气候变化领域集成服务门户(CCPortal): Arctic cloud annual cycle biases in climate models

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DOI	10.5194/acp-19-8759-2019
	Arctic cloud annual cycle biases in climate models
	Taylor P.C.; Boeke R.C.; Li Y.; Thompson W.J.D.
发表日期	2019
ISSN	16807316
起始页码	8759
结束页码	8782
卷号	19 期号:13
英文摘要	Arctic clouds exhibit a robust annual cycle with maximum cloudiness in fall and minimum cloudiness in winter. These variations affect energy flows in the Arctic with a large influence on the surface radiative fluxes. Contemporary climate models struggle to reproduce the observed Arctic cloud amount annual cycle and significantly disagree with each other. The goal of this analysis is to quantify the cloud-influencing factors that contribute to winter-summer cloud amount differences, as these seasons are primarily responsible for the model discrepancies with observations. We find that differences in the total cloud amount annual cycle are primarily caused by differences in low, rather than high, clouds; the largest differences occur between the surface and 950 hPa. Grouping models based on their seasonal cycles of cloud amount and stratifying cloud amount by cloud-influencing factors, we find that model groups disagree most under strong lower tropospheric stability, weak to moderate mid-tropospheric subsidence, and cold lower tropospheric air temperatures. Intergroup differences in low cloud amount are found to be a function of lower tropospheric thermodynamic characteristics. Further, we find that models with a larger low cloud amount in winter have a larger ice condensate fraction, whereas models with a larger low cloud amount in summer have a smaller ice condensate fraction. Stratifying model output by the specifics of the cloud microphysical scheme reveals that models treating cloud ice and liquid condensate as separate prognostic variables simulate a larger ice condensate fraction than those that treat total cloud condensate as a prognostic variable and use a temperature-dependent phase partitioning. Thus, the cloud microphysical parameterization is the primary cause of inter-model differences in the Arctic cloud annual cycle, providing further evidence of the important role that cloud ice microphysical processes play in the evolution and modeling of the Arctic climate system. © 2019 Author(s). This work is distributed under the Creative Commons Attribution 4.0 License.
语种	英语
scopus关键词	annual variation; climate modeling; cloud classification; cloud cover; cloud microphysics; radiative forcing; seasonal variation
来源期刊	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/144291
作者单位	NASA Langley Research Center, Climate Science Branch, Hampton, VA, United States; Science Systems Applications Inc., Hampton, VA, United States; Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States
推荐引用方式 GB/T 7714	Taylor P.C.,Boeke R.C.,Li Y.,et al. Arctic cloud annual cycle biases in climate models[J],2019,19(13).
APA	Taylor P.C.,Boeke R.C.,Li Y.,&Thompson W.J.D..(2019).Arctic cloud annual cycle biases in climate models.Atmospheric Chemistry and Physics,19(13).
MLA	Taylor P.C.,et al."Arctic cloud annual cycle biases in climate models".Atmospheric Chemistry and Physics 19.13(2019).