Evaluating simplified chemical mechanisms within present-day simulations of the Community Earth System Model version 1.2 with CAM4 (CESM1.2 CAM-chem): MOZART-4 vs. Reduced Hydrocarbon vs. Super-Fast chemistry
While state-of-the-art complex chemical mechanisms expand our understanding of atmospheric chemistry, their sheer size and computational requirements often limit simulations to short lengths or ensembles to only a few members. Here we present and compare three 25-year present-day offline simulations...
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| Format: | Article |
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Copernicus GmbH
2019
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| Online Access: | http://hdl.handle.net/1721.1/120143 https://orcid.org/0000-0002-6396-5622 https://orcid.org/0000-0001-5925-3801 |
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| author | Tilmes, Simone Emmons, Louisa Lamarque, Jean-François Cameron-Smith, Philip Brown-Steiner, Benjamin E Selin, Noelle E Prinn, Ronald G |
| author2 | Massachusetts Institute of Technology. Center for Global Change Science |
| author_facet | Massachusetts Institute of Technology. Center for Global Change Science Tilmes, Simone Emmons, Louisa Lamarque, Jean-François Cameron-Smith, Philip Brown-Steiner, Benjamin E Selin, Noelle E Prinn, Ronald G |
| author_sort | Tilmes, Simone |
| collection | MIT |
| description | While state-of-the-art complex chemical mechanisms expand our understanding of atmospheric chemistry, their sheer size and computational requirements often limit simulations to short lengths or ensembles to only a few members. Here we present and compare three 25-year present-day offline simulations with chemical mechanisms of different levels of complexity using the Community Earth System Model (CESM) Version 1.2 CAM-chem (CAM4): the Model for Ozone and Related Chemical Tracers, version 4 (MOZART-4) mechanism, the Reduced Hydrocarbon mechanism, and the Super-Fast mechanism. We show that, for most regions and time periods, differences in simulated ozone chemistry between these three mechanisms are smaller than the model-observation differences themselves. The MOZART-4 mechanism and the Reduced Hydrocarbon are in close agreement in their representation of ozone throughout the troposphere during all time periods (annual, seasonal, and diurnal). While the Super-Fast mechanism tends to have higher simulated ozone variability and differs from the MOZART-4 mechanism over regions of high biogenic emissions, it is surprisingly capable of simulating ozone adequately given its simplicity. We explore the trade-offs between chemical mechanism complexity and computational cost by identifying regions where the simpler mechanisms are comparable to the MOZART-4 mechanism and regions where they are not. The Super-Fast mechanism is 3 times as fast as the MOZART-4 mechanism, which allows for longer simulations or ensembles with more members that may not be feasible with the MOZART-4 mechanism given limited computational resources. |
| first_indexed | 2024-09-23T13:36:40Z |
| format | Article |
| id | mit-1721.1/120143 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T13:36:40Z |
| publishDate | 2019 |
| publisher | Copernicus GmbH |
| record_format | dspace |
| spelling | mit-1721.1/1201432022-09-28T15:02:54Z Evaluating simplified chemical mechanisms within present-day simulations of the Community Earth System Model version 1.2 with CAM4 (CESM1.2 CAM-chem): MOZART-4 vs. Reduced Hydrocarbon vs. Super-Fast chemistry Tilmes, Simone Emmons, Louisa Lamarque, Jean-François Cameron-Smith, Philip Brown-Steiner, Benjamin E Selin, Noelle E Prinn, Ronald G Massachusetts Institute of Technology. Center for Global Change Science Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Massachusetts Institute of Technology. Institute for Data, Systems, and Society Massachusetts Institute of Technology. Joint Program on the Science & Policy of Global Change Brown-Steiner, Benjamin E Selin, Noelle E Prinn, Ronald G While state-of-the-art complex chemical mechanisms expand our understanding of atmospheric chemistry, their sheer size and computational requirements often limit simulations to short lengths or ensembles to only a few members. Here we present and compare three 25-year present-day offline simulations with chemical mechanisms of different levels of complexity using the Community Earth System Model (CESM) Version 1.2 CAM-chem (CAM4): the Model for Ozone and Related Chemical Tracers, version 4 (MOZART-4) mechanism, the Reduced Hydrocarbon mechanism, and the Super-Fast mechanism. We show that, for most regions and time periods, differences in simulated ozone chemistry between these three mechanisms are smaller than the model-observation differences themselves. The MOZART-4 mechanism and the Reduced Hydrocarbon are in close agreement in their representation of ozone throughout the troposphere during all time periods (annual, seasonal, and diurnal). While the Super-Fast mechanism tends to have higher simulated ozone variability and differs from the MOZART-4 mechanism over regions of high biogenic emissions, it is surprisingly capable of simulating ozone adequately given its simplicity. We explore the trade-offs between chemical mechanism complexity and computational cost by identifying regions where the simpler mechanisms are comparable to the MOZART-4 mechanism and regions where they are not. The Super-Fast mechanism is 3 times as fast as the MOZART-4 mechanism, which allows for longer simulations or ensembles with more members that may not be feasible with the MOZART-4 mechanism given limited computational resources. United States. Department of Energy (Grant DE-FG02-94ER61937) 2019-01-29T20:02:41Z 2019-01-29T20:02:41Z 2018-10 2018-08 2019-01-18T16:34:04Z Article http://purl.org/eprint/type/JournalArticle 1991-9603 1991-959X http://hdl.handle.net/1721.1/120143 Brown-Steiner, Benjamin et al. “Evaluating Simplified Chemical Mechanisms Within Present-Day Simulations of the Community Earth System Model Version 1.2 with CAM4 (CESM1.2 CAM-Chem): MOZART-4 Vs. Reduced Hydrocarbon Vs. Super-Fast Chemistry.” Geoscientific Model Development 11, 10 (October 2018): 4155–4174 © 2018 Author(s) https://orcid.org/0000-0002-6396-5622 https://orcid.org/0000-0001-5925-3801 http://dx.doi.org/10.5194/gmd-11-4155-2018 Geoscientific Model Development Creative Commons Attribution 4.0 International license https://creativecommons.org/licenses/by/4.0/ application/pdf Copernicus GmbH Copernicus |
| spellingShingle | Tilmes, Simone Emmons, Louisa Lamarque, Jean-François Cameron-Smith, Philip Brown-Steiner, Benjamin E Selin, Noelle E Prinn, Ronald G Evaluating simplified chemical mechanisms within present-day simulations of the Community Earth System Model version 1.2 with CAM4 (CESM1.2 CAM-chem): MOZART-4 vs. Reduced Hydrocarbon vs. Super-Fast chemistry |
| title | Evaluating simplified chemical mechanisms within present-day simulations of the Community Earth System Model version 1.2 with CAM4 (CESM1.2 CAM-chem): MOZART-4 vs. Reduced Hydrocarbon vs. Super-Fast chemistry |
| title_full | Evaluating simplified chemical mechanisms within present-day simulations of the Community Earth System Model version 1.2 with CAM4 (CESM1.2 CAM-chem): MOZART-4 vs. Reduced Hydrocarbon vs. Super-Fast chemistry |
| title_fullStr | Evaluating simplified chemical mechanisms within present-day simulations of the Community Earth System Model version 1.2 with CAM4 (CESM1.2 CAM-chem): MOZART-4 vs. Reduced Hydrocarbon vs. Super-Fast chemistry |
| title_full_unstemmed | Evaluating simplified chemical mechanisms within present-day simulations of the Community Earth System Model version 1.2 with CAM4 (CESM1.2 CAM-chem): MOZART-4 vs. Reduced Hydrocarbon vs. Super-Fast chemistry |
| title_short | Evaluating simplified chemical mechanisms within present-day simulations of the Community Earth System Model version 1.2 with CAM4 (CESM1.2 CAM-chem): MOZART-4 vs. Reduced Hydrocarbon vs. Super-Fast chemistry |
| title_sort | evaluating simplified chemical mechanisms within present day simulations of the community earth system model version 1 2 with cam4 cesm1 2 cam chem mozart 4 vs reduced hydrocarbon vs super fast chemistry |
| url | http://hdl.handle.net/1721.1/120143 https://orcid.org/0000-0002-6396-5622 https://orcid.org/0000-0001-5925-3801 |
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