Erschienen in:
The Cryosphere, 14 (2020) 2, Seite 497-519
Sprache:
Englisch
DOI:
10.5194/tc-14-497-2020
ISSN:
1994-0424
Entstehung:
Anmerkungen:
Beschreibung:
Abstract. Permafrost is present within almost all of the Antarctic's ice-free areas,but little is known about spatial variations in permafrost temperaturesexcept for a few areas with established ground temperature measurements. Wemodelled a temperature at the top of the permafrost (TTOP) for all theice-free areas of the Antarctic mainland and Antarctic islands at 1 km2resolution during 2000–2017. The model was driven by remotely sensed landsurface temperatures and downscaled ERA-Interim climate reanalysis data, andsubgrid permafrost variability was simulated by variable snow cover. Theresults were validated against in situ-measured ground temperatures from 40permafrost boreholes, and the resulting root-mean-square error was1.9 ∘C. The lowest near-surface permafrost temperature of−36 ∘C was modelled at Mount Markham in the Queen Elizabeth Range inthe Transantarctic Mountains. This is the lowest permafrost temperature onEarth, according to global-scale modelling results. The temperatures weremost commonly modelled between −23 and −18 ∘C for mountainousareas rising above the Antarctic Ice Sheet and between −14 and −8 ∘C for coastal areas. The model performance was good where snowconditions were modelled realistically, but errors of up to 4 ∘Coccurred at sites with strong wind-driven redistribution of snow.