Download or read book Filtering techniques on a stretched grid general circulation model written by Lawrence Takacs and published by . This book was released on 1999 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Technical Report Series on Global Modeling and Data Assimilation Volume 16 written by Lawrence L. Takacs and published by BiblioGov. This book was released on 2013-08 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report documents the techniques used to filter quantities on a stretched grid general circulation model. Standard high-latitude filtering techniques (e.g., using an FFT (Fast Fourier Transformations) to decompose and filter unstable harmonics at selected latitudes) applied on a stretched grid are shown to produce significant distortions of the prognostic state when used to control instabilities near the pole. A new filtering technique is developed which accurately accounts for the non-uniform grid by computing the eigenvectors and eigenfrequencies associated with the stretching. A filter function, constructed to selectively damp those modes whose associated eigenfrequencies exceed some critical value, is used to construct a set of grid-spaced weights which are shown to effectively filter without distortion. Both offline and GCM (General Circulation Model) experiments are shown using the new filtering technique. Finally, a brief examination is also made on the impact of applying the Shapiro filter on the stretched grid.

Download or read book Technical Report Series on Global Modeling and Data Assimilation Volume 16 Filtering Techniques on a Stretched Grid General Circulation Model written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-21 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report documents the techniques used to filter quantities on a stretched grid general circulation model. Standard high-latitude filtering techniques (e.g., using an FFT (Fast Fourier Transformations) to decompose and filter unstable harmonics at selected latitudes) applied on a stretched grid are shown to produce significant distortions of the prognostic state when used to control instabilities near the pole. A new filtering technique is developed which accurately accounts for the non-uniform grid by computing the eigenvectors and eigenfrequencies associated with the stretching. A filter function, constructed to selectively damp those modes whose associated eigenfrequencies exceed some critical value, is used to construct a set of grid-spaced weights which are shown to effectively filter without distortion. Both offline and GCM (General Circulation Model) experiments are shown using the new filtering technique. Finally, a brief examination is also made on the impact of applying the Shapiro filter on the stretched grid.Takacs, Lawrence L. and Sawyer, William and Suarez, Max J. (Editor) and Fox-Rabinowitz, Michael S.Goddard Space Flight CenterATMOSPHERIC GENERAL CIRCULATION MODELS; ASSIMILATION; MATHEMATICAL MODELS; SPATIAL FILTERING; DATA INTEGRATION; COMPUTATIONAL GRIDS; STABILITY; GEOS SATELLITES (ESA); EIGENVECTORS; NONUNIFORMITY; FAST FOURIER TRANSFORMATIONS; POLAR REGIONS; FREQUENCY RESPONSE; HARMONICS; STRETCHING; FINITE DIFFERENCE THEORY

Download or read book Numerical Techniques for Global Atmospheric Models written by Peter H. Lauritzen and published by Springer Science & Business Media. This book was released on 2011-03-29 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book surveys recent developments in numerical techniques for global atmospheric models. It is based upon a collection of lectures prepared by leading experts in the field. The chapters reveal the multitude of steps that determine the global atmospheric model design. They encompass the choice of the equation set, computational grids on the sphere, horizontal and vertical discretizations, time integration methods, filtering and diffusion mechanisms, conservation properties, tracer transport, and considerations for designing models for massively parallel computers. A reader interested in applied numerical methods but also the many facets of atmospheric modeling should find this book of particular relevance.

Download or read book Proceedings of the Annual Climate Diagnostics Workshop written by and published by . This book was released on 2000 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A general filter for stretched grid models written by Dorina Surcel and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Atmospheric Modeling Data Assimilation and Predictability written by Eugenia Kalnay and published by Cambridge University Press. This book was released on 2003 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book, first published in 2002, is a graduate-level text on numerical weather prediction, including atmospheric modeling, data assimilation and predictability.

Download or read book Technical Report Series on Global Modeling and Data Assimilation written by and published by . This book was released on 1999 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 2000-07 with total page 938 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Technical Report Series on Global Modeling and Data Assimilation written by and published by . This book was released on 2001 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Conference on Numerical Weather Prediction written by and published by . This book was released on 1999 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Atlas of Seasonal Means Simulated by the NSIPP 1 Atmospheric GCM written by and published by . This book was released on 2000 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monthly Weather Review written by and published by . This book was released on 1993 with total page 910 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Modeling of the Global Atmosphere in the Climate System written by Philip Mote and published by Springer Science & Business Media. This book was released on 2000-04-30 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt: 21. Simulating Future Climate G. J. Boer 1 Introduction. . . . . . . . . . . . . . . . 489 2 International Aspects . . . . . . . . . . . 490 3 Simulating Historical and Future Climate 492 4 Climate Change in the 20th Century . . . 495 5 Simulating Future Climate Change 498 6 Climate Impact, Adaptation, and Mitigation 501 7 Summary . 502 Index 505 PREFACE Numerical modeling ofthe global atmosphere has entered a new era. Whereas atmospheric modeling was once the domain ofa few research units at universities or government laboratories, it can now be performed almost anywhere thanks to the affordability of computing power. Atmospheric general circulation models (GCMs) are being used by a rapidly growing scientific community in a wide range of applications. With widespread interest in anthropogenic climate change, GCMs have a role also in informing policy discussions. Many of the scientists using GCMs have backgrounds in fields other than atmospheric sciences and may be unaware of how GCMs are constructed. Recognizing this explosion in the application of GCMs, we organized a two week course in order to give young scientists who are relatively new to the field of atmospheric modeling a thorough grounding in the basic principles on which GCMs are constructed, an insight into their strengths and weaknesses, and guid ance on how meaningful numerical experiments are formulated and analyzed. Sponsored by the North Atlantic Treaty Organization (NATO) and other institu tions, this Advanced Study Institute (ASI) took place May 25-June 5, 1998, at II Ciocco, a remote hotel on a Tuscan hillside in Italy.

Download or read book NASA Space Geodesy Program GSFC Data Analysis 1993 VLBI Geodetic Results 1979 1992 written by and published by . This book was released on 1994 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Temperature Data Assimilation with Salinity Corrections Validation for the NSIPP Ocean Data Assimilation System in the Tropical Pacific Ocean 1993 1998 written by and published by . This book was released on 2003 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Modeling of Ocean Dynamics written by Zygmunt Kowalik and published by World Scientific. This book was released on 1993 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: While there are several excellent books dealing with numerical analysis and analytical theory, one has to practically sift through hundreds of references. This monograph is an attempt to partly rectify this situation. It aims to introduce the application of finite-difference methods to ocean dynamics as well as review other complex methods. Systematically presented, the monograph first gives a detailed account of the basics and then go on to discuss the various applications. Recognising the impossibility of covering the entire field of ocean dynamics, the writers have chosen to focus on transport equations (diffusion and advection), shallow water phenomena ? tides, storm surges and tsunamis, three-dimensional time dependent oceanic motion, natural oscillations, and steady state phenomena. The many aspects covered by this book makes it an indispensable handbook and reference source to both professionals and students of this field.