DOI: 10.1175/JCLI-D-12-00143.1
Scopus记录号: 2-s2.0-84871866831
论文题名: Coherent synoptic disturbances in the Australian monsoon
作者: Berry G.J. ; Reeder M.J. ; Jakob C.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2012
卷: 25, 期: 24 起始页码: 8409
结束页码: 8421
语种: 英语
Scopus关键词: African easterly waves
; Australia
; Characteristic length
; Data sets
; East coast
; Extra-tropical Rossby waves
; Isentropic
; Meridional winds
; Mesoscale process
; Monsoons
; Potential vorticity
; Reanalysis
; Southern Hemisphere
; Spectral techniques
; Synoptic climatology
; Synoptic composites
; Synoptic systems
; Time interval
; Weather systems
; Climatology
; Ocean currents
; Rain
; Vorticity
; Atmospheric thermodynamics
; climatology
; easterly wave
; mesoscale meteorology
; monsoon
; potential vorticity
; rainfall
; Rossby wave
; Southern Hemisphere
; synoptic meteorology
; troposphere
; wind
; Australia
英文摘要: Coherent synoptic-scale weather systems within the Australian monsoon are identified and tracked in the isentropic potential vorticity (PV) field from the ECMWF Interim Reanalysis (ERA-Interim) dataset during the Southern Hemisphere summer. The resulting dataset is then used to compile statistics and synoptic composites of Australian monsoon disturbances. On average, a synoptic system is found in the region every 2.5 days. However, the time interval between consecutive events is highly variable, meaning that the synoptic activity in the Australian monsoon is not well represented by commonly employed spectral techniques. The analysis reveals that most synoptic systems originate within the Australian monsoon, but at the 315-K level (approximately 700 hPa) a significant proportion of systems are first detected near the east coast of the continent where extratropical Rossby waves are observed to frequently break. The average Australian monsoon weather system propagates from east to west at approximately 6 m s-1 and has a characteristic length scale of 2000 km. Synoptic composite structures show some resemblance to African easterly waves; they move along a midtropospheric (approximately 700 hPa) easterly wind maximum and have peak meridional winds at this level. Composite rainfall shows that rainfall is significantly enhanced ahead (west) of the synoptic PV maximum and suppressed behind. It is estimated that in some parts of northwestern Australia 40%-50% of the summertime rainfall occurs with a tracked monsoon disturbance in the vicinity. © 2012 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/52108
Appears in Collections: 气候变化事实与影响
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作者单位: Monash Weather and Climate, School of Mathematical Sciences, Monash University, Clayton, VIC, Australia; ARC Centre of Excellence for Climate System Science, School of Mathematical Sciences, Monash University, Clayton, VIC, Australia
Recommended Citation:
Berry G.J.,Reeder M.J.,Jakob C.. Coherent synoptic disturbances in the Australian monsoon[J]. Journal of Climate,2012-01-01,25(24)