Download or read book The Development of an Improved Convective Initiation Scheme for Mesoscale Numerical Weather Prediction Models written by Kenneth T. Waight (III.) and published by . This book was released on 1991 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Development of an Improved Convective Initiation Scheme for Mesoscale Numerical Weather Prediction Models Phase 1 written by and published by . This book was released on 1991 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: A three-dimensional nonhydrostatic cloud model, the Terminal Area Simulation System (TASS), is used to investigate the convective initiation process for an idealized case over central Florida where the forcing is provided by differential surface heating. The surface heating pattern is generated from high resolution land use data by making simple assumptions relating surface characteristics to particular land use types. The cloud model simulation produces a complicated field of both shallow and precipitating cumulus clouds. Current mesoscale parameterization schemes are evaluated for their ability to predict convective initiation. Analysis of the results show that in the first half of the run, localized differential surface sensible heating produces small areas of deep convection associated with surface features. In the latter half of the simulation, mesoscale convergence develops due to the lateral boundary conditions and provides a mesoscale organization which is well resolved by a conventional measure of mesoscale moisture convergence. Subgrid scale convergence is very well correlated with convective activity. Results suggest that the cloud model is a valuable tool for the investigation of realistic convective initiation and evolution, and that a combination of mesoscale and subgrid scale properties are necessary for successful mesoscale modeling of cumulus convection.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 1038 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Parameterization Schemes written by David J. Stensrud and published by Cambridge University Press. This book was released on 2007-05-03 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents: 1.
Download or read book Explicit Simulation and Parameterization of Mesoscale Convective Systems Final Report November 1 1993 April 30 1997 written by and published by . This book was released on 1997 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research has focused on the development of a parameterization scheme for mesoscale convective systems (MCSs), to be used in numerical weather prediction models with grid spacing too coarse to explicitly simulate such systems. This is an extension to cumulus parameterization schemes, which have long been used to account for the unresolved effects of convection in numerical models. Although MCSs generally require an extended sequence of numerous deep convective cells in order to develop into their characteristic sizes and to persist for their typical durations, their effects on the large scale environment are significantly different than that due to the collective effects of numerous ordinary deep convective cells. These differences are largely due to a large stratiform cloud that develops fairly early in the MCS life-cycle, where mesoscale circulations and dynamics interact with the environment in ways that call for a distinct MCS parameterization. Comparing an MCS and a collection of deep convection that ingests the same amount of boundary layer air and moisture over an extended several hour period, the MCS will generally generates more stratiform rainfall, produce longer-lasting and optically thicker cirrus, and result in different vertical distributions of large-scale tendencies due to latent heating and moistening, momentum transfers, and radiational heating.
Download or read book Conference on Numerical Weather Prediction written by and published by . This book was released on with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Model Studies on the Role of Moist Convection as a Mechanism for Interaction Between the Mesoscales written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-11-10 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: A three year research effort is described which had as its goal the development of techniques to improve the numerical prediction of cumulus convection on the meso-beta and meso-gamma scales. Two MESO models are used, the MASS (mesoscale) and TASS (cloud scale) models. The primary meteorological situation studied is the 28-29 Jun. 1986 Cooperative Huntsville Meteorological Experiment (COHMEX) study area on a day with relatively weak large scale forcing. The problem of determining where and when convection should be initiated is considered to be a major problem of current approaches. Assimilation of moisture data from satellite, radar, and surface data is shown to significantly improve mesoscale simulations. The TASS model is shown to reproduce some observed mesoscale features when initialized with 3-D observational data. Convection evolution studies center on comparison of the Kuo and Fritsch-Chappell cumulus parameterization schemes to each other, and to cloud model results. The Fritsch-Chappell scheme is found to be superior at about 30 km resolution, while the Kuo scheme does surprisingly well in simulating convection down to 10 km in cases where convergence features are well-resolved by the model grid. Results from MASS-TASS interaction experiments are presented and discussed. A discussion of the future of convective simulation is given, with the conclusion that significant progress is possible on several fronts in the next few years. Waight, Kenneth T., III and Song, J. Aaron and Zack, John W. and Price, Pamela E. Unspecified Center...
Download or read book Mesoscale Meteorology in Midlatitudes written by Paul Markowski and published by John Wiley & Sons. This book was released on 2011-09-20 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mesoscale Meteorology in Mid-Latitudes presents the dynamics of mesoscale meteorological phenomena in a highly accessible, student-friendly manner. The book's clear mathematical treatments are complemented by high-quality photographs and illustrations. Comprehensive coverage of subjects including boundary layer mesoscale phenomena, orographic phenomena and deep convection is brought together with the latest developments in the field to provide an invaluable resource for mesoscale meteorology students. Mesoscale Meteorology in Mid-Latitudes functions as a comprehensive, easy-to-use undergraduate textbook while also providing a useful reference for graduate students, research scientists and weather industry professionals. Illustrated in full colour throughout Covers the latest developments and research in the field Comprehensive coverage of deep convection and its initiation Uses real life examples of phenomena taken from broad geographical areas to demonstrate the practical aspects of the science
Download or read book The Representation of Cumulus Convection in Numerical Models written by Kerry Emanuel and published by Springer. This book was released on 2015-03-30 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents descriptions of numerical models for testing cumulus in cloud fields. It is divided into six parts. Part I provides an overview of the problem, including descriptions of cumulus clouds and the effects of ensembles of cumulus clouds on mass, momentum, and vorticity distributions. A review of closure assumptions is also provided. A review of "classical" convection schemes in widespread use is provided in Part II. The special problems associated with the representation of convection in mesoscale models are discussed in Part III, along with descriptions of some of the commonly used mesoscale schemes. Part IV covers some of the problems associated with the representation of convection in climate models, while the parameterization of slantwise convection is the subject of Part V.
Download or read book AFOSR Chemical Atmospheric Sciences Program Review written by United States. Air Force. Directorate of Chemical and Atmospheric Sciences and published by . This book was released on with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Improving Numerical Weather Prediction written by Giovanni Leoncini and published by . This book was released on 2009 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mesoscale Meteorological Modeling written by Roger A. Pielke and published by Elsevier. This book was released on 2013-10-22 with total page 625 pages. Available in PDF, EPUB and Kindle. Book excerpt: To effectively utilize mesoscale dynamical simulations of the atmosphere, it is necessary to have an understanding the basic physical and mathematical foundations of the models and to have an appreciation of how a particular atmospheric system works. Mesoscale Meteorological Modeling provides such an overview of mesoscale numerical modeling. Starting with fundamental concepts, this text can be used to evaluate the scientific basis of any simulation model that has been or will be developed. Basic material is provided for the beginner as well as more in-depth treatment for the specialist. This text is useful to both the practitioner and the researcher of the mesoscale phenomena.
Download or read book An Introduction to Numerical Weather Prediction Techniques written by T. N. Krishnamurti and published by CRC Press. This book was released on 2018-05-11 with total page 293 pages. Available in PDF, EPUB and Kindle. Book excerpt: An Introduction to Numerical Weather Prediction Techniques is unique in the meteorological field as it presents for the first time theories and software of complex dynamical and physical processes required for numerical modeling. It was first prepared as a manual for the training of the World Meteorological Organization's programs at a similar level. This new book updates these exercises and also includes the latest data sets. This book covers important aspects of numerical weather prediction techniques required at an introductory level. These techniques, ranging from simple one-dimensional space derivative to complex numerical models, are first described in theory and for most cases supported by fully tested computational software. The text discusses the fundamental physical parameterizations needed in numerical weather models, such as cumulus convection, radiative transfers, and surface energy fluxes calculations. The book gives the user all the necessary elements to build a numerical model. An Introduction to Numerical Weather Prediction Techniques is rich in illustrations, especially tables showing outputs from each individual algorithm presented. Selected figures using actual meteorological data are also used. This book is primarily intended for senior-level undergraduates and first-year graduate students in meteorology. It is also excellent for individual scientists who wish to use the book for self-study. Scientists dealing with geophysical data analysis or predictive models will find this book filled with useful techniques and data-processing algorithms.
Download or read book Radar Meteorology written by Henri Sauvageot and published by Artech House Radar Library (Ha. This book was released on 1992 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Covers a wide range of topics. Should be both interesting and challenging to the novice. ...a handy guide for those in the field". -- Bulletin of the American Meteorological Society
Download or read book Mesoscale Meteorological Modeling written by Roger A Pielke Sr and published by Academic Press. This book was released on 2013-10-08 with total page 743 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 3rd edition of Mesoscale Meteorological Modeling is a fully revised resource for researchers and practitioners in the growing field of meteorological modeling at the mesoscale. Pielke has enhanced the new edition by quantifying model capability (uncertainty) by a detailed evaluation of the assumptions of parameterization and error propagation. Mesoscale models are applied in a wide variety of studies, including weather prediction, regional and local climate assessments, and air pollution investigations. Broad expansion of the concepts of parameterization and parameterization methodology Addition of new modeling approaches, including modeling summaries and summaries of data sets All-new section on dynamic downscaling
Download or read book Constraining Storm scale Forecasts of Deep Convective Initiation with Surface Weather Observations written by Luke Madaus and published by . This book was released on 2016 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: Successfully forecasting when and where individual convective storms will form remains an elusive goal for short-term numerical weather prediction. In this dissertation, the convective initiation (CI) challenge is considered as a problem of insufficiently resolved initial conditions and dense surface weather observations are explored as a possible solution. To better quantify convective-scale surface variability in numerical simulations of discrete convective initiation, idealized ensemble simulations of a variety of environments where CI occurs in response to boundary-layer processes are examined. Coherent features 1-2 hours prior to CI are found in all surface fields examined. While some features were broadly expected, such as positive temperature anomalies and convergent winds, negative temperature anomalies due to cloud shadowing are the largest surface anomaly seen prior to CI. Based on these simulations, several hypotheses about the required characteristics of a surface observing network to constrain CI forecasts are developed. Principally, these suggest that observation spacings of less than 4—5 km would be required, based on correlation length scales. Furthermore, it is anticipated that 2-m temperature and 10-m wind observations would likely be more relevant for effectively constraining variability than surface pressure or 2-m moisture observations based on the magnitudes of observed anomalies relative to observation error. These hypotheses are tested with a series of observing system simulation experiments (OSSEs) using a single CI-capable environment. The OSSE results largely confirm the hypotheses, and with 4-km and particularly 1-km surface observation spacing, skillful forecasts of CI are possible, but only within two hours of CI time. Several facets of convective-scale assimilation, including the need for properly-calibrated localization and problems from non-Gaussian ensemble estimates of the cloud field are discussed. Finally, the characteristics of one candidate dense surface observing network are examined: smartphone pressure observations. Available smartphone pressure observations (and 1-hr pressure tendency observations) are tested by assimilating them into convective-allowing ensemble forecasts for a three-day active convective period in the eastern United States. Although smartphone observations contain noise and internal disagreement, they are effective at reducing short-term forecast errors in surface pressure, wind and precipitation. The results suggest that smartphone pressure observations could become a viable mesoscale observation platform, but more work is needed to enhance their density and reduce error. This work concludes by reviewing and suggesting other novel candidate observation platforms with a potential to improve convective-scale forecasts of CI.
Download or read book Advances in Numerical Model Data Assimilation and Observations for Hazardous Weather Prediction written by Feifei Shen and published by Frontiers Media SA. This book was released on 2023-10-30 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurate and timely forecasting of hazardous weather events induced by meso-scale convection systems (MCSs) is the key to safeguarding lives and property. Yet the MCS forecasting is challenging due to imperfect initial numerical conditions that lack meso-scale convective information and multi-scale dynamic and thermodynamic consistency. Remote sensing observations are the primary source of estimating weather conditions, such as moisture, wind velocity, and precipitation. It is of fundamental pivotality to develop data assimilation technologies to enhance applications of multi-source observations. Performance assessments of new types of observations facilitate the network designment for regional- and storm-scale numerical models. This Research Topic seeks submissions underscoring the improvement of the accuracy of MCS predictions, warnings, and decision support for high-impact weather events as well as observation network designs.
