Journal of the Atmospheric Sciences: Recent submissions
Now showing items 4341-4360 of 13215
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Singular Vectors and Time-Dependent Normal Modes of a Baroclinic Wave-Mean Oscillation
(American Meteorological Society, 2008)Linear disturbance growth is studied in a quasigeostrophic baroclinic channel model with several thousand degrees of freedom. Disturbances to an unstable, nonlinear wave-mean oscillation are analyzed, allowing the comparison ... -
Is There a Statistical Connection between Stratospheric Sudden Warming and Tropospheric Blocking Events?
(American Meteorological Society, 2008)This paper presents statistical analyses of possible associations between major stratospheric sudden warming (SSW) and tropospheric blocking events in the Northern Hemisphere (NH) with 49 yr of NCEP?NCAR reanalysis data ... -
Sling Effect in Collisions of Water Droplets in Turbulent Clouds
(American Meteorological Society, 2007)The effect of turbulence on the collision rate between droplets in clouds is investigated. Because of their inertia, water droplets can be shot out of curved streamlines of the turbulent airflow. The contribution of such ... -
Abrupt Seasonal Migration of the ITCZ into the Summer Hemisphere
(American Meteorological Society, 2008)Although the maximum of solar radiation at the top of the atmosphere moves gradually from one hemisphere to the other as part of the seasonal cycle, the intertropical convergence zone (ITCZ) moves abruptly into the summer ... -
Modulation of Small-Scale Turbulence by Ducted Gravity Waves in the Nocturnal Boundary Layer
(American Meteorological Society, 2008)Constant altitude measurements of temperature and velocity in the residual layer of the nocturnal boundary layer, collected by the Cooperative Institute for Research in Environmental Sciences (CIRES) Tethered Lifting System ... -
A Lagrangian Spectral Parameterization of Gravity Wave Drag Induced by Cumulus Convection
(American Meteorological Society, 2008)A Lagrangian spectral parameterization of gravity wave drag (GWD) induced by cumulus convection (GWDC) is developed based on ray theory and several assumptions and implemented into the NCAR Whole Atmosphere Community Climate ... -
Collisions of Cloud Droplets in a Turbulent Flow. Part V: Application of Detailed Tables of Turbulent Collision Rate Enhancement to Simulation of Droplet Spectra Evolution
(American Meteorological Society, 2008)The present study is a continuation of the series of studies dedicated to the investigation of cloud droplet collisions in turbulent flow with characteristics that are typical of real clouds. Detailed tables of collision ... -
Uniform Asymptotics for the Linear Kelvin Wave in Spherical Geometry
(American Meteorological Society, 2008)The Kelvin wave is the gravest eigenmode of Laplace?s tidal equation. It is widely observed in both the ocean and the atmosphere. In the absence of mean currents, the Kelvin wave depends on two parameters: the zonal ... -
Multiscale Convective Wave Disturbances in the Tropics: Insights from a Two-Dimensional Cloud-Resolving Model
(American Meteorological Society, 2008)Multiscale convective wave disturbances with structures broadly resembling observed tropical waves are found to emerge spontaneously in a nonrotating, two-dimensional cloud model forced by uniform cooling. To articulate ... -
Inertia–Gravity Waves Generated within a Dipole Vortex
(American Meteorological Society, 2007)Vortex dipoles provide a simple representation of localized atmospheric jets. Numerical simulations of a synoptic-scale dipole in surface potential temperature are considered in a rotating, stratified fluid with approximately ... -
Rotor and Subrotor Dynamics in the Lee of Three-Dimensional Terrain
(American Meteorological Society, 2007)The internal structure and dynamics of rotors that form in the lee of topographic ridges are explored using a series of high-resolution eddy-resolving numerical simulations. Surface friction generates a sheet of horizontal ... -
The Effect of Dynamics on Mixed-Phase Clouds: Theoretical Considerations
(American Meteorological Society, 2008)A theoretical framework has been developed describing nonequilibrium formation and maintenance of mixed-phase clouds. The necessary and sufficient conditions required to activate liquid water within a preexisting ice cloud, ... -
Horizontal and Vertical Structure of Easterly Waves in the Pacific ITCZ
(American Meteorological Society, 2008)Outgoing longwave radiation (OLR) and low-level wind fields in the Atlantic and Pacific intertropical convergence zone (ITCZ) are dominated by variability on synoptic time scales primarily associated with easterly waves ... -
Momentum and Energy Transport by Gravity Waves in Stochastically Driven Stratified Flows. Part II: Radiation of Gravity Waves from a Gaussian Jet
(American Meteorological Society, 2008)Interaction between the midlatitude jet and gravity waves is examined, focusing on the nonnormality of the underlying linear dynamics, which plays an essential role in processing the wave activity and selecting structures ... -
Snow Size Distribution Parameterization for Midlatitude and Tropical Ice Clouds
(American Meteorological Society, 2007)Many microphysical process rates involving snow are proportional to moments of the snow particle size distribution (PSD), and in this study a moment estimation parameterization applicable to both midlatitude and tropical ... -
High-Resolution Observations with MU Radar of a KH Instability Triggered by an Inertia–Gravity Wave in the Upper Part of a Jet Stream
(American Meteorological Society, 2008)Kelvin?Helmholtz (KH) instability is likely one of the most important sources of clear-air turbulence in the lower atmosphere. It produces billows, which mix and transport heat and materials vertically in the stably ... -
A New Rossby Wave–Breaking Interpretation of the North Atlantic Oscillation
(American Meteorological Society, 2008)This paper proposes the hypothesis that the low-frequency variability of the North Atlantic Oscillation (NAO) arises as a result of variations in the occurrence of upper-level Rossby wave?breaking events over the North ... -
Analysis of Convectively Coupled Kelvin Waves in the Indian Ocean MJO
(American Meteorological Society, 2008)The active convective phase of the Madden?Julian oscillation (hereafter active MJO) comprises enhanced moist deep convection on its own temporal and spatial scales as well as increased variance in convection associated ... -
MJO and Tropical Cyclogenesis in the Gulf of Mexico and Eastern Pacific: Case Study and Idealized Numerical Modeling
(American Meteorological Society, 2008)The role of the Madden?Julian oscillation (MJO) in modulating the frequency and location of tropical cyclogenesis over the eastern Pacific and the Gulf of Mexico during August?September 1998 is examined. During the ... -
Emission of Inertial Waves by Baroclinically Unstable Flows: Laboratory Experiments with Altimetric Imaging Velocimetry
(American Meteorological Society, 2008)Results from new experiments on baroclinic instability of a coastal jet demonstrate that this almost balanced flow spontaneously emits inertial waves when the Rossby radius of deformation is relatively small such that the ...