%0 Journal Article
%T Discrete Spectra and Continuous Spectrum of the Barotropic Quasi-Geostrophic Model-A Calculation of Meteorological Data<br>Discrete Spectra and Continuous Spectrum of the BarotropicQuasi-Geostrophic Model-A Calculation ofMeteorological Data
%A Zhang Minghua
%A Zeng Qingcun
%A <br>Zhang Minghu
%A Zeng Qingcun
%J 大气科学进展
%D 1999
%I 
%X Atmospheric disturbances at 300 hpa are decomposed into normal modes, referred as discrete-spectrum disturbances which can propagate freely in the observed zonal mean flow, and non-modal transient disturbances, referred as continuous-spectrum disturbances which are continuously sheared and eventually absorbed by the zonal flow. It is shown that normal modes represent only a small fraction of the observed atmospheric disturbances, while continuous-spec-trum disturbances represent the majority of observed disturbances, even when the basic flow is unstable. Daily variabilities of the observed continuous-spectrum disturbances are presented. They are shown to follow the results of wave-packet theory. Calculations suggest that there are abundant sources to excite continuous-spectrum disturbances in the atmosphere.
%K Normal mode
%K Discrete-spectrum
%K Continuous-spectrum
%K Wave-packet<br>
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=28A2F569B2458C17&jid=5434AFBF6CB6E7E8D67733B541F211C7&aid=8C5304E2B99E5E8E3E40D2F21759A312&yid=B914830F5B1D1078&vid=7801E6FC5AE9020C&iid=E158A972A605785F&sid=036D726259190A01&eid=60E9AACF61B3107F&journal_id=0256-1530&journal_name=大气科学进展&referenced_num=0&reference_num=0