Joint Seminar: Besides radiative effects: how shallow convection can interact with large-scale circulations through rain and wind

In this talk I will discuss two others processes through which shallow convection can influence and interact with large-scale circulations, besides their influence on the radiative cooling profile of the lower atmosphere. These are the ability of marine convection to precipitate readily, and the ability of convection to not just mix temperature and moisture, but also momentum. I have long been motivated by such an exploration through studying measurements at Barbados, which show a greater temporal variability of deeper precipitating shallow systems, and a distinct correlation between convection and the near-surface wind. To understand how such small-scale processes might interact with a circulation on much larger scales, I have used a two-column radiative-convective equilibrium model of a Walker-like overturning circulation, which numerically solves for two-dimensional, non-rotating hydrostatic flow, with parameterized convection, clouds and radiative transfer. I will present how the character of the two-column system, and the presence of distinct modes of convection, including shallow cumulus and congestus modes, depends on an intricate interaction among convection, including rain, the circulation and radiation. Neither one of these can be neglected in even a simple description of the system. I will conclude with describing how I will strive to answer those aspects of the system I believe we might know least about - the interaction with wind - in the next couple of years.

Date

21.02.2017

Time

15:15 h

Place

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

Speaker

Louise Nuijens, Department of Geosciences & Remote Sensing, Delft University of Technology (TU Delft)

Organizers

Karsten Peters
Guidi Zhou

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