Journal ArticleDOI
Large-Scale Modes of a Nonrotating Atmosphere with Water Vapor and Cloud–Radiation Feedbacks
Željka Fuchs,David J. Raymond +1 more
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In this paper, a model of a moist equatorial atmosphere is presented in which the precipitation rate is assumed to depend on just the vertically averaged saturation deficit and the convective available potential energy.Abstract:
A minimal model of a moist equatorial atmosphere is presented in which the precipitation rate is assumed to depend on just the vertically averaged saturation deficit and the convective available potential energy. When wind-induced surface heat exchange (WISHE) and cloud–radiation interactions are turned off, there are no growing modes. Gravity waves with wavenumbers smaller than a certain limit respond to a reduced static stability due to latent heat release, and therefore propagate more slowly than dry modes, while those with larger wavenumbers respond to the normal dry static stability. In addition, there exists a stationary mode that decays slowly with time. For realistic parameter values, the effect of reduced static stability on gravity waves is limited to wavelengths greater than the circumference of the earth. WISHE and cloud–radiation interactions both destabilize the stationary mode, but not the gravity waves.read more
Citations
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Journal ArticleDOI
A Simple Multicloud Parameterization for Convectively Coupled Tropical Waves. Part I: Linear Analysis
Boualem Khouider,Andrew J. Majda +1 more
TL;DR: In this paper, a model convective parameterization highlighting the dynamic role of the three cloud types is developed through two baroclinic modes of vertical structure: a deep convective heating mode and a second mode with low-level heating and cooling corresponding respectively to congestus and stratiform clouds.
Journal ArticleDOI
The Mechanics of Gross Moist Stability
TL;DR: The gross moist stability relates the net lateral outflow of moist entropy or moist static energy from an atmospheric convective region to some measure of the strength of the convection in that region as discussed by the authors.
Journal ArticleDOI
The MJO as a Dispersive, Convectively Coupled Moisture Wave: Theory and Observations
Ángel F. Adames,Daehyun Kim +1 more
TL;DR: In this paper, a linear wave theory for the Madden-Julian oscillation (MJO) is extended upon in this study, where column moisture is the only prognostic variable and the horizontal wind is diagnosed as the forced Kelvin and Rossby wave responses to an equatorial heat source/sink.
Journal ArticleDOI
An Idealized Semi-Empirical Framework for Modeling the Madden–Julian Oscillation
Adam H. Sobel,Eric D. Maloney +1 more
TL;DR: In this article, a simple semi-empirical model is presented to explore the hypothesis that the Madden-Julian oscillation can be represented as a moisture mode destabilized by surface flux and cloud-radiative feedbacks.
Journal ArticleDOI
Moisture modes and the Madden-Julian oscillation.
David J. Raymond,Željka Fuchs +1 more
TL;DR: In this paper, a simulation of the interaction between convection and large-scale flows in the tropics suggests that there are two types of convectively coupled disturbances: the moisture mode instability described above and another unstable mode dependent on fluctuations in the convective inhibition.
References
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Journal ArticleDOI
Detection of a 40–50 Day Oscillation in the Zonal Wind in the Tropical Pacific
Roland A. Madden,Paul R. Julian +1 more
TL;DR: In this paper, a very pronounced maximum was noted in the co-spectrum of the 850- and 150-mb zonal wind components in the frequency range 0.0245-0.0190 day−1 (41-53 days period).
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Description of Global-Scale Circulation Cells in the Tropics with a 40–50 Day Period
Roland A. Madden,Paul R. Julian +1 more
TL;DR: In this article, a long time series (5-10 years) of station pressure and upper air data from stations located in the tropics are subjected to spectral and cross-spectral analysis to investigate the spatial extent of a previously detected oscillation in various variables with a period range of 40-50 days.
Journal ArticleDOI
Interaction of a Cumulus Cloud Ensemble with the Large-Scale Environment, Part I
Akio Arakawa,Wayne H. Schubert +1 more
TL;DR: In this paper, large-scale modification of the environment by cumulus clouds is discussed in terms of entrainment, detraining, evaporation, and subsidence, and budget equations for mass, static energy, water vapor, and liquid water are considered.
Journal ArticleDOI
Observations of the 40-50-day tropical oscillation - a review
Roland A. Madden,Paul R. Julian +1 more
TL;DR: The 40-50-day cyclone oscillation is the result of large-scale circulation cells oriented in the equatorial plane that move eastward from at least the Indian Ocean to the central Pacific as discussed by the authors.
Journal ArticleDOI
Convectively Coupled Equatorial Waves: Analysis of Clouds and Temperature in the Wavenumber–Frequency Domain
TL;DR: In this article, a wavenumber-frequency spectrum analysis is performed for all longitudes in the domain 158S−158N using a long (;18 years) twice-daily record of satellite-observed outgoing longwave radiation (OLR), a good proxy for deep tropical convection.