DOI: 10.1002/joc.5847
Scopus记录号: 2-s2.0-85052944635
论文题名: A climatology of quasi-linear convective systems and associated synoptic-scale environments in southern Brazil
作者: Ribeiro B.Z. ; Seluchi M.E.
刊名: International Journal of Climatology
ISSN: 8998418
出版年: 2019
卷: 39, 期: 2 起始页码: 857
结束页码: 877
语种: 英语
英文关键词: quasi-linear convective systems
; severe thunderstorms
; southern Brazil
; synoptic climatology
Scopus关键词: Potential energy
; Sea level
; Storms
; Tracking radar
; Convective available potential energies
; Good discriminators
; Low pressure systems
; Mesoscale Convective System
; Moisture flux convergences
; Quasi-linear convective systems
; Southern Brazil
; Synoptic climatology
; Climatology
; atmospheric dynamics
; climatology
; comparative study
; convective system
; mesoscale meteorology
; potential energy
; synoptic meteorology
; thunderstorm
; wind field
; Argentina
; Brazil
英文摘要: This study presents a 9-year climatology and composite analysis of quasi-linear convective systems (QLCSs) in southern Brazil (SB). QLCSs are identified using radar imagery and defined as a 100-km long, 40-dBZ convective line that lasts for at least 1 hr. QLCS cases associated with at least three severe wind reports are classified as severe. Composites of the synoptic-scale environments and severe convective weather parameters are constructed for severe and non-severe cases of three synoptic patterns found as the most recurrent in QLCS cases. QLCSs are more frequent and more likely to be severe during spring, while very few cases occur during winter. Most cases occur during late night and morning, corroborating previous research of mesoscale convective systems in this area, but the percentages of severe cases are higher in late afternoon and early night. Faster QLCSs, particularly those with velocities greater than 50 km/hr, have higher probability of being severe in comparison to slower systems. The three synoptic patterns more often related to QLCS occurrence in SB are characterized by a mid-level trough upstream of SB (type 1), a mid-level trough west of the Andes (type 2) and predominance of zonal flow over SB (type 3). In general, there is a low-pressure system over northwestern Argentina extending a trough to SB, where low-level moisture flux convergence and warm advection occur. In severe cases, the sea-level pressure is lower in northwestern Argentina and there is greater low-level northwesterly flow over SB. The type 1 is the most frequent pattern when QLCSs are observed in SB and is also the type with higher percentage of severe cases. Convective available potential energy (CAPE) and downdraft CAPE are good discriminators between severe and non-severe cases in type 1 and 2 environments, while the 1,000–500-hPa bulk wind difference is a better predictor in type 3 cases. © 2018 Royal Meteorological Society Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/116587
Appears in Collections: 全球变化的国际研究计划
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作者单位: Centro de Previsão de Tempo e Estudos Climáticos, Instituto Nacional de Pesquisas Espaciais (CPTEC/INPE), Cachoeira Paulista, Brazil; Centro Nacional de Monitoramento e Alertas de Desastres Naturais (CEMADEN), São José dos Campos, Brazil
Recommended Citation:
Ribeiro B.Z.,Seluchi M.E.. A climatology of quasi-linear convective systems and associated synoptic-scale environments in southern Brazil[J]. International Journal of Climatology,2019-01-01,39(2)