AEROSAT International Satellite Aerosol Science Network

Working Group on Aerosol Typing


Review methods to retrieve information on aerosol type from satellite and ground-based remote sensing 


  • Gelsomina Pappalardo, CNR-IMAA (EARLINET/GALION)
  • Ralph Kahn, NASA (MISR)
  • Thomas Popp, DLR
  • Pieternel Levelt, KNMI

Aerosol type is key information for aerosol measurements by satellite borne instruments in two respects. Depending on the
specific measurement technique, aerosol type is an input needed for the satellite retrieval and is output information from

the algorithm.

Typically, aerosol retrievals from satellite measurements make a priori assumptions about aerosol type, usually based on external information. Due to the different information content of different types of instruments, the aerosol type assumptions in the algorithms need to be different. The accuracy of the derived aerosol products strongly depends on the reliability of these assumptions. Different algorithms typically adopt different assumptions. A critical review of these assumptions is warranted, and harmonization of these procedures, though a challenging undertaking, could significantly reduce related uncertainties for making comparisons among the products, and possibly for the products themselves. 

On the other hand, satellite measurements in the past years have provided valuable information about the global distribution of aerosol types, identifying, for example, the main source regions and typical transport paths. Climatological studies of aerosol loading at both regional and global scales typically rely on inferred aerosol type. The inhomogeneity among satellite aerosol typing schemes increases the difficulty in using multiple sensor dataset in a consistent way. Knowledge of the 4-D distribution of the aerosol types at these scales is essential for understanding the impact of the different aerosol sources on climate, precipitation, and air quality. This information is also needed to help plan the next-generation aerosol emissions
policies at continental and global scales. The exchange of expertise and the communication among satellite (and ground-based) measurement communities about this topic is fundamental for improving long-term datasets consistency, and for reducing the uncertainties on aerosol types distribution.

First year Activities/Schedule:

  • Review of the existing aerosol typing schemes as adopted for aerosol satellite measurements. 
  • Review of the aerosol typing from ground-based remote sensing measurements.