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DOI	10.5194/acp-19-9847-2019
	Response of Arctic mixed-phase clouds to aerosol perturbations under different surface forcings
	Eirund G.K.; Possner A.; Lohmann U.
发表日期	2019
ISSN	16807316
起始页码	9847
结束页码	9864
卷号	19 期号:15
英文摘要	The formation and persistence of low-lying mixed-phase clouds (MPCs) in the Arctic depends on a multitude of processes, such as surface conditions, the environmental state, air mass advection, and the ambient aerosol concentration. In this study, we focus on the relative importance of different instantaneous aerosol perturbations (cloud condensation nuclei and ice-nucleating particles; CCN and INPs, respectively) on MPC properties in the European Arctic. To address this topic, we performed high-resolution large-eddy simulation (LES) experiments using the Consortium for Small-scale Modeling (COSMO) model and designed a case study for the Aerosol-Cloud Coupling and Climate Interactions in the Arctic (ACCACIA) campaign in March 2013. Motivated by ongoing sea ice retreat, we performed all sensitivity studies over open ocean and sea ice to investigate the effect of changing surface conditions. We find that surface conditions highly impact cloud dynamics, consistent with the ACCACIA observations: over sea ice, a rather homogeneous, optically thin, mixed-phase stratus cloud forms. In contrast, the MPC over the open ocean has a stratocumulus-like cloud structure. With cumuli feeding moisture into the stratus layer, the cloud over the open ocean features a higher liquid (LWP) and ice water path (IWP) and has a lifted cloud base and cloud top compared to the cloud over sea ice. Furthermore, we analyzed the aerosol impact on the sea ice and open ocean cloud regime. Perturbation aerosol concentrations relevant for CCN activation were increased to a range between 100 and 1000 cm-3 and icenucleating particle perturbations were increased by 100% and 300% compared to the background concentration (at every grid point and at all levels). The perturbations are prognostic to allow for fully interactive aerosol-cloud interactions. Perturbations in the INP concentration increase IWP and decrease LWP consistently in both regimes. The cloud microphysical response to potential CCN perturbations occurs faster in the stratocumulus regime over the ocean, where the increased moisture flux favors rapid cloud droplet formation and growth, leading to an increase in LWP following the aerosol injection. In addition, IWP increases through new ice crystal formation by increased immersion freezing, cloud top rise, and subsequent growth by deposition. Over sea ice, the maximum response in LWP and IWP is delayed and weakened compared to the response over the open ocean surface. Additionally, we find the long-term response to aerosol perturbations to be highly dependent on the cloud regime. Over the open ocean, LWP perturbations are efficiently buffered after 18 h simulation time. Increased ice and precipitation formation relax the LWP back to its unperturbed range. On the contrary, over sea ice the cloud evolution remains substantially perturbed with CCN perturbations ranging from 200 to 1000CCNcm-3. © 2019 Author(s).
语种	英语
scopus关键词	aerosol; atmospheric forcing; cloud condensation nucleus; ice retreat; large eddy simulation; mixed layer; open ocean; perturbation; sea ice; stratocumulus; Arctic
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/144240
作者单位	Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland; Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, United States; Institute for Atmospheric and Environmental Sciences, Goethe University Frankfurt, Frankfurt, Germany
推荐引用方式 GB/T 7714	Eirund G.K.,Possner A.,Lohmann U.. Response of Arctic mixed-phase clouds to aerosol perturbations under different surface forcings[J],2019,19(15).
APA	Eirund G.K.,Possner A.,&Lohmann U..(2019).Response of Arctic mixed-phase clouds to aerosol perturbations under different surface forcings.Atmospheric Chemistry and Physics,19(15).
MLA	Eirund G.K.,et al."Response of Arctic mixed-phase clouds to aerosol perturbations under different surface forcings".Atmospheric Chemistry and Physics 19.15(2019).