Journal of the Atmospheric Sciences: Recent submissions
Now showing items 841-860 of 13215
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Forcing of the Upper-Tropospheric Monsoon Anticyclones
(American Meteorological Society, 2019)AbstractDuring the boreal warm season (May?September), the circulation in the upper troposphere and lower stratosphere is dominated by two large anticyclones: the Asian monsoon anticyclone (AMA) and North American monsoon ... -
The Control of Surface Friction on the Scales of Baroclinic Eddies in a Homogeneous Quasigeostrophic Two-Layer Model
(American Meteorological Society, 2019)AbstractIn idealized models of the extratropical troposphere, both ? and surface friction can control the equilibrated scales of baroclinic eddies by stopping the inverse cascade. A scaling theory on how surface friction ... -
Impact of Stratiform Rainband Heating on the Tropical Cyclone Wind Field in Idealized Simulations
(American Meteorological Society, 2019)AbstractUsing idealized simulations, we examine the storm-scale wind field response of a dry, hurricane-like vortex to prescribed stratiform heating profiles that mimic tropical cyclone (TC) spiral rainbands. These profiles ... -
The Influence of Gravity Waves on the Slope of the Kinetic Energy Spectrum in Simulations of Idealized Midlatitude Cyclones
(American Meteorological Society, 2019)AbstractThe influence of gravity waves generated by surface stress and by topography on the atmospheric kinetic energy (KE) spectrum is examined using idealized simulations of a cyclone growing in baroclinically unstable ... -
The Relationship between the ITCZ and MJO Initiation over the Indian Ocean
(American Meteorological Society, 2019)AbstractUnderstanding convective initiation of the Madden?Julian oscillation (MJO) remains an unmet challenge. MJO initiation has been perceived as a process starting from a convectively suppressed large-scale condition ... -
The Universality of the Normalized Vertical Velocity Variance in Contrast to the Horizontal Velocity Variance in the Convective Boundary Layer
(American Meteorological Society, 2019)AbstractThe vertical turbulent velocity variance normalized by the convective velocity squared as a function of the boundary layer depth?normalized height [i.e., ] in the convective boundary layer (CBL) over a homogeneous ... -
Theoretical Understanding of the Linear Relationship between Convective Updrafts and Cloud-Base Height for Shallow Cumulus Clouds. Part I: Maritime Conditions
(American Meteorological Society, 2019)AbstractZheng and Rosenfeld found linear relationships between the convective updrafts and cloud-base height zb using ground-based observations over both land and ocean. The empirical relationships allow for a novel satellite ... -
A Nonlinear Theory of Atmospheric Blocking: A Potential Vorticity Gradient View
(American Meteorological Society, 2019)AbstractIn this paper, an extended nonlinear multiscale interaction model of blocking events in the equivalent barotropic atmosphere is used to investigate the effect of a slowly varying zonal wind in the meridional direction ... -
On Calculating Deposition Coefficients and Aspect-Ratio Evolution in Approximate Models of Ice Crystal Vapor Growth
(American Meteorological Society, 2019)AbstractModels of ice crystal vapor growth require estimates of the deposition coefficient α when surface attachment kinetics limit growth and when ice crystal shape is predicted. Parametric models can be used to calculate ... -
Entrainment and Mixing in Stratocumulus: Effects of a New Explicit Subgrid-Scale Scheme for Large-Eddy Simulations with Particle-Based Microphysics
(American Meteorological Society, 2019)AbstractThe entrainment and mixing of free-tropospheric air is an essential component of the observed microphysical structure of stratocumulus clouds. Since the relevant scales involved in this process are usually smaller ... -
The Diurnal and Microphysical Characteristics of MJO Rain Events during DYNAMO
(American Meteorological Society, 2019)AbstractThe Madden?Julian oscillation (MJO) dominates the intraseasonal variability of cloud populations of the tropical Indian and Pacific Oceans. Suppressed MJO periods consist primarily of shallow and isolated deep ... -
An Idealized Numerical Study of Shear-Relative Low-Level Mean Flow on Tropical Cyclone Intensity and Size
(American Meteorological Society, 2019)AbstractGiven comparable background vertical wind shear (VWS) magnitudes, the initially imposed shear-relative low-level mean flow (LMF) is hypothesized to modify the structure and convective features of a tropical cyclone ... -
Theoretical Analysis of the Entrainment–Mixing Process at Cloud Boundaries. Part II: Motion of Cloud Interface
(American Meteorological Society, 2019)AbstractThe entrainment?mixing process leads to formation of a cloud?environment interface zone, consisting of the cloud dilution zone, where the liquid water content decreases as the distance from the cloud interior ... -
Turbulent Collapse and Recovery in the Stable Boundary Layer Using an Idealized Model of Pressure-Driven Flow with a Surface Energy Budget
(American Meteorological Society, 2019)AbstractThe evolution of the stable boundary layer is simulated using an idealized single-column model of pressure-driven flow coupled to a surface energy budget. Several commonly used parameterizations of turbulence are ... -
Analytical Solutions for Precipitation Size Distributions at Steady State
(American Meteorological Society, 2019)AbstractAnalytical solutions are derived for the steady-state size distributions of precipitating rain and snow particles assuming growth via collection of suspended cloud particles. Application of the Liouville equation ... -
A Novel Parameterization of Snow Albedo Based on a Two-Layer Snow Model with a Mixture of Grain Habits
(American Meteorological Society, 2019)AbstractSnow albedo plays a critical role in the surface energy budget in snow-covered regions and is subject to large uncertainty due to variable physical and optical characteristics of snow. We develop an optically and ... -
Axisymmetric Constraints on Cross-Equatorial Hadley Cell Extent
(American Meteorological Society, 2019)AbstractWe consider the relevance of known constraints from each of Hide?s theorem, the angular momentum?conserving (AMC) model, and the equal-area model on the extent of cross-equatorial Hadley cells. These theories ... -
Idealized Modeling of the Atmospheric Boundary Layer Response to SST Forcing in the Western Indian Ocean
(American Meteorological Society, 2019)AbstractThe atmospheric response to sea surface temperature (SST) variations forced by oceanic downwelling equatorial Rossby waves is investigated using an idealized convection-resolving model. Downwelling equatorial Rossby ... -
The Role of the Divergent Circulation for Large-Scale Eddy Momentum Transport in the Tropics. Part II: Dynamical Determinants of the Momentum Flux
(American Meteorological Society, 2019)AbstractThis paper investigates the coupling between the rotational and divergent circulations aiming to explain the observations that show that the tropical eddy momentum flux is due to correlations between divergent eddy ... -
Impact of Dry Midlevel Air on the Tropical Cyclone Outer Circulation
(American Meteorological Society, 2019)AbstractThe impact of dry midlevel air on the outer circulation of tropical cyclones is investigated in idealized simulations with and without a moist envelope protecting the inner core. It is found that a dry midlevel ...