Comparison of aircraft and DMSP SSM/I passive microwave measurements over the Bering Sea in April 1995

During April 1995 a NASA ER-2 high-altitude aircraft carrying a Millimeter-Wave Imaging Radiometer (MIR) made two flights over the Bering Sea as part of a mission to study sea ice and snow for improving retrievals of these parameters from passive microwave radiometers. MIR measures radiances at 89 GHz, 150 GHz, three frequencies near 183 GHz, and at 220 GHz. Sea ice features are observable at all frequencies except at 183 GHz, because of strong atmospheric water vapor absorption. The radiometric brightness over ice-free ocean increases with frequency as expected, but the situation is more complex over sea ice.