Green Sahara impact on mid-latitudes during mid-Holocene
International audience In the mid-Holocene (6 kyr before present), North Africa was characterised by a vegetated Sahara and a stronger summer monsoon, resulting in a wetter climate. These conditions, induced by the different Earth's orbital parameters, and maintained by the precipitation-vegeta...
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ftuniversailles:oai:HAL:insu-01660721v1 2023-07-30T04:05:31+02:00 Green Sahara impact on mid-latitudes during mid-Holocene Gaetani, Marco Messori, Gabriele Pausata, Francesco S. R. Zhang, Qiong TROPO - LATMOS Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS) Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Department of Meteorology Stockholm (MISU) Stockholm University Department of Physical Geography Stockholm Vienna, Austria 2017-04 https://insu.hal.science/insu-01660721 en eng HAL CCSD insu-01660721 https://insu.hal.science/insu-01660721 BIBCODE: 2017EGUGA.1914589G 19th EGU General Assembly, EGU2017 https://insu.hal.science/insu-01660721 19th EGU General Assembly, EGU2017, Apr 2017, Vienna, Austria [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology info:eu-repo/semantics/conferenceObject Conference papers 2017 ftuniversailles 2023-07-16T21:14:59Z International audience In the mid-Holocene (6 kyr before present), North Africa was characterised by a vegetated Sahara and a stronger summer monsoon, resulting in a wetter climate. These conditions, induced by the different Earth's orbital parameters, and maintained by the precipitation-vegetation feedback, were associated with a substantial change of the regional atmospheric dynamics, with influences extending across the global Tropics and beyond. In this study, we explore the mid-latitude response to the vegetated Sahara in the mid-Holocene. We use the EC-Earth climate model to simulate the North African environment during mid-Holocene, i.e. extensive vegetation over the Sahara, and a consequent reduced dust emission. Vegetation and dust reduction are prescribed both in combination and in isolation, to determine the specific responses to the individual forcings. A significant response at mid-latitudes is simulated during boreal summer, when the precipitation-vegetation feedback is maximum in the Sahara. Results show increased precipitation over Mediterranean and Middle East, and warm anomalies across western Europe. This response is associated with the modification of the atmospheric circulation in the Euro-Atlantic sector. Specifically, the intensification of the subtropical jetstream favours precipitation across the Middle East, while a positive anomaly in the North Atlantic Oscillation leads the warming further west. These results suggest important implications for the understanding of future climate scenarios in the region, since a number of simulations project wetter conditions in North Africa. Conference Object North Atlantic North Atlantic oscillation Université de Versailles Saint-Quentin-en-Yvelines: HAL-UVSQ |
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Open Polar |
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Université de Versailles Saint-Quentin-en-Yvelines: HAL-UVSQ |
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ftuniversailles |
language |
English |
topic |
[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology |
spellingShingle |
[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology Gaetani, Marco Messori, Gabriele Pausata, Francesco S. R. Zhang, Qiong Green Sahara impact on mid-latitudes during mid-Holocene |
topic_facet |
[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology |
description |
International audience In the mid-Holocene (6 kyr before present), North Africa was characterised by a vegetated Sahara and a stronger summer monsoon, resulting in a wetter climate. These conditions, induced by the different Earth's orbital parameters, and maintained by the precipitation-vegetation feedback, were associated with a substantial change of the regional atmospheric dynamics, with influences extending across the global Tropics and beyond. In this study, we explore the mid-latitude response to the vegetated Sahara in the mid-Holocene. We use the EC-Earth climate model to simulate the North African environment during mid-Holocene, i.e. extensive vegetation over the Sahara, and a consequent reduced dust emission. Vegetation and dust reduction are prescribed both in combination and in isolation, to determine the specific responses to the individual forcings. A significant response at mid-latitudes is simulated during boreal summer, when the precipitation-vegetation feedback is maximum in the Sahara. Results show increased precipitation over Mediterranean and Middle East, and warm anomalies across western Europe. This response is associated with the modification of the atmospheric circulation in the Euro-Atlantic sector. Specifically, the intensification of the subtropical jetstream favours precipitation across the Middle East, while a positive anomaly in the North Atlantic Oscillation leads the warming further west. These results suggest important implications for the understanding of future climate scenarios in the region, since a number of simulations project wetter conditions in North Africa. |
author2 |
TROPO - LATMOS Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS) Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Department of Meteorology Stockholm (MISU) Stockholm University Department of Physical Geography Stockholm |
format |
Conference Object |
author |
Gaetani, Marco Messori, Gabriele Pausata, Francesco S. R. Zhang, Qiong |
author_facet |
Gaetani, Marco Messori, Gabriele Pausata, Francesco S. R. Zhang, Qiong |
author_sort |
Gaetani, Marco |
title |
Green Sahara impact on mid-latitudes during mid-Holocene |
title_short |
Green Sahara impact on mid-latitudes during mid-Holocene |
title_full |
Green Sahara impact on mid-latitudes during mid-Holocene |
title_fullStr |
Green Sahara impact on mid-latitudes during mid-Holocene |
title_full_unstemmed |
Green Sahara impact on mid-latitudes during mid-Holocene |
title_sort |
green sahara impact on mid-latitudes during mid-holocene |
publisher |
HAL CCSD |
publishDate |
2017 |
url |
https://insu.hal.science/insu-01660721 |
op_coverage |
Vienna, Austria |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_source |
19th EGU General Assembly, EGU2017 https://insu.hal.science/insu-01660721 19th EGU General Assembly, EGU2017, Apr 2017, Vienna, Austria |
op_relation |
insu-01660721 https://insu.hal.science/insu-01660721 BIBCODE: 2017EGUGA.1914589G |
_version_ |
1772817476619337728 |