(New York University)
Isentropic analysis, from convection to the global circulation
|What||GR Homepage Meteo Colloquium UG|
Jan 20, 2016 03:30 PM
Jan 20, 2016 04:30 PM
Jan 20, 2016
from 03:30 pm to 04:30 pm
|Contact Name||Fuqing Zhang|
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The idea analyzing atmospheric flows on isentropic surfaces dates back to Bjerknes and the early development of In this talk, I will fist review the global meridional circulation on isentropic coordinates. In contrast to the eulerian circulation that exhibit three overturning cell in each hemisphere, the isentropic circulation only appears as a single Equator-to-Pole cell. Furthermore, when the flow is analyzed on moist isentropes, the mass transport by the circulation doubles. These differences in how the circulation appears in various coordinate systems can be directly linked to the energy and water transport by midlatitudes eddies. modern meteorology. The availability of high resolution Reanalysis and model datasets make it possible today to use isentropic analysis to study complex flow across a wide range of scales.
The methodology has been more recently applied to study convective motions. In this case, the vertical mass transport is sorted in terms of the equivalent potential temperature. This makes it possible to separate the ascent of warm moist air in convective towers from the subsidence of dry air in the environment. This provides a direct method to assess convective mass transport and entrainment in high resolution numerical model.