The tropospheric aerosol has been recognized as an important, although highly uncertain atmospheric constituent affecting the global climate. Therefore, several satellite missions and a number of ground-based instrumentation systems with different measurements capabilities have been established to observe various properties of atmospheric aerosol. At the same time, most aerosol investigators advocate that retrievals using data combined from multiple instruments would improve aerosol characterization accuracy compared to the products of separate processing. However, a potential of such multi-sensor retrieval remains untapped.
We propose to develop, validate and apply a new algorithm implementing enhanced retrieval of vertical distribution of aerosol properties from joint inversion of AERONET data with time and space co-located observations by CALIPSO and other A-Train aerosol instruments.
The project is a continuation of previous efforts by Dubovik et al. (2003) shown that simultaneous inversion of AERONET data with directional and spectral observation of MISR and MODIS instruments allows significant improvements in retrieval of aerosol and surface reflectance properties. However, neither ground-based nor satellite passive radiometric observations have appropriate sensitivity to vertical variability of aerosol. Such, information can be obtained only from lidar observations such as those by CALIPSO. On the other hand, due to lack of angular scattering information and limitations in spectral coverage, lidars in general are less sensitive to the details of aerosol than passive remote sensing observations. Therefore combining passive and active remote sensing methods is clearly beneficial for aerosol characterization.
We expect that combined processing of AERONET/CALIPSO (and possibly PARASOL and MODIS) data will result in:
- Deriving information about not only vertical distribution of total aerosol but also about vertical variability of particle sizes and possibly absorption
- Improving retrieval of both surface and aerosol properties from joint inversion of AERONET and passive satellite observations (here PARSOL and MODIS) by including CALISPSO into joint retrieval
- Enhancing accuracy retrievals of detailed aerosol properties including absorption, particle sizes, phase function, etc. for all AERONET locations
- Development of an enhanced parameterization for aerosol properties (e.g.lidar and depolarization ratios for non-spherical and inhomogeneous aerosol), which can be used to improve the CALIPSO global retrievals
