2012-2016 Grant-in-Aid for Scientific Reserach (S)

Extreme Weather Variations in the Stratosphere-Troposphere Coupled System: Past, Present and Future


Purpose and Background of the Reserach

Stratospheric sudden warming (SSW), which is associated with a breakdown process of wintertime polar vortex, is a typical extreme weather event in the stratosphere-troposphere (S-T) coupled system (right figure). Prediction of SSW occurrence and assessment of its impact on the coupled system have been remained as difficult problems, because SSW is a highly nonlinear dynamical phenomenon characterized by a natural internal variation in the coupled system. It is an unresolved problem how this kind of extreme weather events will respond to the variations of natural and anthropogenic external forcings, such as the 11-year solar irradiance variations and volcanic eruptions for the former and the increase of greenhouse gases or ozone depleting substances for the latter.

In this research, we aim to understand the dynamical linkage among these internal and external variations of the S-T coupled system comprehensively, and to contribute for improving our ability of prediction of extreme weather events.

Schematic illustration of the coupled system


      Maintained by Shigeo Yoden, Kyoto University (yoden"at"kugi.kyoto-u.ac.jp)