气候变化领域集成服务门户(CCPortal): Impacts of Greenland Block Location on Clouds and Surface Energy Fluxes Over the Greenland Ice Sheet

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DOI	10.1029/2020JD033172
	Impacts of Greenland Block Location on Clouds and Surface Energy Fluxes Over the Greenland Ice Sheet
	Ward J.L.; Flanner M.G.; Dunn-Sigouin E.
发表日期	2020
ISSN	2169897X
卷号	125 期号:22
英文摘要	Clouds and blocking activity have been implicated as causes of increased Greenland Ice Sheet (GrIS) melt in the 21st century. Although Greenland blocks (i.e., long-lasting, mostly stationary anticyclones) generally reduce cloud cover and move warm air over Greenland, the elevated GrIS perturbs air and moisture transport in complex ways, implying a need to better understand how blocks affect cloud and surface energy flux anomaly patterns. In this study, we use a combination of daily MODIS cloud data and meteorological and energy flux data from MERRA-2 reanalysis to better understand how Greenland block location, separated into four equal-area quadrants, affects regional cloud and surface energy flux spatial patterns in the summer months of 2002–2018. Overall, cloud fraction and cloud water path reductions are approximately four times greater during northern block days than southern block days. Net cloud radiative forcing anomalies are negative for all Greenland block locations because negative longwave cloud radiative forcing anomalies exceed positive shortwave cloud radiative forcing changes. However, greater cloud cover reductions during northern block days produce more negative net cloud radiative forcing anomalies than southern block days. Greenland-average (i.e., latitude-weighted average of all GrIS grids) net surface energy flux anomalies range from +7 to +12W/m2 for all block quadrants. While net shortwave energy anomalies dominate the total surface energy response during western Greenland block days, sensible heating is responsible for approximately half of positive total surface energy change during eastern Greenland block days. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	cloud radiative forcing; clouds; Greenland block location; Greenland Ice Sheet; surface energy flux
语种	英语
来源期刊	Journal of Geophysical Research: Atmospheres
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/185655
作者单位	Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, United States; Geophysical Institute, University of Bergen and Bjerknes Center for Climate Research, Bergen, Norway
推荐引用方式 GB/T 7714	Ward J.L.,Flanner M.G.,Dunn-Sigouin E.. Impacts of Greenland Block Location on Clouds and Surface Energy Fluxes Over the Greenland Ice Sheet[J],2020,125(22).
APA	Ward J.L.,Flanner M.G.,&Dunn-Sigouin E..(2020).Impacts of Greenland Block Location on Clouds and Surface Energy Fluxes Over the Greenland Ice Sheet.Journal of Geophysical Research: Atmospheres,125(22).
MLA	Ward J.L.,et al."Impacts of Greenland Block Location on Clouds and Surface Energy Fluxes Over the Greenland Ice Sheet".Journal of Geophysical Research: Atmospheres 125.22(2020).