DOI: 10.1002/2017MS001104
Scopus记录号: 2-s2.0-85034412013
论文题名: Stratocumulus to Cumulus Transition by Drizzle
作者: Yamaguchi T ; , Feingold G ; , Kazil J
刊名: Journal of Advances in Modeling Earth Systems
ISSN: 19422466
出版年: 2017
卷: 9, 期: 6 起始页码: 2333
结束页码: 2349
语种: 英语
英文关键词: Aerosols
; Air entrainment
; Budget control
; Drops
; Large eddy simulation
; Precipitation (meteorology)
; Sodium
; Aerosol clouds
; Bulk microphysics
; Cloud droplet number concentrations
; Cumulus cloud
; Droplet concentration
; Stratocumulus clouds
; Stratocumulus to cumulus transition
; Time varying
; Clouds
; aerosol
; cloud droplet
; cloud water
; concentration (composition)
; drizzle
; large eddy simulation
; precipitation (climatology)
; stratocumulus
英文摘要: The stratocumulus to cumulus transition (SCT) is typically considered to be a slow, multiday process, caused primarily by dry air entrainment associated with overshooting cumulus, with minor influence of drizzle. This study revisits the role of drizzle in the SCT with large eddy simulations coupled with a two-moment bulk microphysics scheme that includes a budget on aerosol (Na) and cloud droplet number concentrations (Nc). We show a strong precipitation-induced modulation of the SCT by drizzle initiated in penetrative cumulus under stratocumulus. Lagrangian SCT simulations are initiated with various, moderate Na (100–250 cm−3), which produce little to no drizzle from the stratocumulus. As expected, drizzle formation in cumuli is regulated by cloud depth and Nc, with stronger dependence on cloud depth, so that, for the current case, drizzle is generated in all simulations once cumulus clouds become sufficiently deep. The drizzle generated in the cumuli washes out stratocumulus cloud water and much of the aerosol, and a cumulus state appears for approximately 10 h. With additional simulations with a fixed Nc (100 cm−3), we show that prediction of Nc is necessary for this fast SCT since it is a result of a positive feedback of collision-coalescence-induced aerosol depletion that enhances drizzle formation. A fixed Nc does not permit this feedback, and thus results in weak influence of drizzle on the SCT. Simulations with fixed droplet concentrations that bracket the time varying aerosol/drop concentrations are therefore not representative of the role of drizzle in the SCT. © 2017. The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75720
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
There are no files associated with this item.
作者单位: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Boulder, CO, United States; NOAA Earth System Research Laboratory, Boulder, CO, United States
Recommended Citation:
Yamaguchi T,, Feingold G,, Kazil J. Stratocumulus to Cumulus Transition by Drizzle[J]. Journal of Advances in Modeling Earth Systems,2017-01-01,9(6)