Column-Integrated Moist Static Energy Budget Analysis on Various Time Scales during TOGA COARE

Abstract

Moist static energy (MSE) budgets on different time scales are analyzed in the TOGA COARE data using Lanczos filters to separate variability with different frequencies. Four different time scales (;2-day, ;5-day, ;10-day, and MJO time scales) are chosen based on the power spectrum of the precipitation and previous TOGA COARE studies. The lag regression-slope technique is utilized to depict characteristic patterns of the variability associated with the MSE budgets on the different time scales.This analysis illustrates that the MSE budgets behave in significantly different ways on the different time scales. On shorter time scales, the vertical advection acts as a primary driver of the recharge-discharge mechanism of column MSE. As the time scale gets longer, in contrast, the relative contributions of the other budget terms become greater, and consequently, on the MJO time scale all the budget terms have nearly the same amplitude. Specifically, these results indicate that horizontal advection plays an important role in the eastward propagation of the MJO during TOGA COARE. On the MJO time scale, the export of MSE by the vertical advection is in phase with the precipitation. On shorter time scales, the vertical velocity profile transitions from bottom heavy to top heavy, while on longer time scales, the shape becomes more constant and similar to a first-baroclinic-mode structure. This leads to a more-constant gross moist stability on longer time scales, which the authors estimate.

Modeling the MJO in a cloud‐resolving model with parameterized large‐scale dynamics: Vertical structure, radiation, and horizontal advection of dry air

“…In both MJO events, time‐independent radiation causes increased precipitation before or at the start of the active phase (e.g., the first 10 days, days 36, 40, and 60) and decreased precipitation in the peaks of the active phases by 30–50%, compared to that obtained with specified time‐dependent radiation. Consistent with much previous work [e.g., Lin and Mapes , ; Bony and Emanuel , ; Kim et al ., ; Sobel and Maloney , ; Inoue and Back , ; Creuger and Stevens , ], this evidence suggests that time‐dependent radiative heating anomalies associated with MJO convection are a significant source of moist static energy during the MJO active phase.…”

Intraseasonal Variability and Seasonal March of the Moist Static Energy Budget over the Eastern Maritime Continent during CINDY2011/DYNAMO

“…Their definition of NGMS is the ratio between the anomaly of column-integrated vertical advection of MSE to that of DSE. Testing this assumption is complicated by the difficulty of precisely estimating NGMS from observations; however, several modeling and observational studies indicate that NGMS significantly varies with the MJO phase (Benedict et al 2014;SWK;Wang et al 2015;Inoue and Back 2015). SWK found that NGMS increases as the MJO convective active phase passes.…”

“…The Tropical Ocean Global Atmosphere program Coupled Ocean-Atmosphere Response Experiment (TOGA COARE; Webster and Lukas 1992) conducted a field campaign over the equatorial western Pacific in 1992/93 austral summer, and the Cooperative Indian Ocean Experiment on Intraseasonal Variability in the Year 2011 (CINDY2011)/Dynamics of the MJO (DYNAMO) project conducted a field campaign focusing on central Indian Ocean in 2011/12 austral summer (Yoneyama et al 2013). While there have been a number of studies performing budget analyses of dry static energy (DSE) and moisture using data obtained during these campaigns (Lin and Johnson 1996a, b;Ciesielski 2000, 2013;Johnson et al 2015, and others), only a few studies have focused on MSE budget Inoue and Back 2015). Sobel et al (2014, hereafter SWK) examined the column-integrated MSE budget over the Indian Ocean using datasets collected by the CINDY2011/DYNAMO project together with complementary data.…”

Assessment of a Satellite-Based Atmospheric Budget Analysis Method Using CINDY2011/DYNAMO/AMIE and TOGA COARE Sounding Array Data

“…On the other hand, the horizontal advection of MSE depends on horizontal moisture gradient in the large-scale environment and could irregularly modulate the thermodynamic variability that otherwise would be controlled by internal convective dynamics. While horizontal advection could play crucial roles in the driving mechanism of the MJO (e.g., Benedict and Randall 2007;Maloney 2009;Sobel et al 2014), the relative magnitude of hori- zontal and vertical advections is dependent on the cycle of variability and the horizontal component is least important at daily time scales (Inoue and Back 2015). Figure 13 shows the breakdown of moisture/MSE convergence into horizontal and vertical advections calculated from the ensemble mean of all CINDY/DYNAMO events.…”