Prof. Samuel Stechmann
Department of Mathematics
University of Wisconsin-Madison
Time : Monday, March 30, 2015 at 2:30 PM
Place : Melvin Stern Seminar Room, Room 18 Keen Bldg.
Refreshments will be served at 2:00 PM
One of the most important - and most difficult - atmospheric quantities to model is water. We feel it at the surface as precipitation, and we see it in the sky as clouds, a manifestation of convection. What is the minimal way to model water and waves and convection in the atmosphere?
In this talk, we describe a new model that captures realistic features of clouds and convection yet has, at the same time, a simple mathematical form that is potentially amenable to mathematical analysis. This is in contrast to the models used for operational forecasts, which require a comprehensive treatment of all water processes (including cloud droplets, rain droplets, snow, ice crystals, etc.), and which have a prohibitively complicated mathematical form. Can a minimal model lend insight into the complicating effects of water on atmospheric dynamics? To illustrate and evaluate the realism of the model, simulations will be shown of an individual storm (a 'squall line') and scattered convection. Finally, linear stability and instability criteria will be presented for a precipitating atmosphere, and the criteria will be related to the model's energy.
GFDI Associate Dr. Ming Ye appeared in a recent episode of NOVA, Sinkholes—Buried Alive, which aired January 28, 2015 on PBS. Dr. Ye demonstrated a laboratory model of sinkhole formation designed by Dr. Daniel Kuncicky and run by graduate students Xia Tao and Roger Pacheco. The segment starts at 14:32