MULTISCOSS: MULTI-Frequency SCatterometer Observations of Sea ice and Snow

• Applicants: Professor Dr. Dirk Notz; Professor Dr. Detlef Stammer
• Subject Area: Oceanography
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 552130904

In this project, we will use a novel active multi-frequency, multi-polarisation Scatterometer flown on a helicopter to improve scientific capabilities for the remote sensing of sea ice and snow. Such measurements are important to obtain a better understanding of the evolution of sea ice and snow in the polar regions on the process level, to improve related numerical models, and to assess the potential of future satellite missions that potentially will carry multi-frequency Scatterometers. Active scatterometers flown on satellites are an important instrument for monitoring sea ice. They emit pulses of electromagnetic radiation and measure the amplitude of the back-scattered energy reaching the antenna. Scatterometers have long been used to distinguish between old, multi-year sea ice with its high roughness and its low liquid brine content from young, first-year sea ice with its low roughness and high liquid brine content. However, the full potential of Scatterometers to monitor sea-ice and snow properties has not been exploited yet, as existing instruments have primarily been based on a single frequency. Recently, Scatterometers measuring at two or three dfferent ifrequencies have been used in combination and have given a glimpse of the potential for multi-frequency measurements. The aim of this study is to explore the full potential of scatterometry for sea ice remote sensing by using the novel “Multi3Scat” scatterometer of the Universität Hamburg to measure fully polarimetric sea ice backscatter properties (i.e., at all four polarizations) across five radar frequencies from L band to Ku band at different incident angles together with simultaneous IR and VIS measurements and use these measurements to study and better understand sea ice properties. We aim to derive more detailed insights into sea-ice and snow (where available – pending Polarstern cruise plans) characteristics from these scatterometer measurements than ever before by combining measurements at lower frequencies with their larger footprint and rather deep penetration into the sea-ice cover, and measurements at higher frequencies with their higher resolved footprint that provides primarily information about the surface layer. The measurements and the new insights together with ground truth data will be used to develop new sea ice remote sensing algorithms that have the potential to substantially improve our capabilities to observe the rapidly changing sea ice and snow cover of the polar regions.

• DFG Programme: Research Grants