KlimaCampus Kolloquium: CANCELLED: Multi-scale asymptotic analyses of atmospheric motions



Flows of the Earth's atmosphere cover a very wide range of scales. At the extreme ends of the spacial spectrum we have, e.g., micrometer-sized raindrops and planetary-scale climate phenomena. The range of relevant time scales is equally broad. A central task of theoretical meteorology is to identify specific weather- or climate-related flow phenomena that are associated with particular length and time scales, and to construct simplified models describing these phenomena in terms of some reduced set of effective degrees of freedom.


Textbooks of theoretical meteorology offer derivations of such reduced models from more comprehensive fluid dynamical governing equations through "scale analysis", which involves often ingenious combinations of physical intuition and skillful mathematical derivations. Nevertheless, keeping track of how these models relate to each other and what were the underlying assumptions in their derivations is a formidable task. If one is interested, however, in how phenomena associated with different length and/or time scale interact, then knowing how to consistently couple or synchronize the individual reduced models becomes crucial.


In the first part of the lecture I will introduce a systematization of reduced model equations of theoretical meteorology that is based on the principles of dimensional and asymptotic analysis. This approach allows one to rederive a large number of reduced models of theoretical meteorology in a unified fashion from the full compressible flow equations via classical single-scale asymptotics.


More importantly, this unified approach lends itself naturally to multiple scales analyses, i.e., to studies of how scale-dependent phenomena described by different reduced model equations are coupled across the scales. Part two of this lecture will cover one example of such multiscale interaction theories. I will discuss a theory that suggests a new mechanism for the intensification or attenuation of hurricane-like vortices.




15:15 h


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


Rupert Klein, FU Berlin


Jörn Behrens

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