The Cryospheric Science Group of the Interdisciplinary Centre on Climate Change (IC3) is pleased to welcome PhD student Sonya Antonova, a visiting scholar from Alfred Wegener Institute in Potsdam, Germany, to present her research at our seminar this month.
Her presentation is entitled:
ABSTRACT
Thermokarst lakes are major elements of permafrost landscapes and known to be an important source of carbon dioxide and methane emissions. Deeper lakes remain unfrozen beneath the ice cover that forms seasonally during winter and the sediments therefore maintain their biological activity, contributing to the heat and gas fluxes. In shallower lakes the water column and sediment layers freeze completely and biological activity comes to a halt. It is therefore critical to distinguish lakes that freeze to the bottom in winter from those that remain unfrozen beneath the ice cover. The difference in radar backscatter signatures between the grounded and floating lake ice allows to map them and estimate the time of grounding. Three years time series of TerraSAR-X backscatter with high spatial (up to 3 m) and temporal (11 days) resolution was used to study lake ice regime in the Siberian Lena River Delta. Additionally we used 11-days sequential interferometric coherence time series to support the backscatter observations. The remote sensing data is evaluated by ground-based data and model simulations.