Idealized Hadley circulation interacting with mid-latitudes

by Dr Woosok Moon (NORDITA)

Monday 30 May 2022, 15:45 → 17:45 Europe/Stockholm

Albano 3: 6228 - Mega (22 seats) (Albano Building 3)

zoom link:  https://stockholmuniversity.zoom.us/j/622224375

 

Abstract: The Hadley circulation is a planetary-scale tropical atmospheric circulation  shaping the status of climate, thus deeper understanding of its dynamic features are crucial to diagnose the current state of climate and predict the future climate under global warming.

 

Our theoretical understanding is based upon angular momentum conservation, the basic dynamic constraint governing the fluid dynamics of the Hadley circulation.

Even with the success of representing the structure of the Hadley circulation, the theoretical model shows limitations compared with observation due to missing of interactions with other regions, especially mid-latitudes. Here, we extend the original model  to include the influence of mid-latitude large-scale atmospheric dynamics. The large-scale atmospheric dynamics in mid-latitudes is represented by the planetary-scale heat equation with a parameterized poleward heat flux induced by synoptic eddies. The energy flux balance inside the cell includes the poleward heat flux at the poleward edge of the cell controlled by the baroclinic instability of sub-tropical jets.  Theoretical solutions suggest that global warming, which can reduce the baroclinicity in mid-latitudes, can lead to the poleward expansion of  the Hadley cell due to the update of the energy flux balance inside the Hadley cell.