Azimuth variation in microwave backscatter over the Greenland Ice Sheet

Scatterometer backscatter measurements are becoming an important tool for monitoring the dynamic behavior of the Greenland Ice S heet. However, most Greenland studies assume constant backscatter for varying azimuth angles. Detailed analysis of scatterometer data sets show non-negligible (1-2 dB) azimuth modulation. The magnitude and orientation of the azimuth modulation observed by SeaWinds, NSCAT, and ERS are documented herein. The dominate factor is second order azimuth modulation, which is largest for C-band (ERS). For SeaWinds, the h-pol azimuth modulation is larger than for v-pol.