KlimaCampus Kolloquium: An interplay of Rossby waves and gravity waves in the general circulation of the middle atmosphere

The meridional circulation of the middle atmosphere is maintained by angular momentum deposition associated with waves. The summer-to-winter circulation in the mesosphere is mainly driven by gravity-wave forcing (GWF). However, GWF is not uniformly distributed, reflecting source distribution and filtering by Rossby waves. As a result, the GWF frequently causes anomalous potential vorticity gradient and radiates Rossby waves. Such in-situ Rossby wave radiation gives additional wave forcing and modulates the meridional circulation. In contrast, the two-celled circulation in the stratosphere is mainly driven by planetary-scale and synoptic-scale Rossby waves.

However, the summer hemispheric part of the winter cell is expected to be driven by GWF, because mean easterly wind in summer prohibits Rossby-wave upward propagation. In this seminar, an interplay of Rossby waves and gravity waves in the middle atmospheric is discussed based on recent studies using models and reanalysis data.

Datum

11.05.2017

Uhrzeit

15:15 Uhr

Ort

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

ReferentIn

Kaoru Sato, University of Tokyo

Chair

Elisa Manzini

Zur Übersicht