Seasonality and Regionality of the Madden–Julian Oscillation, Kelvin Wave, and Equatorial Rossby Wave
Seasonality and Regionality of the Madden–Julian Oscillation, Kelvin Wave, and Equatorial Rossby Wave
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DOI：
10.1175/2007jas2179.1
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发表时间：
2007-12
影响因子：
3.1
通讯作者：
H. Masunaga
中科院分区：
文献类型：
--
作者：
H. Masunaga
Abstract The Madden–Julian oscillation (MJO), Kelvin wave, and equatorial Rossby (ER) wave—collectively called intraseasonal oscillations (ISOs)—are investigated using a 25-yr record of outgoing longwave radiation (OLR) measurements as well as the associated dynamical fields. The ISO modes are detected by applying bandpass filters to the OLR data in the frequency–wavenumber space. An automated wave-tracking algorithm is applied to each ISO mode so that convection centers accompanied with the ISOs are traced in space and time in an objective fashion. The identified paths of the individual ISO modes are first examined and found strongly modulated regionally and seasonally. The dynamical structure is composited with respect to the convection centers of each ISO mode. A baroclinic mode of the combined Rossby and Kelvin structure is prominent for the MJO, consistent with existing work. The Kelvin wave exhibits a low-level wind field resembling the shallow-water solution, while a slight lead of low-level conver...
