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GOME stratospheric NO2 data
Introduction Station Data Gridded Data Disclaimer Contact
Introduction:
For the European project QUILT, a complete time series of GOME NO2 columns has been created which can be downloaded in ASCII format as gridded monthly averages or daily values over the QUILT stations.
For a description of the method used to derive the NO2 columns, please see:
- Richter, A., F. Wittrock, M. Weber, S. Beirle, S. Kühl, U. Platt, T. Wagner, W. Wilms-Grabe, and J. P. Burrows, GOME observations of stratospheric trace gas distributions during the splitting vortex event in the Antarctic winter 2002 Part I: Measurements, J. Atmos. Sci., 62 (3), 778-785, 2005
and
- Richter, A. and J.P. Burrows,
Retrieval of Tropospheric NO2 from GOME
Measurements, Adv.
Space Res., 29(11)
,1673-1683, 2002
For data after the end of nominal GOME operations please have a look at our SCIAMACHY pages or go directly to the SCIAMACHY NO2 data page.
GOME total NO2 columns over stations Version 1:
Please also read the disclaimer.
The data format is plain ASCII with 27 header lines starting with a '*' character followed by the lines with the data organized in 9 columns separated by blanks:
column 1: fractional day of year 1993 UT
column 2: fractional day of year UT
column 3: solar zenith angle [°]
column 4: daily average slant column of NO2 [molec cm-2] in 200 km radius
column 5: daily average vertical column of NO2 [molec cm-2] in 200 km radius
column 6: daily minimum slant column of NO2 [molec cm-2] in 200 km radius
column 7: daily minimum vertical column of NO2 [molec cm-2] in 200 km radius
column 8: daily maximum slant column of NO2 [molec cm-2] in 200 km radius
column 9: daily maximum vertical column of NO2 [molec cm-2] in 200 km radius
Gridded GOME total NO2 columns Version 1:
Please also read the disclaimer.
The data format is plain ASCII with 24 header lines starting with a '*' character followed by 360 blocks of data for the 0.5° latitude bands starting with 90°S-89.5°S. Each latitude block consists of 720 0.5° longitude values starting with 180°W-179.5°E and starts with a comment line stating the centre latitude of the block, e.g. "* lat = -89.7500". All values are given in units of 10E14 molec cm-2 using 999.99 as an error flag for missing values.
These are encrypted zip-files, for the password please contact Andreas Richter.
- GOME gridded total NO2 1995
- GOME gridded total NO2 1996
- GOME gridded total NO2 1997
- GOME gridded total NO2 1998
- GOME gridded total NO2 1999
- GOME gridded total NO2 2000
- GOME gridded total NO2 2001
- GOME gridded total NO2 2002
- GOME gridded total NO2 2003
Disclaimer:
GOME NO2 columns provided on this page are a scientific product created at the University of Bremen and based on the operational lv1-spectra provided by DFD/DLR Oberpfaffenhofen and ESA. They are not related to the operational GOME lv2-products distributed by DFD/DLR that also contain NO2 columns. Although the two GOME NO2 data products agree qualitatively, the differences are significant, in particular with respect to seasonal changes.
The NO2 columns in the files provided on this page are total columns assuming a stratospheric profile. Wherever there is substantial NO2 in the troposphere (for example in polluted regions such as Italy or Germany), the columns will exceed the real stratospheric ones and are not very accurate.
To correct for drifts in the GOME instrumental function, all NO2 columns are normalized with respect to the equatorial Pacific where a constant vertical column of 2E15 molec/cm2 of NO2 is assumed. This has two effects: i) any seasonal or interannual variability in NO2 in this region will lead to errors in the NO2 columns at all latitudes and ii) GOME NO2 columns in the tropics are not really independent measurements but strongly influenced by this a priori assumption. However, comparison with results from the SLIMCAT model indicates that the uncertainty introduced by the normalisation is smaller than 5E14 molec/cm2 in all conditions and usually well below this value.
Contact Andreas
Richter.