Journal of the Atmospheric Sciences: Recent submissions
Now showing items 4361-4380 of 13215
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Aspects of a Northern Hemisphere Atmospheric Blocking Climatology
(American Meteorological Society, 2008)A comprehensive climatology of Northern Hemisphere blocking is described based on a PV?? wave-breaking index at the latitude of the climatological storm track and using the 40-yr ECMWF Re-Analysis (ERA-40) dataset. The ... -
The Morphology of Northern Hemisphere Blocking
(American Meteorological Society, 2008)The morphology of regional blocking in the Northern Hemisphere is discussed using the 40-yr ECMWF Re-Analysis (ERA-40) dataset and a measure of blocking based on the reversal at storm-track latitudes of meridional ? contrasts ... -
Poleward-Propagating Intraseasonal Monsoon Disturbances in an Intermediate-Complexity Axisymmetric Model
(American Meteorological Society, 2008)A model of intermediate complexity based on quasi-equilibrium theory?a version of the quasi-equilibrium tropical circulation model with a prognostic atmospheric boundary layer, as well as two free-tropospheric modes in ... -
The Spacing of Orographic Rainbands Triggered by Small-Scale Topography
(American Meteorological Society, 2007)A combination of idealized numerical simulations and analytical theory is used to investigate the spacing between convective orographic rainbands over the Coastal Range of western Oregon. The simulations, which are idealized ... -
Retrieval of Urban Boundary Layer Structures from Doppler Lidar Data. Part II: Proper Orthogonal Decomposition
(American Meteorological Society, 2008)The proper orthogonal decomposition technique is applied to 74 snapshots of 3D wind and temperature fields to study turbulent coherent structures and their interplay in the urban boundary layer over Oklahoma City, Oklahoma. ... -
Subsiding Shells around Shallow Cumulus Clouds
(American Meteorological Society, 2008)In this study large-eddy simulations (LES) are used to gain more knowledge on the shell of subsiding air that is frequently observed around cumulus clouds. First, a detailed comparison between observational and numerical ... -
A Theoretical and Numerical Study of Urban Heat Island–Induced Circulation and Convection
(American Meteorological Society, 2008)Urban heat island?induced circulation and convection in three dimensions are investigated theoretically and numerically in the context of the response of a stably stratified uniform flow to specified low-level heating that ... -
The Geometry of Model Error
(American Meteorological Society, 2008)This paper investigates the nature of model error in complex deterministic nonlinear systems such as weather forecasting models. Forecasting systems incorporate two components, a forecast model and a data assimilation ... -
On the Definition of Precipitation Efficiency
(American Meteorological Society, 2007)A modified definition of precipitation efficiency (PE) is proposed based on either cloud microphysics precipitation efficiency (CMPE) or water cycling processes including water vapor and hydrometeor species [large-scale ... -
Turbulence Anisotropy Carried by Streaks in the Neutral Atmospheric Surface Layer
(American Meteorological Society, 2008)The authors investigate the relationships between coherent structures and turbulence anisotropy in the neutral planetary boundary layer by means of empirical orthogonal function (EOF) analysis of large-eddy simulation (LES) ... -
Retrieval of Urban Boundary Layer Structures from Doppler Lidar Data. Part I: Accuracy Assessment
(American Meteorological Society, 2008)Two coherent Doppler lidars from the U.S. Army Research Laboratory (ARL) and Arizona State University (ASU) were deployed in the Joint Urban 2003 atmospheric dispersion field experiment (JU2003) held in Oklahoma City, ... -
An Enhanced Moisture Convergence–Evaporation Feedback Mechanism for MJO Air–Sea Interaction
(American Meteorological Society, 2008)Simulations using an atmospheric model forced with observed SST climatology and the same atmospheric model coupled to a slab-ocean model are used to investigate the role of air?sea interaction on the dynamics of the MJO. ... -
The Capacitance of Pristine Ice Crystals and Aggregate Snowflakes
(American Meteorological Society, 2008)A new method of accurately calculating the capacitance of realistic ice particles is described: such values are key to accurate estimates of deposition and evaporation (sublimation) rates in numerical weather models. The ... -
Vertical-Mode Decompositions of 2-Day Waves and the Madden–Julian Oscillation
(American Meteorological Society, 2008)Vertical structures of 2-day waves and the Madden?Julian oscillation (MJO) are projected onto vertical normal modes for a quiescent tropical troposphere. Three modes capture the gross tropospheric structure of 2-day waves, ... -
Topographic Instability: Tests
(American Meteorological Society, 2008)Theories of topographic instability predict growth of perturbations of mean flow and wave modes due to their interaction with mountains under favorable conditions. Mountain torques form an important part of this interaction. ... -
On the Occurrence of Hollow Bullet Rosette– and Column-Shaped Ice Crystals in Midlatitude Cirrus
(American Meteorological Society, 2007)Cirrus clouds in mid- and high latitudes are frequently composed of bullet rosette? and column-shaped ice crystals, which can have hollow ends. Bullet rosette?shaped ice crystals are composed of a number of bullets radiating ... -
A Finite-Volume Solution with a Bidirectional Upwind Difference Scheme for the Three-Dimensional Radiative Transfer Equation
(American Meteorological Society, 2007)A new calculation scheme is proposed for the explicitly discretized solution of the three-dimensional (3D) radiation transfer equation (RTE) for inhomogeneous atmospheres. To separate the independent variables involved in ... -
MODIS Observations of Ship Tracks in Summertime Stratus off the West Coast of the United States
(American Meteorological Society, 2007)Three years of 1-km Moderate Resolution Imaging Spectroradiometer (MODIS) observations for morning (Terra) and afternoon (Aqua) summertime marine stratus off the west coast of the United States were analyzed to determine ... -
A Study of Two-Dimensional Dry Convective Plume Modes with Variable Critical Level Height
(American Meteorological Society, 2008)This study investigates the impact of wind speed and critical level height on dry convection above a prescribed heat source. This is done using the Advanced Regional Prediction System (ARPS) model in its two-dimensional ... -
Predictability in Wet and Dry Convective Turbulence
(American Meteorological Society, 2008)There is a growing interest in understanding the role that moisture plays in atmospheric dynamics, particularly in its effect on predictability. Current research indicates that when moisture effects are added to an atmospheric ...