page 1 validation by model assimilation and/or satellite intercomparison - esrin 9–13 december...
Post on 01-Jan-2016
217 Views
Preview:
TRANSCRIPT
Page 1Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Monitoring of near-real-time SCIAMACHY, MIPAS, and GOMOS data at
ECMWF
Author: Antje Dethof (ECMWF)
ECMWF model
Operational ozone assimilation
Monitoring of Meteo products
- SCIAMACHY (SCI_RV__2P)
- MIPAS (MIP_NLE_2P)
Summary
Outline
Page 2Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Global spectral model (u,v,T,ps,q,o3,cc,cl,ci)
Resolution: - TL511 40 km (TL159)
- 60 levels up to 0.1 hPa ( 65 km)
Comprehensive physics package
Ozone is prognostic model variable
Data assimilation system: 12-hour 4D-Var (6-hour 3D-Var)
The ECMWF model
Page 3Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Operational ozone assimilation (4D-Var)• GOME (ERS2): - Total column ozone - NRT retrievals from KNMI (version FD 3.1) - approx. 20000 obs daily (14000 used)
• Blacklist criteria: - at solar elevations < 10° - at latitudes > 40° in NH - at latitudes < -50° in SH - QC flag > 0
• SBUV/2 (NESDIS retrievals): - NOAA-16 - NOAA-14 passive - NOAA-17 passive (since 20020804,18z)
- 6 ozone layers: 0.1-1 hPa, 1-2 hPa, 2-4 hPa, 4-8 hPa, 8-16 hPa, 16hPa – surface
- approx. 1400 obs daily (1200 used)
• Blacklist criteria: - at solar elevations < 6° - QC flag > 0
Page 4Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Passive assimilation: Data are not assimilated actively, but go through the assimilation system and statistics (e.g. first-guess departures) are calculated
Use assimilation system to evaluate data quality, biases, instrument and algorithm stability (can also show model problems)
Output statistics:
- Number of data
- Mean
- Stdev of
Monitoring
Observations
Departures (first-guess, analysis)
Page 5Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Meteo products from ftp-ops.pdk.envisat.esa.int, converted into BUFR format at ECMWF
SCIAMACHY ozone data about 25 DU lower than KNMI GOME data in tropics and mid-latitudes
Unrealistically large values at high latitudes
Unrealistically low values at high southern latitudes that were seen earlier have disappeared
No geolocation information (e.g. sza, fov) in Meteo data
Monitoring of SCIAMACHY Meteo data (SCI_RV__2P) Ozone
Page 6Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
SCIAMACHY total column ozone: 18.-24.11.2002
SCIAMACHY GOME (KNMI)
Page 7Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
SCIAMACHY total column ozone: 18.-24.11.2002SCIAMACHY GOME (KNMI)
Observation values
Fg departures
Unrealistically
large values
25 DU
Page 8Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Good agreement of MIPAS temperatures with ECMWF analyzed temperatures over large part of stratosphere (diff < 2%)
Largest differences at 0.1 hPa (ECMWF model top)
MIPAS temperatures too low at bottom end of profiles
(cloud contamination ?)
Upgrade on 13.11.2002, 12z:
Reduced fg-departures (MIPAS – ECMWF) below 60-80 hPa
Increased number of profiles extending below 100 hPa
Cooling above 1 hPa between 65-90S
Monitoring of MIPAS Meteo data (MIP_NLE_2P)Temperature
Page 9Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
4.-10.11.02 11.-17.11.02
DeparturesMIPAS - EC
Improvement after 13.11.02
MIPAS
ECMWF
T profiles – global averages
Page 10Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Temperature (zonal means at 100 hPa): 11.-17.11.2002
More data at 100 hPa after 13.11.2002
11.11.
17.11.
Time
MIPAS
Page 11Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Reasonable agreement with ECMWF ozone over large part
of stratosphere Some differences might be explained by known ECMWF model bias: e.g. – tropical O3 max. lower in ECMWF than MIPAS
- 90-65ºN: ECMWF > MIPAS over large part of stratosphere
Unrealistically large MIPAS ozone values in lower stratosphere (cloud contamination ?)
Upgrade on 13.11.2002, 12z: Reduced departures (MIPAS – ECMWF) in lower stratosphere Reduced number of unrealistically large MIPAS ozone values, but some large values remain
MIPAS Ozone
Page 12Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Ozone profiles: 0 – 20ºS
MIPAS
ECMWF
Improvement after 13.11.02
11.-17.11.024.-10.11.02
Page 13Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Ozone scatter plot (4.-10.11.02): 100-150 hPa
Unrealistically large
values in tropics
Page 14Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
MIPAS water vapour values generally larger than ECMWF
values (sign in agreement with known dry bias of ECMWF analyses in stratosphere) Unrealistically large MIPAS water vapour values at bottom end of profiles (cloud contamination ?)
Upgrade on 13.11.2002, 12z: Reduced MIPAS water vapour values between 20-100 hPa Fewer unrealistically large water vapour values at bottom end of profiles, but some large values remain
MIPAS - Water Vapour
Page 15Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Water vapour profiles: 0-20ºS (11.-17.11.02)
MIPAS
ECMWF
Dry bias of ECMWF Cloud contamination of MIPAS?
11.11. 17.11.
Time
Zonal mean MIPAS (60-80 hPa)
Change on 13.11.02
Page 16Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002
Monitoring of Meteo products at ECMWF
SCIAMACHY: Values ca. 10% lower than ECMWF or GOME (KNMI) over large parts of globe
MIPAS: Profile values seem reasonable, possible cloud contamination at bottom of profiles
GOMOS: Worse data quality than MIPAS. Large scatter. Water vapour values unrealistically large.
Continuation of monitoring
Experimental assimilation of ENVISAT data
Please add geolocation information to L2 products
Summary and Outlook
top related