Presented by Annette Bartsch, Zentralanstalt für Meteorologie und Geodynamik, Austria, at the ESA-CliC Earth Observation and Arctic Science Priorities Meeting, Norway, 2015
Changes in ground thermal regime reflect changes in air temperature and precipitation. A major short coming for permafrost and related flux monitoring is the lack of circumpolar time series of with sufficient accuracy and thematic detail respectively. This includes land surface temperature, snow water equivalent, precipitation and surface material properties.
Subsurface conditions are measured in situ with boreholes (GTN-P).
Permafrost extent and state can be estimated with models, some use satellite derived land surface temperature and snow water equivalent/depth. Land surface type and terrain datasets provide boundary conditions. Soil properties need to be known in order to account for changes related to climate change. This includes carbon and ice/water content. Carbon exchange with the atmosphere is measured e.g. with flux towers and airplanes but sources need to be quantified.
This can be supported by remotely sensed data of sufficient spatial resolution and thematic detail. In addition transport of carbon to lakes, rivers and oceans needs to be estimated. Erosion rates can be quantified with high spatial resolution satellite data.
A challenge for calculation of circumpolar estimates and trends of surface parameters with global satellite products are subscale phenomena, especially related to the varying fraction of water-non water.
Future mission concepts for permafrost monitoring need to address snow and off snow applications. SAR X/Ku-band combinations are required for assessment of snow conditions and X/C/L combination for the snow-free period in order to monitor changes in land surface hydrology (lakes, wetlands) and terrain. Temporally consistent thermal and microwave acquisitions may reduce uncertainties in monitoring phase change during the transition periods.
Sentinel 1 data could be used to establish a circumpolar baseline of the magnitude of subsidence, rock glaciers movements, and thaw lakes (incl. winter freeze up) dynamics and thus enable quantification of permafrost changes and frozen-ground regimes feedbacks to climate and terrestrial ecosystems in the future as well as link to regional archive analyses for retrieval of past changes.
A summary of requirements for permafrost monitoring with respect to satellite data is available as white paper which has been prepared in response to the request by the WMO Polar Space Task Group.
http://www.climate-cryosphere.org/media-gallery/1352-2014-bartsch-permaforsteomonitoring
For more information on the meeting this was presented at, see http://www.climate-cryosphere.org/meetings/esa-arctic-2015