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

2015 ◽  
Vol 72 (5) ◽  
pp. 1856-1871 ◽  
Author(s):  
Kuniaki Inoue ◽  
Larissa Back
Keyword(s):  
Time Scales ◽  
Time Scale ◽  
Moist Static Energy ◽  
Vertical Advection ◽  
Budget Analysis ◽  
Toga Coare ◽  
Primary Driver ◽  
Moist Static Energy Budget ◽  
Static Energy ◽  
Different Time Scales

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.

scholarly journals Moist Static Energy Budget of MJO-like Disturbances in the Atmosphere of a Zonally Symmetric Aquaplanet

2012 ◽  
Vol 25 (8) ◽  
pp. 2782-2804 ◽  
Author(s):  
Joseph Allan Andersen ◽  
Zhiming Kuang
Keyword(s):  
Spectral Feature ◽  
Low Frequency ◽  
Atmospheric Model ◽  
Moist Static Energy ◽  
Eddy Activity ◽  
Vertical Advection ◽  
Time Space ◽  
Synoptic Eddies ◽  
Moist Static Energy Budget ◽  
Static Energy

Abstract A Madden–Julian oscillation (MJO)-like spectral feature is observed in the time–space spectra of precipitation and column-integrated moist static energy (MSE) for a zonally symmetric aquaplanet simulated with Superparameterized Community Atmospheric Model (SPCAM). This disturbance possesses the basic structural and propagation features of the observed MJO. To explore the processes involved in propagation and maintenance of this disturbance, this study analyzes the MSE budget of the disturbance. The authors observe that the disturbances propagate both eastward and poleward. The column-integrated longwave heating is the only significant source of column-integrated MSE acting to maintain the MJO-like anomaly balanced against the combination of column-integrated horizontal and vertical advection of MSE and latent heat flux. Eastward propagation of the MJO-like disturbance is associated with MSE generated by both column integrated horizontal and vertical advection of MSE, with the column longwave heating generating MSE that retards the propagation. The contribution to the eastward propagation by the column-integrated horizontal advection of MSE is dominated by synoptic eddies. Further decomposition indicates that the advection contribution to the eastward propagation is dominated by meridional advection of MSE by anomalous synoptic eddies caused by the suppression of eddy activity ahead of the MJO convection. This suppression is linked to the barotropic conversion mechanism, with the gradients of the low-frequency wind experienced by the synoptic eddies within the MJO envelope acting to modulate the eddy kinetic energy. The meridional eddy advection’s contribution to poleward propagation is dominated by the mean state’s (meridionally varying) eddy activity acting on the anomalous MSE gradients associated with the MJO.

scholarly journals Moist Static Energy Budget of the MJO during DYNAMO

2014 ◽  
Vol 71 (11) ◽  
pp. 4276-4291 ◽  
Author(s):  
Adam Sobel ◽  
Shuguang Wang ◽  
Daehyun Kim
Keyword(s):  
Indian Ocean ◽  
Energy Budget ◽  
Active Phase ◽  
Turbulent Fluxes ◽  
Radiative Heating ◽  
Moist Static Energy ◽  
Horizontal Advection ◽  
Vertical Advection ◽  
Moist Static Energy Budget ◽  
Static Energy

Abstract The authors analyze the column-integrated moist static energy budget over the region of the tropical Indian Ocean covered by the sounding array during the Cooperative Indian Ocean Experiment on Intraseasonal Variability in the Year 2011 (CINDY2011)/Dynamics of the Madden–Julian Oscillation (DYNAMO) field experiment in late 2011. The analysis is performed using data from the sounding array complemented by additional observational datasets for surface turbulent fluxes and atmospheric radiative heating. The entire analysis is repeated using the ECMWF Interim Re-Analysis (ERA-Interim). The roles of surface turbulent fluxes, radiative heating, and advection are quantified for the two MJO events that occurred in October and November using the sounding data; a third event in December is also studied in the ERA-Interim data. These results are consistent with the view that the MJO’s moist static energy anomalies grow and are sustained to a significant extent by the radiative feedbacks associated with MJO water vapor and cloud anomalies and that propagation of the MJO is associated with advection of moist static energy. Both horizontal and vertical advection appear to play significant roles in the events studied here. Horizontal advection strongly moistens the atmosphere during the buildup to the active phase of the October event when the low-level winds switch from westerly to easterly. Horizontal advection strongly dries the atmosphere in the wake of the active phases of the November and December events as the westerlies associated with off-equatorial cyclonic gyres bring subtropical dry air into the convective region from the west and north. Vertical advection provides relative moistening ahead of the active phase and drying behind it, associated with an increase of the normalized gross moist stability.

A Moist Static Energy Budget Analysis of Quasi-2-Day Waves Using Satellite and Reanalysis Data

2016 ◽  
Vol 73 (2) ◽  
pp. 743-759 ◽  
Author(s):  
Yukari Sumi ◽  
Hirohiko Masunaga
Keyword(s):  
Large Scale ◽  
Deep Convection ◽  
Reanalysis Data ◽  
Convective Heating ◽  
Moist Static Energy ◽  
Wave Dynamics ◽  
Vertical Advection ◽  
Budget Analysis ◽  
Static Energy ◽  
Thermodynamic Processes

Abstract A moist static energy (MSE) budget analysis is applied to quasi-2-day waves to examine the effects of thermodynamic processes on the wave propagation mechanism. The 2-day waves are defined as westward inertia–gravity (WIG) modes identified with filtered geostationary infrared measurements, and the thermodynamic parameters and MSE budget variables computed from reanalysis data are composited with respect to the WIG peaks. The composite horizontal and vertical MSE structures are overall as theoretically expected from WIG wave dynamics. A prominent horizontal MSE advection is found to exist, although the wave dynamics is mainly regulated by vertical advection. The vertical advection decreases MSE around the times of the convective peak, plausibly resulting from the first baroclinic mode associated with deep convection. Normalized gross moist stability (NGMS) is used to examine the thermodynamic processes involving the large-scale dynamics and convective heating. NGMS gradually decreases to zero before deep convection and reaches a maximum after the convection peak, where low (high) NGMS leads (lags) deep convection. The decrease in NGMS toward zero before the occurrence of active convection suggests an increasingly efficient conversion from convective heating to large-scale dynamics as the wave comes in, while the increase afterward signifies that this linkage swiftly dies out after the peak.

scholarly journals Impacts of Shallow Convection on MJO Simulation: A Moist Static Energy and Moisture Budget Analysis

2013 ◽  
Vol 26 (8) ◽  
pp. 2417-2431 ◽  
Author(s):  
Qiongqiong Cai ◽  
Guang J. Zhang ◽  
Tianjun Zhou
Keyword(s):  
Boundary Layer ◽  
Deep Convection ◽  
Lower Troposphere ◽  
Longwave Radiation ◽  
Reanalysis Data ◽  
Specific Humidity ◽  
Moist Static Energy ◽  
Shallow Convection ◽  
Budget Analysis ◽  
Static Energy

Abstract The role of shallow convection in Madden–Julian oscillation (MJO) simulation is examined in terms of the moist static energy (MSE) and moisture budgets. Two experiments are carried out using the NCAR Community Atmosphere Model, version 3.0 (CAM3.0): a “CTL” run and an “NSC” run that is the same as the CTL except with shallow convection disabled below 700 hPa between 20°S and 20°N. Although the major features in the mean state of outgoing longwave radiation, 850-hPa winds, and vertical structure of specific humidity are reasonably reproduced in both simulations, moisture and clouds are more confined to the planetary boundary layer in the NSC run. While the CTL run gives a better simulation of the MJO life cycle when compared with the reanalysis data, the NSC shows a substantially weaker MJO signal. Both the reanalysis data and simulations show a recharge–discharge mechanism in the MSE evolution that is dominated by the moisture anomalies. However, in the NSC the development of MSE and moisture anomalies is weaker and confined to a shallow layer at the developing phases, which may prevent further development of deep convection. By conducting the budget analysis on both the MSE and moisture, it is found that the major biases in the NSC run are largely attributed to the vertical and horizontal advection. Without shallow convection, the lack of gradual deepening of upward motion during the developing stage of MJO prevents the lower troposphere above the boundary layer from being preconditioned for deep convection.

Quantifying the interplay of clouds and their environment through an energetic lens during EUREC4A

2021 ◽  
Author(s):  
Anna Lea Albright ◽  
Sandrine Bony ◽  
Bjorn Stevens ◽  
Raphaela Vogel
Keyword(s):  
Large Scale ◽  
Hydrological Cycle ◽  
Trade Wind ◽  
Energy Budgets ◽  
Moist Static Energy ◽  
Radiative Effect ◽  
The North ◽  
Cloud Radiative Effect ◽  
Moist Static Energy Budget ◽  
Static Energy

<p>The trades form an important link in the atmospheric energy supply, transporting moisture and momentum to the deep tropics and influencing the global hydrological cycle. Trade-wind cumuli are the most ubiquitous cloud type over tropical oceans, yet models disagree in simulating their response to warming. Our study takes advantage of extensive in-situ soundings performed during the EUREC4A campaign, which took place in the downstream trades of the North Atlantic in winter 2020. We employ 1068 dropsondes made in a ca. 2deg x 2deg area to close the moisture and energy budgets of the subcloud layer and atmospheric column. Our motivation for closing moisture and energy budgets using EUREC4A data is two-fold. First, we try to understand which large-scale environmental factors control variability in subcloud layer moisture and moist static energy, given their influence on setting convective potential. Second, we quantify the interplay between clouds and their environment through an energetic lens. The cloud radiative effect emerges as a residual from the total column moist static energy budget, yielding an energetic estimate of clouds. We quantify how this cloud radiative effect compares with coincident satellite and geometric (i.e. cloud fraction) estimates of cloudiness, varies on different scales, and relates to large-scale environmental conditions.</p>

scholarly journals Evaluation of Moist Static Energy in a Simulated Tropical Cyclone

Atmosphere ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 319
Author(s):  
Lijun Yu ◽  
Shuhui Wu ◽  
Zhanhong Ma
Keyword(s):  
Tropical Cyclone ◽  
Potential Temperature ◽  
Surface Heat ◽  
Heat Fluxes ◽  
Moist Static Energy ◽  
Surface Heat Fluxes ◽  
Budget Analysis ◽  
Study Results ◽  
Static Energy ◽  
Radial Outflow

The characteristics of moist static energy (MSE) and its budget in a simulated tropical cyclone (TC) are examined in this study. Results demonstrate that MSE in a TC system is enhanced as the storm strengthens, primarily because of two mechanisms: upward transfer of surface heat fluxes and subsequent warming of the upper troposphere. An inspection of the interchangeable approximation between MSE and equivalent potential temperature (θe) suggests that although MSE is capable of capturing overall structures of θe, some important features will still be distorted, specifically the low-MSE pool outside the eyewall. In this low-MSE region, from the budget analysis, the discharge of MSE in the boundary layer may even surpass the recharge of MSE from the ocean. Unlike the volume-averaged MSE, the mass-weighted MSE in a fixed volume following the TC shows no apparent increase as the TC intensifies, because the atmosphere becomes continually thinner accompanying the warming of the storm. By calculating a mass-weighted volume MSE budget, the TC system is found to export MSE throughout its lifetime, since the radial outflow overwhelms the radial inflow. Moreover, the more intensified the TC is, the more export of MSE there tends to be. The input of MSE by surface heat fluxes is roughly balanced by the combined effects of radiation and lateral export, wherein a great majority of the imported MSE is reduced by radiation, while the export of MSE from the TC system to the environment accounts for only a small portion.

scholarly journals Stationarity Testing of Accumulated Ethernet Traffic

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Zhiping Lu ◽  
Ming Li ◽  
Wei Zhao
Keyword(s):  
Time Scales ◽  
Unit Root ◽  
Time Scale ◽  
Unit Root Tests ◽  
Quantitative Results ◽  
Different Time Scales

We investigate the stationarity property of the accumulated Ethernet traffic series. We applied several widely used stationarity and unit root tests, such as Dickey-Fuller test and its augmented version, Phillips-Perron test, as well as the Kwiatkowski-Phillips-Schmidt-Shin test and some of its generalizations, to the assessment of the stationarity of the traffic traces at the different time scales. The quantitative results in this research provide evidence that when the time scale increases, the accumulated traffic series are more stationary.

scholarly journals Dr. Yanai’s Contributions to the Discovery and Science of the MJO

2016 ◽  
Vol 56 ◽  
pp. 4.1-4.18 ◽  
Author(s):  
Eric D. Maloney ◽  
Chidong Zhang
Keyword(s):  
Kinetic Energy ◽  
Potential Energy ◽  
Energy Budget ◽  
Momentum Transport ◽  
Energy Budgets ◽  
Equatorial Waves ◽  
Madden Julian Oscillation ◽  
Moist Static Energy ◽  
Moist Static Energy Budget ◽  
Static Energy

Abstract This chapter reviews Professor Michio Yanai’s contributions to the discovery and science of the Madden–Julian oscillation (MJO). Professor Yanai’s work on equatorial waves played an inspirational role in the MJO discovery by Roland Madden and Paul Julian. Professor Yanai also made direct and important contributions to MJO research. These research contributions include work on the vertically integrated moist static energy budget, cumulus momentum transport, eddy available potential energy and eddy kinetic energy budgets, and tropical–extratropical interactions. Finally, Professor Yanai left a legacy through his students, who continue to push the bounds of MJO research.

scholarly journals Diagnosing ocean feedbacks to the MJO: SST-modulated surface fluxes and the moist static energy budget

2016 ◽  
Vol 121 (14) ◽  
pp. 8350-8373 ◽  
Author(s):  
Charlotte A. DeMott ◽  
James J. Benedict ◽  
Nicholas P. Klingaman ◽  
Steven J. Woolnough ◽  
David A. Randall
Keyword(s):  
Energy Budget ◽  
Surface Fluxes ◽  
Moist Static Energy ◽  
Moist Static Energy Budget ◽  
Static Energy

EMERGING PROPERTIES IN POPULATION DYNAMICS WITH DIFFERENT TIME SCALES

1995 ◽  
Vol 03 (02) ◽  
pp. 591-602 ◽  
Author(s):  
PIERRE AUGER ◽  
JEAN-CHRISTOPHE POGGIALE
Keyword(s):  
Differential Equations ◽  
Time Scales ◽  
Time Scale ◽  
Population Level ◽  
Nonlinear Process ◽  
Linear Process ◽  
Fast Time ◽  
Slow Part ◽  
Spatial Patches ◽  
Different Time Scales

The aim of this work is to show that at the population level, emerging properties may occur as a result of the coupling between the fast micro-dynamics and the slow macrodynamics. We studied a prey-predator system with different time scales in a heterogeneous environment. A fast time scale is associated to the migration process on spatial patches and a slow time scale is associated to the growth and the interactions between the species. Preys go on the spatial patches on which some resources are located and can be caught by the predators on them. The efficiency of the predators to catch preys is patch-dependent. Preys can be more easily caught on some spatial patches than others. Perturbation theory is used in order to aggregate the initial system of ordinary differential equations for the patch sub-populations into a macro-system of two differential equations governing the total populations. Firstly, we study the case of a linear process of migration for which the aggregated system is formally identical to the slow part of the full system. Then, we study an example of a nonlinear process of migration. We show that under these conditions emerging properties appear at the population level.

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