Journal of the Atmospheric Sciences: Recent submissions
Now showing items 2821-2840 of 13215
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Vortex Dipoles for Surface Quasigeostrophic Models
(American Meteorological Society, 2007)A new class of exact vortex dipole solutions is derived for surface quasigeostrophic (sQG) models. The solutions extend the two-dimensional barotropic modon to fully three-dimensional, continuously stratified flow and are ... -
Momentum Flux Spectrum of Convectively Forced Internal Gravity Waves and Its Application to Gravity Wave Drag Parameterization. Part II: Impacts in a GCM (WACCM)
(American Meteorological Society, 2007)Impacts of a spectral parameterization of gravity wave drag (GWD) induced by cumulus convection (GWDC) in the NCAR Whole Atmosphere Community Climate Model (WACCM1b) are investigated. In the spectral GWDC parameterization, ... -
Intraseasonal Variability in a Dry Atmospheric Model
(American Meteorological Society, 2007)A long integration of a primitive equation dry atmospheric model with time-independent forcing under boreal winter conditions is analyzed. A variety of techniques such as time filtering, space?time spectral analysis, and ... -
Inertia–Gravity Waves Spontaneously Generated by Jets and Fronts. Part I: Different Baroclinic Life Cycles
(American Meteorological Society, 2007)The spontaneous generation of inertia?gravity waves in idealized life cycles of baroclinic instability is investigated using the Weather Research and Forecasting Model. Two substantially different life cycles of baroclinic ... -
Cliff–Ramp Patterns and Kelvin–Helmholtz Billows in Stably Stratified Shear Flow in the Upper Troposphere: Analysis of Aircraft Measurements
(American Meteorological Society, 2007)Cliff?ramp patterns (CR) are a common feature of scalar turbulence, characterized by a sharp temperature increase (cliff) followed by a more gradual temperature decrease (ramp). Aircraft measurements obtained from NOAA ... -
Anisotropies and Universality of Buoyancy-Dominated Turbulent Fluctuations: A Large-Eddy Simulation Study
(American Meteorological Society, 2007)Turbulent fluctuations of both velocity and temperature fields, issuing from high-resolution large-eddy simulations, have been analyzed in convective boundary layers. The numerically simulated flows are strongly anisotropic ... -
Collisions of Cloud Droplets in a Turbulent Flow. Part IV: Droplet Hydrodynamic Interaction
(American Meteorological Society, 2007)The paper presents a computationally accurate and efficient method for calculation of cloud droplets? collision efficiency in a turbulent flow with the properties typical of atmospheric clouds. According to Part III, the ... -
A New Characterization of Rain and Clouds: Results from a Statistical Inversion of Count Data
(American Meteorological Society, 2007)Most variables in meteorology are statistically heterogeneous. The statistics of data from several different locations, then, can be thought of as an amalgamation of information contained in several contributing probability ... -
A Midlatitude Cirrus Cloud Climatology from the Facility for Atmospheric Remote Sensing. Part V: Cloud Structural Properties
(American Meteorological Society, 2007)In this fifth of a series of papers describing the extended-time high cloud observation program from the University of Utah Facility for Atmospheric Remote Sensing, the structural properties of cirrus clouds over Salt Lake ... -
Multiscale Organization of Convection Simulated with Explicit Cloud Processes on an Aquaplanet
(American Meteorological Society, 2007)This study investigated the multiscale organization of tropical convection on an aquaplanet in a model experiment with a horizontal mesh size of 3.5 km (for a 10-day simulation) and 7 km (for a 40-day simulation). The ... -
Idealized Numerical Simulations of the Interactions between Buoyant Plumes and Density Currents
(American Meteorological Society, 2007)Idealized numerical experiments using a large-eddy simulation (LES) model are performed to examine the fundamental dynamical processes associated with the interactions between buoyant plumes and density currents. The aim ... -
Wave Activity on the Tropical Easterly Jet
(American Meteorological Society, 2007)This article examines the question of the existence of waves on the tropical easterly jet (TEJ) over West Africa. The TEJ is a well-known feature of the Asian monsoon and waves on the jet have been implicated in various ... -
Modal and Nonmodal Perturbations of Monochromatic High-Frequency Gravity Waves: Primary Nonlinear Dynamics
(American Meteorological Society, 2007)The primary nonlinear dynamics of high-frequency gravity waves (HGWs) perturbed by their most prominent normal modes (NMs) or singular vectors (SVs) in a rotating Boussinesq fluid have been studied by direct numerical ... -
Cancellation of Aerosol Indirect Effects in Marine Stratocumulus through Cloud Thinning
(American Meteorological Society, 2007)Applying perturbation theory within a mixed layer framework, the response of the marine boundary layer (MBL) cloud thickness h to imposed increases of the cloud droplet concentration Nd as a surrogate for increases in cloud ... -
Convectively Coupled Kelvin Waves in an Idealized Moist General Circulation Model
(American Meteorological Society, 2007)The dynamics of convectively coupled Kelvin waves and their dependence on convection scheme parameters are studied within a simplified moist general circulation model. The model consists of the primitive equations on the ... -
Relating Overreflection and Wave Geometry to the Counterpropagating Rossby Wave Perspective: Toward a Deeper Mechanistic Understanding of Shear Instability
(American Meteorological Society, 2007)The two major approaches to understanding plane parallel shear instability?the counterpropagating Rossby wave (CRW) and overreflection (OR) approaches?illuminate very different fundamental aspects. This work examines how ... -
Climate Response Using a Three-Dimensional Operator Based on the Fluctuation–Dissipation Theorem
(American Meteorological Society, 2007)The fluctuation?dissipation theorem (FDT) states that for systems with certain properties it is possible to generate a linear operator that gives the response of the system to weak external forcing simply by using covariances ... -
Dynamics of the Southern Hemisphere Spiral Jet
(American Meteorological Society, 2007)The formation of the Southern Hemisphere spiral jet is investigated using observations over a 40-yr period. It is found that between late March and early April, the upper-tropospheric westerly jet in the Southern Hemisphere ... -
Evidence for Tilted Toroidal Circulations in Cumulus
(American Meteorological Society, 2007)Intense vortical circulations, often organized in counterrotating vortex pairs, were detected in midcontinental cumulus congestus over southeast Wyoming in July 2003. The sampled clouds developed in dry environments and ... -
Heating Structures of the TRMM Field Campaigns
(American Meteorological Society, 2007)Heating profiles calculated from sounding networks and other observations during three Tropical Rainfall Measuring Mission (TRMM) field campaigns [the Kwajalein Experiment (KWAJEX), TRMM Large-Scale Biosphere?Atmosphere ...