Pan-Antarctic map of near-surface permafrost temperatures at 1 km2 scale
| Authors | |
|---|---|
| Year of publication | 2020 |
| Type | Article in Periodical |
| Magazine / Source | The Cryosphere |
| MU Faculty or unit | |
| Citation | |
| Web | https://www.the-cryosphere.net/14/497/2020/ |
| Doi | http://dx.doi.org/10.5194/tc-14-497-2020 |
| Keywords | JAMES-ROSS-ISLAND; PENINSULA LIVINGSTON ISLAND; CALM-S SITE; MCMURDO DRY VALLEYS; ACTIVE-LAYER; THERMAL REGIME; BYERS PENINSULA; SNOW COVER; TEMPORAL VARIABILITY; MARITIME ANTARCTICA |
| Description | Permafrost is present within almost all of the Antarctic's ice-free areas, but little is known about spatial variations in permafrost temperatures except for a few areas with established ground temperature measurements. We modelled a temperature at the top of the permafrost (TTOP) for all the ice-free areas of the Antarctic mainland and Antarctic islands at 1 km(2) resolution during 2000-2017. The model was driven by remotely sensed land surface temperatures and downscaled ERA-Interim climate reanalysis data, and subgrid permafrost variability was simulated by variable snow cover. The results were validated against in situ-measured ground temperatures from 40 permafrost boreholes, and the resulting root-mean-square error was 1.9 degrees C. The lowest near-surface permafrost temperature of -36 degrees C was modelled at Mount Markham in the Queen Elizabeth Range in the Transantarctic Mountains. This is the lowest permafrost temperature on Earth, according to global-scale modelling results. The temperatures were most commonly modelled between -23 and -18 degrees C for mountainous areas rising above the Antarctic Ice Sheet and between -14 and -8 degrees C for coastal areas. The model performance was good where snow conditions were modelled realistically, but errors of up to 4 degrees C occurred at sites with strong wind-driven redistribution of snow. |
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