Dale Winebrenner’s interests are in the physics of light and radio waves, and in the exploration of icy environments on Earth and elsewhere based on that physics. His past work includes contributions to the theory of wave scattering from rough surfaces and synthetic aperture radar imaging of the ocean surface. Since joining the Polar Science Center of the Applied Physics Laboratory-UW he has worked on the physics of remote sensing of sea ice and the great ice sheets on Greenland and Antarctica.
For sea ice, Dr. Winebrenner has developed a physically based method to observe the springtime melting and fall freeze-up transitions on Arctic sea ice using synthetic aperture radar, and has shown that polarimetric microwave backscattering from thin sea ice depends on ice thickness and thus may be useful for remote thickness estimation. Most recently he has begun work on the in situ observation of optical fluorescence from chlorophyll in sea ice, with the aim of estimating phototrophic biomass near the ice-water interface.
On the ice sheets, he has investigated the physics of microwave emission and used that physics to map (decadal-scale) mean surface temperature and accumulation rate fields, for both Greenland and Antarctica. Most recently, he has begun to investigate meter-wavelength radar sounding of ice sheets. The first result of this work is a new means of estimating electromagnetic absorption within the ice sheet. Because absorption is tied strongly to temperature, and in particular to near-basal temperature which is also tied to ice mechanical properties, sounding can be used to probe for properties directly related to ice sheet flow.
All of this work is, or has been, greatly enhanced by working with students at levels from undergraduate to postdoctoral. Dr. Winebrenner’s research faculty appointments in the departments of Electrical Engineering and Earth and Space Sciences provide the opportunity to supervise and mentor student research in a variety of contexts.