AEROSAT International Satellite Aerosol Science Network
To coordinate complementary activities for intercomparing satellite aerosol datasets:
Extensive validation has been done for most current satellite aerosol datasets, but for every new dataset collection (i.e. global and covering several years of data), a comprehensive validation (to ground reference measurements) and intercomparison (to other satellite and model datasets) needs to be conducted to understand its strengths and limitations. A new dataset means either an incrementally new version of an existing dataset (upgraded algorithm, new algorithm) or a dataset from an entirely new instrument. Organizing this validation and intercomparison is the foremost responsibility of the respective data provider, whereas conducting the validation can and probably should be performed by both the instrument team and independent validation experts or user teams.
When it comes to broader intercomparisons of several datasets, AERO-SAT can contribute by
Within ESA’s Aerosol_cci project the use of the AEROCOM model evaluation tools and the “Kinne scoring” (evaluating spatial and temporal correlations) for daily gridded satellite datasets was chosen for model-user-oriented dataset validation in addition to direct level-2 validation – in all cases AERONET was used as reference source. Limitations in coverage for spectral AOD of AERONET may be overcome by adding a quasi-reference using a “best” satellite dataset over ocean or in remote regions can be agreed upon. Limitations of AERONET particle type retrievals might be mitigated by field campaign data coincident with satellite observations, and by comparison with instruments that provide some constraints on particle type, such as POLDER and MISR.
The link to the GCOS requirements for accuracy is not always easy and it could be analysed in how far validation could be optimized to provide exactly the same quantities as used in the GCOS satellite supplement (e.g. combined absolute +
relative accuracy threshold).
Activities & Schedule
WG duration: Three years. At the end of year 1 the WG shall review its gap analysis and will recommend concrete activities for years 2 and 3.
Year #2 + #3 (depending on results of year #1)