SEMINAR: MPO Seminar:David Nolan, TODAY,at 2:00 p.m.,Slab Seminar room,S/A 103

[Sandrine Apelbaum <sapelbaum@rsmas.miami.edu>]

MPO Seminar

Dr. David Nolan

“Fun with Point-Downscaling"

Room: Slab Seminar room, S/A 103

Date: Friday,November 5, 2:00 p.m.

Abstract:

Determining the atmospheric and oceanic conditions that are favorable or
unfavorable for tropical cyclone (TC) genesis is a matter of great
interest. Such interest has increased further due to the possibility that
TC activity may increase (or decrease) due to global climate change. Until
recently, determining the favorability of a particular climate for TC
genesis has been achieved through three methods: 1) combining large-scale
evironmental parameters such as sea surface temperature, shear, and
stability into a single “genesis parameter;” 2) counting the number of
tropical cyclone-like vortices simulated in global climate models; 3)
counting the number of tropical cyclones in a higher-resolution, regional
model with boundary conditions from a global model, the so-called
“regional downscaling.”

We present a new method which allows for much higher resolution
simulations and more direct control over the surrounding environment. A
doubly-periodic domain is initialized with pre-defined profiles of
temperature, humidity, and wind as a function of height. These profiles
may be idealized, may come from observations, or from future climate
scenarios. With small modifications to the equations of motion, the winds
can be balanced so that the wind profiles remain nearly constant across
the domain as the simulation proceeds. The development of a pre-cursor
tropical cyclone disturbance embededded in this environment is then
simulated. The rate of development (or failure) is an indicator of the
favorability of that particular sounding and wind profile for TC genesis.
Since the entire environment may be described by a single “point”
sounding, we call this “point-downscaling.” Along with TC genesis, the
point-downscaling technique can be used to evaluate favorability of
particular soundings for rapid intensification and other structural
changes.

Sandrine Apelbaum

Meteorology and Physical Oceanography 
Rosenstiel School of Marine and Atmospheric Science
University of Miami
4600 Rickenbacker Causeway
Miami, FL 33149-1098
Tel     (305) 421-4057
Fax     (305) 421-4696

sapelbaum@rsmas.miami.edu