Brief communication: Improving ERA5-Land soil temperature in permafrost regions using an optimized multi-layer snow scheme
<p>We previously reported a notable warm bias in ERA5-Land soil temperature in permafrost regions that was supposedly being caused by an underestimation of snow density. In this study, we implemented and evaluated a new multi-layer snow scheme in the land surface scheme of ERA5-Land, i.e., HTE...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2022-07-01
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| Series: | The Cryosphere |
| Online Access: | https://tc.copernicus.org/articles/16/2701/2022/tc-16-2701-2022.pdf |
| Summary: | <p>We previously reported a notable warm bias in ERA5-Land soil temperature in permafrost regions that was supposedly being caused by an underestimation of snow density. In this study, we implemented and evaluated a new multi-layer snow scheme in the land surface scheme of ERA5-Land, i.e., HTESSEL, with revised snow densification parameterizations. We compared permafrost soil temperatures from the numerical experiments with observations and the original ERA5-Land with a single-layer snow scheme. The revised HTESSEL significantly improved the representation of soil temperature in permafrost regions compared to ERA5-Land. The daily warm bias in winter was reduced by about 0.6–3.0 <span class="inline-formula"><sup>∘</sup>C</span> across the 522 observing stations in high-latitude permafrost regions, and the resulting modeled near-surface permafrost extent was improved (11.0–<span class="inline-formula">12.9×10<sup>6</sup></span> <span class="inline-formula">km<sup>2</sup></span> during 2001–2018), comparing reasonably with observed estimates for continuous and discontinuous permafrost areas. We therefore suggest that a better-resolved snow scheme with a multi-layer snow profile should be included in next-generation reanalyses as a first step towards improving the representation of permafrost.</p> |
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| ISSN: | 1994-0416 1994-0424 |