New insights into the environmental factors controlling the ground thermal regime across the Northern Hemisphere: a comparison between permafrost and non-permafrost areas
The thermal state of permafrost affects Earth surface systems and human activity in the Arctic and has implications for global climate. Improved understanding of the local-scale variability in the global ground thermal regime is required to account for its sensitivity to changing climatic and geoeco...
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ftdoajarticles:oai:doaj.org/article:d322fc01827943ebbb4b14e33095966d 2023-05-15T13:03:23+02:00 New insights into the environmental factors controlling the ground thermal regime across the Northern Hemisphere: a comparison between permafrost and non-permafrost areas O. Karjalainen M. Luoto J. Aalto J. Hjort 2019-02-01T00:00:00Z https://doi.org/10.5194/tc-13-693-2019 https://doaj.org/article/d322fc01827943ebbb4b14e33095966d EN eng Copernicus Publications https://www.the-cryosphere.net/13/693/2019/tc-13-693-2019.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-13-693-2019 1994-0416 1994-0424 https://doaj.org/article/d322fc01827943ebbb4b14e33095966d The Cryosphere, Vol 13, Pp 693-707 (2019) Environmental sciences GE1-350 Geology QE1-996.5 article 2019 ftdoajarticles https://doi.org/10.5194/tc-13-693-2019 2022-12-31T10:32:09Z The thermal state of permafrost affects Earth surface systems and human activity in the Arctic and has implications for global climate. Improved understanding of the local-scale variability in the global ground thermal regime is required to account for its sensitivity to changing climatic and geoecological conditions. Here, we statistically related observations of mean annual ground temperature (MAGT) and active-layer thickness (ALT) to high-resolution ( ∼1 km 2 ) geospatial data of climatic and local environmental conditions across the Northern Hemisphere. The aim was to characterize the relative importance of key environmental factors and the magnitude and shape of their effects on MAGT and ALT. The multivariate models fitted well to both response variables with average R 2 values being ∼0.94 and 0.78. Corresponding predictive performances in terms of root-mean-square error were ∼1.31 ∘ C and 87 cm. Freezing (FDD) and thawing (TDD) degree days were key factors for MAGT inside and outside the permafrost domain with average effect sizes of 6.7 and 13.6 ∘ C, respectively. Soil properties had marginal effects on MAGT (effect size =0.4 –0.7 ∘ C). For ALT, rainfall (effect size =181 cm) and solar radiation (161 cm) were most influential. Analysis of variable importance further underlined the dominance of climate for MAGT and highlighted the role of solar radiation for ALT. Most response shapes for MAGT ≤0 ∘ C and ALT were non-linear and indicated thresholds for covariation. Most importantly, permafrost temperatures had a more complex relationship with air temperatures than non-frozen ground. Moreover, the observed warming effect of rainfall on MAGT <math xmlns="http://www.w3.org/1998/Math/MathML" id="M13" display="inline" overflow="scroll" dspmath="mathml"><msub><mi/><mrow><mo>≤</mo><mn mathvariant="normal">0</mn><mspace width="0.125em" linebreak="nobreak"/><msup><mi/><mo>∘</mo></msup><mrow class="unit"><mi ... Article in Journal/Newspaper Active layer thickness Arctic permafrost The Cryosphere Directory of Open Access Journals: DOAJ Articles Arctic The Cryosphere 13 2 693 707 |
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Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 O. Karjalainen M. Luoto J. Aalto J. Hjort New insights into the environmental factors controlling the ground thermal regime across the Northern Hemisphere: a comparison between permafrost and non-permafrost areas |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
The thermal state of permafrost affects Earth surface systems and human activity in the Arctic and has implications for global climate. Improved understanding of the local-scale variability in the global ground thermal regime is required to account for its sensitivity to changing climatic and geoecological conditions. Here, we statistically related observations of mean annual ground temperature (MAGT) and active-layer thickness (ALT) to high-resolution ( ∼1 km 2 ) geospatial data of climatic and local environmental conditions across the Northern Hemisphere. The aim was to characterize the relative importance of key environmental factors and the magnitude and shape of their effects on MAGT and ALT. The multivariate models fitted well to both response variables with average R 2 values being ∼0.94 and 0.78. Corresponding predictive performances in terms of root-mean-square error were ∼1.31 ∘ C and 87 cm. Freezing (FDD) and thawing (TDD) degree days were key factors for MAGT inside and outside the permafrost domain with average effect sizes of 6.7 and 13.6 ∘ C, respectively. Soil properties had marginal effects on MAGT (effect size =0.4 –0.7 ∘ C). For ALT, rainfall (effect size =181 cm) and solar radiation (161 cm) were most influential. Analysis of variable importance further underlined the dominance of climate for MAGT and highlighted the role of solar radiation for ALT. Most response shapes for MAGT ≤0 ∘ C and ALT were non-linear and indicated thresholds for covariation. Most importantly, permafrost temperatures had a more complex relationship with air temperatures than non-frozen ground. Moreover, the observed warming effect of rainfall on MAGT <math xmlns="http://www.w3.org/1998/Math/MathML" id="M13" display="inline" overflow="scroll" dspmath="mathml"><msub><mi/><mrow><mo>≤</mo><mn mathvariant="normal">0</mn><mspace width="0.125em" linebreak="nobreak"/><msup><mi/><mo>∘</mo></msup><mrow class="unit"><mi ... |
format |
Article in Journal/Newspaper |
author |
O. Karjalainen M. Luoto J. Aalto J. Hjort |
author_facet |
O. Karjalainen M. Luoto J. Aalto J. Hjort |
author_sort |
O. Karjalainen |
title |
New insights into the environmental factors controlling the ground thermal regime across the Northern Hemisphere: a comparison between permafrost and non-permafrost areas |
title_short |
New insights into the environmental factors controlling the ground thermal regime across the Northern Hemisphere: a comparison between permafrost and non-permafrost areas |
title_full |
New insights into the environmental factors controlling the ground thermal regime across the Northern Hemisphere: a comparison between permafrost and non-permafrost areas |
title_fullStr |
New insights into the environmental factors controlling the ground thermal regime across the Northern Hemisphere: a comparison between permafrost and non-permafrost areas |
title_full_unstemmed |
New insights into the environmental factors controlling the ground thermal regime across the Northern Hemisphere: a comparison between permafrost and non-permafrost areas |
title_sort |
new insights into the environmental factors controlling the ground thermal regime across the northern hemisphere: a comparison between permafrost and non-permafrost areas |
publisher |
Copernicus Publications |
publishDate |
2019 |
url |
https://doi.org/10.5194/tc-13-693-2019 https://doaj.org/article/d322fc01827943ebbb4b14e33095966d |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Active layer thickness Arctic permafrost The Cryosphere |
genre_facet |
Active layer thickness Arctic permafrost The Cryosphere |
op_source |
The Cryosphere, Vol 13, Pp 693-707 (2019) |
op_relation |
https://www.the-cryosphere.net/13/693/2019/tc-13-693-2019.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-13-693-2019 1994-0416 1994-0424 https://doaj.org/article/d322fc01827943ebbb4b14e33095966d |
op_doi |
https://doi.org/10.5194/tc-13-693-2019 |
container_title |
The Cryosphere |
container_volume |
13 |
container_issue |
2 |
container_start_page |
693 |
op_container_end_page |
707 |
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1766335512258281472 |