Published in:
The Cryosphere, 14 (2020) 2, Seite 497-519
Language:
English
DOI:
10.5194/tc-14-497-2020
ISSN:
1994-0424
Origination:
Footnote:
Description:
<jats:p>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.
</jats:p>