Joint Seminar: The vertical structure of the tropical atmosphere

The climatology of precipitation in the tropics is largely controlled by the distribution of large-scale ascent. Such ascending motion is often characterised as being either "top-heavy", with vertical motion peaking in the upper troposphere, or "bottom-heavy" with vertical motion peaking in the lower troposphere. This vertical structure plays a key role in determining precipitation rates and energy transports within the tropics, but the physical factors that control it remain uncertain.

In this talk, I will present a prototype theory for the vertical structure of the tropical overturning circulation based on a simple model of moist convection coupled to gravity wave dynamics. The theory elucidates how mixing and microphysical processes in moist convection influence the large-scale circulation, and it highlights the importance of small deviations in the lapse rate from that of a moist adiabat for determining its vertical structure. I will present observational support for some aspects of the simple model, but I will also explore its limitations. A full theory for the circulation's vertical structure requires incorporating radiative as well as dynamical constraints on the circulation, and including the effects of Bowen ratio variations over the land.
 

Datum

28.06.2023

Uhrzeit

13:30 Uhr

Ort

Bundesstr. 53, room 022/023
Seminar Room 022/023, Ground Floor, Bundesstrasse 53, 20146 Hamburg, Hamburg

Chair

Jiawei Bao

Zur Übersicht