Download or read book Evaluation of a High Resolution Wind Model Over a Complex Terrain Surface written by Sam S. Chang and published by . This book was released on 2009 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: A complete and comprehensive description of the high resolution wind (HRW) model is presented. The HRW model has been in development at the U.S. Army Research Laboratory, formerly U.S. Army Atmospheric Sciences Laboratory, since 1978. This model is a two-dimensional, diagnostic atmospheric surface-layer wind model with a horizontal grid spacing of the order of 100 m over a domain of about 5 by 5 km. It uses Gauss? principle of least constraint and a direct variational relaxation method to adjust an initially uniform wind field to conform with topography, mass conservation, and buoyancy forces. A distinctive feature of the model is the use of a non-orthogonal, terrain following, warped coordinate system. A valuable observational dataset of surface wind has been provided from the field study of Meteorology and Diffusion Over Non-Uniform Areas (MADONA) at Porton Down, Salisbury, England during September and October 1992. Using the MADONA data, a critical evaluation for the HRW model for 39 cases has been carried out. The results of this study are presented, indicating both the range of validity and the limitations of the HRW model.

Download or read book Evaluation of High Density Surface Observations in Complex Terrain and Their Contribution to the MM5 Model written by and published by . This book was released on 2007 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study evaluates the data assimilation capabilities of Three Dimensional Multiquadric Interpolation (3DMQ) and the MM5 model when incorporating mesoscale observations from the United States Air Force Academy (USAFA) High Wind Alert system (HWAS). These mesoscale observations are incorporated into a triple nested (12, 4, and 1.33 km) high resolution model simulation and evaluated for their impact upon analyzed and forecasted wind values at USAFA during a severe downslope wind event that occurred on 6 March 2004. This evaluation is the first step in developing future forecasting and analysis tools for use by the military in various operations in complex terrain. The development of deployable automated tactical weather sensors in forward deployed locations requires an evaluation of the impact and usefulness these sensors would have on analysis forecast tools and mesoscale Numerical Weather Prediction (NWP) models. The juxtaposition of the HWAS network in complex terrain and the aviation training operations at USAFA provides an ideal set of data, mission and location for testing and evaluating a high resolution nested grid mesoscale NWP model. This study shows that incorporating HWAS observations into the 3DMQ data assimilation process has a significant impact upon verification of analyzed wind fields with the biggest impact occurring at the 1.33 km grid scale. Using these analyzed fields as initial conditions for MM5 model simulations, this study shows the ability of the 1.33 km model forecast wind fields to verify significantly better than either the 4 or 12 km through 18, 24, and 30 hour forecasts. Additionally, this study shows the limited, yet discernable impact HWAS observations have upon forecasted winds in the first several hours of MM5 model runs during a severe downslope wind event at USAFA.

Download or read book Evaluation and Development of a High Resolution Wind Model for Wildfire Applications in Complex Terrain written by Natalie Suzanne Wagenbrenner and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurate modeling of near-surface winds is important for wildfire applications, including wildfire behavior and spread as well as post-fire processes, including wind-driven dust and ash emissions from burned soils. The work presented in this dissertation investigates a high resolution wind model for use in wildfire applications in complex terrain and includes (1) an observational field study to collect high resolution surface wind data from two types of complex terrain features; (2) use of these observed data to evaluate a suite of Numerical Weather Prediction (NWP) model near surface wind predictions and dynamical downscaling of those predictions with a high resolution wind model; and (3) field quantification of wind erosion from soils burned by wildfire. Unique flow features, including upslope, downslope, and synoptically-driven flow events were presented for an isolated mountain and a steep river canyon. Evaluations with these observed datasets indicated that NWP surface winds can be improved in complex terrain via dynamic downscaling with a high resolution wind model, WindNinja, so long as the average approach flow to the area of interest can be reasonably defined (i.e., the initial wind field must be appropriately defined). The biggest improvements occurred during periods of synoptically-driven events when observed winds speeds exceeded 10 m s-1. Results from the post-fire field campaign demonstrated that post-fire landscapes can be significant sources of particulates and that dust emissions can persist for up to a year post-fire. Data collected during this study represents the first real-time measurements of PM10 fluxes from a burned landscape. These data will be useful in evaluating windblown dust emissions algorithms applied to burned landscapes.

Download or read book High resolution Toposcale Wind Model written by Joseph A. Ball and published by . This book was released on 1975 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Complex Terrain Wind Model Evaluation written by Martin E. Lee and published by . This book was released on 1992 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book EPA Complex Terrain Model Development written by and published by . This book was released on 1988 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Prototype Windflow Modeling System for Tactical Weather Support Operations written by John M. Lanicci and published by . This book was released on 1987 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report documents the culmination of a three-year development and testing effort on a two-dimensional (x-y plane) surface-layer windflow model for complex terrain. The model was acquired from the U.S. Army Atmospheric Sciences Laboratory (ASL) at White Sands, New Mexico in 1984. The version of the model described in this report has been adapted to run using real time data on both the Zenith-100 and IBM-compatible Zenith-248 computers. The model accepts input of a single surface observation (or forecast) of wind, temperature, and cloud cover, and uses this information along with terrain information and the date/time to diagnose the surface-layer stability. The model then performs a variational analysis of the windfield, adjusting the winds through a relaxation technique until the windfield conforms to effects of topography, stability, ambient flow conditions, and mass continuity. The model is designed to produce high-resolution wind analyses, typically running on domains on the order of 10 X 10 km, with horizontal grid spacing of 100 to 200 m. We present an overview of potential military and nonmilitary uses for the model, and describe the relevant physics and computer architecture of the model and its two utility plotting routines. A user's guide, included here as Section 4, is primarily aimed at providing operational users such as forecasters some guidelines for using the model and interpreting the output. Finally, we present the results of an operational test of the model in support of Army Special Forces operations at Ft. Devens, Massachusetts. The test results illustrate the model's potential as a tactical weather support tool for low-level aviation and paradrop activities.

Download or read book Analysis of Surface Wind Over Complex Terrain written by and published by . This book was released on 2009 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Atmospheric Processes over Complex Terrain written by William Blumen and published by Springer. This book was released on 2016-06-30 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of the American Meteorological Society are "the development and dissemination of knowledge of meteorology in all its phases and applications, and the advancement of its professional ideals." The organization of the Society took place in affiliation with the American Association for the Advancement of Science at Saint Louis, Missouri, December 29, 1919, and its incorporation, at Washington, D. C., January 21, 1920. The work of the Society is carried on by the Bulletin, the Journal, and Meteorological Monographs, by papers and discussions at meetings of the Society, through the offices of the Secretary and the Executive Secretary, and by correspondence. All of the Americas are represented in the membership of the Society as well as many foreign countries.

Download or read book The Performance of a Mesoscale Surface Wind Field Model Over Complex Terrain written by Ken Kaung Lai and published by . This book was released on 1989 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A High Resolution Three Dimensional Computationally Efficient Diagnostic Wind Model Initial Development Report written by and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This document describes a three-dimensional, high resolution, computationally efficient, diagnostic model for flow over complex terrain using a mass consistent approach. The differences between the current model and similar approaches are (a) the lower boundary conditions and (b) an efficient numerical method. The model includes the effects of topography and small surface features such as forest areas and building on the overall flow. The numerical implementation takes advantage of a multigrid method that greatly improves the computation speed. The framework of the model and associated implementations are described here. Several preliminary test cases for the model are also given in this documentation.

Download or read book Monthly Weather Review written by and published by . This book was released on 2007 with total page 1652 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Complex Terrain Wind Model Evaluation written by Martin E. Lee and published by . This book was released on 1992 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Forest Atmosphere Interaction written by B.A. Hutchison and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 683 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of meteorological phenomena upon forest produc tivity and forestry operations have been of concern for many years. With the evolution of system-level studies of forest eco system structure and function in the International Biological Program and elsewhere, more fundamental interactions between forest ecosystems and the atmosphere received scientific atten tion but the emphasis on meteorological and climatological effects on forest processes remained. More recently, as recogni tion has developed of potential and actual problems associated with the atmospheric transport, dispersion, and deposition of airborne pollutants, the effects of forest canopies upon boundary-layer meteorological phenomena has come under scientific scrutiny. Looking to the future, with rising atmospheric con centrations of C02 and increasing competition for the finite fresh-water resources of the earth, interest in the role of forests in global C02 and water balances can also be expected to intensify. Thus, the nature of forest canopy-atmosphere interac tions, that is to say, the meteorological phenomena occurring in and above forest canopies, are of importance to a wide variety of scientific and social-issues. Demands for forest meteorological information currently exceed levels of knowledge and given the economic constraints of science in general and environmental sciences in particular, chances for major improvements in scien tific support in the near future are slim. Unfortunately, studies of environmental phenomena in and above forests are costly and logistically difficult. Trees, the ecological dominants of forest ecosystems, are the largest of all terrestrial organisms.

Download or read book Geoinformatics and Atmospheric Science written by Tomasz Niedzielski and published by Birkhäuser. This book was released on 2017-09-09 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents recent developments in atmospheric sciences driven by numerical modeling which makes use of geospatial technologies and increasing computational power. It gathers examples of how geoinformatics supports meteorological, climatological and water-related studies. One of the most important features of geospatial technologies is that they provide methods and tools which may be utilized in real time or near real time in order to monitor and predict atmospheric processes. This is particularly crucial in areas where dynamics of atmospheric phenomena is considerable and causes difficulties in accurate forecasting. One of such areas is the transitional zone between oceanic and continental features of the mid-latitude climate. Good examples of investigations into the transitional zone come from Poland and its neighboring countries. The topical volume provides the reader with a selection of papers on physically-based and data-based modelling of weather-related phenomena over Poland. This main theme of the topical volume is extended to cover case studies on the use of geoinformatics in atmospheric studies in other regions at a range of spatial scales.

Download or read book 17th Conference Agricultural and Forest Meteorology and Seventh Conference Biometeorology and Aerobiology written by and published by . This book was released on 1985 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: