DOI: 10.1002/2015JD023318
论文题名: Dynamical, convective, and microphysical control on wintertime distributions of water vapor and clouds in the tropical tropopause layer
作者: Ueyama R. ; Jensen E.J. ; Pfister L. ; Kim J.-E.
刊名: Journal of Geophysical Research: Atmospheres
ISSN: 2169897X
出版年: 2015
卷: 120, 期: 19 起始页码: 10483
结束页码: 10500
语种: 英语
英文关键词: dehydration
; stratospheric water vapor
; tropical tropopause
Scopus关键词: atmospheric convection
; atmospheric wave
; cirrus
; cloud cover
; cloud microphysics
; dehydration
; geostationary satellite
; humidity
; microwave limb sounder
; potential temperature
; radiative transfer
; satellite imagery
; spatiotemporal analysis
; stratosphere
; temperature profile
; trophic environment
; tropopause
; water vapor
; winter
英文摘要: Processes that influence the humidity and cirrus cloud abundance in the Tropical Tropopause Layer (TTL) during boreal winter 2006-2007 are investigated in simulations of clouds along backward trajectories of parcels ending at the 372 K potential temperature (100 hPa) level in the tropics. Trajectories are calculated using offline calculations of seasonal mean tropical radiative heating rates along with reanalysis temperature and wind data with enhanced wave-driven variability in the TTL. The one-dimensional (vertical) time-dependent cloud microphysical model is initialized with water vapor measurements from the Microwave Limb Sounder and the evolution of clouds along each trajectory is simulated using temperature profiles extracted from reanalysis data and convective cloud top heights estimated from 3-hourly geostationary satellite imagery. Averaged over the tropics, waves dehydrate the 100 hPa level by 0.5 ppmv, while convection and cloud microphysical processes moisten by 0.3 and 0.7 ppmv, respectively. The tropical mean cloud occurrence frequencies in the middle to upper TTL agree well with those based on satellite observations (spatial correlation of 0.8). Waves and convection enhance cloud occurrence at the cold point tropopause by 4% and 2%, respectively. Temporal variability of the heating rates as indicated by the ERA-Interim 6-hourly heating rate fields dehydrates the TTL by 0.4 ppmv and decreases the cloud occurrence by 4% because parcels are more likely to encounter the coldest temperatures and dehydrate near the cold point, limiting cloud formation above. The final dehydration locations of parcels, concentrated near the dateline in the tropical Pacific, are insensitive to various model parameters. ©2015. 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/63004
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: NASA Ames Research Center, Moffett Field, CA, United States; Bay Area Environmental Research Institute, Petaluma, CA, United States; NorthWest Research Associates, CoRA Office, Boulder, CO, United States
Recommended Citation:
Ueyama R.,Jensen E.J.,Pfister L.,et al. Dynamical, convective, and microphysical control on wintertime distributions of water vapor and clouds in the tropical tropopause layer[J]. Journal of Geophysical Research: Atmospheres,2015-01-01,120(19)