DOI: 10.1175/JCLI-D-14-00511.1
Scopus记录号: 2-s2.0-84943786594
论文题名: Summertime moisture transport to the southern South American Altiplano: Constraints from in situ measurements of water vapor isotopic composition
作者: Galewsky J. ; Samuels-Crow K.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2015
卷: 28, 期: 7 起始页码: 2635
结束页码: 2649
语种: 英语
Scopus关键词: Boundary layers
; Condensation
; Distillation
; Drought
; Isotopes
; Mixing
; Natural convection
; High relative humidities
; Intraseasonal variability
; Isotopic composition
; Monsoons
; Outgoing longwave radiation
; Rayleigh distillation
; South America
; Subtropics
; Water vapor
; atmospheric moisture
; in situ measurement
; isotopic composition
; mixing ratio
; monsoon
; seasonal variation
; subtropical region
; summer
; water vapor
; Altiplano
; Andes
; Bolivia
; Chile
英文摘要: Austral summer transport of water vapor to the southern South American Altiplano is investigated using in situ measurements of water vapor isotopic composition collected from 1 November 2012 to 10 February 2013 on the Chajnantor Plateau in the Chilean Andes. Onset of the wet season in December was associated with an increase in mixing ratios from an average of 1500 ppmv during the winter dry season to 5400 ppmv in early December. Water vapor isotopes δD and δ18O increased from dry season averages of -235‰ and -31‰, respectively, to wet season averages of -142‰ and -17‰, reaching as high as -70‰ and -17‰, respectively. The highest water vapor d values were close to those measured in coastal settings, suggesting little condensation during transport to the site. About 5% of the wet season data have d values that are lower than expected for Rayleigh distillation and are associated with high relative humidity (>75%), easterly winds, and periods of low outgoing longwave radiation over the Altiplano, consistent with moistening by deep convection. The remainder of the data have d values that are greater than expected for Rayleigh distillation, up to 250‰ above the Rayleigh curve. These data are consistent with mixing between very dry air and moist air from the boundary layer. The data show intraseasonal variability coherently linked to the position of the Bolivian high, with moist air associated with a southward displacement in the Bolivian high. The humidity over the southern Altiplano during the wet season reflects a balance among advective drying, advective moistening with little condensation, and convective moistening. © 2015 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/50799
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM, United States
Recommended Citation:
Galewsky J.,Samuels-Crow K.. Summertime moisture transport to the southern South American Altiplano: Constraints from in situ measurements of water vapor isotopic composition[J]. Journal of Climate,2015-01-01,28(7)