Introduction

The Global Ozone Monitoring by Occultation of Stars (GOMOS) instrument is an atmospheric sensor on board the European environmental satellite ENVISAT launched successfully in March 2002. GOMOS is an ESA funded instrument and was developed as a joint project of Finland and France and contributes, together with SCIAMACHY and MIPAS, to atmospheric sounding and the monitoring of ozone with high accuracy.

The main scientific objective of the stellar occultation instrument is to monitor ozone and ozone trends in the stratosphere and mesosphere with high accuracy and high vertical resolution at global coverage. Moreover, GOMOS enables to measure atmospheric parameters related to stratospheric ozone chemistry like NO2, NO3, H2O and aerosol as well as ozone dynamics like temperature, air density and turbulence.

These tasks are achieved by measuring stellar spectra in the ultraviolet to near infrared range while stars are being eclipsed by the Earth. Thus, it can be regarded as a demonstrator for the stellar occultation technique and a precursor for upcoming occultation instruments.

More information about this measuring technique you can get here.

Available Data

After the end of the commissioning phase operational value added GOMOS data products (Level 3+) will be available at the World Data Center for Remote Sensing of the Atmosphere at DLR-DFD. For requests or ordering simply send us an email.

The operational data processing for GOMOS will be done in the German Processing and Archiving Center (D-PAC) as a part of the ESA ground segment located at the German Remote Sensing Data Center (DLR-DFD) in close cooperation with the FIN-CoPAC.

An overview about the ESA level 1 and 2 data products (level 1 and 2) is given here. For ordering GOMOS level 1 and 2 data please contact ESA helpdesk.

The Off-line Level 2 processing takes place at Fin-CoPAC, FMI Arctic Research Center Finland. Quality vertically gridded GOMOS Level 2 data can be obtained from Finish Meteorological Institute. Please contact Erkki Kyrölä.

GOMOS information and access on the BADC website you can get here: http://badc.nerc.ac.uk/data/gomos/index-old.html

Links to further information

• General information on GOMOS is available on the ESA web pages.
• Comprehensive information is given by the GOMOS user guide.
• The GOMOS data sheet from WDC-RSAT.
• Data products of the project EVIVA (ENVISAT Value Adding for Continuous Monitoring of Atmospheric Trace Gases and Aerosols)
• GOMOS validation is co-ordinated by ACRI: http://www.enviport.org/gomos/

As one of the atmospheric instruments on ENVISAT, GOMOS data will complement information obtained with MIPAS, MERIS and SCIAMACHY.

Contact

If you would like to know more about the GOMOS instrument or the GOMOS data products, please contact:
WDC-Team (WDC-RSAT)
E. Kyrölä (GOMOS Expert Support Laboratory)
Alain Hauchecorne (GOMOS Expert Support Laboratory)
Didier Fussen (GOMOS Expert Support Laboratory)

References

Bertaux, J.L., Kyrölä, E., Wehr, T.: Stellar Occultation Technique for Atmospheric Ozone Monitoring: GOMOS on ENVISAT. ESA Earth Observation Quarterly, No. 67, p.17-20, October 2000 .

ESA: Envisat GOMOS: An Instrument for Global Ozone Monitoring. ESA SP-1244, 2000.

Ratier, G., Levrini, G., Popescu, A., Paulsen, T., Readings, C., Langen, J.: GOMOS: Envisat´s Contribution to Measuring Long-Term Trends in Ozone and other Trace Gases. ESA Bulletin, No. 97, p.20-27, March 1999.

GOMOS on ENVISAT: an overview, E. Kyrölä et al., Advances in Space Research, 33 1020-1028, 2004.

First results on GOMOS/ENVISAT: J.L. Bertaux et al., Advances in Space Research, 33, issue 7, p.1029-1035, 2004.

GOMOS Algorithm Theoretical Basis Document, version 2.0, edited by E. Kyrölä and L. Blanot, 2007.