Examination of the Physical, Electrical, and Microwave, Evolution of Sea Water Into Young Ice

Abstract : Knowledge of the interrelationships between ice thickness, its temperature profile, the distribution of salinity, the dielectric property profile, and the roughness of the air-ice interface is important to the understanding of the backscatter response of new and young sea ice. Backscatter, physical, and electrical property measurements were made during the first 120 hours of growth for a saline ice sheet grown in a laboratory outdoor tank. The purpose of this work is to describe the evolution of open water to ice 15 cm thick. Ambient air temperatures were -15 deg C. During the critical growth period to 10 cm and then warmed to 10 deg C during the final 5 cm of growth. Radar backscatter data were obtained at 5.3, 9.6, 13.6, and 16.6 GHz to correlate with the changes in the microwave signatures with ice thickness, ice surface temperature, the salinity profile, the dielectric profile, and modifications which occur naturally to the air-ice interface of the ice sheet. Linear antenna transmit-receive polarizations were used and include vertical- vertical and horizontal-horizontal. Angle of incidence scans were made from vertical to 50 deg. The change in the backscatter response with changing ice thickness is documented and discussed in terms of the physical-chemical- electrical property changes.