Predicting Clear-Sky Reflectance Over Snow/Ice Regions
Abstract
Satellite remote sensing of clouds requires an accurate estimate of the clear-sky radiances for a given scene to detect clouds and aerosols and to retrieve their microphysical properties. Knowing the spatial and angular variability of clear-sky albedo is essential for predicting the clear-sky radiance at solar wavelengths. The Clouds and the Earth's Radiant Energy System (CERES) Project uses the near-infrared (NIR; 1.24, 1.6 or 2.13 μm), visible (VIS; 0.63 μm) and vegetation (VEG; 0.86 μm) channels available on Terra and Aqua Moderate Resolution Imaging Spectroradiometers (MODIS) to help identify clouds and retrieve their properties in both snow-free and snow-cover conditions. Due to the defect of Aqua 1.6 μm radiances, it is especially critical to accurately predict the 2.13 μm clear-sky albedo and reflectance for both Aqua and Terra. This paper presents the method of generating monthly clear-sky overhead albedo maps for 2.13 μm over both snow-free and snow-covered surfaces using one year of Aqua-MODIS (Moderate Resolution Imaging Spectroradiometer) data. The clear-sky albedos are derived using a radiative transfer parameterization of the impact of the atmosphere, including aerosols, on the observed reflectances. This paper examines the accuracy of this approach by comparing observed 2.13 μm reflectance with predicted value over clear-sky snow/ice regions.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.A31G2907C
- Keywords:
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- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0319 Cloud optics;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0321 Cloud/radiation interaction;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0360 Radiation: transmission and scattering;
- ATMOSPHERIC COMPOSITION AND STRUCTURE