Journal of the Atmospheric Sciences: Recent submissions
Now showing items 4921-4940 of 13215
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Homoclinic Dynamics: A Scenario for Atmospheric Ultralow-Frequency Variability
(American Meteorological Society, 2002)In this paper, a link will be established between atmospheric ultralow-frequency variability (ULFV) and the occurrence of homoclinic dynamics in models of large-scale atmospheric flow. It is known that uncoupled atmosphere ... -
Walker-Type Mean Circulations and Convectively Coupled Tropical Waves as an Interacting System
(American Meteorological Society, 2002)Interactions between convectively coupled tropical waves and Walker-type mean circulations are examined using a two-dimensional analytic model wherein drying and cooling of the boundary layer by convective and mesoscale ... -
Simulation of the Intraseasonal Oscillation in the ECHAM-4 Model: The Impact of Coupling with an Ocean Model
(American Meteorological Society, 2002)Three 15-yr integrations were made with the ECHAM-4 atmospheric GCM (AGCM); in the first integration, the model lower boundary conditions were the observed monthly mean sea surface temperatures, and, in the second, the ... -
First Radar Echoes and the Early ZDR History of Florida Cumulus
(American Meteorological Society, 2002)The early histories of radar echo and polarization differential reflectivity (ZDR) from growing cumulus clouds observed in Florida with a 10-cm-wavelength radar are reported in detail. Raindrops 1 to several millimeters ... -
Impact of a Spectral Gravity Wave Parameterization on the Stratosphere in the Met Office Unified Model
(American Meteorological Society, 2002)The impact of a parameterized spectrum of gravity waves on the simulation of the stratosphere in the Met Office Unified Model (UM) is investigated. In the extratropical mesosphere, the gravity wave forcing acts against the ... -
Using a Physical Reference Frame to Study Global Circulation Variability
(American Meteorological Society, 2002)The 3D structures of the free oscillations of an adiabatic and hydrostatic atmosphere around a basic state at rest were used as a physical filtering for atmospheric data. This filtering procedure allows for the consideration ... -
The Mean-Meridional Transport Circulation of the Troposphere in an Idealized GCM
(American Meteorological Society, 2002)Large numbers of particle trajectories are used to characterize the mean-meridional transport circulation of an idealized general circulation model (GCM). The GCM has a uniform land surface, no topography or land?sea ... -
Selection of Modes in Convective Low-Order Models
(American Meteorological Society, 2002)The development of physically sound low-order models (LOMs) of convective flow is discussed. LOMs are constructed in the form of coupled three-mode systems known in mechanics as Volterra gyrostats. This structure ensures ... -
Vertical Transports by Plumes within the Moderately Convective Marine Atmospheric Surface Layer
(American Meteorological Society, 2002)Bursts in the kinematic vertical transports of heat and horizontal momentum in a moderately convective marine atmospheric surface layer are studied by applying the variable interval time averaging (VITA) detection method ... -
Latitudinal Variations Observed in Gravity Waves with Short Vertical Wavelengths
(American Meteorological Society, 2002)Knowledge of the latitudinal variations in the occurrence of gravity waves is important for their parameterization in global models. Observations of gravity waves with short vertical scales have shown a pronounced peak in ... -
Parameterization of the Bulk Effects of Lateral and Cloud-Top Entrainment in Transient Shallow Cumulus Clouds
(American Meteorological Society, 2002)A parameterization of shallow cumulus clouds for use in atmospheric general circulation models is proposed. The parameterization uses a bulk representation of an ensemble of transient clouds. Entrainment of environmental ... -
Multichannel Satellite Retrieval of Cloud Parameter Probability Distribution Functions
(American Meteorological Society, 2002)A retrieval method has been developed to directly retrieve statistics of cloud parameters from Geostationary Operational Environmental Satellite (GOES) visible and infrared imager data. This method retrieves cloud parameter ... -
Jovian Dynamics. Part II: The Genesis and Equilibration of Vortex Sets
(American Meteorological Society, 2002)To extend studies of the dynamics of thin atmospheric layers, the generation and equilibration of multiple anticyclonic vortex sets associated with long solitary baroclinic Rossby waves are examined numerically using a ... -
Role of Gravity Waves in Triggering Deep Convection during TOGA COARE
(American Meteorological Society, 2002)The role of gravity waves in the initiation of convection over oceanic regions during the Tropical Ocean Global Atmosphere Coupled Ocean?Atmosphere Response Experiment (TOGA COARE) experiment is investigated. First, an ... -
Wave–Mean Flow Feedback and the Persistence of Simulated Zonal Flow Vacillation
(American Meteorological Society, 2002)The structure of eddies forcing the vacillation of the southern midlatitude tropospheric zonal-mean zonal wind and the significance of wave?mean flow feedbacks on its persistence are assessed using a 100-yr 8-h dataset ... -
Relationship between Potential Vorticity Tendency and Tropical Cyclone Motion
(American Meteorological Society, 2002)This paper proposes a consistent conceptual framework to explain tropical cyclone (TC) motion based on the concept of potential vorticity tendency (PVT) and to verify this framework based on analyses of different observational ... -
The Two-Dimensional Response of a Tropical Jet to Propagating Lines of Convection
(American Meteorological Society, 2002)This paper uses simple one- and two-dimensional models to investigate the influence of a propagating line of convective forcing on a tropical jet, representative of the African easterly jet. The results are used to infer ... -
Relation between Kinematic Boundaries, Stirring, and Barriers for the Antarctic Polar Vortex
(American Meteorological Society, 2002)Maximum stretching lines in the lower stratosphere around the Antarctic polar vortex are diagnosed using a method based on finite-size Lyapunov exponents. By analogy with the mathematical results known for simple dynamical ... -
Vortex Rossby Waves in a Numerically Simulated Tropical Cyclone. Part II: The Role in Tropical Cyclone Structure and Intensity Changes
(American Meteorological Society, 2002)In Part I, the author analyzed the asymmetric structure in the inner core of a numerically simulated tropical cyclone and found that the asymmetry near the eyewall in the mid?lower troposphere is dominated by wavenumber-1 ... -
Vortex Rossby Waves in a Numerically Simulated Tropical Cyclone. Part I: Overall Structure, Potential Vorticity, and Kinetic Energy Budgets
(American Meteorological Society, 2002)The asymmetric structure in the inner core of a numerically simulated tropical cyclone is analyzed in this study. The simulated tropical cyclone is found to be highly asymmetric in the inner core. In the mid?lower troposphere, ...