validation of envisat products using poam iii o 3 , no 2 , h 2 o and o 2 profiles
DESCRIPTION
Validation of ENVISAT Products using POAM III O 3 , NO 2 , H 2 O and O 2 profiles. Authors: F. GOUTAIL, A. BAZUREAU. Description of POAM instrument Constituents measured List of profiles available Example of Profiles Comparison with GOMOS Conclusion. - PowerPoint PPT PresentationTRANSCRIPT
Page 1Validation by Model Assimilation and/or Satellite Intercomparison - 9–13 Dec. 2002
Validation of ENVISAT Products using POAM III O3, NO2, H2O and O2 profiles
Authors: F. GOUTAIL, A. BAZUREAU
- Description of POAM instrument- Constituents measured- List of profiles available- Example of Profiles- Comparison with GOMOS - Conclusion
Acknowledgements : R. Bevilacqua and NRL POAM III Science Team
Page 2Validation by Model Assimilation and/or Satellite Intercomparison - 9–13 Dec. 2002
Description of POAM III Instrument
Launched on SPOT 4 satellite (CNES) on March 1998
Heliosynchronous quasi-polar orbit : HN (sunrise) – HS (sunset)
14 profiles/ day in each hemisphere (at the same latitude)
Between 54 – 71 °N
Between 62 - 87 °S
Solar occultation technique in UV- visible band
Vertical profiles of O3, NO2, H2O, O2
Vertical resolution
1 km for O3
1.5 to 2.5 km for NO2
varying with seasonHN
HS
Page 3Validation by Model Assimilation and/or Satellite Intercomparison - 9–13 Dec. 2002
POAM III Validation results
Northern Hemisphere Southern Hemisphere
Ozone < 5-10 % (13- 60 km) < 5 -10% (13- 60 km)
NO2 < 10% (20- 45 km) < 10% (20- 45 km)
H2O 5% (15- 45 km) 8% (15- 45 km)
Aerosol1.018 m
< 30% (10- 24 km)
+ low bias comparedto SAGE
< 30% (10- 21 km)
+ high bias comparedto SAGE
Page 4Validation by Model Assimilation and/or Satellite Intercomparison - 9–13 Dec. 2002
List of profiles available• Since July 2002
• Monthly “package” for each hemisphere
from July to November 2002.
Profiles of O3, NO2, H2O, O2 and aerosol extinction coefficient at 1018 nm
Profiles of Pressure and Temperature from NMC analysis
• Very soon : December POAM III profiles
• Future developments : all aerosol extinction coefficient profiles and …
all errors bars (for all constituents)
- POAM III HDF data Version 2 -
Page 5Validation by Model Assimilation and/or Satellite Intercomparison - 9–13 Dec. 2002
Example of profiles POAM III and GOMOS
Page 6Validation by Model Assimilation and/or Satellite Intercomparison - 9–13 Dec. 2002
Comparisons with GOMOS : Southern Hemisphere - July 2002
Coincidence criterions :
time < 24 hours
distances < 800 km
20 “matches” found :
13 25Eta Tau (2.8)
7 87Alp Tau (0.8)
Page 7Validation by Model Assimilation and/or Satellite Intercomparison - 9–13 Dec. 2002
Comparisons with GOMOS : Southern Hemisphere - July 2002
Pressure and temperature profiles : NMC analysis versus ECMWF
Analysis conducted for each star .100
POAM
GOMOSPOAM
Page 8Validation by Model Assimilation and/or Satellite Intercomparison - 9–13 Dec. 2002
Comparisons with GOMOS : Southern Hemisphere - July 2002Constituents profiles comparisons :
.100
POAM
GOMOSPOAM
Page 9Validation by Model Assimilation and/or Satellite Intercomparison - 9–13 Dec. 2002
Comparisons with GOMOS : Southern Hemisphere - July 2002Constituents profiles comparisons :
.100
POAM
GOMOSPOAM
Page 10Validation by Model Assimilation and/or Satellite Intercomparison - 9–13 Dec. 2002
Comparisons with GOMOS : Northern Hemisphere - September 2002
on workCoincidence criterions :
time < 24 hours
distances < 800 km
47 “matches” found
49 Del Cap (2.8)
20 distances GOMOS / POAM III
< 400 km
Page 11Validation by Model Assimilation and/or Satellite Intercomparison - 9–13 Dec. 2002
Comparisons with GOMOS : Northern Hemisphere - September 2002Pressure and temperature profiles : NMC analysis versus ECMWF model
.100
POAM
GOMOSPOAM
Page 12Validation by Model Assimilation and/or Satellite Intercomparison - 9–13 Dec. 2002
Comparisons with GOMOS : Northern Hemisphere - September 2002Constituents profiles comparisons :
.100
POAM
GOMOSPOAM
Page 13Validation by Model Assimilation and/or Satellite Intercomparison - 9–13 Dec. 2002
Comparisons POAM III / GOMOS : SUMMARYComparisons of pressure and temperature relative difference profiles for each star :
.100
POAM
GOMOSPOAM
Page 14Validation by Model Assimilation and/or Satellite Intercomparison - 9–13 Dec. 2002
Comparisons POAM III / GOMOS : SUMMARY (2)
.100
POAM
GOMOSPOAM
Page 15Validation by Model Assimilation and/or Satellite Intercomparison - 9–13 Dec. 2002
ConclusionsComparison and validation programs are now ready for ENVISAT instruments validation
Reading PDS format programs not yet well mastered (several problems with Enviview)
Extraction of ENVISAT instrument profiles still hard working …
• Waiting for GOMOS aerosol extinction coefficients profiles
• Waiting for new GOMOS processing for O3, O2, NO2, H2O
• MIPAS profiles coincident with POAM III available ?
• First SCIAMACHY profiles are waited in January 2003