EVOLUTION OF ELECTROMAGNETIC SIGNATURES OF SEA-ICE FROM INITIAL FORMATION TO THE ESTABLISHMENT OF THICK FIRST-YEAR ICE

The spatial and temporal distribution of new and young sea ice types a re of particular interest because of the influence this can exert on t he heat and mass balance of the polar sea ice. The objective of the pr esent work is to characterize the temporal evolution of the electromag netic (EM) signatures of sea ice from initial formation through the de velopment of first-year (FY) ice on the basis of the temporal variatio ns in the physical properties of the ice. The time series of young sea ice signatures, including microwave emissivity, radar backscatter, an d visible and infrared spectral albedo, has been measured at successiv e stages in the growth and development of sea ice, both under laborato ry and field conditions. These observations have been accompanied by s tudies of the physical properties that influence the interaction betwe en radiation and the ice. This has resulted in a consistent data set o f concurrent multispectral observations that covers essentially all ph ases of the development of the different types of sea ice from initial formation to thick FY ice. Mutually consistent theoretical models cov ering the entire wavelength range of the observations are applied to s elected cases and successfully match the observations. Principal compo nent analysis (PCA) of the data set suggests combinations of the set o f frequencies to effectively distinguish among different stages in the temporal evolution of the sea ice.