:: ESA DUE Permafrost ::

Products

Permafrost is a subsurface phenomenon and cannot be directly observed with satellite data. Yet, monitoring can be done based on indicators and via permafrost models. Indicators are especially thermokarst lake dynamics and surface elevation changes. Those phenomena need to be observed on a local scale. Regional to circumpolar monitoring requires the use of permafrost models. Relevant satellite-observable parameters are land surface temperature (LST), snow extent, snow water equivalent (SWE), vegetation, and soil moisture. Existing services will be integrated into the processing system and adapted to the needs of permafrost modelling. All satellite datasets will be made available via a WebGIS which will tie into the permafrost information system of the International Permafrost Association (IPA).

Land surface temperature

Land surface temperature is available from passive sensors such as MODIS, AATSR, and AMSR-E. It can be used as a forcing parameter for all permafrost models.

Snow

The amount of snow determines insulation properties. An operational monitoring service for snow extent and SWE is currently being set up within the ESA DUE project GlobSnow.

Vegetation

Vegetation layer also insulates the ground. A number of global and regional land cover maps are available (e.g. from GlobCover). They need to be merged and assessed for the purpose of modelling of permafrost and fluxes. Arctic specific datasets like the Circum Polar Arctic Vegetation Map product with 15 physiognomic vegetation types are used as reference for vegetation between the Arctic coastline and the northern tree limit.

Soil moisture Polar view of soil moisture anomalies from METOP ASCAT data of July 2007. 1-day composite (July 30th)

Thermal conductivity is influenced by soil moisture. A near real-time (NRT) product based on METOP ASCAT is available from EUMETSAT. This service will be improved under the viewpoint of frozen ground conditions.

Observation strategy

The circumpolar datasets will be acquired weekly to monthly with a spatial resolution of 25 km x 25 km. Selected areas will also be monitored at 1 km x 1 km for snow extent (SE), LST, soil moisture, and vegetation.