Planetary wave reflection and its impact on tropospheric cold weather over Asia during January 2008

Reflection of stratospheric planetary waves and its impact on tropospheric cold weather over Asia during January 2008 were investigated by applying two dimensional Eliassen-Palm (EP) flux and three-dimensional Plumb wave activity fluxes. The planetary wave propagation can clearly be seen in the longitude-height and latitude-height sections of the Plumb wave activity flux and EP flux, respectively, when the stratospheric basic state is partially reflective. Primarily, a wave packet emanating from Baffin Island/coast of Labrador propagated eastward, equatorward and was reflected over Central Eurasia and parts of China, which in turn triggered the advection of cold wind from the northern part of the boreal forest regions and Siberia to the subtropics. The wide region of Central Eurasia and China experienced extreme cold weather during the second ten days of January 2008, whereas the extraordinary persistence of the event might have occurred due to an anomalous blocking high in the Urals-Siberia region.