitude from Jan-June 2003 v5.01/5.04
10 Jan v5.04
12 May v5.01
error
error
2 Mar v5.04
20 Jun v5.04
error
error
50 0 50
latitude
50 0 50
latitude
14NO2 VCD (SCIAMACHY-GOME 3.0)/GOME W3.0
Daily comparisons as function of solar zenith
angle (SZA) from Jan-June 2003 v5.01/5.04 SH
(solid) NH (light)
12 May v5.01
10 Jan v5.04
error
error
20 Jun v5.04
2 Mar v5.04
error
error
30 40 50 60
70 80 sza
20 40 60
80 sza
15Summary SCIAMACHY total ozone v5.01/5.04
- Global validation with GOME WFDOAS V1 from
Jan-June 2003 by fast binning method - Slight underestimation of GOME WFDOAS (within
0.5 to 2, RMS 2), in accordance with ACVE-2
results - Results improves when only SCIAMACHY data below
85 or even 75 SZA are used - (Coupled) dependencies to seasons, latitudes and
total ozone - increase of deviation from summer to winter as
atmospheric variability increases - detected in GOME GDP 2.4 (see Lambert et al.,
2000) and attributed to no temp. correction in
O3 cross sections, AMF calculations, atmospheric
profile shape effect, spectral analysis when
atmosphere optically thick, not including ozone
filling-in as part of Ring effect - Update to GDP 4.0 or to WFDOAS of SCIAMACHY
total ozone will probably lead to agreements
within 1 with groundbased or GOME WFDOAS for
SCIAMACHY data lt85!
16Summary SCIAMACHY total NO2 v5.01/5.04
- Global validation with GOME 3.0 from Jan-June
2003 by fast binning method - Results show latitudinal dependence and in
Winter-Spring in the Northern Hemisphere strong
dependence to SZA! - Results for SCIAMACHY 5.01/5.04 worse then for
verification orbits v5.0 case 1 or case 4
(release 3/2004) and the results of ACVE-2!
17ACKNOLEDGEMENTS
- DLR ESA/ESRIN for GOME and SCIAMACHY lv 1 lv
2 data - For Funding
- ESA-ESRIN (AO-project 651 SATVAL and contract
16402/02/I-LG) - DLR-Bonn (contract No. 50 EE0025)
- BMBF (FKZ 01 SF9994, 7ATF42 (GOMSTRAT) within the
AFO 2000) - European Union (EU project EVK2-CT-2001-00133
CANDIDOZ)
18GOME WFDOAS TOMS V8
GOME
Brewer DS
TOMS
from Weber et al., ACPD 2004
19GOME WFDOAS TOMS V8
GOME
TOMS
from Weber et al., ACPD 2004
Thanks to Bob Evans, NOAA