首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Equatorial modes observed in atmospheric variables
Authors:L Kiranmayi  G S Bhat
Institution:(1) Global Modeling and Assimilation Office, NASA/Goddard Space Flight Center, Mail Code 610.1, Greenbelt, MD 20771, USA;(2) School of Ocean and Earth Science and Technology, International Pacific Research Center, University of Hawaii at Manoa, Honolulu, HI 96822, USA
Abstract:Wavenumber-frequency spectral analysis of different atmospheric variables has been carried out using 25 years of data. The area considered is the tropical belt 25°S–25°N. A combined FFT-wavelet analysis method has been used for this purpose. Variables considered are outgoing long-wave radiation (OLR), 850 hPa divergence, zonal and meridional winds at 850, 500 and 200 hPa levels, sea level pressure and 850 hPa geopotential height. It is shown that the spectra of different variables have some common properties, but each variable also has few features different from the rest. While Kelvin mode is prominent in OLR and zonal winds, it is not clearly observed in pressure and geopotential height fields; the latter two have a dominant wavenumber zero mode not seen in other variables except in meridional wind at 200 hPa and 850 hPa divergences. Different dominant modes in the tropics show significant variations on sub-seasonal time scales.
Keywords:
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号