Global satellite validation of SCIAMACHY O 3 and N O 2 columns with GOME WFDOAS /3.0
description
Transcript of Global satellite validation of SCIAMACHY O 3 and N O 2 columns with GOME WFDOAS /3.0
Institut für Umweltphysik/Fernerkundung Physik/ElektrotechnikFachbereich 1
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
Global satellite validation of SCIAMACHY O3
and NO2 columns with GOME WFDOAS/3.0
Institut für Umweltphysik/Fernerkundung Physik/ElektrotechnikFachbereich 1
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
Institut für Umweltphysik/Fernerkundung Physik/ElektrotechnikFachbereich 1
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)
SH Polar
NH Polar
mid-lat
&
tropics
coincidence criteria: 300 km & same day
from Weber et al., ACPD 2004
GOME WFD global validation with ground-based
Institut für Umweltphysik/Fernerkundung Physik/ElektrotechnikFachbereich 1
SCIAMACHY total O3 with GOME WFDOAS
All O3 data of one day (16 Apr 2003)
in 2.5° latitudinal X 2.5° longitudinal grids, only SCIAMACHY data <90° SZA
comparison of SCIAMACHY and GOME within the same grid
GOME WFDOAS V1.0 SCIAMACHY v5.01
Institut für Umweltphysik/Fernerkundung Physik/ElektrotechnikFachbereich 1
70°S-23°N –1.5% to –3% (+1-2%)23°N-60°N –1.5% to +3% (+2-3%)
(SCIAMACHY v5.01-GOME-WFD)/GOME-WFD at 16 Apr 2004
SCIAMACHY total O3 with GOME WFDOAS
Institut für Umweltphysik/Fernerkundung Physik/ElektrotechnikFachbereich 1
tO3: (SCIA v5.01/5.04-GOME WFD/GOME WFD)
Polar LatitudesNorth South
SCIAMACHY to GOMEwinter: –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 < 300 strong increase in scatter of mean relative deviation and of RMS
Institut für Umweltphysik/Fernerkundung Physik/ElektrotechnikFachbereich 1
Mid LatitudesNorth South
SCIAMACHY to GOMEwinter: –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%)
tO3: (SCIA v5.01/5.04-GOME WFD/GOME WFD)
Institut für Umweltphysik/Fernerkundung Physik/ElektrotechnikFachbereich 1
Tropics Global
SCIAMACHY to GOME –2.5 to –0.5% (+1%) –2 to +0.5% (+2%)
tO3: (SCIA v5.01/5.04-GOME WFD/GOME WFD)
Institut für Umweltphysik/Fernerkundung Physik/ElektrotechnikFachbereich 1
comparison as a function of solar zenith angle (SZA)
one day Jan to June 2003
SCIA to GOMEmean relative deviation: 20° to 60° increase of mean relative deviation with SZA,
>60°to 85° decrease, >85° increase again RMS: >85° SZA RMS much higher than below no dependence to number of bins
tO3: (SCIA v5.01/5.04-GOME WFD/GOME WFD)
Institut für Umweltphysik/Fernerkundung Physik/ElektrotechnikFachbereich 1
comparison as a function of total ozone
one day Jan to June 2003
SCIAMACHY to GOMEmean relative deviation: increase with total ozone to <390 DU
>390 DU small decrease with total ozone RMS: dependence to no. of bins only for half year mean
tO3: (SCIA v5.01/5.04-GOME WFD/GOME WFD)
Institut für Umweltphysik/Fernerkundung Physik/ElektrotechnikFachbereich 1
V4.0: V5.0-old: 70°S-80°N -60%–0% 70°S-80°N -60%–0%
(+/-2-15%) (+/-2-15%)
Verification orbits 2508 & 251023 Aug 2002
SCIAMACHYto GOME 3.0
Case1 from 5.0-verif.: 65°S-80°N -7%–15%
(+/-2-15%)
NO2 VCD : (SCIAMACHY-GOME 3.0)/GOME W3.0
Status March 2004no latitudinal dependence!
% e
rror
50 0
latitude
50 0 50
latitude
% e
rror
% e
rror
50 0 50
latitude
Institut für Umweltphysik/Fernerkundung Physik/ElektrotechnikFachbereich 1
NO2 VCD : (SCIAMACHY-GOME 3.0)/GOME 3.0
Daily comparisons
as function of latitude
from Jan-June2003
v5.01/5.04
% e
rror
% e
rror
50 0 50
latitude
10 Janv5.04
2 Marv5.04
20 Junv5.04
12 Mayv5.01
50 0 50
latitude
% e
rror
% e
rror
Institut für Umweltphysik/Fernerkundung Physik/ElektrotechnikFachbereich 1
NO2 SCD : (SCIAMACHY-GOME 3.0)/GOME W3.0%
err
or
% e
rror
% e
rror
10 Janv5.04
2 Marv5.04
50 0 50
latitude
12 Mayv5.01
Daily comparisonsas function of latitude
from Jan-June2003
v5.01/5.04
20 Junv5.04
% e
rror
50 0 50
latitude
Institut für Umweltphysik/Fernerkundung Physik/ElektrotechnikFachbereich 1
NO2 VCD : (SCIAMACHY-GOME 3.0)/GOME W3.0
% e
rror
% e
rror
20 Junv5.04
20 40 60 80
sza
12 Mayv5.01
10 Janv5.04
% e
rror
2 Marv5.04
% e
rror
30 40 50 60 70 80
sza
Daily comparisons
as function of solar zenith angle
(SZA)
from Jan-June2003
v5.01/5.04
SH (solid)NH (light)
Institut für Umweltphysik/Fernerkundung Physik/ElektrotechnikFachbereich 1
Summary: 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 <85°!
Institut für Umweltphysik/Fernerkundung Physik/ElektrotechnikFachbereich 1
Summary: 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!
Institut für Umweltphysik/Fernerkundung Physik/ElektrotechnikFachbereich 1
ACKNOLEDGEMENTS
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)
Institut für Umweltphysik/Fernerkundung Physik/ElektrotechnikFachbereich 1
GOME WFDOAS & TOMS V8
Brewer DS
GOME
TOMS
from Weber et al., ACPD 2004
Institut für Umweltphysik/Fernerkundung Physik/ElektrotechnikFachbereich 1
GOME WFDOAS & TOMS V8
GOME
TOMS
Thanks to Bob Evans, NOAA
from Weber et al., ACPD 2004