The land surface temperature (LST) is related to all components of the energy balance and is therefore a crucial parameter for the energy budget of permafrost environments. The sensitivity of permafrost towards degradation and the potential activation of a massive carbon source is directly associated with the energy exchange processes occurring at the soil-atmosphere interface.

Especially wet tundra landscapes, where large quantities of carbon are stored in frozen organic soils, may become a massive source of green house gases under a warmer climate. The satellite observations indicate strong warming trends of LST during summer over the entire Arctic, which is essential for the summer thaw depth of permafrost soils.

Hence, the monitoring of LST in permafrost environments monitoring of LST can be an important tool to assess the effects of climate change in the usually remote and inaccessible permafrost envirmoments. The spatial resolution of satellite LST products typically ranges from 60 meters (Landsat) to one kilometer (MODIS).

Temperature differences on smaller scales are therefore not resolved, but are nevertheless critical when they occur systematically over long time periods. In such cases, they result from sustained differences in the surface energy balance and might indicate differences in the thermal state of the subjacent permafrost, potentially triggering processes such as initial thermo karst erosion.

In particular, sub-resolution LST variations are expected to occur in highly fractionated landscapes. This is especially true for permafrost environments, such as the wet polygonal tundra, where a sharp contrast between wet and dry surface patches occurs on scales of several meters. Hence, it is desirable to elucidate the sub-resolution surface temperature variability and its impact on the accuracy of satellite permafrost monitoring schemes.

With a thermal imaging system mounted on a 10m tower we measured surface temperature variability on a small scale at our sites on Svalbard and in Siberia during the snow free period.