Loading...
Thumbnail Image
Item

Pan-Antarctic map of near-surface permafrost temperatures at 1 km2 scale

Abstract
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 km2 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 ∘C. The lowest near-surface permafrost temperature of −36 ∘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 ∘C for mountainous areas rising above the Antarctic Ice Sheet and between −14 and −8 ∘C for coastal areas. The model performance was good where snow conditions were modelled realistically, but errors of up to 4 ∘C occurred at sites with strong wind-driven redistribution of snow.
Type
Journal Article
Type of thesis
Series
Citation
Obu, J., Westermann, S., Vieira, G., Abramov, A., Balks, M. R., Bartsch, A., … Ramos, M. (2020). Pan-Antarctic map of near-surface permafrost temperatures at 1 km2 scale. The Cryosphere, 14(2), 497–519. https://doi.org/10.5194/tc-14-497-2020
Date
2020
Publisher
Copernicus GmbH
Degree
Supervisors
Rights
© Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License.