DOI: 10.1029/2017JD028068
Scopus记录号: 2-s2.0-85048975797
论文题名: Microphysical Properties of Tropical Tropopause Layer Cirrus
作者: Woods S. ; Lawson R.P. ; Jensen E. ; Bui T.P. ; Thornberry T. ; Rollins A. ; Pfister L. ; Avery M.
刊名: Journal of Geophysical Research: Atmospheres
ISSN: 2169897X
出版年: 2018
卷: 123, 期: 11 起始页码: 6053
结束页码: 6069
语种: 英语
英文关键词: cirrus
; ice habit
; microphysics
; TTL
Scopus关键词: altitude
; cirrus
; cloud microphysics
; concentration (composition)
; dehydration
; energy budget
; ice
; size distribution
; stratosphere
; temperature gradient
; tropical region
; tropopause
; Pacific Ocean
; Pacific Ocean (West)
英文摘要: Pervasive cirrus clouds in the tropical tropopause layer (TTL) play an important role in determining the composition of stratospheric air through dehydration of tropospheric air entering the stratosphere. This dehydration affects Earth's energy budget and climate, yet uncertainties remain regarding the microphysical processes that govern TTL cirrus. TTL cirrus were sampled with the NASA Global Hawk UAV for over 30 hr in the Western Pacific in 2014 during the Airborne Tropical TRopopause EXperiment. In situ measurements by a Fast Cloud Droplet Probe and Hawkeye probe (combination Fast Cloud Droplet Probe, Two-Dimensional Stereo optical array probe, and Cloud Particle Imager) provided particle concentrations and sizing between 1- and 1,280-μm diameter and high resolution images for habit identification. We present the variability in ice concentrations, size distributions, and habits as functions of temperature, altitude, and time since convective influence. Observed ice particles were predominantly small and quasi-spheroidal in shape, with the percentage of quasi-spheroids increasing with decreasing temperature. In comparison to the large fraction of the population consisting of quasi-spheroids, faceted habits (columns, plates, rosettes, and budding rosettes) constituted a smaller percentage of the overall population and exhibited the opposite correlation with temperature. The trend of higher percentages of faceted crystals occurring at warmer temperatures may be due to diffusional growth or aggregation as particles descend through cloud, and/or the more rapid diffusional growth rate at warmer temperatures. Sampling was typically well away from deep convection, however, and very few aggregates were observed, so the trend of higher percentages of faceted habits is likely attributable to diffusional growth. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/113712
Appears in Collections: 气候减缓与适应
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作者单位: SPEC, Inc., Boulder, CO, United States; NASA Ames Research Center, Moffet Field, CA, United States; NOAA ESRL/CIRES, Boulder, CO, United States; NASA Langley Research Center, Hampton, VA, United States
Recommended Citation:
Woods S.,Lawson R.P.,Jensen E.,et al. Microphysical Properties of Tropical Tropopause Layer Cirrus[J]. Journal of Geophysical Research: Atmospheres,2018-01-01,123(11)