Atmospheric instability

About: Atmospheric instability is a research topic. Over the lifetime, 1193 publications have been published within this topic receiving 34784 citations.

A short course in cloud physics

Abstract: Thermodynamics of dry air Water vapor and its thermodynamic effects Parcel buoyancy and atmospheric stability Mixing and convection Observed properties of clouds Formation of cloud droplets Droplet growth by condensation Initiation of rain in nonfreezing clouds Formation and growth of ice crystals Rain and snow Weather radar Precipitation processes Severe storm and hail Weather modification Numerical cloud models References Appendix Answers to selected problems Index

On Formation and Intensification of Tropical Cyclones Through Latent Heat Release by Cumulus Convection

Abstract: The effect on large scale motions of latent heat release by deep cumulus convection in a conditionally unstable atmosphere is investigated and a method devised to include this effect directly in the equations for large scale flow This method is then applied to the hurricane formation problem by incorporating it into time-dependent, circular symmetric dynamic hurricane models, either in gradient-wind balance or unbalanced Numerical integrations of a two-level approximation of the balanced model have been carried out for two different formulations of the problem (including or not including a frictional radial flow), both starting from a hypothetical initial state characterized by a weak barotropic circular vortex with a maximum tangential velocity of 10 m sec−1 at a distance of 1412 km from the center The results obtained without frictional radial flow showed slow intensification of the tangential flow, to about 25 m sec−1, and establishment of a strong radial temperature gradient in the upper

Air Pollution Meteorology and Dispersion

Abstract: Preface Acknowledgments 1. INTRODUCTION TO AIR POLLUTION 1.1 The Air Pollution Problem 1.2 Sources of Air Pollution 1.3 Air Pollutants 1.4 Effects of Air Pollution 1.5 Regulatory Control of Air Pollution 2. ATMOSPHERIC STRUCTURE AND DYNAMICS 2.1 Introduction 2.2 Composition and Thermal Structure of the Atmosphere 2.3 State Variables and Thermodynamics 2.4 Atmospheric Stability 2.5 Conservation Laws and Atmospheric Dynamics 2.6 Large-scale Inviscid Flows 2.7 Small-scale Viscous Flows 2.8 Applications 3. ATMOSPHERIC SYSTEMS AND POLLUTANT TRANSPORT 3.1 Introduction 3.2 Macroscale Systems 3.3 Synoptic Weather Systems 3.4 Mesoscale Systems 3.5 Microscale Systems 4. MICROMETEOROLOGY AND PLANETARY BOUNDARY LAYER 4.1 Introduction and Definitions 4.2 Earth-Atmosphere Exchange Processes 4.3 Vertical Distribution of Thermodynamic Variables 4.4 Vertical Distribution of Winds in the PBL 4.5 Turbulence 4.6 Gradient-transport Theories 4.7 Similarity Theories 4.8 Boundary-layer Parameterization for Dispersion APPLICATIONS 5. STATISTICAL DESCRIPTION OF ATMOSPHERIC TURBULENCE 5.1 Reynolds Averaging 5.2 Probability Functions 5.3 Autocorrelation Functions 5.4 Spectrum Functions 5.5 Taylor's Hypothesis 5.6 Statistical Theory of Turbulence 5.7 Observed Spectra and Scales 5.8 Effects of Smoothing and Finite Sampling 5.9 Lagrangian Description of Turbulence 5.10 Parameterization of Turbulence for Diffusion Applications 6. GRADIENT TRANSPORT THEORIES 6.1 Eulerian Approach to Describing Diffusion 6.2 Mass Conservation and Diffusion Equations 6.3 Molecular Diffusion 6.4 Turbulent Diffusion 6.5 Constant K (Fickian Diffusion) - Theory 6.6 Variable K-Theory 6.7 Limitations of Gradient Transport Theories 6.8 Experimental Verification of K-Theories 6.9 Applications of K-Theories to Atmospheric Dispersion 7. STATISTICAL THEORIES OF DIFFUSION 7.1 Lagrangian Approach to Describing Diffusion 7.2 Statistical Theory of Absolute Diffusion 7.3 Plume Diffusion from Continuous Sources 7.4 Statistical Theory of Relative Diffusion 7.5 Puff Diffusion from Instantaneous Releases 7.6 Fluctuating Plume Models 7.7 Experimental Verification of Statistical Theories 7.8 Applications to Atmospheric Dispersion and Limitations 8. SIMILARITY THEORIES OF DISPERSION 8.1 Dispersion in Stratified Shear Flows 8.2 Lagrangian Similarity Theory for the Neutral Surface Layer 8.3 Lagrangian Similarity Theory for the Stratified Surface Layer 8.4 The Mixed-layer Similarity Theory 8.5 Experimental Verification of Similarity Theories 8.6 Applications to Dispersion in the PBL 8.7 Limitations of Similarity Theories 9. GAUSSIAN DIFFUSION MODELS 9.1 Basis and Justification for Gaussian Models 9.2 Gaussian Plume and Puff Diffusion Models 9.3 Diffusion Experiments 9.4 Empirical Dispersion Parameterization Schemes 9.5 Further Improvements in Dispersion Parameterization 9.6 The Maximum Ground-Level Concentration 9.7 Model Evaluations and Uncertainties 9.8 Limitations of Gaussian Diffusion Models 9.9 Practical Applications of Gaussian Diffusion Models 10. PLUME RISE, SETTLING, AND DEPOSITION 10.1 Momentum and Buoyancy Effects of Release 10.2 Plume-rise Theory and Observations 10.3 Gravitational Settling of Particles 10.4 Dry Deposition 10.5 Dispersion-Deposition Models 10.6 Applications 11. NUMERICAL DISPERSION MODELS 11.1 Introduction 11.2 Short-range Gradient Transport Models 11.3 Turbulence Kinetic Energy Models 11.4 Higher Order Closure Models 11.5 Large-eddy Simulations 11.6 Lagrangian Stochastic Models 12. URBAN AND REGIONAL AIR QUALITY MODELS 12.1 Introduction 12.2 Components of an Air Quality Model 12.3 Urban Diffusion and Air Quality 12.4 Regional Air Quality Models 12.5 Applications of Air Quality Models References Symbols Index All Chapters end with Problems and Exercises

An Air–Sea Interaction Theory for Tropical Cyclones. Part II: Evolutionary Study Using a Nonhydrostatic Axisymmetric Numerical Model

Abstract: In Part I of this study an analytical model for a steady-state tropical cyclone is constructed on the assumption that boundary-layer air parcels are conditionally neutral to displacements along the angular momentum surfaces of the hurricane vortex. The reversible thermodynamics implied by this assumption allows the mature storm to be thought of as a simple Carnot engine, acquiring heat at the high-temperature ocean surface and losing heat near the low-temperature tropopause. Although the oceanic heat source is universally recognized as the sine qua non for the mature hurricane, there is also wide acceptance of conditional instability of the second kind (CISK) (which makes no specific reference to surface heat fluxes) as the formative mechanism. This ambivalence is seen in that all numerical-simulation studies find it essential to have transfer from the ocean surface yet all start from a conditionally unstable atmosphere. The hypothesis put forward in Part I, based on the steady-state theory, is t...

Dust-Storm Source Areas Determined by the Total Ozone Monitoring Spectrometer and Surface Observations

Abstract: Dust storms are recognized as having a very wide range of environmental impacts. Their geomorphological interest lies in the amount of deflation and wind erosion they indicate and their role in loess formation. Atmospheric mineral-dust loading is one of the largest uncertainties in global climate-change modeling and is known to have an important impact on the radiation budget and atmospheric instability. Major gaps remain in our understanding of the geomorphological context of terrestrial sources and the transport mechanisms responsible for the production and distribution of atmospheric dust, all of which are important in reducing uncertainties in the modeling of past and future climate. Using meteorological data from ground stations, from the space-borne Total Ozone Monitoring Spectrometer (TOMS), and from the National Center for Environmental Prediction–National Center for Atmospheric Research reanalysis project, we illustrate the key source regions of dust and demonstrate the primacy of the Sa...