Modelling ground thermal regime in bordering (dis)continuous permafrost environments

Area of Science:

• Geosciences
• Permafrost Science
• Antarctic Research

Background:

• Permafrost significantly influences geomorphological dynamics in maritime Antarctic ecosystems.
• Understanding the ground thermal regime is crucial for assessing permafrost stability and its relationship with glacial retreat.

Purpose of the Study:

• To analyze and model the ground thermal regime in transition zones between continuous and discontinuous permafrost.
• To investigate the relationship between permafrost thermal conditions and the timing of glacial retreat.
• To assess the impact of topography, snow cover, and deglaciation timing on ground temperatures.

Main Methods:

• Installation of a 10-site ground temperature monitoring transect on Byers Peninsula, Livingston Island.
• Recording of air temperatures and snow thickness using an automated weather station.
• Modeling of Temperatures on the Top of Permafrost (TTOP) and comparison with measured ground temperatures.

Main Results:

• Mean annual air temperatures were higher than the regional average during the study period (2017-2019).
• Mean annual ground temperatures at 10 cm depth ranged from 0.3 to -1.1°C, consistent with modeled TTOP values.
• Positive ground temperatures at the warmest site were linked to prolonged snow cover, suggesting a potential for permafrost degradation.

Conclusions:

• Snow cover is a primary driver of warmer ground temperatures and potential permafrost degradation in the study area.
• While topography and deglaciation timing influence inter-site variations, snow cover exerts a stronger control on the ground thermal regime.
• Findings highlight the sensitivity of Antarctic permafrost to climatic changes and snow dynamics.