LGM Paleoclimate Constraints Inform Cloud Parameterizations and Equilibrium Climate Sensitivity in CESM2

The Community Earth System Model version 2 (CESM2) simulates a high equilibrium climate sensitivity (ECS > 5°C) and a Last Glacial Maximum (LGM) that is substantially colder than proxy temperatures. In this study, we examine the role of cloud parameterizations in simulating the LGM cooling in CES...

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Main Authors: Zhu, Jiang, Otto-Bliesner, Bette L., Brady, Esther C., Gettelman, Andrew, Bacmeister, Julio T., Neale, Richard B., Poulsen, Christopher J., Shaw, Jonah K., McGraw, Zachary S., Kay, Jennifer E.
Format: Article in Journal/Newspaper
Language:unknown
Published: Wiley Periodicals, Inc. 2022
Subjects:
Online Access:https://hdl.handle.net/2027.42/172265
https://doi.org/10.1029/2021MS002776
id ftumdeepblue:oai:deepblue.lib.umich.edu:2027.42/172265
record_format openpolar
institution Open Polar
collection University of Michigan: Deep Blue
op_collection_id ftumdeepblue
language unknown
topic Community Earth System Model version 2
cloud parameterizations
cloud feedback
equilibrium climate sensitivity
Last Glacial Maximum
Geological Sciences
Science
spellingShingle Community Earth System Model version 2
cloud parameterizations
cloud feedback
equilibrium climate sensitivity
Last Glacial Maximum
Geological Sciences
Science
Zhu, Jiang
Otto-Bliesner, Bette L.
Brady, Esther C.
Gettelman, Andrew
Bacmeister, Julio T.
Neale, Richard B.
Poulsen, Christopher J.
Shaw, Jonah K.
McGraw, Zachary S.
Kay, Jennifer E.
LGM Paleoclimate Constraints Inform Cloud Parameterizations and Equilibrium Climate Sensitivity in CESM2
topic_facet Community Earth System Model version 2
cloud parameterizations
cloud feedback
equilibrium climate sensitivity
Last Glacial Maximum
Geological Sciences
Science
description The Community Earth System Model version 2 (CESM2) simulates a high equilibrium climate sensitivity (ECS > 5°C) and a Last Glacial Maximum (LGM) that is substantially colder than proxy temperatures. In this study, we examine the role of cloud parameterizations in simulating the LGM cooling in CESM2. Through substituting different versions of cloud schemes in the atmosphere model, we attribute the excessive LGM cooling to the new CESM2 schemes of cloud microphysics and ice nucleation. Further exploration suggests that removing an inappropriate limiter on cloud ice number (NoNimax) and decreasing the time-step size (substepping) in cloud microphysics largely eliminate the excessive LGM cooling. NoNimax produces a more physically consistent treatment of mixed-phase clouds, which leads to an increase in cloud ice content and a weaker shortwave cloud feedback over mid-to-high latitudes and the Southern Hemisphere subtropics. Microphysical substepping further weakens the shortwave cloud feedback. Based on NoNimax and microphysical substepping, we have developed a paleoclimate-calibrated CESM2 (PaleoCalibr), which simulates well the observed twentieth century warming and spatial characteristics of key cloud and climate variables. PaleoCalibr has a lower ECS (∼4°C) and a 20% weaker aerosol-cloud interaction than CESM2. PaleoCalibr represents a physically more consistent treatment of cloud microphysics than CESM2 and is a valuable tool in climate change studies, especially when a large climate forcing is involved. Our study highlights the unique value of paleoclimate constraints in informing the cloud parameterizations and ultimately the future climate projection.Plain Language SummaryThe Community Earth System Model version 2 (CESM2) shows a much higher equilibrium climate sensitivity (ECS > 5°C) than its predecessor models (≤4°C), which, if true, implies a greater future warming than previously thought and a more severe challenge for climate adaptation and mitigation. It is critical to determine whether the high ...
format Article in Journal/Newspaper
author Zhu, Jiang
Otto-Bliesner, Bette L.
Brady, Esther C.
Gettelman, Andrew
Bacmeister, Julio T.
Neale, Richard B.
Poulsen, Christopher J.
Shaw, Jonah K.
McGraw, Zachary S.
Kay, Jennifer E.
author_facet Zhu, Jiang
Otto-Bliesner, Bette L.
Brady, Esther C.
Gettelman, Andrew
Bacmeister, Julio T.
Neale, Richard B.
Poulsen, Christopher J.
Shaw, Jonah K.
McGraw, Zachary S.
Kay, Jennifer E.
author_sort Zhu, Jiang
title LGM Paleoclimate Constraints Inform Cloud Parameterizations and Equilibrium Climate Sensitivity in CESM2
title_short LGM Paleoclimate Constraints Inform Cloud Parameterizations and Equilibrium Climate Sensitivity in CESM2
title_full LGM Paleoclimate Constraints Inform Cloud Parameterizations and Equilibrium Climate Sensitivity in CESM2
title_fullStr LGM Paleoclimate Constraints Inform Cloud Parameterizations and Equilibrium Climate Sensitivity in CESM2
title_full_unstemmed LGM Paleoclimate Constraints Inform Cloud Parameterizations and Equilibrium Climate Sensitivity in CESM2
title_sort lgm paleoclimate constraints inform cloud parameterizations and equilibrium climate sensitivity in cesm2
publisher Wiley Periodicals, Inc.
publishDate 2022
url https://hdl.handle.net/2027.42/172265
https://doi.org/10.1029/2021MS002776
genre Arctic
genre_facet Arctic
op_relation Zhu, Jiang; Otto-Bliesner, Bette L.
Brady, Esther C.; Gettelman, Andrew; Bacmeister, Julio T.; Neale, Richard B.; Poulsen, Christopher J.; Shaw, Jonah K.; McGraw, Zachary S.; Kay, Jennifer E. (2022). "LGM Paleoclimate Constraints Inform Cloud Parameterizations and Equilibrium Climate Sensitivity in CESM2." Journal of Advances in Modeling Earth Systems 14(4): n/a-n/a.
1942-2466
https://hdl.handle.net/2027.42/172265
doi:10.1029/2021MS002776
Journal of Advances in Modeling Earth Systems
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Manabe, S., & Broccoli, A. J. ( 1985 ). A comparison of climate model sensitivity with data from the Last Glacial Maximum. Journal of the Atmospheric Sciences, 42 ( 23 ), 2643 – 2651. https://doi.org/10.1175/1520-0469(1985)042<2643:ACOCMS>2.0.CO;2
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Ohgaito, R., Abe-Ouchi, A., O’Ishi, R., Takemura, T., Ito, A., Hajima, T., et al. ( 2018 ). Effect of high dust amount on surface temperature during the Last Glacial Maximum: A modelling study using MIROC-ESM. Climate of the Past, 14 ( 11 ), 1565 – 1581. https://doi.org/10.5194/cp-14-1565-2018
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Sherwood, S. C., Webb, M. J., Annan, J. D., Armour, K. C., Forster, P. M., Hargreaves, J. C., et al. ( 2020 ). An assessment of Earth’s climate sensitivity using multiple lines of evidence. Reviews of Geophysics, 58 ( 4 ), e2019RG000678. https://doi.org/10.1029/2019RG000678
Shin, S. I., Liu, Z., Otto-Bliesner, B., Brady, E., Kutzbach, J., & Harrison, S. ( 2003 ). A simulation of the Last Glacial Maximum climate using the NCAR-CCSM. Climate Dynamics, 20 ( 2–3 ), 127 – 151. https://doi.org/10.1007/s00382-002-0260-x
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spelling ftumdeepblue:oai:deepblue.lib.umich.edu:2027.42/172265 2023-08-20T04:03:12+02:00 LGM Paleoclimate Constraints Inform Cloud Parameterizations and Equilibrium Climate Sensitivity in CESM2 Zhu, Jiang Otto-Bliesner, Bette L. Brady, Esther C. Gettelman, Andrew Bacmeister, Julio T. Neale, Richard B. Poulsen, Christopher J. Shaw, Jonah K. McGraw, Zachary S. Kay, Jennifer E. 2022-04 application/pdf https://hdl.handle.net/2027.42/172265 https://doi.org/10.1029/2021MS002776 unknown Wiley Periodicals, Inc. National Academy of Sciences Zhu, Jiang; Otto-Bliesner, Bette L. Brady, Esther C.; Gettelman, Andrew; Bacmeister, Julio T.; Neale, Richard B.; Poulsen, Christopher J.; Shaw, Jonah K.; McGraw, Zachary S.; Kay, Jennifer E. (2022). "LGM Paleoclimate Constraints Inform Cloud Parameterizations and Equilibrium Climate Sensitivity in CESM2." Journal of Advances in Modeling Earth Systems 14(4): n/a-n/a. 1942-2466 https://hdl.handle.net/2027.42/172265 doi:10.1029/2021MS002776 Journal of Advances in Modeling Earth Systems Patnaude, R., Diao, M., Liu, X., & Chu, S. ( 2021 ). Effects of thermodynamics, dynamics and aerosols on cirrus clouds based on in situ observations and NCAR CAM6. Atmospheric Chemistry and Physics, 21 ( 3 ), 1835 – 1859. https://doi.org/10.5194/acp-21-1835-2021 Manabe, S., & Broccoli, A. J. ( 1985 ). A comparison of climate model sensitivity with data from the Last Glacial Maximum. Journal of the Atmospheric Sciences, 42 ( 23 ), 2643 – 2651. https://doi.org/10.1175/1520-0469(1985)042<2643:ACOCMS>2.0.CO;2 Marchand, R., Ackerman, T., Smyth, M., & Rossow, W. B. ( 2010 ). A review of cloud top height and optical depth histograms from MISR, ISCCP, and MODIS. Journal of Geophysical Research, 115 ( D16 ), D16206. https://doi.org/10.1029/2009JD013422 Meehl, G. A., Arblaster, J. M., Bates, S., Richter, J. H., Tebaldi, C., Gettelman, A., et al. ( 2020 ). Characteristics of future warmer base states in CESM2. Earth and Space Science, 7 ( 9 ), e2020EA001296. https://doi.org/10.1029/2020ea001296 Meehl, G. A., Senior, C. A., Eyring, V., Flato, G., Lamarque, J.-F., Stouffer, R. J., et al. ( 2020 ). Context for interpreting equilibrium climate sensitivity and transient climate response from the CMIP6 Earth system models. Science Advances, 6 ( 26 ), eaba1981. https://doi.org/10.1126/sciadv.aba1981 Mülmenstädt, J., Salzmann, M., Kay, J. E., Zelinka, M. D., Ma, P.-L., Nam, C., et al. ( 2021 ). An underestimated negative cloud feedback from cloud lifetime changes. Nature Climate Change, 11 ( 6 ), 508 – 513. https://doi.org/10.1038/s41558-021-01038-1 Myers, T. A., Scott, R. C., Zelinka, M. D., Klein, S. A., Norris, J. R., & Caldwell, P. M. ( 2021 ). Observational constraints on low cloud feedback reduce uncertainty of climate sensitivity. Nature Climate Change, 11 ( 6 ), 501 – 507. https://doi.org/10.1038/s41558-021-01039-0 Nam, C., Bony, S., Dufresne, J.-L., & Chepfer, H. ( 2012 ). The ‘too few, too bright’ tropical low-cloud problem in CMIP5 models. Geophysical Research Letters, 39 ( 21 ). https://doi.org/10.1029/2012GL053421 Ohgaito, R., Abe-Ouchi, A., O’Ishi, R., Takemura, T., Ito, A., Hajima, T., et al. ( 2018 ). Effect of high dust amount on surface temperature during the Last Glacial Maximum: A modelling study using MIROC-ESM. Climate of the Past, 14 ( 11 ), 1565 – 1581. https://doi.org/10.5194/cp-14-1565-2018 Otto-Bliesner, B. L., Brady, E. C., Clauzet, G., Tomas, R., Levis, S., & Kothavala, Z. ( 2006 ). Last Glacial Maximum and Holocene climate in CCSM3. Journal of Climate, 19 ( 11 ), 2526 – 2544. https://doi.org/10.1175/JCLI3748.1 Peltier, W. R., Argus, D. F., & Drummond, R. ( 2015 ). Space geodesy constrains ice age terminal deglaciation: The global ICE-6G_C (VM5a) model. Journal of Geophysical Research: Solid Earth, 120 ( 1 ), 450 – 487. https://doi.org/10.1002/2014JB011176 Pincus, R., Platnick, S., Ackerman, S. A., Hemler, R. S., & Patrick Hofmann, R. J. ( 2012 ). Reconciling simulated and observed views of clouds: MODIS, ISCCP, and the limits of instrument simulators. Journal of Climate, 25 ( 13 ), 4699 – 4720. https://doi.org/10.1175/jcli-d-11-00267.1 Santos, S. P., Caldwell, P. M., & Bretherton, C. S. ( 2020 ). Numerically relevant timescales in the MG2 microphysics model. Journal of Advances in Modeling Earth Systems, 12 ( 4 ), e2019MS001972. https://doi.org/10.1029/2019MS001972 Schmittner, A., Urban, N. M., Shakun, J. D., Mahowald, N. M., Clark, P. U., Bartlein, P. J., et al. ( 2011 ). Climate sensitivity estimated from temperature reconstructions of the Last Glacial Maximum. Science, 334 ( 6061 ), 1385 – 1388. https://doi.org/10.1126/science.1203513 Shaw, J. K., McGraw, Z., Bruno, O., Storelvmo, T., & Hofer, S. ( 2022 ). Using satellite observations to evaluate model microphysical representation of Arctic mixed-phase clouds. Geophysical Research Letters, 49 ( 3 ), e2021GL096191. https://doi.org/10.1029/2021GL096191 Sherwood, S. C., Webb, M. J., Annan, J. D., Armour, K. C., Forster, P. M., Hargreaves, J. C., et al. ( 2020 ). An assessment of Earth’s climate sensitivity using multiple lines of evidence. Reviews of Geophysics, 58 ( 4 ), e2019RG000678. https://doi.org/10.1029/2019RG000678 Shin, S. I., Liu, Z., Otto-Bliesner, B., Brady, E., Kutzbach, J., & Harrison, S. ( 2003 ). A simulation of the Last Glacial Maximum climate using the NCAR-CCSM. Climate Dynamics, 20 ( 2–3 ), 127 – 151. https://doi.org/10.1007/s00382-002-0260-x Swales, D. J., Pincus, R., & Bodas-Salcedo, A. ( 2018 ). The Cloud Feedback Model Intercomparison Project Observational Simulator Package: Version 2. Geoscientific Model Development, 11 ( 1 ), 77 – 81. https://doi.org/10.5194/gmd-11-77-2018 Tan, I., Storelvmo, T., & Zelinka, M. D. 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Proceedings of the National Academy of Sciences, 107 ( 25 ), 11217 – 11222. https://doi.org/10.1073/pnas.0910818107 IndexNoFollow Community Earth System Model version 2 cloud parameterizations cloud feedback equilibrium climate sensitivity Last Glacial Maximum Geological Sciences Science Article 2022 ftumdeepblue https://doi.org/10.1029/2021MS00277610.1029/2020ea00129610.1126/sciadv.aba198110.1038/s41558-021-01038-110.5194/cp-14-1565-201810.1126/science.120351310.1029/2019RG00067810.1029/2000JD90071910.1175/JCLI4143.110.1029/2019GL08578210.1002/2017GL07340610.5194 2023-07-31T20:31:48Z The Community Earth System Model version 2 (CESM2) simulates a high equilibrium climate sensitivity (ECS > 5°C) and a Last Glacial Maximum (LGM) that is substantially colder than proxy temperatures. In this study, we examine the role of cloud parameterizations in simulating the LGM cooling in CESM2. Through substituting different versions of cloud schemes in the atmosphere model, we attribute the excessive LGM cooling to the new CESM2 schemes of cloud microphysics and ice nucleation. Further exploration suggests that removing an inappropriate limiter on cloud ice number (NoNimax) and decreasing the time-step size (substepping) in cloud microphysics largely eliminate the excessive LGM cooling. NoNimax produces a more physically consistent treatment of mixed-phase clouds, which leads to an increase in cloud ice content and a weaker shortwave cloud feedback over mid-to-high latitudes and the Southern Hemisphere subtropics. Microphysical substepping further weakens the shortwave cloud feedback. Based on NoNimax and microphysical substepping, we have developed a paleoclimate-calibrated CESM2 (PaleoCalibr), which simulates well the observed twentieth century warming and spatial characteristics of key cloud and climate variables. PaleoCalibr has a lower ECS (∼4°C) and a 20% weaker aerosol-cloud interaction than CESM2. PaleoCalibr represents a physically more consistent treatment of cloud microphysics than CESM2 and is a valuable tool in climate change studies, especially when a large climate forcing is involved. Our study highlights the unique value of paleoclimate constraints in informing the cloud parameterizations and ultimately the future climate projection.Plain Language SummaryThe Community Earth System Model version 2 (CESM2) shows a much higher equilibrium climate sensitivity (ECS > 5°C) than its predecessor models (≤4°C), which, if true, implies a greater future warming than previously thought and a more severe challenge for climate adaptation and mitigation. It is critical to determine whether the high ... Article in Journal/Newspaper Arctic University of Michigan: Deep Blue