Journal of the Atmospheric Sciences: Recent submissions
Now showing items 3061-3080 of 13215
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Fluctuations in an Equilibrium Convective Ensemble. Part I: Theoretical Formulation
(American Meteorological Society, 2006)To provide a theoretical basis for stochastic parameterization of cumulus convection, the equilibrium fluctuations of a field of cumulus clouds under homogeneous large-scale forcing are derived statistically, using the ... -
The Growth of Ice Crystals by Molecular Diffusion
(American Meteorological Society, 2006)The mass transfer of water molecules by diffusion onto ice particles is best described by their Sherwood number (Sh), a dimensionless quantity, which combines molecular and convective effects and depends on the airflow as ... -
Fluctuations in an Equilibrium Convective Ensemble. Part II: Numerical Experiments
(American Meteorological Society, 2006)The theoretical predictions derived in Part I of this study for the equilibrium fluctuations of an idealized ensemble of noninteracting, pointlike cumulus clouds are tested against three-dimensional cloud resolving model ... -
Equatorial Superrotation and Barotropic Instability: Static Stability Variants
(American Meteorological Society, 2006)Altering the tropospheric static stability changes the nature of the equatorial superrotation associated with unstable, low-latitude, westerly jets, according to calculations with a dry, global, multilevel, spectral, ... -
Impacts of Nucleating Aerosol on Florida Storms. Part I: Mesoscale Simulations
(American Meteorological Society, 2006)Toward the end of the Cirrus Regional Study of Tropical Anvils and Cirrus Layer?Florida Area Cirrus Experiment (CRYSTAL?FACE) field campaign held during July 2002, high concentrations of Saharan dust, which can serve as ... -
Four-Dimensional Data Assimilation and Balanced Dynamics
(American Meteorological Society, 2006)The problem of spurious excitation of gravity waves in the context of four-dimensional data assimilation is investigated using a simple model of balanced dynamics. The model admits a chaotic vortical mode coupled to a ... -
The Role of Scales in the Dynamics of Parameterization Uncertainties
(American Meteorological Society, 2006)The dynamics of model error due to parameterization uncertainties are investigated in the context of two spatially distributed systems: the one-dimensional convection system known as the extended Kuramoto?Sivashinsky ... -
Ellipticity Conditions of the Shallow Water Balance Equations for Atmospheric Data
(American Meteorological Society, 2006)Nonlinear normal mode initialization equations, which provide required balance relations for atmospheric data, are considered in the generalized case of shallow water equations in arbitrary orthogonal coordinates. Using ... -
Local Structure of Turbulence in Stably Stratified Boundary Layers
(American Meteorological Society, 2006)The ?flux based? local scaling in the stably stratified boundary layer is valid only in cases with strong, continuous turbulence, when the gradient Richardson number Ri is constant and subcritical. To extend the local ... -
Large-Eddy Simulations of Trade Wind Cumuli: Investigation of Aerosol Indirect Effects
(American Meteorological Society, 2006)The effects of aerosol on warm trade cumulus clouds are investigated using a large-eddy simulation with size-resolved cloud microphysics. It is shown that, as expected, increases in aerosols cause a reduction in precipitation ... -
Sensitivity of Radiative–Convective Equilibrium Simulations to Horizontal Resolution
(American Meteorological Society, 2006)This paper investigates the impacts of horizontal resolution on the statistical behavior of convection. An idealized radiative?convective equilibrium is simulated for model resolutions ranging between 2 and 50 km. The ... -
Tropical Wave Driving of the Annual Cycle in Tropical Tropopause Temperatures. Part II: Model Results
(American Meteorological Society, 2006)The atmospheric response to a localized distribution of tropical heating is examined in terms of the stationary waves excited and how these impact the mean flow near the tropical tropopause. This is done by examining ... -
Dynamics of Sheared Convective Boundary Layer Entrainment. Part II: Evaluation of Bulk Model Predictions of Entrainment Flux
(American Meteorological Society, 2006)Several bulk model?based entrainment parameterizations for the atmospheric convective boundary layer (CBL) with wind shear are reviewed and tested against large-eddy simulation (LES) data to evaluate their ability to model ... -
Tropical Wave Driving of the Annual Cycle in Tropical Tropopause Temperatures. Part I: ECMWF Analyses
(American Meteorological Society, 2006)A quantitative examination of the annual cycle in the tropical tropopause temperatures, tropical ascent, momentum balance, and wave driving is performed using ECMWF analyses to determine how the annual cycle in tropical ... -
Self-Organization of Atmospheric Macroturbulence into Critical States of Weak Nonlinear Eddy–Eddy Interactions
(American Meteorological Society, 2006)It is generally held that atmospheric macroturbulence can be strongly nonlinear. Yet weakly nonlinear models successfully account for scales and structures of baroclinic eddies in Earth's atmosphere. Here a theory and ... -
Behavior of Planetary Waves before and after Stratospheric Sudden Warming Events in Several Phases of the Equatorial QBO
(American Meteorological Society, 2006)Almost a thousand stratospheric sudden warming (SSW) events are obtained through long time integrations with a simple global circulation model, and a statistical analysis based on such a large number of samples is made to ... -
The Structure of Thermals in Cumulus from Airborne Dual-Doppler Radar Observations
(American Meteorological Society, 2006)A newly developed technique for airborne dual-Doppler observations with the Wyoming Cloud Radar is used to characterize the velocity fields in vertical planes across cumulus turrets. The clouds sampled were continental in ... -
Flow Regimes of Nonlinear Heat Island Circulation
(American Meteorological Society, 2006)Previous laboratory and numerical experiments show that the nonlinear heat island circulation has two different flow regimes: One has two maximums of updraft at both edges of the heat island (type E), while the other has ... -
Conditional Nonlinear Optimal Perturbations of a Two-Dimensional Quasigeostrophic Model
(American Meteorological Society, 2006)Conditional nonlinear optimal perturbations (CNOPs) of a two-dimensional quasigeostrophic model are obtained numerically. The CNOP is the initial perturbation whose nonlinear evolution attains the maximum value of the cost ... -
Tropical Cyclogenesis Associated with Rossby Wave Energy Dispersion of a Preexisting Typhoon. Part II: Numerical Simulations
(American Meteorological Society, 2006)The cyclogenesis events associated with the tropical cyclone (TC) energy dispersion are simulated in a 3D model. A new TC with realistic dynamic and thermodynamic structures forms in the wake of a preexisting TC when a ...