气候变化领域集成服务门户(CCPortal): Sensitivity analysis of an aerosol-aware microphysics scheme in Weather Research and Forecasting (WRF) during case studies of fog in Namibia

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DOI	10.5194/acp-22-10221-2022
	Sensitivity analysis of an aerosol-aware microphysics scheme in Weather Research and Forecasting (WRF) during case studies of fog in Namibia
	Weston, Michael John; Piketh, Stuart John; Burnet, Frederic; Broccardo, Stephen; Denjean, Cyrielle; Bourrianne, Thierry; Formenti, Paola
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	10221
结束页码	10245
卷号	22 期号:15 页码:25
英文摘要	Aerosol-aware microphysics parameterisation schemes are increasingly being introduced into numerical weather prediction models, allowing for regional and case-specific parameterisation of cloud condensation nuclei (CCN) and cloud droplet interactions. In this paper, the Thompson aerosol-aware microphysics scheme, within the Weather Research and Forecasting (WRF) model, is used for two fog cases during September 2017 over Namibia. Measurements of CCN and fog microphysics were undertaken during the AErosols, RadiatiOn and CLOuds in southern Africa (AEROCLO-sA) field campaign at Henties Bay on the coast of Namibia during September 2017. A key concept of the microphysics scheme is the conversion of water-friendly aerosols to cloud droplets (hereafter referred to as CCN activation), which could be estimated from the observations. A fog monitor 100 (FM-100) provided cloud droplet size distribution, number concentration (N-t) , liquid water content (LWC), and mean volumetric diameter (MVD). These measurements are used to evaluate and parameterise WRF model simulations of N-t, LWC, and MVD. A sensitivity analysis was conducted through variations to the initial CCN concentration, CCN radius, and the minimum updraft speed, which are important factors that influence droplet activation in the microphysics scheme of the model. The first model scenario made use of the default settings with a constant initial CCN number concentration of 300 cm(-3) and underestimated the cloud droplet number concentration, while the LWC was in good agreement with the observations. This resulted in droplet size being larger than the observations. Another scenario used modelled data as CCN initial conditions, which were an order of magnitude higher than other scenarios. However, these provided the most realistic values of N-t, LWC, MVD, and droplet size distribution. From this, it was concluded that CCN activation of around 10 % in the simulations is too low, while the observed appears to be higher reaching between 20 % and 80 %, with a mean (median) of 0.55 (0.56) during fog events. To achieve this level of activation in the model, the minimum updraft speed for CCN activation was increased from 0.01 to 0.1 m s(-1). This scenario provided N-t, LWC, MVD, and droplet size distribution in the range of the observations, with the added benefit of a realistic initial CCN concentration. These results demonstrate the benefits of a dynamic aerosol-aware scheme when parameterised with observations.
学科领域	Environmental Sciences; Meteorology & Atmospheric Sciences
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000839563800001
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/273330
作者单位	Khalifa University of Science & Technology; North West University - South Africa; Centre National de la Recherche Scientifique (CNRS); Meteo France; Universite de Toulouse; Centre National de la Recherche Scientifique (CNRS); UDICE-French Research Universities; Universite Paris Cite; Universite Paris-Est-Creteil-Val-de-Marne (UPEC); National Aeronautics & Space Administration (NASA); NASA Ames Research Center
推荐引用方式 GB/T 7714	Weston, Michael John,Piketh, Stuart John,Burnet, Frederic,et al. Sensitivity analysis of an aerosol-aware microphysics scheme in Weather Research and Forecasting (WRF) during case studies of fog in Namibia[J],2022,22(15):25.
APA	Weston, Michael John.,Piketh, Stuart John.,Burnet, Frederic.,Broccardo, Stephen.,Denjean, Cyrielle.,...&Formenti, Paola.(2022).Sensitivity analysis of an aerosol-aware microphysics scheme in Weather Research and Forecasting (WRF) during case studies of fog in Namibia.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(15),25.
MLA	Weston, Michael John,et al."Sensitivity analysis of an aerosol-aware microphysics scheme in Weather Research and Forecasting (WRF) during case studies of fog in Namibia".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.15(2022):25.