Journal of the Atmospheric Sciences: Recent submissions
Now showing items 4201-4220 of 13215
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New Observations of Precipitation Initiation in Warm Cumulus Clouds
(American Meteorological Society, 2008)The mechanism responsible for formation of rain in warm clouds has been debated for over six decades. Here, the authors analyze new measurements of shallow cumulus made with a phase Doppler interferometer during the Rain ... -
A Low-Order Model Investigation of the Analysis of Gravity Waves in the Ensemble Kalman Filter
(American Meteorological Society, 2009)The behavior of the ensemble Kalman filter (EnKF) is examined in the context of a model that exhibits a nonlinear chaotic (slow) vortical mode coupled to a linear (fast) gravity wave of a given amplitude and frequency. It ... -
Mixing in Shallow Cumulus Clouds Studied by Lagrangian Particle Tracking
(American Meteorological Society, 2008)Mixing between shallow cumulus clouds and their environment is studied using large-eddy simulations. The origin of in-cloud air is studied by two distinct methods: 1) by analyzing conserved variable mixing diagrams (Paluch ... -
Zonal Jets as Transport Barriers in Planetary Atmospheres
(American Meteorological Society, 2008)The connection between transport barriers and potential vorticity (PV) barriers in PV-conserving flows is investigated with a focus on zonal jets in planetary atmospheres. A perturbed PV staircase model is used to illustrate ... -
Three-Dimensional Structure and Dynamics of African Easterly Waves. Part III: Genesis
(American Meteorological Society, 2008)This paper promotes the view that African easterly waves (AEWs) are triggered by localized forcing, most likely associated with latent heating upstream of the region of observed AEW growth. A primitive equation model is ... -
Subgrid-Scale Parameterization with Conditional Markov Chains
(American Meteorological Society, 2008)A new approach is proposed for stochastic parameterization of subgrid-scale processes in models of atmospheric or oceanic circulation. The new approach relies on two key ingredients: first, the unresolved processes are ... -
Observations of Gap Flow in the Wipp Valley on 20 October 1999: Evidence of Subsidence
(American Meteorological Society, 2009)Using extensive observations collected from various platforms around the Brenner Pass in the Austrian Alps during the Mesoscale Alpine Programme, a detailed description of the kinematic and thermodynamic structure of the ... -
Exponential Size Distributions for Snow
(American Meteorological Society, 2008)Using airborne data from several recent field projects, the authors have taken another look at the properties of exponential ice particle size distributions (PSDs) when the PSDs are broad. Two primary questions are addressed: ... -
Correlative Evolutions of ENSO and the Seasonal Cycle in the Tropical Pacific Ocean
(American Meteorological Society, 2009)This study examines whether shifts between the correlative evolutions of ENSO and the seasonal cycle in the tropical Pacific Ocean can produce effects that are large enough to alter the evolution of the coupled atmosphere?ocean ... -
Gravity Wave Generation around the Polar Vortex in the Stratosphere Revealed by 3-Hourly Radiosonde Observations at Syowa Station
(American Meteorological Society, 2008)Intensive radiosonde observations were performed at Syowa Station (69.0°S, 39.6°E) over about 10 days in each of March, June, October, and December 2002 to examine inertia?gravity wave characteristics in the Antarctic lower ... -
How Well Does Water Activity Determine Homogeneous Ice Nucleation Temperature in Aqueous Sulfuric Acid and Ammonium Sulfate Droplets?
(American Meteorological Society, 2009)Frozen fraction measurements made using a droplet free-fall freezing tube apparatus are presented and used, along with other recent laboratory measurements, to evaluate how well both the water activity idea and the translated ... -
Analysis of the Impact of Model Nonlinearities in Inverse Problem Solving
(American Meteorological Society, 2008)In this study, the relationship between nonlinear model properties and inverse problem solutions is analyzed using a numerical technique based on the inverse problem theory formulated by Mosegaard and Tarantola. According ... -
Spontaneous Imbalance and Hybrid Vortex–Gravity Structures
(American Meteorological Society, 2009)After reviewing the background, this article discusses the recently discovered examples of hybrid propagating structures consisting of vortex dipoles and comoving gravity waves undergoing wave capture. It is shown how these ... -
The Emergence of Multiple Robust Zonal Jets from Freely Evolving, Three-Dimensional Stratified Geostrophic Turbulence with Applications to Jupiter
(American Meteorological Society, 2008)Three-dimensional numerical simulations of freely evolving stratified geostrophic turbulence on the ? plane are presented as a simplified model of zonal jet formation on Jupiter. This study samples the parameter space that ... -
Mesoscale Model Initialization of the Fourier Method for Mountain Waves
(American Meteorological Society, 2008)A Fourier method is combined with a mesoscale model to simulate mountain waves. The mesoscale model describes the nonlinear low-level flow and predicts the emerging wave field above the mountain. This solution serves as ... -
Radiative–Convective Feedbacks in Idealized States of Radiative–Convective Equilibrium
(American Meteorological Society, 2008)This paper examines feedbacks between the radiative heating of clouds and convection in the context of numerical radiative?convective equilibrium experiments conducted using both 2D and 3D versions of a cloud-resolving ... -
Wave–Turbulence Interactions in a Breaking Mountain Wave
(American Meteorological Society, 2008)The mean and turbulent structures in a breaking mountain wave are considered through an ensemble of high-resolution (essentially large-eddy simulation) wave-breaking calculations. Of particular interest are the turbulent ... -
Entropic Aspects of Supercooled Droplet Freezing
(American Meteorological Society, 2008)The freezing of supercooled water droplets in the atmosphere, with an emphasis on the entropic aspects of the problem, is examined. Supercooled water is a metastable state and, therefore, the associated phase transition ... -
Decoupling of Balanced and Unbalanced Motions and Inertia–Gravity Wave Emission: Small versus Large Rossby Numbers
(American Meteorological Society, 2008)This paper provides a brief review of recent results on decoupling of fast [inertia?gravity wave (IGW)] and slow (vortex) motions at small Rossby numbers obtained in the framework of the geostrophic adjustment of localized ... -
Global Gravity Wave Variances from Aura MLS: Characteristics and Interpretation
(American Meteorological Society, 2008)The gravity wave (GW)?resolving capabilities of 118-GHz saturated thermal radiances acquired throughout the stratosphere by the Microwave Limb Sounder (MLS) on the Aura satellite are investigated and initial results ...