Assessment of AMSR-E Antarctic Winter Sea-Ice Concentrations Using Aqua MODIS

Abstract

An assessment of the standard Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) sea-ice concentrations for the Antarctic winter is made from a comparison of nearly 40 000 AMSR-E sea-ice concentration values with geolocated sea-ice concentrations derived from ten Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) scenes acquired on October 1st and 2nd of 2005 and 2006. The standard AMSR-E sea-ice concentration products are produced using the National Aeronautics and Space Administration Team 2 sea-ice algorithm. The ten MODIS scenes cover portions of almost all the sea-ice regions surrounding the Antarctic continent. The AMSR-E averaged ice concentration biases relative to MODIS (AMSR-E minus MODIS) ranged from less than -0.5% to - 18%, and the corresponding averaged root-mean-square (rms) errors ranged from 2% to 24%. One scene [October 1, 2006 (0550 UT)] had both the largest bias (-18%) and rms error (24%), whereas the other nine scenes had an average bias of - 1.5% and an average rms error of 4.9%. The biases and rms errors are correlated with the fractions of new ice and open water. This is consistent with the findings that the largest errors in ice concentration derived from the AMSR-E occur in the marginal ice zone (MIZ) and along the ice edge and are likely caused by sea-ice flooding in the MIZ and new-ice production at the ice edge.