DOI: 10.1175/JCLI-D-14-00149.1
Scopus记录号: 2-s2.0-84909606637
论文题名: Subtropical cyclones over the southwestern South Atlantic: Climatological aspects and case study
作者: Gozzo L.F. ; da Rocha R.P. ; Reboita M.S. ; Sugahara S.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2014
卷: 27, 期: 22 起始页码: 8543
结束页码: 8562
语种: 英语
Scopus关键词: Climatology
; Geographical distribution
; Storms
; Convective activity
; Cyclogenesis/cyclolysis
; Ecmwf re-analysis
; Interannual variability
; Seasonal variability
; Subtropical cyclones
; Vertical temperature gradients
; Vertical wind shear
; Tropics
; climatology
; cyclogenesis
; hurricane
; precipitation intensity
; synoptic meteorology
; temperature anomaly
; tropical cyclone event
; Atlantic Ocean
; Atlantic Ocean (South)
英文摘要: Hurricane Catarina (2004) and subtropical storm Anita (2010) called attention to the development of subtropical cyclones (SCs) over the South Atlantic basin. Besides strong and organized storms, a large number of weaker, shallower cyclones with both extratropical and tropical characteristics form in the region, impacting the SouthAmerican coast. Themain focus of this study is to simulate a climatology of subtropical cyclones and their synoptic pattern over the South Atlantic, proposing a broader definition of these systems. In addition, a case study is presented to discuss the main characteristics of one weak SC. The Interim ECMWF Re-Analysis (ERAInterim) and NCEP-NCAR reanalysis are used to construct the 33-yr (1979-2011) climatology, and a comparison between them is established. Both reanalyses show good agreement in the SCs' intensity, geographical distribution, and seasonal variability, but the interannual variability is poorly correlated. Anomaly composites for austral summer show that subtropical cyclogenesis occurs under a dipole-blocking pattern in upper levels. Upward motion is enhanced by the vertical temperature gradient between amidtropospheric cold cutoff low/trough and the intense low-level warm air advection by the South Atlantic subtropical high. Turbulent fluxes in the cyclone region are not above average during cyclogenesis, but the subtropical high flow advects great amounts of moisture from distant regions to fuel the convective activity. Although most of the SCs develop during austral summer (December-February), it is in autumn (March-May) that the most ''tropical'' environment is found (stronger surface fluxes and weaker vertical wind shear), leading to the most intense episodes. © 2014 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/51296
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Atmospheric Sciences, Universidade de São Paulo, São Paulo, Brazil; Natural Resources Institute, Universidade de Itajuba, Minas Gerais, Brazil; Instituto de Pesquisas Meteorologicas, Faculdade de Ciencias, UNESP, Bauru, Brazil
Recommended Citation:
Gozzo L.F.,da Rocha R.P.,Reboita M.S.,et al. Subtropical cyclones over the southwestern South Atlantic: Climatological aspects and case study[J]. Journal of Climate,2014-01-01,27(22)