Land–sea temperature contrasts at the Last Interglacial and their impact on the hydrological cycle
<p>Due to different orbital configurations, high northern latitude summer insolation was higher during the Last Interglacial period (LIG; 129–116 thousand years before present, ka) than during the pre-industrial period (PI), while high southern latitude summer insolation was lower. The climati...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2021-04-01
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| Series: | Climate of the Past |
| Online Access: | https://cp.copernicus.org/articles/17/869/2021/cp-17-869-2021.pdf |
| _version_ | 1818447036125544448 |
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| author | N. K.-H. Yeung N. K.-H. Yeung L. Menviel K. J. Meissner K. J. Meissner A. S. Taschetto A. S. Taschetto T. Ziehn M. Chamberlain |
| author_facet | N. K.-H. Yeung N. K.-H. Yeung L. Menviel K. J. Meissner K. J. Meissner A. S. Taschetto A. S. Taschetto T. Ziehn M. Chamberlain |
| author_sort | N. K.-H. Yeung |
| collection | DOAJ |
| description | <p>Due to different orbital configurations, high northern latitude summer insolation was higher during the Last Interglacial period (LIG; 129–116 thousand years before present, ka) than during the pre-industrial period (PI), while high southern latitude summer insolation was lower. The climatic response to these changes is studied here with focus on the Southern Hemisphere monsoons, by performing an equilibrium experiment of the LIG at 127 ka with the Australian Earth System Model, ACCESS-ESM1.5, as part of the Paleoclimate Model Intercomparison Project 4 (PMIP4). Simulated mean surface air temperature between 40 and 60<span class="inline-formula"><sup>∘</sup></span> N over land during boreal summer is 6.5 <span class="inline-formula"><sup>∘</sup></span>C higher at the LIG compared to PI, which leads to a northward shift of the Intertropical Convergence Zone (ITCZ) and a strengthening of the North African and Indian monsoons. Despite 0.4 <span class="inline-formula"><sup>∘</sup></span>C cooler conditions in austral summer in the Southern Hemisphere (0–90<span class="inline-formula"><sup>∘</sup></span> S), annual mean air temperatures are 1.2 <span class="inline-formula"><sup>∘</sup></span>C higher at southern mid-latitudes to high latitudes (40–80<span class="inline-formula"><sup>∘</sup></span> S). These differences in temperature are coincident with a large-scale reorganisation of the atmospheric circulation. The ITCZ shifts southward in the Atlantic and Indian sectors during the LIG austral summer compared to PI, leading to increased precipitation over the southern tropical oceans. However, weaker Southern Hemisphere insolation during LIG austral summer induces a significant cooling over land, which in turn weakens the land–sea temperature contrast, leading to an overall reduction (<span class="inline-formula">−</span>20 %) in monsoonal precipitation over the Southern Hemisphere's continental regions compared to PI. The intensity and areal extent of the Australian, South American and South African monsoons are consistently reduced in LIG. This is associated with greater pressure and subsidence over land due to a strengthening of the Southern Hemisphere Hadley cell during austral summer.</p> |
| first_indexed | 2024-12-14T19:57:14Z |
| format | Article |
| id | doaj.art-77fae1f7090b40b6ac10629b49d3dc7b |
| institution | Directory Open Access Journal |
| issn | 1814-9324 1814-9332 |
| language | English |
| last_indexed | 2024-12-14T19:57:14Z |
| publishDate | 2021-04-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Climate of the Past |
| spelling | doaj.art-77fae1f7090b40b6ac10629b49d3dc7b2022-12-21T22:49:16ZengCopernicus PublicationsClimate of the Past1814-93241814-93322021-04-011786988510.5194/cp-17-869-2021Land–sea temperature contrasts at the Last Interglacial and their impact on the hydrological cycleN. K.-H. Yeung0N. K.-H. Yeung1L. Menviel2K. J. Meissner3K. J. Meissner4A. S. Taschetto5A. S. Taschetto6T. Ziehn7M. Chamberlain8Climate Change Research Centre, University of New South Wales, Sydney NSW, AustraliaARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney NSW, AustraliaClimate Change Research Centre, University of New South Wales, Sydney NSW, AustraliaClimate Change Research Centre, University of New South Wales, Sydney NSW, AustraliaARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney NSW, AustraliaClimate Change Research Centre, University of New South Wales, Sydney NSW, AustraliaARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney NSW, AustraliaCSIRO Oceans and Atmosphere, Aspendale VIC, AustraliaCSIRO Oceans and Atmosphere, Hobart TAS, Australia<p>Due to different orbital configurations, high northern latitude summer insolation was higher during the Last Interglacial period (LIG; 129–116 thousand years before present, ka) than during the pre-industrial period (PI), while high southern latitude summer insolation was lower. The climatic response to these changes is studied here with focus on the Southern Hemisphere monsoons, by performing an equilibrium experiment of the LIG at 127 ka with the Australian Earth System Model, ACCESS-ESM1.5, as part of the Paleoclimate Model Intercomparison Project 4 (PMIP4). Simulated mean surface air temperature between 40 and 60<span class="inline-formula"><sup>∘</sup></span> N over land during boreal summer is 6.5 <span class="inline-formula"><sup>∘</sup></span>C higher at the LIG compared to PI, which leads to a northward shift of the Intertropical Convergence Zone (ITCZ) and a strengthening of the North African and Indian monsoons. Despite 0.4 <span class="inline-formula"><sup>∘</sup></span>C cooler conditions in austral summer in the Southern Hemisphere (0–90<span class="inline-formula"><sup>∘</sup></span> S), annual mean air temperatures are 1.2 <span class="inline-formula"><sup>∘</sup></span>C higher at southern mid-latitudes to high latitudes (40–80<span class="inline-formula"><sup>∘</sup></span> S). These differences in temperature are coincident with a large-scale reorganisation of the atmospheric circulation. The ITCZ shifts southward in the Atlantic and Indian sectors during the LIG austral summer compared to PI, leading to increased precipitation over the southern tropical oceans. However, weaker Southern Hemisphere insolation during LIG austral summer induces a significant cooling over land, which in turn weakens the land–sea temperature contrast, leading to an overall reduction (<span class="inline-formula">−</span>20 %) in monsoonal precipitation over the Southern Hemisphere's continental regions compared to PI. The intensity and areal extent of the Australian, South American and South African monsoons are consistently reduced in LIG. This is associated with greater pressure and subsidence over land due to a strengthening of the Southern Hemisphere Hadley cell during austral summer.</p>https://cp.copernicus.org/articles/17/869/2021/cp-17-869-2021.pdf |
| spellingShingle | N. K.-H. Yeung N. K.-H. Yeung L. Menviel K. J. Meissner K. J. Meissner A. S. Taschetto A. S. Taschetto T. Ziehn M. Chamberlain Land–sea temperature contrasts at the Last Interglacial and their impact on the hydrological cycle Climate of the Past |
| title | Land–sea temperature contrasts at the Last Interglacial and their impact on the hydrological cycle |
| title_full | Land–sea temperature contrasts at the Last Interglacial and their impact on the hydrological cycle |
| title_fullStr | Land–sea temperature contrasts at the Last Interglacial and their impact on the hydrological cycle |
| title_full_unstemmed | Land–sea temperature contrasts at the Last Interglacial and their impact on the hydrological cycle |
| title_short | Land–sea temperature contrasts at the Last Interglacial and their impact on the hydrological cycle |
| title_sort | land sea temperature contrasts at the last interglacial and their impact on the hydrological cycle |
| url | https://cp.copernicus.org/articles/17/869/2021/cp-17-869-2021.pdf |
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