DOI: 10.1002/jgrd.50878
论文题名: Entrainment rates and microphysics in POST stratocumulus
作者: Gerber H. ; Frick G. ; Malinowski S.P. ; Jonsson H. ; Khelif D. ; Krueger S.K.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 21 起始页码: 12094
结束页码: 12109
语种: 英语
英文关键词: CTEI
; entrainment
; entrainment interface layer
; stratocumulus
Scopus关键词: Air entrainment
; Cooling
; Evaporation
; Evaporative cooling systems
; Mixing
; Probes
; Research aircraft
; Conditional sampling
; CTEI
; Droplet evaporation
; Evaporative cooling
; Interface layer
; Radiative cooling
; stratocumulus
; Temperature probes
; Clouds
; aircraft
; cloud microphysics
; entrainment
; probe
; sampling
; spatiotemporal analysis
; stratocumulus
; California
; United States
英文摘要: An aircraft field study (POST; Physics of Stratocumulus Top) was conducted off the central California coast in July and August 2008 to deal with the known difficulty of measuring entrainment rates in the radiatively important stratocumulus (Sc) prevalent in that area. The Center for Interdisciplinary Remotely-Piloted Aircraft Studies Twin Otter research aircraft flew 15 quasi-Lagrangian flights in unbroken Sc and carried a full complement of probes including three high-data-rate probes: ultrafast temperature probe, particulate volume monitor probe, and gust probe. The probes' colocation near the nose of the Twin Otter permitted estimation of entrainment fluxes and rates with an in-cloud resolution of 1 m. Results include the following: Application of the conditional sampling variation of classical mixed layer theory for calculating the entrainment rate into cloud top for POST flights is shown to be inadequate for most of the Sc. Estimated rates resemble previous results after theory is modified to take into account both entrainment and evaporation at cloud top given the strong wind shear and mixing at cloud top. Entrainment rates show a tendency to decrease for large shear values, and the largest rates are for the smallest temperature jumps across the inversion. Measurements indirectly suggest that entrained parcels are primarily cooled by infrared flux divergence rather than cooling from droplet evaporation, while detrainment at cloud top causes droplet evaporation and cooling in the entrainment interface layer above cloud top. Key Points Wind shear and mixing at stratocumulus top affect entrainment Radiative cooling exceeds evaporative cooling in entrained parcels Detrainment occurs at stratocumulus top ©2013 The Authors. Journal of Geophysical Research: Atmospheres published by Wiley on behalf of the American Geophysical Union. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/63198
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Gerber Scientific, Inc., 1643 Bentana Way, Reston, VA 20190, United States; Naval Research Laboratory, Washington, DC, United States; Institute of Geophysics, Faculty of Physics, University of Warsaw, Warsaw, Poland; Center for Interdisciplinary Remotely-Piloted Aircraft Studies, Naval Postgraduate School, Monterey, CA, United States; Department of Mechanical and Aerospace Engineering, University of California, Irvine, CA, United States; Department of Atmospheric Sciences, University of Utah, Salt Lake City, UT, United States
Recommended Citation:
Gerber H.,Frick G.,Malinowski S.P.,et al. Entrainment rates and microphysics in POST stratocumulus[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(21)