Journal of the Atmospheric Sciences: Recent submissions
Now showing items 861-880 of 13215
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Assessing the Influence of Microphysical and Environmental Parameter Perturbations on Orographic Precipitation
(American Meteorological Society, 2019)AbstractMicrophysical (MP) schemes contain parameters whose values can impact the amount and location of forecasted precipitation, and sensitivity is typically explored by perturbing one parameter at a time while holding ... -
Two Contrasting African Easterly Wave Behaviors
(American Meteorological Society, 2019)AbstractThe dominant structural variability of African easterly waves (AEWs) is explored using an empirical orthogonal function (EOF) approach. The structure of AEWs is obtained by projecting the wind fields from reanalysis ... -
The Role of the Divergent Circulation for Large-Scale Eddy Momentum Transport in the Tropics. Part I: Observations
(American Meteorological Society, 2019)AbstractThis work investigates the role played by the divergent circulation for meridional eddy momentum transport in the tropical atmosphere. It is shown that the eddy momentum flux in the deep tropics arises primarily ... -
The Influence of Vertical Wind Shear on Moist Thermals
(American Meteorological Society, 2019)AbstractAlthough it is well established that vertical wind shear helps to organize and maintain convective systems, there is a longstanding colloquial notion that it inhibits the development of deep convection. To investigate ... -
Modification of Potential Vorticity near the Tropopause by Nonconservative Processes in the ECMWF Model
(American Meteorological Society, 2019)AbstractThe upper-level potential vorticity (PV) structure plays a key role in the evolution of extratropical weather systems. PV is modified by nonconservative processes, such as cloud latent heating, radiative transfer, ... -
The Early Development of the 2015/16 Quasi-Biennial Oscillation Disruption
(American Meteorological Society, 2019)AbstractAn unprecedented disruption of the quasi-biennial oscillation (QBO) started to develop from late 2015. The early development of this event is analyzed using the space?time spectra of eddies from reanalysis data. ... -
Stratospheric Trailing Gravity Waves from New Zealand
(American Meteorological Society, 2019)AbstractGravity waves are frequently observed in the stratosphere, trailing long distances from mid- to high-latitude topography. Two such trailing-wave events documented over New Zealand are examined using observations, ... -
Eurasian Cold Air Outbreaks under Different Arctic Stratospheric Polar Vortex Strengths
(American Meteorological Society, 2019)AbstractThis study analyzes the differences and similarities of Eurasian cold air outbreaks (CAOs) under the weak (CAOW), strong (CAOS), and neutral (CAON) stratospheric polar vortex states and examines the potential links ... -
Intensification Variability of Tropical Cyclones in Directional Shear Flows: Vortex Tilt–Convection Coupling
(American Meteorological Society, 2019)AbstractThe coupling of vortex tilt and convection, and their effects on the intensification variability of tropical cyclones (TCs) in directional shear flows, is investigated in this study. The height-dependent vortex ... -
Vertical Structure and Microphysical Characteristics of Frontal Systems Passing over a Three-Dimensional Coastal Mountain Range
(American Meteorological Society, 2019)AbstractAs midlatitude cyclones pass over a coastal mountain range, the processes producing their clouds and precipitation are modified, leading to considerable spatial variability in precipitation amount and composition. ... -
Effect of Wind Speed and Leads on Clear-Sky Cooling over Arctic Sea Ice during Polar Night
(American Meteorological Society, 2019)AbstractA simple analytical model of the atmospheric boundary layer (ABL) coupled to sea ice is presented. It describes clear-sky cooling over sea ice during polar night in the presence of leads. The model solutions show ... -
Evaluating Simulated Microphysics during OLYMPEX Using GPM Satellite Observations
(American Meteorological Society, 2019)AbstractThis study evaluates moist physics in the Weather Research and Forecasting (WRF) Model using observations collected during the Olympic Mountains Experiment (OLYMPEX) field campaign by the Global Precipitation ... -
Effects of Sea Spray on the Dynamics and Microphysics of an Idealized Tropical Cyclone
(American Meteorological Society, 2019)AbstractThe effect of sea spray particles (SSP) on the intensity and microphysical structure of an idealized tropical cyclone (TC) is investigated using the Weather Research and Forecasting Model with a new spectral bin ... -
What Is the Predictability Limit of Midlatitude Weather?
(American Meteorological Society, 2019)AbstractUnderstanding the predictability limit of day-to-day weather phenomena such as midlatitude winter storms and summer monsoonal rainstorms is crucial to numerical weather prediction (NWP). This predictability limit ... -
Quantifying the Annular Mode Dynamics in an Idealized Atmosphere
(American Meteorological Society, 2019)AbstractThe linear response function (LRF) of an idealized GCM, the dry dynamical core with Held?Suarez physics, is used to accurately compute how eddy momentum and heat fluxes change in response to the zonal wind and ... -
Evolution of an Axisymmetric Tropical Cyclone before Reaching Slantwise Moist Neutrality
(American Meteorological Society, 2019)AbstractIn a previous study, the authors showed that the intensification process of a numerically simulated axisymmetric tropical cyclone (TC) can be divided into two periods denoted by ?phase I? and ?phase II.? The ... -
Upscale Impact of Mesoscale Convective Systems and Its Parameterization in an Idealized GCM for an MJO Analog above the Equator
(American Meteorological Society, 2019)AbstractThe Madden?Julian oscillation (MJO) typically contains several superclusters and numerous embedded mesoscale convective systems (MCSs). It is hypothesized here that the poorly simulated MJOs in current coarse-resolution ... -
Shapes and Fall Orientations of Ice Particle Aggregates
(American Meteorological Society, 2019)AbstractTesting the often-made assumption that ice particle aggregates (snowflakes) are well represented by oblate spheroids, ellipsoid fits are applied to aggregate images. An algorithm to retrieve both the ellipsoidal ... -
Effects of the Mean Flow on Martian Transient Eddy Activity: Studies with an Idealized General Circulation Model
(American Meteorological Society, 2019)AbstractThe extent to which the eddy statistics of the Martian atmosphere can be inferred from the mean state and highly simplified assumptions about diabatic and frictional processes is investigated using an idealized ... -
Diffusivity-Factor Approximation for Spectral Outgoing Longwave Radiation
(American Meteorological Society, 2019)AbstractAccurate integration of directional radiance shows that the conventional diffusivity-factor approximation with a constant diffusivity angle results in an overestimation of the outgoing longwave radiation (OLR) in ...