Enhanced Degradation of Permafrost Under Increasing Inundation in The Kuparuk Delta, Alaska
Abstract
Permafrost in the Alaskan Arctic may be degrading in response to continuous amplified warming. Advanced degradation of ice-rich permafrost could significantly alter the water balance by increasing runoff and standing water. How do the hydrological changes, in turn, affect the permafrost conditions?
Here, we present an investigation into the effect of river dynamics on the permafrost thermal state in Kuparuk delta, Alaska. Flood water occurrence was retrieved based on the river discharge and the ArcticDEM with a spatial resolution of 2 m. Driven by ground and river water temperature, permafrost temperatures and active layer thickness (ALT) along a cross-section in the Kuparuk floodplain were simulated with the Control Volume Permafrost Model (CVPM). The results indicate that permafrost warms during flood conditions, and ALT can increase for about 40 cm with sustained inundation in the floodplain. Water bodies in the Kuparuk delta extended since the 1980s according to the satellite observations, which may contribute to the degradation of local permafrost conditions. More generally, Alaskan permafrost is vulnerable to future changes in timing and magnitude of freshwater flooding as a result of earlier spring snowmelt, ice-wedge degradation, glacier recession and thinning. Degradation of permafrost in floodplains could potentially lead to the release of old carbon.- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.C43C1809Z
- Keywords:
-
- 0702 Permafrost;
- CRYOSPHEREDE: 0736 Snow;
- CRYOSPHEREDE: 0738 Ice;
- CRYOSPHEREDE: 1847 Modeling;
- HYDROLOGY