Microwave radiometry and snow water equivalence retrievals on snow covered sea ice in the marine cryosphere
Drobot, Sheldon D.
Snow water equivalence (SWE) derivation over sea ice requires a better understanding of how variations in the evolving snow-sea ice mixture affect microwave emission. In this thesis, the effects of (a) variation in liquid water content within a seasonally dynamic snowpack and (b) heterogeneity in underlying ice are examined. Geophysical snow data and in situ passive microwave signatures were collected in the Canadian Arctic Archipelago during the spring of 1996 under the Collaborative-Interdisciplinary Cryospheric Experiment (C-ICE). Surface based radiometer measurements were collected at 19, 37 and 85GHz (both vertical and horizontal polarizations). Snow data and Special Sensor Microwave/Imager (SSM/I) data were collected from 1993-1995 during the Seasonal Sea Ice Monitoring and Modelling (SIMMS) program. Results indicate SWE can be derived with an in situ microwave radiometer when the snowpack is dry. Multiple regression techniques are shown to better estimate in situ SWE over the case site. With increased water in liquid phase, emission from the snowpack causes current algorithms to overestimate SWE. Variation in ice type and spatial pattern of the ice limit the applicability of SWE derivation with SSM/I. The presence of multiyear ice (MYI) lowers emissivity values that leads to an underestimation of SWE with current algorithms.