Larissa Back
University of Wisconsin-Madison
"Moist static energy budgets and gross moist stability in observations over the tropical oceans"
Precipitation and column-integrated moisture are closely related over the tropical oceans. Hence, understanding processes that change column moisture provides a systematic way to understand mean rainfall and rainfall changes. The column moist static energy budget is a useful tool for this, since temperature variations are small in the tropics due to the large Rossby radius.
New diagnostic applications of moist static energy budgets that utilize the gross moist stability (GMS) in satellite data will be introduced. A rapidly varying version of the GMS describes whether rainfall is increasing or decreasing. The “GMS plane” of the divergence of column moist static energy against the divergence of column dry static energy behaves as a phase plane in which each convective life-cycle can be viewed as an orbiting fluctuation around the critical line, or characteristic GMS. Hence, position on the GMS plane can qualitatively predict future convective evolution. The slope of the critical line is the characteristic GMS that is relevant to moisture mode theories of the Madden Julian Oscillation, and simple models of the tropical circulation. Geographic variations of this quantity are examined.
Host: Ding Ma
