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,...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2018-06-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/18/8439/2018/acp-18-8439-2018.pdf |
| _version_ | 1798045311350865920 |
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| author | T. Tang D. Shindell B. H. Samset O. Boucher P. M. Forster Ø. Hodnebrog G. Myhre J. Sillmann A. Voulgarakis T. Andrews G. Faluvegi G. Faluvegi D. Fläschner T. Iversen M. Kasoar V. Kharin A. Kirkevåg J.-F. Lamarque D. Olivié T. Richardson C. W. Stjern T. Takemura |
| author_facet | T. Tang D. Shindell B. H. Samset O. Boucher P. M. Forster Ø. Hodnebrog G. Myhre J. Sillmann A. Voulgarakis T. Andrews G. Faluvegi G. Faluvegi D. Fläschner T. Iversen M. Kasoar V. Kharin A. Kirkevåg J.-F. Lamarque D. Olivié T. Richardson C. W. Stjern T. Takemura |
| author_sort | T. Tang |
| collection | DOAJ |
| 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. |
| first_indexed | 2024-04-11T23:18:36Z |
| format | Article |
| id | doaj.art-3bcdd185045e4bc3ae3aa8321ec8d62d |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-04-11T23:18:36Z |
| publishDate | 2018-06-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-3bcdd185045e4bc3ae3aa8321ec8d62d2022-12-22T03:57:31ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242018-06-01188439845210.5194/acp-18-8439-2018Dynamical response of Mediterranean precipitation to greenhouse gases and aerosolsT. Tang0D. Shindell1B. H. Samset2O. Boucher3P. M. Forster4Ø. Hodnebrog5G. Myhre6J. Sillmann7A. Voulgarakis8T. Andrews9G. Faluvegi10G. Faluvegi11D. Fläschner12T. Iversen13M. Kasoar14V. Kharin15A. Kirkevåg16J.-F. Lamarque17D. Olivié18T. Richardson19C. W. Stjern20T. Takemura21Nicholas School of the Environment, Duke University, Durham, USANicholas School of the Environment, Duke University, Durham, USACICERO Center for International Climate and Environmental Research, Oslo, NorwayInstitute Pierre-Simon Laplace, Université Pierre et Marie Curie/CNRS, Paris, FranceUniversity of Leeds, Leeds, UKCICERO Center for International Climate and Environmental Research, Oslo, NorwayCICERO Center for International Climate and Environmental Research, Oslo, NorwayCICERO Center for International Climate and Environmental Research, Oslo, NorwayImperial College London, London, UKMet Office Hadley Centre, Exeter, UKColumbia University, New York, USANASA Goddard Institute for Space Studies, New York, USAMax-Planck-Institut für Meteorologie, Hamburg, GermanyNorwegian Meteorological Institute, Oslo, NorwayImperial College London, London, UKCanadian Centre for Climate Modelling and Analysis, Victoria, BC, CanadaNorwegian Meteorological Institute, Oslo, NorwayNational Center for Atmospheric Research, Boulder, USANorwegian Meteorological Institute, Oslo, NorwayUniversity of Leeds, Leeds, UKCICERO Center for International Climate and Environmental Research, Oslo, NorwayKyushu University, Fukuoka, JapanAtmospheric 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.https://www.atmos-chem-phys.net/18/8439/2018/acp-18-8439-2018.pdf |
| spellingShingle | T. Tang D. Shindell B. H. Samset O. Boucher P. M. Forster Ø. Hodnebrog G. Myhre J. Sillmann A. Voulgarakis T. Andrews G. Faluvegi G. Faluvegi D. Fläschner T. Iversen M. Kasoar V. Kharin A. Kirkevåg J.-F. Lamarque D. Olivié T. Richardson C. W. Stjern T. Takemura Dynamical response of Mediterranean precipitation to greenhouse gases and aerosols Atmospheric Chemistry and Physics |
| title | 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_short | Dynamical response of Mediterranean precipitation to greenhouse gases and aerosols |
| title_sort | dynamical response of mediterranean precipitation to greenhouse gases and aerosols |
| url | https://www.atmos-chem-phys.net/18/8439/2018/acp-18-8439-2018.pdf |
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