Figure 1. PSR data for 37 GHz horizontal polarization taken during the only P-3 flight line completed during the 2003 campaign.

Antarctic AMSR-E Sea Ice (AASI) Experiment

Because there are no outer land boundaries that limit the growth and advance of sea ice in the region, the Antarctic sea ice cover is different from that in the Arctic. In winter, the ice cover expands from the outer boundary of Antarctica until atmospheric and oceanic forces limit its northward advance, while in the spring and summer, the ice retreats rapidly because of its vulnerability to atmospheric and oceanic heat and wave action. The sea ice cover is expansive in winter and the changes with season are dramatic. The microwave emissivity of the surface is thus very variable spatially. Such variations in emissivity in different seasons and under different weather conditions must be studied in detail because they affect the performance of the sea ice algorithms used in interpretation of the AMSR-E microwave radiometer data.

Since the advent of microwave remote sensing, there has been no airborne passive microwave sea ice flight program over the Antarctic. AASI experiment was aimed at providing the much needed aircraft remote sensing data set for the region. Aircraft microwave radiometer data are needed for validation of AMSR-E radiometer measurements because they provide intermediate resolution and spatial coverage that enables accurate interpretation of the satellite data.

NOAA's Environmental Technology Laboratory has developed the first wideband airborne polarimetric microwave imaging radiometer, the Polarimetric Scanning Radiometer (PSR) to provide comprehensive validation of all AMSR-E bands. The AASI campaign was to be conducted out of Punta Arenas from August 23 to September 6. The first research flight began on August 25, 2003 but it had to be aborted due to aircraft problems. A repeat of this experiment occured 14-24 October 2004. Figure 1 shows PSR data for 37 GHz horizontal polarization taken during the P-3 2003 flight line. Indeed, the expected high variability in the surface emissivity measurements is revealed.