Algorithm for retrieval of the effective snow grain size and pollution amount from satellite measurements

• Published in: Remote sensing of environment 2011-10, Vol.115 (10), p.2674-2685
• Main Authors: Zege, E.P., Katsev, I.L., Malinka, A.V., Prikhach, A.S., Heygster, G., Wiebe, H.
• Format: Article
• Language: English
• Subjects: Aerosols; Algorithms; Animal, plant and microbial ecology; Applied geophysics; Atmospheres; Biological and medical sciences; Earth sciences; Earth, ocean, space; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General aspects. Techniques; Internal geophysics; Polar regions; Pollution; Pollution abatement; Remote sensing; Retrieval; Satellite; Satellites; Snow; Teledetection and vegetation maps
• ISSN: 0034-4257; 1879-0704
• DOI: 10.1016/j.rse.2011.06.001

We present an algorithm for retrieval of the effective Snow Grain Size and Pollution amount (SGSP) from satellite measurements. As well as our previous version (Zege et al., 2008, 1998), the new algorithm is based on the analytical solution for snow reflectance within the asymptotic radiative transfer theory. The SGSP algorithm does not use any assumptions on snow grain shape and allows for the snow pack bidirectional reflectance distribution function (BRDF). The algorithm includes a new atmospheric correction procedure that allows for snow BRDF. This SGSP algorithm has been thoroughly validated with computer simulations. Its sensitivity to the atmosphere model has been investigated. It is shown that the inaccuracy of the snow characteristic retrieval due to the uncertainty in the aerosol and molecular atmosphere model is negligible, as compared to that due to the measurement errors at least for aerosol loads typical for polar regions. The significant advantage of the SGSP over conventional algorithms, which use a priori assumptions about particle shape and (or) not allow for the BRDF of the individual snow pack, is that the developed retrieval still works at low sun elevations, which are typical for polar regions. ► Retrieval of the Snow Grain Size and Pollution (SGSP) from satellite measurements. ► No assumptions on snow grain shape. ► Allows for the snow pack bidirectional reflectance distribution function. ► New atmospheric correction procedure. ► Works at low sun elevations, typical for polar regions.