气候变化领域集成服务门户(CCPortal): CO2 Increase Experiments Using the CESM: Relationship to Climate Sensitivity and Comparison of CESM1 to CESM2

CCPortal

DOI	10.1029/2020MS002120
	CO2 Increase Experiments Using the CESM: Relationship to Climate Sensitivity and Comparison of CESM1 to CESM2
	Bacmeister J.T.; Hannay C.; Medeiros B.; Gettelman A.; Neale R.; Fredriksen H.B.; Lipscomb W.H.; Simpson I.; Bailey D.A.; Holland M.; Lindsay K.; Otto-Bliesner B.
发表日期	2020
ISSN	19422466
卷号	12 期号:11
英文摘要	We examine the response of the Community Earth System Model Versions 1 and 2 (CESM1 and CESM2) to abrupt quadrupling of atmospheric CO2 concentrations (4xCO2) and to 1% annually increasing CO2 concentrations (1%CO2). Different estimates of equilibrium climate sensitivity (ECS) for CESM1 and CESM2 are presented. All estimates show that the sensitivity of CESM2 has increased by 1.5 K or more over that of CESM1. At the same time the transient climate response (TCR) of CESM1 and CESM2 derived from 1%CO2 experiments has not changed significantly—2.1 K in CESM1 and 2.0 K in CESM2. Increased initial forcing as well as stronger shortwave radiation feedbacks are responsible for the increase in ECS seen in CESM2. A decomposition of regional radiation feedbacks and their contribution to global feedbacks shows that the Southern Ocean plays a key role in the overall behavior of 4xCO2 experiments, accounting for about 50% of the total shortwave feedback in both CESM1 and CESM2. The Southern Ocean is also responsible for around half of the increase in shortwave feedback between CESM1 and CESM2, with a comparable contribution arising over tropical ocean. Experiments using a thermodynamic slab-ocean model (SOM) yield estimates of ECS that are in remarkable agreement with those from fully coupled Earth system model (ESM) experiments for the same level of CO2 increase. Finally, we show that the similarity of TCR in CESM1 and CESM2 masks significant regional differences in warming that occur in the 1%CO2 experiments for each model. ©2020. The Authors.
英文关键词	climate sensitivity; cloud feedback
语种	英语
scopus关键词	Oceanography; Climate response; Climate sensitivity; CO2 concentration; Earth system model; Global feedback; Regional differences; Short-wave radiation; Slab ocean models; Carbon dioxide; air-sea interaction; carbon dioxide; carbon dioxide enrichment; climate feedback; climate modeling; decomposition analysis; global warming; sensitivity analysis; shortwave radiation; thermodynamics; Southern Ocean
来源期刊	Journal of Advances in Modeling Earth Systems
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/156585
作者单位	Climate and Global Dynamics Laboratory, NCAR, Boulder, CO, United States; Department of Physics and Technology, UiT the Arctic University of Norway, Tromsø, Norway
推荐引用方式 GB/T 7714	Bacmeister J.T.,Hannay C.,Medeiros B.,et al. CO2 Increase Experiments Using the CESM: Relationship to Climate Sensitivity and Comparison of CESM1 to CESM2[J],2020,12(11).
APA	Bacmeister J.T..,Hannay C..,Medeiros B..,Gettelman A..,Neale R..,...&Otto-Bliesner B..(2020).CO2 Increase Experiments Using the CESM: Relationship to Climate Sensitivity and Comparison of CESM1 to CESM2.Journal of Advances in Modeling Earth Systems,12(11).
MLA	Bacmeister J.T.,et al."CO2 Increase Experiments Using the CESM: Relationship to Climate Sensitivity and Comparison of CESM1 to CESM2".Journal of Advances in Modeling Earth Systems 12.11(2020).