Employing airborne radiation and cloud microphysics observations to improve cloud representation in ICON at kilometer-scale resolution in the Arctic

doi:10.5194/acp-2020-641

GSTDTAP > 地球科学

DOI	10.5194/acp-2020-641
	Employing airborne radiation and cloud microphysics observations to improve cloud representation in ICON at kilometer-scale resolution in the Arctic
	Jan Kretzschmar, Johannes Stapf, Daniel Klocke, Manfred Wendisch, and Johannes Quaas
	2020-07-02
发表期刊	Atmospheric Chemistry and Physics
出版年	2020
英文摘要	Clouds play a potentially important role in Arctic climate change, but are poorly represented in current atmospheric models across scales. To improve the representation of Arctic clouds in models, it is necessary to compare models to observations to consequently reduce this uncertainty. This study compares aircraft observations from the Arctic Cloud Observations Using Airborne Measurements during Polar Day (ACLOUD) campaign in May/June 2017 around Svalbard, Norway – to simulations using the ICON (ICOsahedral Non-hydrostatic) model in its numerical weather prediction (NWP) set-up at 1.2 km resolution. By comparing measurements of solar and terrestrial irradiances during ACLOUD flights to the respective properties in ICON, we showed that the model systematically overestimates the transmissivity of the mostly liquid clouds during the campaign. This model bias is traced back to the way cloud condensation nuclei (CCN) get activated into cloud droplets in the two-moment, bulk microphysical scheme used in this study. This process is parameterized as function of grid-scale vertical velocity in the microphysical scheme used, but in-cloud turbulence cannot sufficiently be resolved at 1.2 km horizontal resolution in Arctic clouds. By parameterizing subgrid-scale vertical motion as a function of turbulent kinetic energy, we are able to achieve a more realistic CCN activation into cloud droplets. Additionally, we showed that by scaling the presently used CCN activation profile, the hydrometeor number concentration could be modified to be in better agreement with ACLOUD observations in our revised CCN activation parameterization. This consequently results in an improved representation of cloud optical properties in our ICON simulations.
领域	地球科学
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引用统计
文献类型	期刊论文
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/281735
专题	地球科学
推荐引用方式 GB/T 7714	Jan Kretzschmar, Johannes Stapf, Daniel Klocke, Manfred Wendisch, and Johannes Quaas. Employing airborne radiation and cloud microphysics observations to improve cloud representation in ICON at kilometer-scale resolution in the Arctic[J]. Atmospheric Chemistry and Physics,2020.
APA	Jan Kretzschmar, Johannes Stapf, Daniel Klocke, Manfred Wendisch, and Johannes Quaas.(2020).Employing airborne radiation and cloud microphysics observations to improve cloud representation in ICON at kilometer-scale resolution in the Arctic.Atmospheric Chemistry and Physics.
MLA	Jan Kretzschmar, Johannes Stapf, Daniel Klocke, Manfred Wendisch, and Johannes Quaas."Employing airborne radiation and cloud microphysics observations to improve cloud representation in ICON at kilometer-scale resolution in the Arctic".Atmospheric Chemistry and Physics (2020).