Estimation of Thin Ice Thickness From the Advanced Microwave Scanning Radiometer-EOS for Coastal Polynyas in the Chukchi and Beaufort Seas

In this paper, a thin ice thickness algorithm for coastal polynyas in the Chukchi and Beaufort Seas has been attempted which uses the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) 89-GHz brightness temperature data at a 6.25-km resolution. Thermal ice thickness estimated from the Moderate Resolution Imaging Spectroradiometer (MODIS) ice surface temperature data for a set of control points is used in conjunction with the AMSR-E brightness temperature data to develop a regression relationship between the thermal ice thickness and the passive microwave polarization ratio. The MODIS thermal ice thickness has been determined from the calculation of conductive heat flux through the ice-air interface. The relationship is then applied across the polynyas to derive thin ice thickness information at different points. In the development of the algorithm, the MODIS-derived thermal thickness is assumed to be the standard reference. Validation of the algorithm has been carried out using an independent MODIS-derived thermal ice thickness data set. It is observed that the model error is 1.3 cm within the thickness range of 1-10 cm. This method is expected to be useful in high latitudes where in situ observations are sparse.