亚欧大陆科学资源管理

During boreal summer, two remarkable upper-level wave trains over Eurasia were documented in literature, i.e., Circumglobal Teleconnection (CGT) and Silk Road Pattern (SRP). They are widely discussed because of their influences throughout the entire mid-latitude Eurasia. SRP was defined by 200 hPa meridional winds [1]. Enomoto et al. [2] found that the wave train influenced the climate variation over Japan when they detected the mechanism of Bonin High, and then named it as “Silk Road Pattern”. SRP has 3 prominent action centers, which are located in west-central Asia, Mongolia and the Far East, respectively [3].

A circumglobal atmospheric teleconnection pattern in upper troposphere was first suggested by Branstator [4]. He used the empirical orthogonal function (EOF) analysis and indicated that the first two EOFs of the monthly mean 300 hPa meridional winds in winter season are circumglobal patterns, which extend completely around the globe. These two wave patterns are in spatial quadrature with each other, and coincide with the subtropical jet at most longitudes. Watanabe [5] suggested that the circumglobal pattern in monthly mean data can be identified in daily data as corresponding to eastward propagating wave packets, extending eastward from the North Atlantic, across Europe and South Asia, all the way to the northwest Pacific. Ding and Wang [6] defined such stationary teleconnection in summer as “Circumglobal Teleconnection”, by utilizing one-point correlation analysis of 200 hPa geopotential heights. The CGT is a wave train with a global zonal wavenumber-5 structure, with 6 main activity centers over Western Europe, European Russia, west-central Asia, East Asia, North Pacific and North America, respectively.