The path to CAM6: coupled simulations with CAM5.4 and CAM5.5
This paper documents coupled simulations of two developmental versions of the Community Atmosphere Model (CAM) towards CAM6. The configuration called CAM5.4 introduces new microphysics, aerosol, and ice nucleation changes, among others to CAM. The CAM5.5 configuration represents a more radical depar...
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Online Access: | http://www.osti.gov/servlets/purl/1463022 https://www.osti.gov/biblio/1463022 https://doi.org/10.5194/gmd-11-235-2018 |
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ftosti:oai:osti.gov:1463022 2023-07-30T04:01:58+02:00 The path to CAM6: coupled simulations with CAM5.4 and CAM5.5 Bogenschutz, Peter A. Gettelman, Andrew Hannay, Cecile Larson, Vincent E. Neale, Richard B. Craig, Cheryl Chen, Chih -Chieh 2023-06-28 application/pdf http://www.osti.gov/servlets/purl/1463022 https://www.osti.gov/biblio/1463022 https://doi.org/10.5194/gmd-11-235-2018 unknown http://www.osti.gov/servlets/purl/1463022 https://www.osti.gov/biblio/1463022 https://doi.org/10.5194/gmd-11-235-2018 doi:10.5194/gmd-11-235-2018 54 ENVIRONMENTAL SCIENCES 58 GEOSCIENCES 2023 ftosti https://doi.org/10.5194/gmd-11-235-2018 2023-07-11T09:28:05Z This paper documents coupled simulations of two developmental versions of the Community Atmosphere Model (CAM) towards CAM6. The configuration called CAM5.4 introduces new microphysics, aerosol, and ice nucleation changes, among others to CAM. The CAM5.5 configuration represents a more radical departure, as it uses an assumed probability density function (PDF)-based unified cloud parameterization to replace the turbulence, shallow convection, and warm cloud macrophysics in CAM. This assumed PDF method has been widely used in the last decade in atmosphere-only climate simulations but has never been documented in coupled mode. Here, we compare the simulated coupled climates of CAM5.4 and CAM5.5 and compare them to the control coupled simulation produced by CAM5.3. We find that CAM5.5 has lower cloud forcing biases when compared to the control simulations. Improvements are also seen in the simulated amplitude of the Niño-3.4 index, an improved representation of the diurnal cycle of precipitation, subtropical surface wind stresses, and double Intertropical Convergence Zone biases. Degradations are seen in Amazon precipitation as well as slightly colder sea surface temperatures and thinner Arctic sea ice. Simulation of the 20th century results in a credible simulation that ends slightly colder than the control coupled simulation. The authors find this is due to aerosol indirect effects that are slightly stronger in the new version of the model and propose a solution to ameliorate this. Altogether, in these early coupled simulations, CAM5.5 produces a credible climate that is appropriate for science applications and is ready for integration into the National Center for Atmospheric Research's (NCAR's) next-generation climate model. Other/Unknown Material Arctic Sea ice SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Arctic Geoscientific Model Development 11 1 235 255 |
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SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
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54 ENVIRONMENTAL SCIENCES 58 GEOSCIENCES Bogenschutz, Peter A. Gettelman, Andrew Hannay, Cecile Larson, Vincent E. Neale, Richard B. Craig, Cheryl Chen, Chih -Chieh The path to CAM6: coupled simulations with CAM5.4 and CAM5.5 |
topic_facet |
54 ENVIRONMENTAL SCIENCES 58 GEOSCIENCES |
description |
This paper documents coupled simulations of two developmental versions of the Community Atmosphere Model (CAM) towards CAM6. The configuration called CAM5.4 introduces new microphysics, aerosol, and ice nucleation changes, among others to CAM. The CAM5.5 configuration represents a more radical departure, as it uses an assumed probability density function (PDF)-based unified cloud parameterization to replace the turbulence, shallow convection, and warm cloud macrophysics in CAM. This assumed PDF method has been widely used in the last decade in atmosphere-only climate simulations but has never been documented in coupled mode. Here, we compare the simulated coupled climates of CAM5.4 and CAM5.5 and compare them to the control coupled simulation produced by CAM5.3. We find that CAM5.5 has lower cloud forcing biases when compared to the control simulations. Improvements are also seen in the simulated amplitude of the Niño-3.4 index, an improved representation of the diurnal cycle of precipitation, subtropical surface wind stresses, and double Intertropical Convergence Zone biases. Degradations are seen in Amazon precipitation as well as slightly colder sea surface temperatures and thinner Arctic sea ice. Simulation of the 20th century results in a credible simulation that ends slightly colder than the control coupled simulation. The authors find this is due to aerosol indirect effects that are slightly stronger in the new version of the model and propose a solution to ameliorate this. Altogether, in these early coupled simulations, CAM5.5 produces a credible climate that is appropriate for science applications and is ready for integration into the National Center for Atmospheric Research's (NCAR's) next-generation climate model. |
author |
Bogenschutz, Peter A. Gettelman, Andrew Hannay, Cecile Larson, Vincent E. Neale, Richard B. Craig, Cheryl Chen, Chih -Chieh |
author_facet |
Bogenschutz, Peter A. Gettelman, Andrew Hannay, Cecile Larson, Vincent E. Neale, Richard B. Craig, Cheryl Chen, Chih -Chieh |
author_sort |
Bogenschutz, Peter A. |
title |
The path to CAM6: coupled simulations with CAM5.4 and CAM5.5 |
title_short |
The path to CAM6: coupled simulations with CAM5.4 and CAM5.5 |
title_full |
The path to CAM6: coupled simulations with CAM5.4 and CAM5.5 |
title_fullStr |
The path to CAM6: coupled simulations with CAM5.4 and CAM5.5 |
title_full_unstemmed |
The path to CAM6: coupled simulations with CAM5.4 and CAM5.5 |
title_sort |
path to cam6: coupled simulations with cam5.4 and cam5.5 |
publishDate |
2023 |
url |
http://www.osti.gov/servlets/purl/1463022 https://www.osti.gov/biblio/1463022 https://doi.org/10.5194/gmd-11-235-2018 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Sea ice |
genre_facet |
Arctic Sea ice |
op_relation |
http://www.osti.gov/servlets/purl/1463022 https://www.osti.gov/biblio/1463022 https://doi.org/10.5194/gmd-11-235-2018 doi:10.5194/gmd-11-235-2018 |
op_doi |
https://doi.org/10.5194/gmd-11-235-2018 |
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Geoscientific Model Development |
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11 |
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235 |
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255 |
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