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

In this work we examine the seasonal co-evolution of: the microwave sc attering coefficient (sigma degrees) as observed with ERS-1; the radia tive components of the surface energy balance; and the physical and el ectrical 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 observ ed radiation balance between multiyear (MYI) and first-year (FYI) ice sites. We found that the surface skin temperature (T-S) and the longwa ve flux (L) could be considered statistically indistinguishable betwe en MYI and FYI for conditions experienced during the 1993 Seasonal Sea Ice Monitoring and Modelling Site (SIMMS'93) experiment. The shortwav e flux (K) and net all-wave flux (Q*) were however statistically dist inguishable between the MYI and FYI sites. In Hypothesis Set 2 we inve stigated 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 sea sonal behaviour of sigma degrees which is distinct from the seasonal p attern of sigma degrees for first-year forms and that the time series of sigma degrees could be used in ice type discrimination. In Hypothes is Set 3 we conducted a multivariate analysis to explore the relations hip between components of the radiation balance and the seasonal evolu tion of sigma degrees. We found that of all the radiation variables te sted, K explained a statistically significant portion of the observed seasonal variation in sigma degrees at the FYI site but not at the MY I site.