Important Ice Processes Are Missed by the Community Earth System Model in Southern Ocean Mixed-Phase Clouds: Bridging SOCRATES Observations to Model Developments
Global climate models (GCMs) are challenged by difficulties in simulating cloud phase and cloud radiative effect over the Southern Ocean (SO). Some of the new-generation GCMs predict too much liquid and too little ice in mixed-phase clouds. This misrepresentation of cloud phase in GCMs results in we...
Published in: | Journal of Geophysical Research: Atmospheres |
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2023
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Online Access: | https://scholarworks.sjsu.edu/faculty_rsca/2240 https://doi.org/10.1029/2022JD037513 https://scholarworks.sjsu.edu/context/faculty_rsca/article/3239/viewcontent/Important_20Ice_20Processes_20Are_20Missed_20by_20the_20Community_20Earth_20System_20Model_20in_20Southern_20Ocean_20Mixed_Phase_20Clouds_20__20Bridging_20SOCRATES_20Observations_20to_20Model_20Developments.pdf |
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ftsanjosestate:oai:scholarworks.sjsu.edu:faculty_rsca-3239 2023-07-30T04:07:01+02:00 Important Ice Processes Are Missed by the Community Earth System Model in Southern Ocean Mixed-Phase Clouds: Bridging SOCRATES Observations to Model Developments Zhao, Xi Liu, Xiaohong Burrows, Susannah DeMott, Paul J. Diao, Minghui McFarquhar, Greg M. Patade, Sachin Phillips, Vaughan Roberts, Greg C. Sanchez, Kevin J. Shi, Yang Zhang, Meng 2023-02-27T08:00:00Z application/pdf https://scholarworks.sjsu.edu/faculty_rsca/2240 https://doi.org/10.1029/2022JD037513 https://scholarworks.sjsu.edu/context/faculty_rsca/article/3239/viewcontent/Important_20Ice_20Processes_20Are_20Missed_20by_20the_20Community_20Earth_20System_20Model_20in_20Southern_20Ocean_20Mixed_Phase_20Clouds_20__20Bridging_20SOCRATES_20Observations_20to_20Model_20Developments.pdf unknown SJSU ScholarWorks https://scholarworks.sjsu.edu/faculty_rsca/2240 doi:10.1029/2022JD037513 https://scholarworks.sjsu.edu/context/faculty_rsca/article/3239/viewcontent/Important_20Ice_20Processes_20Are_20Missed_20by_20the_20Community_20Earth_20System_20Model_20in_20Southern_20Ocean_20Mixed_Phase_20Clouds_20__20Bridging_20SOCRATES_20Observations_20to_20Model_20Developments.pdf Faculty Research, Scholarly, and Creative Activity cloud microphysics ice formation ice nucleating particle secondary ice production Meteorology and Climate Science text 2023 ftsanjosestate https://doi.org/10.1029/2022JD037513 2023-07-17T19:09:29Z Global climate models (GCMs) are challenged by difficulties in simulating cloud phase and cloud radiative effect over the Southern Ocean (SO). Some of the new-generation GCMs predict too much liquid and too little ice in mixed-phase clouds. This misrepresentation of cloud phase in GCMs results in weaker negative cloud feedback over the SO and a higher climate sensitivity. Based on a model comparison with observational data obtained during the Southern Ocean Cloud Radiation and Aerosol Transport Experimental Study, this study addresses a key uncertainty in the Community Earth System Model version 2 (CESM2) related to cloud phase, namely ice formation in pristine remote SO clouds. It is found that sea spray organic aerosols (SSOAs) are the most important type of ice nucleating particles (INPs) over the SO with concentrations 1 order of magnitude higher than those of dust INPs based on measurements and CESM2 simulations. Secondary ice production (SIP) which includes riming splintering, rain droplet shattering, and ice-ice collisional fragmentation as implemented in CESM2 is the dominant ice production process in moderately cold clouds with cloud temperatures greater than −20°C. SIP enhances the in-cloud ice number concentrations (Ni) by 1–3 orders of magnitude and predicts more mixed-phase (with percentage occurrence increased from 15% to 21%), in better agreement with the observations. This study highlights the importance of accurately representing the cloud phase over the pristine remote SO by considering the ice nucleation of SSOA and SIP processes, which are currently missing in most GCM cloud microphysics parameterizations. Text Southern Ocean San José State University: SJSU ScholarWorks Southern Ocean Journal of Geophysical Research: Atmospheres 128 4 |
institution |
Open Polar |
collection |
San José State University: SJSU ScholarWorks |
op_collection_id |
ftsanjosestate |
language |
unknown |
topic |
cloud microphysics ice formation ice nucleating particle secondary ice production Meteorology and Climate Science |
spellingShingle |
cloud microphysics ice formation ice nucleating particle secondary ice production Meteorology and Climate Science Zhao, Xi Liu, Xiaohong Burrows, Susannah DeMott, Paul J. Diao, Minghui McFarquhar, Greg M. Patade, Sachin Phillips, Vaughan Roberts, Greg C. Sanchez, Kevin J. Shi, Yang Zhang, Meng Important Ice Processes Are Missed by the Community Earth System Model in Southern Ocean Mixed-Phase Clouds: Bridging SOCRATES Observations to Model Developments |
topic_facet |
cloud microphysics ice formation ice nucleating particle secondary ice production Meteorology and Climate Science |
description |
Global climate models (GCMs) are challenged by difficulties in simulating cloud phase and cloud radiative effect over the Southern Ocean (SO). Some of the new-generation GCMs predict too much liquid and too little ice in mixed-phase clouds. This misrepresentation of cloud phase in GCMs results in weaker negative cloud feedback over the SO and a higher climate sensitivity. Based on a model comparison with observational data obtained during the Southern Ocean Cloud Radiation and Aerosol Transport Experimental Study, this study addresses a key uncertainty in the Community Earth System Model version 2 (CESM2) related to cloud phase, namely ice formation in pristine remote SO clouds. It is found that sea spray organic aerosols (SSOAs) are the most important type of ice nucleating particles (INPs) over the SO with concentrations 1 order of magnitude higher than those of dust INPs based on measurements and CESM2 simulations. Secondary ice production (SIP) which includes riming splintering, rain droplet shattering, and ice-ice collisional fragmentation as implemented in CESM2 is the dominant ice production process in moderately cold clouds with cloud temperatures greater than −20°C. SIP enhances the in-cloud ice number concentrations (Ni) by 1–3 orders of magnitude and predicts more mixed-phase (with percentage occurrence increased from 15% to 21%), in better agreement with the observations. This study highlights the importance of accurately representing the cloud phase over the pristine remote SO by considering the ice nucleation of SSOA and SIP processes, which are currently missing in most GCM cloud microphysics parameterizations. |
format |
Text |
author |
Zhao, Xi Liu, Xiaohong Burrows, Susannah DeMott, Paul J. Diao, Minghui McFarquhar, Greg M. Patade, Sachin Phillips, Vaughan Roberts, Greg C. Sanchez, Kevin J. Shi, Yang Zhang, Meng |
author_facet |
Zhao, Xi Liu, Xiaohong Burrows, Susannah DeMott, Paul J. Diao, Minghui McFarquhar, Greg M. Patade, Sachin Phillips, Vaughan Roberts, Greg C. Sanchez, Kevin J. Shi, Yang Zhang, Meng |
author_sort |
Zhao, Xi |
title |
Important Ice Processes Are Missed by the Community Earth System Model in Southern Ocean Mixed-Phase Clouds: Bridging SOCRATES Observations to Model Developments |
title_short |
Important Ice Processes Are Missed by the Community Earth System Model in Southern Ocean Mixed-Phase Clouds: Bridging SOCRATES Observations to Model Developments |
title_full |
Important Ice Processes Are Missed by the Community Earth System Model in Southern Ocean Mixed-Phase Clouds: Bridging SOCRATES Observations to Model Developments |
title_fullStr |
Important Ice Processes Are Missed by the Community Earth System Model in Southern Ocean Mixed-Phase Clouds: Bridging SOCRATES Observations to Model Developments |
title_full_unstemmed |
Important Ice Processes Are Missed by the Community Earth System Model in Southern Ocean Mixed-Phase Clouds: Bridging SOCRATES Observations to Model Developments |
title_sort |
important ice processes are missed by the community earth system model in southern ocean mixed-phase clouds: bridging socrates observations to model developments |
publisher |
SJSU ScholarWorks |
publishDate |
2023 |
url |
https://scholarworks.sjsu.edu/faculty_rsca/2240 https://doi.org/10.1029/2022JD037513 https://scholarworks.sjsu.edu/context/faculty_rsca/article/3239/viewcontent/Important_20Ice_20Processes_20Are_20Missed_20by_20the_20Community_20Earth_20System_20Model_20in_20Southern_20Ocean_20Mixed_Phase_20Clouds_20__20Bridging_20SOCRATES_20Observations_20to_20Model_20Developments.pdf |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Faculty Research, Scholarly, and Creative Activity |
op_relation |
https://scholarworks.sjsu.edu/faculty_rsca/2240 doi:10.1029/2022JD037513 https://scholarworks.sjsu.edu/context/faculty_rsca/article/3239/viewcontent/Important_20Ice_20Processes_20Are_20Missed_20by_20the_20Community_20Earth_20System_20Model_20in_20Southern_20Ocean_20Mixed_Phase_20Clouds_20__20Bridging_20SOCRATES_20Observations_20to_20Model_20Developments.pdf |
op_doi |
https://doi.org/10.1029/2022JD037513 |
container_title |
Journal of Geophysical Research: Atmospheres |
container_volume |
128 |
container_issue |
4 |
_version_ |
1772820072592572416 |