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Tropospheric NO2 data from SCIAMACHY

SCIAMACHY tropospheric NO2 V0.5   V0.7/V0.8   V3.0 

As part of our ACCENT activities, a preliminary time series of SCIAMACHY tropospheric NO2 columns has been created which can be downloaded as gridded monthly averages. This will be replaced by a new version as soon as more and better calibrated data becomes available.

These files are encrypted, for the password please contact Andreas Richter.

SCIAMACHY tropospheric excess NO2 columns Version 0.5:

For a description of the method used to derive the NO2 columns, please see:

Richter, A. and J.P. Burrows, Retrieval of Tropospheric NO2 from GOME Measurements, Adv. Space Res., 29(11) ,1673-1683, 2002    

This is the simplest data analysis, which is using a standard airmass factor independent of location and season. This data set is mainly useful for applications have to avoid interference with a priori assumptions. If you are interested in the best estimate of the tropospheric NO2 column, please use V0.7 of our data product!

SCIAMACHY tropospheric excess NO2 columns Version 0.7/0.8: 

This data set differs from Version 0.5 in the use of airmass factors that are based on vertical NO2 profiles predicted by the MOZART model. The airmass factors are based on data from 1997 and are averaged over months. While these airmass factors are identical to those used for the GOME tropospheric NO2 columns V2, the SCIAMACHY tropospheric NO2 columns V0.7/V0.8 still have

  1. a simple reference sector based correction for the stratospheric column
  2. a simple intensity based cloud filter that will be replaced by a more accurate cloud product when available

Details on the retrieval algorithm a first application can be found in

  • Richter, A., Burrows, J. P., Nüß, H., Granier, C, Niemeier, U., Increase in tropospheric nitrogen dioxide over China observed from space, Nature, 437, 129-132, doi: 10.1038/nature04092, 2005

  • A short algorithm description for the University of Bremen tropospheric NO2 product is available here.

  • The product description file including a description of the file formats can be downloaded here.

As there are still large gaps in the raw data provided by ESA, these files are preliminary only and will be replaced as soon as more data with better calibration becomes available. For 2002 and 2003 this has already been done and the results are available as V0.8 data below.

Gridded monthly data

Individual swath files

The same data but as individual ASCII swath files giving the location and value for each measurement pixel is available on request from Andreas Richter.

SCIAMACHY tropospheric NO2 columns Version 3.0: 

This data set differs from earlier Versions in several important aspects:

  1. stratospheric NO2 correction was done using the SCIAMACHY limb profile observations (Hilboll et al., 2013)
  2. a tropospheric background has been added using output from the OSLO-CTM (see Hilboll et al., 2013) making the reuslts tropospheric columns as opposed to excess tropospheric columns
  3. cloud screeening is based on the updated FRESCO+ cloud retrieval (Wang et al., 2008, doi:10.5194/acp-8-6565-2008)
  4. additional screening using an intensity threshold has been performed to remove snow contaminated pixels
  5. air mass factors have been interpolated in space to remove artefacts from the coarse resolution of teh MOZART climatology used as a priori

Details on the retrieval can be found in

Gridded monthly data

Individual swath files

The same data but as individual ASCII swath files giving the location and value for each measurement pixel is available on request from Andreas Hilboll.

 

If you have any questions or requests, please contact Andreas Richter.

web master:  folkard@iup.physik.uni-bremen.de      Last Update: 25-05-18      Data Privacy