| DOI: | 10.1175/JCLI-D-12-00736.1
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| Scopus记录号: | 2-s2.0-84884917721
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| 论文题名: | Observational evidence that enhanced subsidence reduces subtropical marine boundary layer cloudiness |
| 作者: | Myers T.A.; Norris J.Y.
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| 刊名: | Journal of Climate
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| ISSN: | 8948755
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| 出版年: | 2013
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| 卷: | 26, 期:19 | | 起始页码: | 7507
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| 结束页码: | 7524
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| 语种: | 英语
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| Scopus关键词: | Atmospheric circulation
; Cumulus cloud
; Inversion strength
; Marine boundary layers
; Positive correlations
; Satellite cloud data
; Stratiform clouds
; Temperature inversions
; Atmospheric temperature
; Boundary layers
; Climatology
; Clouds
; Global warming
; Tropics
; Subsidence
; atmospheric circulation
; boundary layer
; climatology
; cloud cover
; cumulus
; global warming
; marine atmosphere
; satellite data
; statistical analysis
; stratiform cloud
; subsidence
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| 英文摘要: | Conventional wisdom suggests that subsidence favors the presence of marine stratus and stratocumulus because regions of enhanced boundary layer cloudiness are observed to climatologically co-occur with regions of enhanced subsidence. Here it is argued that the climatological positive correlation between subsidence and cloudiness is not the result of a direct physicalmechanismconnecting the two. Instead, it arises because enhanced subsidence is typically associated with stronger temperature inversions capping the marine boundary layer, and stronger temperature inversions favor greater cloudiness. Through statistical analysis of satellite cloud data and meteorological reanalyses for the subsidence regime over tropical (30°S-30°N) oceans, it is shown that enhanced subsidence promotes reduced cloudiness for the same value of inversion strength and that a stronger inversion favors greater cloudiness for the same value of subsidence. Using a simple conceptual model, it is argued that enhanced subsidence leads to reduced cloud thickness, liquidwater path, and cloud fraction by pushing down the top of themarine boundary layer.Moreover, a stronger inversion reduces entrainment drying andwarming, thus leading to amore humid boundary layer and greater cloud thickness, liquidwater path, and cloud fraction. These two mechanisms typically oppose each other for geographical and seasonal cloud variability because enhanced subsidence is usually associated with stronger inversions. If global warming results in stronger inversions but weaker subsidence, the two mechanisms could both favor increased subtropical low-level cloudiness. © 2013 American Meteorological Society. |
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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/51627
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| Appears in Collections: | 气候变化事实与影响
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作者单位: | Scripps Institution of Oceanography, University of California, San Diego, San Diego, La Jolla, CA, United States
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| Recommended Citation: | |
Myers T.A.,Norris J.Y.. Observational evidence that enhanced subsidence reduces subtropical marine boundary layer cloudiness[J]. Journal of Climate,2013-01-01,26(19)
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