气候变化领域集成服务门户(CCPortal): Exploring Impacts of Size-Dependent Evaporation and Entrainment in a Global Model

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DOI	10.1029/2019JD031817
	Exploring Impacts of Size-Dependent Evaporation and Entrainment in a Global Model
	Karset I.H.H.; Gettelman A.; Storelvmo T.; Alterskjær K.; Berntsen T.K.
发表日期	2020
ISSN	2169897X
卷号	125 期号:4
英文摘要	While most observations indicate well-buffered clouds to aerosol perturbations, global models do not. Among the suggested mechanisms for this discrepancy is the models' lack of connections between cloud droplet size and two processes that can contribute to reduced cloudiness when droplets become more numerous and smaller: evaporation and entrainment. In this study, we explore different implementations of size-dependent evaporation and entrainment in the global atmospheric model CAM5.3-Oslo. We study their impact on the preindustrial-to-present day change in liquid water path ((Formula presented.)) and the corresponding aerosol indirect effect ((Formula presented.)). Impacts of the 2014–2015 fissure eruption in Holuhraun, Iceland, are also presented. Our entrainment modifications only have a moderate effect on (Formula presented.) (changes from (Formula presented.) 1.07 W m (Formula presented.) to (Formula presented.) 0.98 W m (Formula presented.)), and a small impact on the signal from the Holuhraun eruption compared to other suggested compensating mechanisms. Simulations with added size-dependent evaporation in the top of the stratiform clouds also show small evaporation differences between PI and PD. Moderate changes in (Formula presented.) were achieved when also including an entrainment feedback to the evaporation changes, mixing air between the cloudtop layer and the layer above. These changes were not associated with the size dependency, but changes in the cloud susceptibility to aerosols in both PI and PD when adding evaporation. We find that increased evaporation of smaller droplets at stratiform cloud tops can reduce (Formula presented.), but can increase (Formula presented.) in some areas due to enhanced shallow convection caused by destabilization. ©2020. The Authors.
英文关键词	aerosols; climate; clouds; GCM; model; radiation
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/186175
作者单位	Department of Geosciences, Section for Meteorology and Oceanography, University of Oslo, Oslo, Norway; National Center for Atmospheric Research, Boulder, CO, United States; CICERO Center for International Climate Research, Oslo, Norway
推荐引用方式 GB/T 7714	Karset I.H.H.,Gettelman A.,Storelvmo T.,et al. Exploring Impacts of Size-Dependent Evaporation and Entrainment in a Global Model[J],2020,125(4).
APA	Karset I.H.H.,Gettelman A.,Storelvmo T.,Alterskjær K.,&Berntsen T.K..(2020).Exploring Impacts of Size-Dependent Evaporation and Entrainment in a Global Model.Journal of Geophysical Research: Atmospheres,125(4).
MLA	Karset I.H.H.,et al."Exploring Impacts of Size-Dependent Evaporation and Entrainment in a Global Model".Journal of Geophysical Research: Atmospheres 125.4(2020).