Journal of the Atmospheric Sciences: Recent submissions
Now showing items 2901-2920 of 13215
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Synoptic Responses to Mountain Gravity Waves Encountering Directional Critical Levels
(American Meteorological Society, 2007)A heuristic model is used to study the synoptic response to mountain gravity waves (GWs) absorbed at directional critical levels. The model is a semigeostrophic version of the Eady model for baroclinic instability adapted ... -
Modeling the Interactions between Aerosols and Liquid Water Clouds with a Self-Consistent Cloud Scheme in a General Circulation Model
(American Meteorological Society, 2007)To model aerosol?cloud interactions in general circulation models (GCMs), a prognostic cloud scheme of cloud liquid water and amount is expanded to include droplet number concentration (Nd) in a way that allows them to be ... -
Multiscale Mountain Waves Influencing a Major Orographic Precipitation Event
(American Meteorological Society, 2007)This study combines high-resolution mesoscale model simulations and comprehensive airborne Doppler radar observations to identify kinematic structures influencing the production and mesoscale distribution of precipitation ... -
Optimal Perturbations in Quasigeostrophic Turbulence
(American Meteorological Society, 2007)This paper tests the hypothesis that optimal perturbations in quasigeostrophic turbulence are excited sufficiently strongly and frequently to account for the energy-containing eddies. Optimal perturbations are defined here ... -
Statistical Analyses of Satellite Cloud Object Data from CERES. Part III: Comparison with Cloud-Resolving Model Simulations of Tropical Convective Clouds
(American Meteorological Society, 2007)The present study evaluates the ability of a cloud-resolving model (CRM) to simulate the physical properties of tropical deep convective cloud objects identified from a Clouds and the Earth?s Radiant Energy System (CERES) ... -
Statistics and Parameterizations of the Effect of Turbulence on the Geometric Collision Kernel of Cloud Droplets
(American Meteorological Society, 2007)Collision statistics of cloud droplets in turbulent flow have been calculated for 12 droplet size combinations in four flow fields with levels of the eddy dissipation rate of turbulent kinetic energy ranging from 95 to ... -
Resonance in Optimal Perturbation Evolution. Part I: Two-Layer Eady Model
(American Meteorological Society, 2007)A detailed investigation has been performed of the role of the different growth mechanisms (resonance, potential vorticity unshielding, and normal-mode baroclinic instability) in the evolution of optimal perturbations ... -
Resonance in Optimal Perturbation Evolution. Part II: Effects of a Nonzero Mean PV Gradient
(American Meteorological Society, 2007)Optimal perturbations are constructed for a two-layer ?-plane extension of the Eady model. The surface and interior dynamics is interpreted using the concept of potential vorticity building blocks (PVBs), which are zonally ... -
Nucleation Processes in Deep Convection Simulated by a Cloud-System-Resolving Model with Double-Moment Bulk Microphysics
(American Meteorological Society, 2007)A novel type of limited double-moment scheme for bulk microphysics is presented here for cloud-system-resolving models (CSRMs). It predicts the average size of cloud droplets and crystals, which is important for representing ... -
Bulk Models of the Sheared Convective Boundary Layer: Evaluation through Large Eddy Simulations
(American Meteorological Society, 2007)A set of first-order model (FOM) equations, describing the sheared convective boundary layer (CBL) evolution, is derived. The model output is compared with predictions of the zero-order bulk model (ZOM) for the same CBL ... -
Temperature Dependence of Evaporation Coefficient for Water Measured in Droplets in Nitrogen under Atmospheric Pressure
(American Meteorological Society, 2007)The evaporation and the thermal accommodation coefficients for water in nitrogen were investigated by means of the analysis of evaporation of pure water droplet as a function of temperature. The droplet was levitated in ... -
Toward Understanding the Dynamical Origin of Atmospheric Regime Behavior in a Baroclinic Model
(American Meteorological Society, 2007)Dynamical mechanisms of atmospheric regime behavior are investigated in the context of a quasigeostrophic three-level T21 model of the wintertime atmospheric circulation over the Northern Hemisphere. The model, driven by ... -
Reply to “Comments on the Gravity Wave Theory of J. Weinstock Concerning Dissipation Induced by Nonlinear Effects”
(American Meteorological Society, 2007) -
Evolution of Water Vapor Concentrations and Stratospheric Age of Air in Coupled Chemistry-Climate Model Simulations
(American Meteorological Society, 2007)Stratospheric water vapor concentrations and age of air are investigated in an ensemble of coupled chemistry-climate model simulations covering the period from 1960 to 2005. Observed greenhouse gas concentrations, halogen ... -
Atmospheric Fronts along the East Coast of Taiwan Studied by ERS Synthetic Aperture Radar Images
(American Meteorological Society, 2007)The existence of quasi-stationary alongshore atmospheric fronts typically located 30?70 km off the east coast of Taiwan is demonstrated by analyzing synthetic aperture radar (SAR) images of the sea surface acquired by the ... -
A Mechanism for the Poleward Propagation of Zonal Mean Flow Anomalies
(American Meteorological Society, 2007)Observational studies have shown that tropospheric zonal mean flow anomalies frequently undergo quasi-periodic poleward propagation. A set of idealized numerical model runs is examined to investigate the physical mechanism ... -
Horizontal Wavenumber Spectra of Vertical Vorticity and Horizontal Divergence in the Upper Troposphere and Lower Stratosphere
(American Meteorological Society, 2007)The author shows that the horizontal two-point correlations of vertical vorticity and the associated vorticity wavenumber spectrum can be constructed from previously measured velocity structure functions in the upper ... -
Simulated Convective Lines with Parallel Stratiform Precipitation. Part II: Governing Dynamics and Associated Sensitivities
(American Meteorological Society, 2007)This article is the second of two describing convective lines with parallel stratiform (PS) precipitation. The PS mode appears to be the preferred organizational structure in environments with line-parallel vertical wind ... -
Intraseasonal Variability of the Zonal-Mean Extratropical Tropopause Height
(American Meteorological Society, 2007)The physical processes that drive the fluctuations of the extratropical tropopause height are examined with the National Centers for Environmental Prediction?National Center for Atmospheric Research (NCEP?NCAR) reanalysis ... -
Observations of Stably Stratified Shear-Driven Atmospheric Turbulence at Low and High Richardson Numbers
(American Meteorological Society, 2007)Stably stratified shear-driven turbulence is analyzed using the gradient Richardson number, Ri, as the stability parameter. The method overcomes the statistical problems associated with the widely used Monin?Obukhov stability ...