Pan-Antarctic map of near-surface permafrost temperatures at 1 km<sup>2</sup> scale
<p>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...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2020-02-01
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| Series: | The Cryosphere |
| Online Access: | https://www.the-cryosphere.net/14/497/2020/tc-14-497-2020.pdf |
| Summary: | <p>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<span class="inline-formula"><sup>2</sup></span>
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 <span class="inline-formula"><sup>∘</sup></span>C. The lowest near-surface permafrost temperature of
<span class="inline-formula">−36</span> <span class="inline-formula"><sup>∘</sup></span>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 <span class="inline-formula">−23</span> and <span class="inline-formula">−18</span> <span class="inline-formula"><sup>∘</sup></span>C for mountainous
areas rising above the Antarctic Ice Sheet and between <span class="inline-formula">−14</span> and <span class="inline-formula">−8</span> <span class="inline-formula"><sup>∘</sup></span>C for coastal areas. The model performance was good where snow
conditions were modelled realistically, but errors of up to 4 <span class="inline-formula"><sup>∘</sup></span>C
occurred at sites with strong wind-driven redistribution of snow.</p> |
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| ISSN: | 1994-0416 1994-0424 |