1994: Modeling synthetic aperture radar (SAR) scattering from a seasonally varying snow-covered sea icc volume at 5.3 and 9.25 GHz. Polar Research 13. 35-54.A scrics of scnsitivity analyses using dielectric, mixture and microwave scattering models is presented. Data from thc Seasonal Sea Ice Monitoring and Modeling Site (SIMMS) in 1990 and 1991 are used to initialize the models. The objective of thc research is to investigate the role of various geophysical and clcctrical properties in spccifying the total relative scattering cross section (u") of snow covered first-year sea ice during thc spring period.Thc scasonal transition period from the Winter SAR scattering season to Early Melt was shown to signal a transition in dielectric properties which caused the snow volumc to become a factor in the microwavc scattering process. Thc effcct of the thermal insulation of a snow coveron sea ice was shown to be significant for both E' and E". Highcr atmospheric tcmperatures caused proportionally greater changes in the dielectric propcrtics of the sea ice at the base of thc snow cover. Model u" was computed for a range of scnsor. scnsor-earth geomctry. and geophysical propcrties. I n the Winter season the surface roughness terms (u,, and L) wcre shown to have a significant impact on u" when thc ice surface was the primary scattering mechanism. Once the snow cover began to warm and water was available in a liquid phase. the ice surface bccame masked because of the decrease in microwave penetration depths. During this period the water volumc variablc dominated u", both from its impact on d. and due to its control ovcr the dielectric mismatch created at thc air/snow interfacc.