Mechanisms linking volcanic aerosols to the Atlantic meridional overturning circulation
This study examines the sensitivity of the climate system to volcanic aerosol forcing in the third climate configuration of the Met Office Unified Model (HadCM3). The main test case was based on the 1880s when there were several volcanic eruptions, the well-known Krakatau being the largest. These er...
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ftunivreading:oai:centaur.reading.ac.uk:28614 2024-02-11T10:01:03+01:00 Mechanisms linking volcanic aerosols to the Atlantic meridional overturning circulation Iwi, Alan M. Hermanson, Leon Haines, Keith Sutton, Rowan T. 2012 https://centaur.reading.ac.uk/28614/ unknown American Meteorological Society Iwi, A. M., Hermanson, L. <https://centaur.reading.ac.uk/view/creators/90000517.html>, Haines, K. <https://centaur.reading.ac.uk/view/creators/90000002.html> orcid:0000-0003-2768-2374 and Sutton, R. T. <https://centaur.reading.ac.uk/view/creators/90000057.html> orcid:0000-0001-8345-8583 (2012) Mechanisms linking volcanic aerosols to the Atlantic meridional overturning circulation. Journal of Climate, 25 (8). pp. 3039-3051. ISSN 1520-0442 doi: https://doi.org/10.1175/2011JCLI4067.1 <https://doi.org/10.1175/2011JCLI4067.1> Article PeerReviewed 2012 ftunivreading https://doi.org/10.1175/2011JCLI4067.1 2024-01-25T23:55:55Z This study examines the sensitivity of the climate system to volcanic aerosol forcing in the third climate configuration of the Met Office Unified Model (HadCM3). The main test case was based on the 1880s when there were several volcanic eruptions, the well-known Krakatau being the largest. These eruptions increased atmospheric aerosol concentrations and induced a period of global cooling surface temperatures. In this study, an ensemble of HadCM3 has been integrated with the standard set of radiative forcings and aerosols from the Intergovernmental Panel on Climate Change Fourth Assessment Report simulations, from 1860 to present. A second ensemble removes the volcanic aerosols from 1880 to 1899. The all-forcings ensemble shows an attributable 1.2-Sv (1 Sv ≡ 106 m3 s−1) increase in the Atlantic meridional overturning circulation (AMOC) at 45°N—with a 0.04-PW increase in meridional heat transport at 40°N and increased northern Atlantic SSTs—starting around 1894, approximately 11 years after the first eruption, and lasting a further 10 years at least. The mechanisms responsible are traced to the Arctic, with suppression of the global water cycle (high-latitude precipitation), which leads to an increase in upper-level Arctic and Greenland Sea salinities. This then leads to increased convection in the Greenland–Iceland–Norwegian (GIN) Seas, enhanced Denmark Strait overflows, and AMOC changes with density anomalies traceable southward along the western Atlantic boundary. The authors investigate whether a similar response to the Pinatubo eruption in 1991 could still be ongoing, but do not find strong evidence. Article in Journal/Newspaper Arctic Climate change Denmark Strait Greenland Greenland Sea Iceland CentAUR: Central Archive at the University of Reading Arctic Greenland Journal of Climate 25 8 3039 3051 |
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Open Polar |
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CentAUR: Central Archive at the University of Reading |
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ftunivreading |
language |
unknown |
description |
This study examines the sensitivity of the climate system to volcanic aerosol forcing in the third climate configuration of the Met Office Unified Model (HadCM3). The main test case was based on the 1880s when there were several volcanic eruptions, the well-known Krakatau being the largest. These eruptions increased atmospheric aerosol concentrations and induced a period of global cooling surface temperatures. In this study, an ensemble of HadCM3 has been integrated with the standard set of radiative forcings and aerosols from the Intergovernmental Panel on Climate Change Fourth Assessment Report simulations, from 1860 to present. A second ensemble removes the volcanic aerosols from 1880 to 1899. The all-forcings ensemble shows an attributable 1.2-Sv (1 Sv ≡ 106 m3 s−1) increase in the Atlantic meridional overturning circulation (AMOC) at 45°N—with a 0.04-PW increase in meridional heat transport at 40°N and increased northern Atlantic SSTs—starting around 1894, approximately 11 years after the first eruption, and lasting a further 10 years at least. The mechanisms responsible are traced to the Arctic, with suppression of the global water cycle (high-latitude precipitation), which leads to an increase in upper-level Arctic and Greenland Sea salinities. This then leads to increased convection in the Greenland–Iceland–Norwegian (GIN) Seas, enhanced Denmark Strait overflows, and AMOC changes with density anomalies traceable southward along the western Atlantic boundary. The authors investigate whether a similar response to the Pinatubo eruption in 1991 could still be ongoing, but do not find strong evidence. |
format |
Article in Journal/Newspaper |
author |
Iwi, Alan M. Hermanson, Leon Haines, Keith Sutton, Rowan T. |
spellingShingle |
Iwi, Alan M. Hermanson, Leon Haines, Keith Sutton, Rowan T. Mechanisms linking volcanic aerosols to the Atlantic meridional overturning circulation |
author_facet |
Iwi, Alan M. Hermanson, Leon Haines, Keith Sutton, Rowan T. |
author_sort |
Iwi, Alan M. |
title |
Mechanisms linking volcanic aerosols to the Atlantic meridional overturning circulation |
title_short |
Mechanisms linking volcanic aerosols to the Atlantic meridional overturning circulation |
title_full |
Mechanisms linking volcanic aerosols to the Atlantic meridional overturning circulation |
title_fullStr |
Mechanisms linking volcanic aerosols to the Atlantic meridional overturning circulation |
title_full_unstemmed |
Mechanisms linking volcanic aerosols to the Atlantic meridional overturning circulation |
title_sort |
mechanisms linking volcanic aerosols to the atlantic meridional overturning circulation |
publisher |
American Meteorological Society |
publishDate |
2012 |
url |
https://centaur.reading.ac.uk/28614/ |
geographic |
Arctic Greenland |
geographic_facet |
Arctic Greenland |
genre |
Arctic Climate change Denmark Strait Greenland Greenland Sea Iceland |
genre_facet |
Arctic Climate change Denmark Strait Greenland Greenland Sea Iceland |
op_relation |
Iwi, A. M., Hermanson, L. <https://centaur.reading.ac.uk/view/creators/90000517.html>, Haines, K. <https://centaur.reading.ac.uk/view/creators/90000002.html> orcid:0000-0003-2768-2374 and Sutton, R. T. <https://centaur.reading.ac.uk/view/creators/90000057.html> orcid:0000-0001-8345-8583 (2012) Mechanisms linking volcanic aerosols to the Atlantic meridional overturning circulation. Journal of Climate, 25 (8). pp. 3039-3051. ISSN 1520-0442 doi: https://doi.org/10.1175/2011JCLI4067.1 <https://doi.org/10.1175/2011JCLI4067.1> |
op_doi |
https://doi.org/10.1175/2011JCLI4067.1 |
container_title |
Journal of Climate |
container_volume |
25 |
container_issue |
8 |
container_start_page |
3039 |
op_container_end_page |
3051 |
_version_ |
1790596783181660160 |