Toward a minimal representation of aerosols in climate models: description and evaluation in the Community Atmosphere Model CAM5
A modal aerosol module (MAM) has been developed for the Community Atmosphere Model version 5 (CAM5), the atmospheric component of the Community Earth System Model version 1 (CESM1). MAM is capable of simulating the aerosol size distribution and both internal and external mixing between aerosol compo...
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Copernicus Publications
2012
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Online Access: | https://doi.org/10.5194/gmd-5-709-2012 https://doaj.org/article/da6fd867a0eb467fb99e302d28ddf079 |
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ftdoajarticles:oai:doaj.org/article:da6fd867a0eb467fb99e302d28ddf079 2023-05-15T15:15:25+02:00 Toward a minimal representation of aerosols in climate models: description and evaluation in the Community Atmosphere Model CAM5 X. Liu R. C. Easter S. J. Ghan R. Zaveri P. Rasch X. Shi J.-F. Lamarque A. Gettelman H. Morrison F. Vitt A. Conley S. Park R. Neale C. Hannay A. M. L. Ekman P. Hess N. Mahowald W. Collins M. J. Iacono C. S. Bretherton M. G. Flanner D. Mitchell 2012-05-01T00:00:00Z https://doi.org/10.5194/gmd-5-709-2012 https://doaj.org/article/da6fd867a0eb467fb99e302d28ddf079 EN eng Copernicus Publications http://www.geosci-model-dev.net/5/709/2012/gmd-5-709-2012.pdf https://doaj.org/toc/1991-959X https://doaj.org/toc/1991-9603 doi:10.5194/gmd-5-709-2012 1991-959X 1991-9603 https://doaj.org/article/da6fd867a0eb467fb99e302d28ddf079 Geoscientific Model Development, Vol 5, Iss 3, Pp 709-739 (2012) Geology QE1-996.5 article 2012 ftdoajarticles https://doi.org/10.5194/gmd-5-709-2012 2022-12-30T21:48:09Z A modal aerosol module (MAM) has been developed for the Community Atmosphere Model version 5 (CAM5), the atmospheric component of the Community Earth System Model version 1 (CESM1). MAM is capable of simulating the aerosol size distribution and both internal and external mixing between aerosol components, treating numerous complicated aerosol processes and aerosol physical, chemical and optical properties in a physically-based manner. Two MAM versions were developed: a more complete version with seven lognormal modes (MAM7), and a version with three lognormal modes (MAM3) for the purpose of long-term (decades to centuries) simulations. In this paper a description and evaluation of the aerosol module and its two representations are provided. Sensitivity of the aerosol lifecycle to simplifications in the representation of aerosol is discussed. Simulated sulfate and secondary organic aerosol (SOA) mass concentrations are remarkably similar between MAM3 and MAM7. Differences in primary organic matter (POM) and black carbon (BC) concentrations between MAM3 and MAM7 are also small (mostly within 10%). The mineral dust global burden differs by 10% and sea salt burden by 30–40% between MAM3 and MAM7, mainly due to the different size ranges for dust and sea salt modes and different standard deviations of the log-normal size distribution for sea salt modes between MAM3 and MAM7. The model is able to qualitatively capture the observed geographical and temporal variations of aerosol mass and number concentrations, size distributions, and aerosol optical properties. However, there are noticeable biases; e.g., simulated BC concentrations are significantly lower than measurements in the Arctic. There is a low bias in modeled aerosol optical depth on the global scale, especially in the developing countries. These biases in aerosol simulations clearly indicate the need for improvements of aerosol processes (e.g., emission fluxes of anthropogenic aerosols and precursor gases in developing countries, boundary layer nucleation) and ... Article in Journal/Newspaper Arctic black carbon Directory of Open Access Journals: DOAJ Articles Arctic Geoscientific Model Development 5 3 709 739 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Geology QE1-996.5 |
spellingShingle |
Geology QE1-996.5 X. Liu R. C. Easter S. J. Ghan R. Zaveri P. Rasch X. Shi J.-F. Lamarque A. Gettelman H. Morrison F. Vitt A. Conley S. Park R. Neale C. Hannay A. M. L. Ekman P. Hess N. Mahowald W. Collins M. J. Iacono C. S. Bretherton M. G. Flanner D. Mitchell Toward a minimal representation of aerosols in climate models: description and evaluation in the Community Atmosphere Model CAM5 |
topic_facet |
Geology QE1-996.5 |
description |
A modal aerosol module (MAM) has been developed for the Community Atmosphere Model version 5 (CAM5), the atmospheric component of the Community Earth System Model version 1 (CESM1). MAM is capable of simulating the aerosol size distribution and both internal and external mixing between aerosol components, treating numerous complicated aerosol processes and aerosol physical, chemical and optical properties in a physically-based manner. Two MAM versions were developed: a more complete version with seven lognormal modes (MAM7), and a version with three lognormal modes (MAM3) for the purpose of long-term (decades to centuries) simulations. In this paper a description and evaluation of the aerosol module and its two representations are provided. Sensitivity of the aerosol lifecycle to simplifications in the representation of aerosol is discussed. Simulated sulfate and secondary organic aerosol (SOA) mass concentrations are remarkably similar between MAM3 and MAM7. Differences in primary organic matter (POM) and black carbon (BC) concentrations between MAM3 and MAM7 are also small (mostly within 10%). The mineral dust global burden differs by 10% and sea salt burden by 30–40% between MAM3 and MAM7, mainly due to the different size ranges for dust and sea salt modes and different standard deviations of the log-normal size distribution for sea salt modes between MAM3 and MAM7. The model is able to qualitatively capture the observed geographical and temporal variations of aerosol mass and number concentrations, size distributions, and aerosol optical properties. However, there are noticeable biases; e.g., simulated BC concentrations are significantly lower than measurements in the Arctic. There is a low bias in modeled aerosol optical depth on the global scale, especially in the developing countries. These biases in aerosol simulations clearly indicate the need for improvements of aerosol processes (e.g., emission fluxes of anthropogenic aerosols and precursor gases in developing countries, boundary layer nucleation) and ... |
format |
Article in Journal/Newspaper |
author |
X. Liu R. C. Easter S. J. Ghan R. Zaveri P. Rasch X. Shi J.-F. Lamarque A. Gettelman H. Morrison F. Vitt A. Conley S. Park R. Neale C. Hannay A. M. L. Ekman P. Hess N. Mahowald W. Collins M. J. Iacono C. S. Bretherton M. G. Flanner D. Mitchell |
author_facet |
X. Liu R. C. Easter S. J. Ghan R. Zaveri P. Rasch X. Shi J.-F. Lamarque A. Gettelman H. Morrison F. Vitt A. Conley S. Park R. Neale C. Hannay A. M. L. Ekman P. Hess N. Mahowald W. Collins M. J. Iacono C. S. Bretherton M. G. Flanner D. Mitchell |
author_sort |
X. Liu |
title |
Toward a minimal representation of aerosols in climate models: description and evaluation in the Community Atmosphere Model CAM5 |
title_short |
Toward a minimal representation of aerosols in climate models: description and evaluation in the Community Atmosphere Model CAM5 |
title_full |
Toward a minimal representation of aerosols in climate models: description and evaluation in the Community Atmosphere Model CAM5 |
title_fullStr |
Toward a minimal representation of aerosols in climate models: description and evaluation in the Community Atmosphere Model CAM5 |
title_full_unstemmed |
Toward a minimal representation of aerosols in climate models: description and evaluation in the Community Atmosphere Model CAM5 |
title_sort |
toward a minimal representation of aerosols in climate models: description and evaluation in the community atmosphere model cam5 |
publisher |
Copernicus Publications |
publishDate |
2012 |
url |
https://doi.org/10.5194/gmd-5-709-2012 https://doaj.org/article/da6fd867a0eb467fb99e302d28ddf079 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic black carbon |
genre_facet |
Arctic black carbon |
op_source |
Geoscientific Model Development, Vol 5, Iss 3, Pp 709-739 (2012) |
op_relation |
http://www.geosci-model-dev.net/5/709/2012/gmd-5-709-2012.pdf https://doaj.org/toc/1991-959X https://doaj.org/toc/1991-9603 doi:10.5194/gmd-5-709-2012 1991-959X 1991-9603 https://doaj.org/article/da6fd867a0eb467fb99e302d28ddf079 |
op_doi |
https://doi.org/10.5194/gmd-5-709-2012 |
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Geoscientific Model Development |
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3 |
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709 |
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