Moist static energy budget analysis over the tropical ocean

In this dissertation work, we analyze moist static energy (MSE) budgets and associated quantities in a various ways. First, we investigate MSE budgets on four different time scales (around 2-day, 5-day, 10-day, and MJO time scales) with the TOGA COARE field campaign data set and a lag-regression analysis. This analysis reveals that the MSE budgets behave in significantly different ways on the different time scales. On the shorter time scales, the vertical MSE advection acts as a primary driver of the recharge-discharge cycle of column MSE. As the time scale gets longer, in contrast, the relative contributions of the other budget terms become greater. Vertical velocity profiles also exhibit significantly different patterns among the different time scales, leading to different behaviors of the gross moist stability (GMS) among the time scales.;Second, utilizing the same TOGA COARE data, we investigate the GMS and its relevant quantities in a unique way. In this analysis, we coined the critical GMS, which is a ratio of the diabatic MSE source to the intensity of convection, and the drying efficiency, which is defined as the GMS minus the critical GMS. Our analysis reveals that convection amplifies/decays via negative/positive drying efficiency, which is associated with a bottom-heavy/top-heavy vertical velocity profile, respectively. We also propose various ways of computing quasi-time-independent "characteristic GMS", and discuss the physical interpretations of it.;Finally, we present a novel diagnostic application of the GMS, called the "GMS plane analysis". It is demonstrated with satellite-based data sets. The analysis reveals that the GMS plane acts as a phase plane in which each convective life-cycle can be viewed as an orbiting fluctuation around some critical line that is determined by the feedback mechanisms of the diabatic MSE source terms. The geographic variability of the characteristic GMS is depicted. We also discuss general misconceptions in the past MSE budget studies which, implicitly or explicitly, attempted to associate the temporal variability of MSE budgets with the linear moisture-mode theory.