Characterization of Desert Dust from Ground-Based and Satellite Remote Sensing Observations

Abstract:

The coarse mode aerosols observed in the nature are mostly related to dust and especially mineral desert dust. The mineral dust has very significant influence on environment and climate. Therefore, it has always been one of the main subjects of global and regional remote sensing monitoring. This presentation will outline the challenges and possible prospective of characterizing the desert dust using remote sensing observation. The optical properties of desert dust have several particular features that distinguish it from other type of aerosols and needed to be accounted in remote sensing methods. Specifically the particles of desert dust are rather large, non-spherical, notably absorbing in UV and nearly non-absorbing in near IR, etc. Correspondingly, the sensitivities of the various remote sensing observations are quite different. For example, it is very difficult adequately characterize desert dust from space over very bright land surfaces. Another challenge is characterization of desert dust size distribution shape especially for very large particles. From the viewpoint of the modeling of optical properties, the main problem is the development of adequate model for accounting for particle non-sphericity. The purpose of this presentation is to discuss how these complications are addressed in existing methods of remote sensing observations including both passive (spectral, multi-angular and polarimetric) and active observations. Some rather new methods utilizing different types of observations will be also discussed.