GEOG Researcher awarded grant from NASA for a project entitled “Improving NASA's atmospheric correction using historic aerosol/ocean color data”

Jean-Claude Roger (UMD PI) was awarded from NASA for a project entitled “Improving NASA's atmospheric correction using historic aerosol/ocean color data”. The project will be led by Nima Pahlevan from NASA Goddard Space Flight Center.

Coastal and inland waters are at the proximity of human settlements and under pressure due to direct influence by human activities and climate change. Optical remote sensing has proven to enable quantifying the health status of these critical environments by measuring spectral water-leaving radiances. The remote sensing reflectance (Rrs) is the key parameter for the retrieval of bio-optical and biogeochemical properties in the upper water column. It is well-recognized that the retrieval of bio-geochemical properties (e.g., concentrations of chlorophyll-a) is very sensitive to small errors in Rrs.

The NASA’s heritage Gordon & Wang atmospheric correction (AC) has been shown to generate climate-quality global Rrs over open oceans. However, the sensitivity to small errors is higher across all the spectral bands over coastal/inland waters due to higher spatial and temporal variability of aerosols.

However, the coastal/inland aerosol models are not well-represented in the Look-Up-Tables because they are derived over only two AERONET stations on the east coast of the United States. This lack of representativeness associated with the existing coastal/inland models can result in high uncertainties in AC and the resulting Rrs products.

The project proposes to improve the quality of Rrs products in coastal/inland waters for the existing and future optical imagery by constraining the retrievals using historic and climatological data.