Thermal regimes and phases of surface temperature in Livingston and Deception islands, Antarctica, 2007–2021: influence of snow cover and implications for frozen ground

Abstract The study of the ground surface temperature (GST) regimes from 2007 to 2021 at different stations on Livingston and Deception islands, South Shetland Islands, in the north-western sector of the Antarctic Peninsula (AP), shows that soils undergo similar cooling in early winter before a shallow snow mantle covers the sites. All monitoring sites along the study period go through seasonal phases of cooling, attenuation, insulation, fusion and zero curtain during winter, although thermal equilibrium is only reached at some stations located at lower elevations on Livingston Island. GST evolution at these stations and the duration of snow periods show oscillations, with turning points in the years 2014 and 2015, when temperatures were at their minimum and snow durations were at their maximum, in agreement with the cooling period occurring in the north-western AP in the early twenty-first century. The thermal regime is mainly controlled by snow cover and its onset and offset dates based only on descriptive patterns, not on statistical testing, more than by altitudinal, topographical, geological or geomorphological factors.