DOI: 10.1175/JCLI-D-16-0595.1
Scopus记录号: 2-s2.0-85019083799
论文题名: Oceanic impetus for convective onset of the Madden-Julian oscillation in the western Indian ocean
作者: Rydbeck A.V. ; Jensen T.G.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2017
卷: 30, 期: 11 起始页码: 4299
结束页码: 4316
语种: 英语
Scopus关键词: Atmospheric boundary layer
; Atmospheric movements
; Atmospheric temperature
; Atmospheric thermodynamics
; Boundary layers
; Climatology
; Mechanical waves
; Natural convection
; Ocean currents
; Surface waters
; Atmosphere-ocean interactions
; Indian ocean
; Madden-Julian oscillation
; Oceanic variabilities
; Rossby wave
; Oceanography
英文摘要: A theory for intraseasonal atmosphere-ocean-atmosphere feedback is supported whereby oceanic equatorial Rossby waves are partly forced in the eastern Indian Ocean by the Madden-Julian oscillation (MJO), reemerge in the western Indian Ocean ~70 days later, and force large-scale convergence in the atmospheric boundary layer that precedes MJO deep convection. Downwelling equatorial Rossby waves permit high sea surface temperature (SST) and enhance meridional and zonal SST gradients that generate convergent circulations in the atmospheric boundary layer. The magnitude of the SST and SST gradient increases are 0.25°C and 1.5°C Mm-1 (1 megameter is equal to 1000 km), respectively. The atmospheric circulations driven by the SST gradient are estimated to be responsible for up to 45% of the intraseasonal boundary layer convergence observed in the western Indian Ocean. The SST-induced boundary layer convergence maximizes 3-4 days prior to the convective maximum and is hypothesized to serve as a trigger for MJO deep convection. Boundary layer convergence is shown to further augment deep convection by locally increasing boundary layer moisture. Warm SST anomalies facilitated by downwelling equatorial Rossby waves are also associated with increased surface latent heat fluxes that occur after MJO convective onset. Finally, generation of the most robust downwelling equatorial Rossby waves in the western Indian Ocean is shown to have a distinct seasonal distribution. © 2017 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49637
Appears in Collections: 气候变化事实与影响
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作者单位: American Society for Engineering Education, Washington, DC, United States; Oceanography Division, Naval Research Laboratory, Stennis Space Center, Mississippi, United States
Recommended Citation:
Rydbeck A.V.,Jensen T.G.. Oceanic impetus for convective onset of the Madden-Julian oscillation in the western Indian ocean[J]. Journal of Climate,2017-01-01,30(11)