Aerosol sulfate loading and shortwave direct radiative forcing over the North Atlantic Ocean
Shortwave radiative forcing of climate by anthropogenic sulfate aerosols is estimated to be equal in magnitude but opposite in sign to that of greenhouse warming, with a global annual average value of approximately -1 W m{sup -2} uncertain to at least a factor of two. Estimates of the 2 contribution...
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ftosti:oai:osti.gov:475621 2023-07-30T04:05:32+02:00 Aerosol sulfate loading and shortwave direct radiative forcing over the North Atlantic Ocean Nemesure, S. Benkovitz, C.M. Schwartz, S.E. 2009-11-12 application/pdf http://www.osti.gov/servlets/purl/475621 https://www.osti.gov/biblio/475621 unknown http://www.osti.gov/servlets/purl/475621 https://www.osti.gov/biblio/475621 54 ENVIRONMENTAL SCIENCES ;99 MATHEMATICS COMPUTERS INFORMATION SCIENCE MANAGEMENT LAW MISCELLANEOUS AEROSOLS OPTICAL PROPERTIES AMMONIUM SULFATES ALBEDO ATLANTIC OCEAN CLIMATE MODELS HUMIDITY GREENHOUSE EFFECT CALCULATION METHODS HEAT TRANSFER ATMOSPHERIC CHEMISTRY 2009 ftosti 2023-07-11T08:34:14Z Shortwave radiative forcing of climate by anthropogenic sulfate aerosols is estimated to be equal in magnitude but opposite in sign to that of greenhouse warming, with a global annual average value of approximately -1 W m{sup -2} uncertain to at least a factor of two. Estimates of the 2 contributions to this forcing by the direct effect are -0.4 W m{sup -2}. It is therefore necessary to accurately and efficiently represent this forcing in climate models, specifically including spatial and temporal variability. Here we explore a method to expedite the process for determining this forcing. The method utilizes an approach where the forcing is computed precisely at several discrete radii (r) and then integrated over an arbitrary aerosol size distribution. Additionally, the forcing is calculated at several values of relative humidity (RH), solar zenith angle (SZA), and aerosol optical thickness ({tau}). The parameters can be interpolated to provide the forcing at specific intermediate values. Alternatively, an empirical relationship between the forcing and the above mentioned variables can be utilized to further reduce computation time. At present, the calculations are restricted to ammonium sulfate particles over an ocean surface. The advantage of the ocean surface is the constant and low albedo compared to the highly variable albedo of land surfaces. Ultimately, the sensitivity of forcing to surface albedo and composition will be included. Other/Unknown Material North Atlantic SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
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SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
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ftosti |
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topic |
54 ENVIRONMENTAL SCIENCES ;99 MATHEMATICS COMPUTERS INFORMATION SCIENCE MANAGEMENT LAW MISCELLANEOUS AEROSOLS OPTICAL PROPERTIES AMMONIUM SULFATES ALBEDO ATLANTIC OCEAN CLIMATE MODELS HUMIDITY GREENHOUSE EFFECT CALCULATION METHODS HEAT TRANSFER ATMOSPHERIC CHEMISTRY |
spellingShingle |
54 ENVIRONMENTAL SCIENCES ;99 MATHEMATICS COMPUTERS INFORMATION SCIENCE MANAGEMENT LAW MISCELLANEOUS AEROSOLS OPTICAL PROPERTIES AMMONIUM SULFATES ALBEDO ATLANTIC OCEAN CLIMATE MODELS HUMIDITY GREENHOUSE EFFECT CALCULATION METHODS HEAT TRANSFER ATMOSPHERIC CHEMISTRY Nemesure, S. Benkovitz, C.M. Schwartz, S.E. Aerosol sulfate loading and shortwave direct radiative forcing over the North Atlantic Ocean |
topic_facet |
54 ENVIRONMENTAL SCIENCES ;99 MATHEMATICS COMPUTERS INFORMATION SCIENCE MANAGEMENT LAW MISCELLANEOUS AEROSOLS OPTICAL PROPERTIES AMMONIUM SULFATES ALBEDO ATLANTIC OCEAN CLIMATE MODELS HUMIDITY GREENHOUSE EFFECT CALCULATION METHODS HEAT TRANSFER ATMOSPHERIC CHEMISTRY |
description |
Shortwave radiative forcing of climate by anthropogenic sulfate aerosols is estimated to be equal in magnitude but opposite in sign to that of greenhouse warming, with a global annual average value of approximately -1 W m{sup -2} uncertain to at least a factor of two. Estimates of the 2 contributions to this forcing by the direct effect are -0.4 W m{sup -2}. It is therefore necessary to accurately and efficiently represent this forcing in climate models, specifically including spatial and temporal variability. Here we explore a method to expedite the process for determining this forcing. The method utilizes an approach where the forcing is computed precisely at several discrete radii (r) and then integrated over an arbitrary aerosol size distribution. Additionally, the forcing is calculated at several values of relative humidity (RH), solar zenith angle (SZA), and aerosol optical thickness ({tau}). The parameters can be interpolated to provide the forcing at specific intermediate values. Alternatively, an empirical relationship between the forcing and the above mentioned variables can be utilized to further reduce computation time. At present, the calculations are restricted to ammonium sulfate particles over an ocean surface. The advantage of the ocean surface is the constant and low albedo compared to the highly variable albedo of land surfaces. Ultimately, the sensitivity of forcing to surface albedo and composition will be included. |
author |
Nemesure, S. Benkovitz, C.M. Schwartz, S.E. |
author_facet |
Nemesure, S. Benkovitz, C.M. Schwartz, S.E. |
author_sort |
Nemesure, S. |
title |
Aerosol sulfate loading and shortwave direct radiative forcing over the North Atlantic Ocean |
title_short |
Aerosol sulfate loading and shortwave direct radiative forcing over the North Atlantic Ocean |
title_full |
Aerosol sulfate loading and shortwave direct radiative forcing over the North Atlantic Ocean |
title_fullStr |
Aerosol sulfate loading and shortwave direct radiative forcing over the North Atlantic Ocean |
title_full_unstemmed |
Aerosol sulfate loading and shortwave direct radiative forcing over the North Atlantic Ocean |
title_sort |
aerosol sulfate loading and shortwave direct radiative forcing over the north atlantic ocean |
publishDate |
2009 |
url |
http://www.osti.gov/servlets/purl/475621 https://www.osti.gov/biblio/475621 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
http://www.osti.gov/servlets/purl/475621 https://www.osti.gov/biblio/475621 |
_version_ |
1772817517324009472 |