Realizing the full potential of Remotely Sensed Active Layer Thickness (ReSALT) Products

Kevin M Schaefer, National Snow and Ice Data Center, kevin.schaefer@nsidc.org (Presenter)
Albert Chen, Stanford, acchen@stanford.edu
Lin Liu, Chinese University of Hong Kong, liulin@cuhk.edu.hk
Andrew Parsekian, University of Wyoming, aparseki@uwyo.edu
Elchin Jafarov, National Snow and Ice Data Center, elchin@nsidc.org
Santosh Panda, University of Alaska Fairbanks, skpanda@alaska.edu
Howard Zebker, Stanford, zebker@stanford.edu

The Remotely Sensed Active Layer Thickness (ReSALT) product uses the Interferometric Synthetic Aperture Radar (InSAR) technique to measure ground subsidence, Active layer thickness (ALT), and thermokarst activity in permafrost regions. ReSALT supports field operations and other activities for the Arctic-Boreal Vulnerability Experiment (ABoVE) field campaign in Alaska and northwest Canada and is a precursor for a potential NISAR product. Active layer thickness (ALT) is a critical parameter for monitoring the status of permafrost and thermokarst activity is one of the key drivers of change in permafrost regions. The ReSALT product currently includes 1) long-term subsidence trends resulting from the melting and subsequent drainage of excess ground ice in permafrost, 2) seasonal subsidence resulting from the expansion of soil water into ice as the active layer freezes and thaws, and 3) ALT estimated from the seasonal subsidence assuming a vertical profile of water within the soil column. ReSALT includes uncertainties for all parameters and is validated against in situ measurements from the Circumpolar Active Layer Monitoring (CALM) network and Ground Penetrating Radar. We present high resolution ReSALT products on the North Slope of Alaska: Prudhoe Bay, Barrow, Toolik Lake, Happy Valley, and the Anaktuvik fire zone. We propose to expand the ReSALT product to include maps of individual thermokarst features identified as spatial anomalies in the subsidence trends, with quantified expansion rates. We illustrate the technique with multiple examples of thermokarst features on the North Slope of Alaska. Knowing the locations and expansion rates for individual features allows us to evaluate risks to human infrastructure. Our results highlight the untapped potential of the InSAR technique to remotely sense ALT and thermokarst dynamics over large areas of the Arctic.

Presentation Type:  Poster

Session:  General Contributions   (Tue 4:35 PM)

Associated Project(s): 

• Schaefer, Kevin: Remotely-Sensed Active Layer Thickness (ReSALT) Product Derived from InSAR Data Over North American Arctic Regions ...details

Poster Location ID: 221