Monitoring and assimilation of SCIAMACHY data at ECMWF

Antje Dethof, ECMWF

Global means, 1 Mar – 30 June 2004

Monitoring of SCIAMACHY ozone columns

ESA NRT retrievals KNMI TOSOMI retrievals

Mar Apr May Mar Apr May Jun

Mar Apr MayMar Apr May Jun

Monitoring of SCIAMACHY ozone columns,

Global means 1 - 31 Oct 2004 ESA NRT retrievals KNMI TOSOMI retrievals

Problem with climatology?

KNMI NRT L2 TOSOMI product

ESA NRT L2 product, April 2004

(obs-fg)/fg [%]SCIA [DU]Data gap

Assimilation of SCIAMACHY (TOSOMI) ozone

TOMS

No SCIA

With SCIA

23 May 2004

Assimilation of SCIAMACHY (TOSOMI) ozone

TOMS

No SCIA

With SCIA

11 Sept 2004

Fit to ozone sonde profiles

Assimilation of SCIAMACHY (TOSOMI) ozone

No SCIANo SCIA

with SCIAwith SCIA

Fit to Neumayer ozone sonde profiles (lat=-71, lon=-8)

Assimilation of SCIAMACHY (TOSOMI) ozone

Problem from assim. of ozone columns

Fit to SBUV/2 data from NOAA-16 (1 – 23 May 2004)

Obs-ana=3.2 DU

Stdv=14.7 DU

Obs-ana=-10.5 DU

Stdv=14.7 DU

Assimilation of SCIAMACHY (TOSOMI) ozone

Ozone layer: 16 hPa - surface

No SCIA with SCIA

Conclusions

• Passive monitoring shows:- Problems with ESA NRT SCI_RV__2P data before April 2004

(improved after 27 April 2004, but new problems in

October 2004)

- Data coverage: Some data not available in NRT (improved since August2004)

- Differences between ESA and KNMI retrievals (reduced after change on 27 April)

• Assimilation of TOSOMI SCIAMACHY data :- Improved fit of ECMWF ozone column and profiles to independent data

- Included in the operational ECMWF system since 28 September 2004