Permafrost Dynamics and Degradation in Polar Arctic From Satellite Radar Observations, Yamal Peninsula (original) (raw)

Remote Sensing of Landscape Change in Permafrost Regions

Amplification of global warming in Arctic and boreal regions is causing significant changes to permafrost-affected landscapes. The nature and extent of the change is complicated by ecological responses that take place across strong gradients in environmental conditions and disturbance regimes. Emerging remote sensing techniques based on a growing array of satellite and airborne platforms that cover a wide range of spatial and temporal scales increasingly allow robust detection of changes in permafrost landscapes. In this review, we summarise recent developments (2010 À 15) in remote sensing applications to detect and monitor landscape changes involving surface temperatures, snow cover, topography, surface water, vegetation cover and structure, and disturbances from fire and human activities. We then focus on indicators of degrading permafrost, including thermokarst lakes and drained lake basins, thermokarst bogs and fens, thaw slumps and active-layer detachment slides, thermal erosion gullies, thermokarst pits and troughs, and coastal erosion and flooding. Our review highlights the expanding sensor capabilities, new image processing and mul-tivariate analysis techniques, enhanced public access to data and increasingly long image archives that are facilitating novel insights into the multi-decadal dynamics of permafrost landscapes. Remote sensing methods that appear especially promising for change detection include: repeat light detection and ranging, interferometric synthetic aperture radar and airborne geophysics for detecting topographic and subsurface changes; temporally dense analyses at high spatial resolution; and multi-sensor data fusion. Remotely sensed data are also becoming used more frequently as driving parameters in permafrost model and mapping schemes.

Arctic permafrost landscapes in transition: towards an integrated Earth system approach

Arctic Science, 2017

Permafrost science and engineering are of vital importance for northern development and climate adaptation given that buildings, roads, and other infrastructure in many parts of the Arctic depend on permafrost stability. Permafrost also has wide-ranging effects on other features of the Arctic environment including geomorphology, biogeochemical fluxes, tundra plant and animal ecology, and the functioning of lake, river, and coastal marine ecosystems. This review presents an Earth system perspective on permafrost landscapes as an approach towards integration across disciplines. The permafrost system can be described by a three-layer conceptual model, with an upper buffer layer that contains vegetation or infrastructure. Snow and liquid water strongly affect the thermal properties and stability of these layers and their associated interfaces, resulting in critical times and places for accelerated degradation of permafrost and for exchanges of mass and heat with the hydrosphere and atmo...