| DOI: | 10.1175/JCLI-D-16-0782.1
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| Scopus记录号: | 2-s2.0-85027258741
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| 论文题名: | Dry intrusions: Lagrangian climatology and dynamical impact on the planetary boundary layer |
| 作者: | Raveh-Rubin S.
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| 刊名: | Journal of Climate
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| ISSN: | 8948755
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| 出版年: | 2017
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| 卷: | 30, 期:17 | | 起始页码: | 6661
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| 结束页码: | 6682
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| 语种: | 英语
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| Scopus关键词: | Atmospheric thermodynamics
; Climatology
; Lagrange multipliers
; Plasma stability
; Storms
; Troposphere
; Dry intrusions
; Dry-air intrusions
; Eastern north pacific
; Extratropical cyclones
; Heat budgets/fluxes
; Lagrangian circulation/transport
; Planetary boundary layers
; Potential temperature
; Boundary layers
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| 英文摘要: | Dry-air intrusions (DIs) are dry, deeply descending airstreams from the upper troposphere toward the planetary boundary layer (PBL). The significance of DIs spans a variety of aspects, including the interaction with convection, extratropical cyclones and fronts, the PBL, and extreme surface weather. Here, a Lagrangian definition for DI trajectories is used and applied to ECMWF interim reanalysis (ERA-Interim) data. Based on the criterion of a minimum descent of 400 hPa during 48 h, a first global Lagrangian climatology of DI trajectories is compiled for the years 1979-2014, allowing quantitative understanding of the occurrence and variability of DIs, as well as the dynamical and thermodynamical interactions that determine their impact. DIs occur mainly in winter. While traveling equatorward from 40°-50° latitude, DIs typically reach the lower troposphere (with maximum frequencies of ~10% in winter) in the storm-track regions, as well as over the Mediterranean Sea, Arabian Sea, and eastern North Pacific, off the western coast of South America, South Africa, and Australia, and across the Antarctic coast. The DI descent is nearly adiabatic, with a mean potential temperature decrease of 3 K in two days. Relative humidity drops strongly during the first descent day and increases in the second day, because of mixing into the moist PBL. Significant destabilization of the lower levels occurs beneath DIs, accompanied by increased 10-m wind gusts, intense surface heat and moisture fluxes, and elevated PBL heights. Interestingly, only 1.2% of all DIs are found to originate from the stratosphere. © 2017 American Meteorological Society. |
| 资助项目: | NSF, National Science Foundation
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| Citation statistics: |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/49852
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| Appears in Collections: | 气候变化事实与影响
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作者单位: | Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
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| Recommended Citation: | |
Raveh-Rubin S.. Dry intrusions: Lagrangian climatology and dynamical impact on the planetary boundary layer[J]. Journal of Climate,2017-01-01,30(17)
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