GODIVA - GOME Data Products In SupportOf The Winter 1999 THESEO Campaign

D.W. Arlander 5, A.P.H. Goede1, C.P. Tanzi1, I. Aben1, J.P. Burrows2, M. Weber2, A. Richter2, K. Bramstedt2, D. Perner3,P.S. Monks4, D. Llewellyn-Jones4, G.K. Corlett4, G.H. Hansen5, K.K. Tørnkvist5, U. Platt6, T. Wagner6, C. Leue6,

K. Pfeilsticker6, P. Taalas7, H. Kelder8, H. Eskes8 and A. Piters8.

IntroductionGODIVA (GOME Data Interpretation, Valida-tion and Application) is a European Commu-nity pilot project funded through Theme 3(Space Techniques applied to EnvironmentalMonitoring and Research). The main aims in-clude the improvement of the accuracy of ex-isting GOME data products, i.e. radiances,ozone and NO2 vertical columns, and to de-velop new advanced GOME data products suchas ozone profiles, OClO, BrO, HCHO and SO2columns. GODIVA is a project for defining enduser needs and developing validated near real-time (NRT) data products and other data prod-ucts needed for short-term logistical planningand post-campaign data interpretation. TheGOME NRT level 1 data products (radianceand solar irradiance) were generated by theGOME data processor (GDP) located at theKiruna ground station, which is one of five ESA(European Space Agency) stations receivingglobal data from the ERS-2 (European RemoteSensing satellite). A maximum of ten out of the14 daily GOME orbits are transmitted toKiruna. The GDP is operated by the DeutscheFernerkundungsdatenzentrum DFD of DLR(Deutsche Luft und Raumfahrt) Oberpfaffen-hofen. After each completed orbit, the data wassent via ftp from Kiruna to the NADIR database.

ResultsThe data received at NADIR could then be ana-lysed either at NILU or sent further to otherGODIVA project partners in support of theTHESEO (Third European Stratospheric Ex-periment Ozone). In the future, a similarprocessing chain could be envisged for produc-ing input for atmospheric chemistry transportand numerical weather prediction models. Ex-amples of several of the above mentioned prod-ucts from periods of interest during the winterof 1999 are shown. In Figure 1, slant columnOClO from 6’ Feb. is shown. A very strongcorrelation between high OClO and low tem-peratures (sub-200 Kelvin) with coinciding highpotential vorticity at the 475K and 550Kisentropic levels was observed for several peri-ods during February. Such information can yieldinformation on the vertical distribution of OClOas well as possible chlorine activation withinthe polar vortex.

In Figure 2, vertical column BrO values in-dicated elevated tropospheric BrO in northernCanada and Siberia. This naturally occuring

Affiliations:1) Space Research Organization Netherlands (SRON), Sorbonnelaan 2, 3584 CA Utrecht, the Netherlands.2) Institute of Remote Sensing (IFE), Univ. of Bremen, Postfach 33 04 40, D-28334 Bremen, Germany.3) Max-Planck-Institute for Air Chemistry, (MPI) , P.O. Box 3060, D-55020 Mainz, Germany .4) Department of Chemistry, Univ. of Leicester, University Road, Leicester, LE1 7RH, United Kingdom.5) Norwegian Institute for Air Research (NILU) , P.O. Box 100, N-2027 Kjeller, Norway.6) Institute of Environmental Physics, Univ. of Heidelberg, Im Neuenheimer Feld 366, D-69120 Heidelberg,

Germany.7) Finnish Meteorological Institute (FMI) , P.O. Box 503, 00101 Helsinki, Finland.8) Royal Netherlands Meteorological Institute, (KNMI), P.O. Box 201, 3730 AE De Bilt, the Netherlands.

Figure1. Slant column OClO from NRTGOME data on February 6th, 1999.

Figure 2. Vertical column BrO from NRTGOME data on March 31st, 1999.

Figure 3. Total column ozone and locations ofground pixels used for the calculation of ozoneprofiles shown in Figures 4 and 5.

Figure 4. NRT GOME ozone profiles plottedas a function of latitude and altitude.

Figure 5. NRT GOME ozone profiles plottedas a function of latitude and altitude

GODIVA websites:Coordination:www.sron.nl/divisions/eos/godivaOClO:www.nilu.no/projects/nadir/index.htmlBrO:www.iup.physik.uni-bremen.de/gome/bro/html/gome_tab_99_bro_1.htmlOzone Profiles:www.iup.physik.uni-bremen.de/ifepage/gprof_theseo.htmlGlobal Ozone Maps:www.knmi.nl/onderzk/atmosam/

AcknowledgementsThe GODIVA consortium is very grateful toDLR and ESA for providing the level 1GOME NRT data free of charge to theNADIR data base at NILU during the monthsof February and March of 1999. The SwedishSpace Corporation is also recognized forlogistical support in Kiruna.

phenomenon can lead to substantial ozone de-pletion in the lower troposphere during thespring in the Arctic and Antarctic. In Figures 4and 5, ozone profiles over northern Europe are

derived using the Bremen FURM retrieval al-gorithm. This inversion scheme uses the radiativetransfer code GOMETRAN++ as the forwardmodel to derive ozone profiles from the UV spec-tral region. 24-hour forecasts for the temperatureand pressure profiles are provided by ECMWFfor use in the NRT evaluations.