Seminar by Prof. Changhyun Yoo from Ewha Womans University
28 November 2024
KST 10:30 – 11:30
The Seminar is being held in Room 1010 (Jasmin) – Integrated mechanical engineering building. Click here for the campus map.
This seminar presents an investigation of the latitudinal distribution of precipitation, focusing on its relationship to large-scale atmospheric dynamics, in particular the vertical motion of the Transformed Eulerian Mean (TEM). The analysis shows that the subtropical precipitation minimum (~20°N) and the midlatitude maximum (~40°N) are more closely aligned with TEM dynamics than with the Hadley cell of the conventional Eulerian framework. Key findings indicate that the subtropical descent is primarily driven by the meridional flux of zonal momentum from large-scale eddies (i.e., eddy momentum flux; EMF), while the midlatitude ascent is associated with the heat flux.
In addition, the research highlights that when poleward EMF is anomalously strong, a secondary precipitation peak shifts to ~60°N, corresponding to enhanced TEM ascent. The zonal mean moisture transport anomaly shows a consistent picture with the changes in the TEM circulation. We speculate that the TEM circulation and associated moisture and potential vorticity transport can be understood as a zonal mean representation of dry air intrusions and warm conveyor belts, providing a novel perspective on precipitation systems. The seminar will emphasize the importance of TEM dynamics in shaping precipitation patterns and discuss the implications of potential future changes in the EMF on these distributions.