DOI: 10.1175/JCLI-D-11-00599.1
Scopus记录号: 2-s2.0-84867682047
论文题名: Climatology and formation of tropical midlevel clouds at the Darwin ARM Site
作者: Riihimaki L.D. ; Mcfarlane S.A. ; Comstock J.M.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2012
卷: 25, 期: 19 起始页码: 6835
结束页码: 6850
语种: 英语
Scopus关键词: Atmospheric radiation measurement programs
; Australia
; Cloud lidar
; Cloud-top temperatures
; Data sets
; High frequency
; High probability
; Latent cooling
; Low temperatures
; Melting levels
; Monsoon season
; Stable layer
; Stratiform precipitation
; Supercooled liquid water
; Thin layers
; Atmospheric thermodynamics
; Climatology
; Clouds
; Cryogenic liquids
; Melting
; Optical radar
; Radar measurement
; Supercooling
; Tropics
; Precipitation (meteorology)
; air temperature
; atmospheric convection
; climatology
; condensation
; lidar
; melting
; monsoon
; observational method
; radar
; stratiform cloud
; tropical meteorology
; Australia
; Darwin
; Northern Territory
英文摘要: A 4-yr climatology of midlevel clouds is presented from vertically pointing cloud lidar and radar measurements at the Atmospheric Radiation Measurement Program (ARM) site at Darwin, Australia. Few studies exist of tropical midlevel clouds using a dataset of this length. Seventy percent of clouds with top heights between 4 and 8 km are less than 2 km thick. These thin layer clouds have a peak in cloud-top temperature around the melting level (08C) and also a second peak around212.58C. The diurnal frequency of thin clouds is highest during the night and reaches a minimum around noon, consistent with variation caused by solar heating. Using a 1.5-yr subset of the observations, the authors found that thin clouds have a high probability of containing supercooled liquid water at low temperatures: ;20% of clouds at 2308C, ;50% of clouds at 2208C, and ;65% of clouds at 2108C contain supercooled liquid water. The authors hypothesize that thin midlevel clouds formed at the melting level are formed differently during active and break monsoon periods and test this over three monsoon seasons. A greater frequency of thin midlevel clouds are likely formed by increased condensation following the latent cooling of melting during active monsoon periods when stratiform precipitation is most frequent. This is supported by the high percentage (65%) of midlevel clouds with preceding stratiform precipitation and the high frequency of stable layers slightly warmer than 08C. In the break monsoon, a distinct peak in the frequency of stable layers at 08C matches the peak in thin midlevel cloudiness, consistent with detrainment from convection. © 2012 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/52214
Appears in Collections: 气候变化事实与影响
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作者单位: Pacific Northwest National Laboratory, Richland, WA, United States
Recommended Citation:
Riihimaki L.D.,Mcfarlane S.A.,Comstock J.M.. Climatology and formation of tropical midlevel clouds at the Darwin ARM Site[J]. Journal of Climate,2012-01-01,25(19)