EGU21-4946, updated on 04 Mar 2021
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Intercomparison of Cloud Products based on S5P/TROPOMI Level 1b Data Version 1 and the updated Version 2

Miriam Latsch1, Andreas Richter1, John P. Burrows1, Thomas Wagner2, Holger Sihler2, Michel van Roozendael3, Diego Loyola4, Pieter Valks4, Athina Argyrouli4, Ronny Lutz4, Pepijn Veefkind5, Henk Eskes5, Maarten Sneep5, Ping Wang5, and Richard Siddans6
Miriam Latsch et al.
  • 1Institute of Environmental Physics, University of Bremen, Bremen, Germany
  • 2Max-Planck-Institute for Chemistry, Mainz, Germany
  • 3Belgian Institute for Space Aeronomy, Brussels, Belgium
  • 4Remote Sensing Technology Institute, German Aerospace Center, Wessling, Germany
  • 5KNMI, Royal Netherlands Meteorological Institute, De Bilt, the Netherlands
  • 6Science and Technology Facilities Council, Rutherford Appleton Laboratory, Chilton, UK

The first European Sentinel satellite for monitoring the composition of the Earth’s atmosphere, the Sentinel 5 Precursor (S5p), carries the TROPOspheric Monitoring Instrument (TROPOMI) to map trace species of the global atmosphere at high spatial resolution. Retrievals of tropospheric trace gas columns from satellite measurements are strongly influenced by clouds. Thus, cloud retrieval algorithms were developed and implemented in the trace gas processing chain to consider this impact.

In this study, different cloud products available for NO2 retrievals based on the TROPOMI level 1b data version 1 and an updated TROPOMI level 1b test data set of version 2 (Diagnostic Data Set 2B, DDS2B) are analyzed. The data sets include a) the TROPOMI level 2 OCRA/ROCINN (Optical Cloud Recognition Algorithm/Retrieval of Cloud Information using Neural Networks) cloud products CRB (cloud as reflecting boundaries) and CAL (clouds as layers), b) the FRESCO (Fast Retrieval Scheme for Clouds from Oxygen absorption bands) cloud product,  c) the cloud fraction from the NO2 fitting window, d) the VIIRS (Visible Infrared Imaging Radiometer Suite) cloud product, and e) the MICRU (Mainz Iterative Cloud Retrieval Utilities) cloud fraction. The cloud products are compared with regard to cloud fraction, cloud height, cloud albedo/optical thickness, flagging and quality indicators in all 4 seasons. In particular, the differences of the cloud products under difficult situations such as snow or ice cover and sun glint are investigated.

We present results of a statistical analysis on a limited data set comparing cloud products from the current and the upcoming lv2 data versions and their approaches. The aim of this study is to better understand TROPOMI cloud products and their quantitative impacts on trace gas retrievals.

How to cite: Latsch, M., Richter, A., Burrows, J. P., Wagner, T., Sihler, H., van Roozendael, M., Loyola, D., Valks, P., Argyrouli, A., Lutz, R., Veefkind, P., Eskes, H., Sneep, M., Wang, P., and Siddans, R.: Intercomparison of Cloud Products based on S5P/TROPOMI Level 1b Data Version 1 and the updated Version 2, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-4946,, 2021.

Corresponding presentation materials formerly uploaded have been withdrawn.