SEMINAR: MPO Special Seminar, Dr. Kazuaki Yasunaga,TODAY at 3:00 p.m., MSC 343

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

MPO Special Seminar

Dr. Kazuaki Yasunaga

JAMSTEC, Yokosuka, Japan

MPO visitor for the past year

“Do different types of equatorial waves modulate convective and
stratiform precipitation differently?"

Room: MSC 343

Date: Monday,October 18, 3:00 p.m.

Abstract

The present study explores the modulation of convective and stratiform precipitation by convectively coupled equatorial waves. We take two
approaches to this problem: cross-spectral analysis, and space-time filtered composites of TRMM precipitation systems. Results indicate
that higher-frequency and more divergent waves such as the Kelvin wave and inertio-gravity wave families modulate stratiform precipitation
a lot, presumably by modulating mesoscale organized precipitation systems in which stratiform rain is most prevalent. Consistently, these
waves also modulate mid-tropospheric divergence a lot. We hypothesize that these waves affect such systems through their density field, felt
by convection through low-level buoyancy (convective inhibition). In contrast, slower and more rotational (Rossby, Rossby-gravity, TD
or "easterly") waves primarily modulate convective rain and are coherent with divergence only near the surface and tropopause. These slower waves
also have stronger signatures in column precipitable water, suggesting that they may have their influence more through moisture advection,
perhaps felt mainly by convective cells through entrainment.

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