AN EXAMINATION OF THE RELATION BETWEEN THE SPRING PERIOD EVOLUTION OF THE SCATTERING COEFFICIENT (SIGMA-DEGREES) AND RADIATIVE FLUXES OVER LANDFAST SEA-ICE

In this work we examine the seasonal co-evolution of: the microwave scattering coefficient (sigma degrees) as observed with ERS-1; the radiative components of the surface energy balance; and the physical and electrical properties of the snow/sea-ice system. We conduct three sets of hypothesis tests designed to illuminate specific aspects of this co-evolution. In Hypothesis Set 1 we contrasted components of the observed radiation balance between multiyear (MYI) and first-year (FYI) ice sites. We found that the surface skin temperature (T-S) and the longwave flux (L*) could be considered statistically indistinguishable between MYI and FYI for conditions experienced during the 1993 Seasonal Sea Ice Monitoring and Modelling Site (SIMMS'93) experiment. The shortwave flux (K*) and net all-wave flux (Q*) were however statistically distinguishable between the MYI and FYI sites. In Hypothesis Set 2 we investigated the nature of the seasonal evolution in sigma degrees for six different ice sites (three multiyear and three first-year types). We showed that multiyear ice forms have a particular pattern in their seasonal behaviour of sigma degrees which is distinct from the seasonal pattern of sigma degrees for first-year forms and that the time series of sigma degrees could be used in ice type discrimination. In Hypothesis Set 3 we conducted a multivariate analysis to explore the relationship between components of the radiation balance and the seasonal evolution of sigma degrees. We found that of all the radiation variables tested, K* explained a statistically significant portion of the observed seasonal variation in sigma degrees at the FYI site but not at the MYI site.