Dynamical response of Mediterranean precipitation to greenhouse gases and aerosols
Atmospheric aerosols and greenhouse gases affect cloud properties, radiative balance and, thus, the hydrological cycle. Observations show that precipitation has decreased in the Mediterranean since the beginning of the 20th century, and many studies have investigated possible mechanisms. So far, how...
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ftncar:oai:drupal-site.org:articles_21739 2023-07-30T04:02:02+02:00 Dynamical response of Mediterranean precipitation to greenhouse gases and aerosols Tang, Tao (author) Shindell, Drew (author) Samset, Bjørn H. (author) Boucher, Oliviér (author) Forster, Piers M. (author) Hodnebrog, Øivind (author) Myhre, Gunnar (author) Sillmann, Jana (author) Voulgarakis, Apostolos (author) Andrews, Timothy (author) Faluvegi, Gregory (author) Fläschner, Dagmar (author) Iversen, Trond (author) Kasoar, Matthew (author) Kharin, Viatcheslav (author) Kirkevåg, Alf (author) Lamarque, Jean-Francois (author) Olivié, Dirk (author) Richardson, Thomas (author) Stjern, Camilla W. (author) Takemura, Toshihiko (author) 2018-06-15 https://doi.org/10.5194/acp-18-8439-2018 en eng Atmospheric Chemistry and Physics--Atmos. Chem. Phys.--1680-7324 articles:21739 ark:/85065/d7st7sms doi:10.5194/acp-18-8439-2018 Copyright 2018 Author(s). This work is licensed under a Creative Commons Attribution 4.0 International license. article Text 2018 ftncar https://doi.org/10.5194/acp-18-8439-2018 2023-07-17T18:23:49Z Atmospheric aerosols and greenhouse gases affect cloud properties, radiative balance and, thus, the hydrological cycle. Observations show that precipitation has decreased in the Mediterranean since the beginning of the 20th century, and many studies have investigated possible mechanisms. So far, however, the effects of aerosol forcing on Mediterranean precipitation remain largely unknown. Here we compare the modeled dynamical response of Mediterranean precipitation to individual forcing agents in a set of global climate models (GCMs). Our analyses show that both greenhouse gases and aerosols can cause drying in the Mediterranean and that precipitation is more sensitive to black carbon (BC) forcing than to well-mixed greenhouse gases (WMGHGs) or sulfate aerosol. In addition to local heating, BC appears to reduce precipitation by causing an enhanced positive sea level pressure (SLP) pattern similar to the North Atlantic Oscillation Arctic Oscillation, characterized by higher SLP at midlatitudes and lower SLP at high latitudes. WMGHGs cause a similar SLP change, and both are associated with a northward diversion of the jet stream and storm tracks, reducing precipitation in the Mediterranean while increasing precipitation in northern Europe. Though the applied forcings were much larger, if forcings are scaled to those of the historical period of 1901-2010, roughly one-third (31 +/- 17 %) of the precipitation decrease would be attributable to global BC forcing with the remainder largely attributable to WMGHGs, whereas global scattering sulfate aerosols would have negligible impacts. Aerosol-cloud interactions appear to have minimal impacts on Mediterranean precipitation in these models, at least in part because many simulations did not fully include such processes; these merit further study. The findings from this study suggest that future BC and WMGHG emissions may significantly affect regional water resources, agricultural practices, ecosystems and the economy in the Mediterranean region. Article in Journal/Newspaper Arctic black carbon North Atlantic North Atlantic oscillation OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Arctic Atmospheric Chemistry and Physics 18 11 8439 8452 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
op_collection_id |
ftncar |
language |
English |
description |
Atmospheric aerosols and greenhouse gases affect cloud properties, radiative balance and, thus, the hydrological cycle. Observations show that precipitation has decreased in the Mediterranean since the beginning of the 20th century, and many studies have investigated possible mechanisms. So far, however, the effects of aerosol forcing on Mediterranean precipitation remain largely unknown. Here we compare the modeled dynamical response of Mediterranean precipitation to individual forcing agents in a set of global climate models (GCMs). Our analyses show that both greenhouse gases and aerosols can cause drying in the Mediterranean and that precipitation is more sensitive to black carbon (BC) forcing than to well-mixed greenhouse gases (WMGHGs) or sulfate aerosol. In addition to local heating, BC appears to reduce precipitation by causing an enhanced positive sea level pressure (SLP) pattern similar to the North Atlantic Oscillation Arctic Oscillation, characterized by higher SLP at midlatitudes and lower SLP at high latitudes. WMGHGs cause a similar SLP change, and both are associated with a northward diversion of the jet stream and storm tracks, reducing precipitation in the Mediterranean while increasing precipitation in northern Europe. Though the applied forcings were much larger, if forcings are scaled to those of the historical period of 1901-2010, roughly one-third (31 +/- 17 %) of the precipitation decrease would be attributable to global BC forcing with the remainder largely attributable to WMGHGs, whereas global scattering sulfate aerosols would have negligible impacts. Aerosol-cloud interactions appear to have minimal impacts on Mediterranean precipitation in these models, at least in part because many simulations did not fully include such processes; these merit further study. The findings from this study suggest that future BC and WMGHG emissions may significantly affect regional water resources, agricultural practices, ecosystems and the economy in the Mediterranean region. |
author2 |
Tang, Tao (author) Shindell, Drew (author) Samset, Bjørn H. (author) Boucher, Oliviér (author) Forster, Piers M. (author) Hodnebrog, Øivind (author) Myhre, Gunnar (author) Sillmann, Jana (author) Voulgarakis, Apostolos (author) Andrews, Timothy (author) Faluvegi, Gregory (author) Fläschner, Dagmar (author) Iversen, Trond (author) Kasoar, Matthew (author) Kharin, Viatcheslav (author) Kirkevåg, Alf (author) Lamarque, Jean-Francois (author) Olivié, Dirk (author) Richardson, Thomas (author) Stjern, Camilla W. (author) Takemura, Toshihiko (author) |
format |
Article in Journal/Newspaper |
title |
Dynamical response of Mediterranean precipitation to greenhouse gases and aerosols |
spellingShingle |
Dynamical response of Mediterranean precipitation to greenhouse gases and aerosols |
title_short |
Dynamical response of Mediterranean precipitation to greenhouse gases and aerosols |
title_full |
Dynamical response of Mediterranean precipitation to greenhouse gases and aerosols |
title_fullStr |
Dynamical response of Mediterranean precipitation to greenhouse gases and aerosols |
title_full_unstemmed |
Dynamical response of Mediterranean precipitation to greenhouse gases and aerosols |
title_sort |
dynamical response of mediterranean precipitation to greenhouse gases and aerosols |
publishDate |
2018 |
url |
https://doi.org/10.5194/acp-18-8439-2018 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic black carbon North Atlantic North Atlantic oscillation |
genre_facet |
Arctic black carbon North Atlantic North Atlantic oscillation |
op_relation |
Atmospheric Chemistry and Physics--Atmos. Chem. Phys.--1680-7324 articles:21739 ark:/85065/d7st7sms doi:10.5194/acp-18-8439-2018 |
op_rights |
Copyright 2018 Author(s). This work is licensed under a Creative Commons Attribution 4.0 International license. |
op_doi |
https://doi.org/10.5194/acp-18-8439-2018 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
18 |
container_issue |
11 |
container_start_page |
8439 |
op_container_end_page |
8452 |
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1772812758240198656 |