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 Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-11 with total page 60 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 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 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 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 Technical Report Series on Global Modeling and Data Assimilation Volume 10 Dynamical Aspects of Climate Simulations Using the GEOS General Circulation Model written by and published by . This book was released on 1996 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 A Variable Resolution Stretched Grid General Circulation Model and Data Assimilation System with Multiple Areas of Interest written by Michael S. Fox-Rabinovitz and published by BiblioGov. This book was released on 2013-08 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: The new stretched-grid design with multiple (four) areas of interest, one at each global quadrant, is implemented into both a stretched-grid GCM (general circulation model) and a stretched-grid data assimilation system (DAS). The four areas of interest include: the U.S./Northern Mexico, the El Nino area/Central South America, India/China, and the Eastern Indian Ocean/Australia. Both the stretched-grid GCM and DAS annual (November 1997 through December 1998) integrations are performed with 50 km regional resolution. The efficient regional down-scaling to mesoscales is obtained for each of the four areas of interest while the consistent interactions between regional and global scales and the high quality of global circulation, are preserved. This is the advantage of the stretched-grid approach. The global variable resolution DAS incorporating the stretched-grid GCM has been developed and tested as an efficient tool for producing regional analyses and diagnostics with enhanced mesoscale resolution. The anomalous regional climate events of 1998 that occurred over the U.S., Mexico, South America, China, India, African Sahel, and Australia are investigated in both simulation and data assimilation modes. Tree assimilated products are also used, along with gauge precipitation data, for validating the simulation results. The obtained results show that the stretched-grid GCM and DAS are capable of producing realistic high quality simulated and assimilated products at mesoscale resolution for regional climate studies and applications.

Download or read book Global Modeling and Data Assimilation written by and published by . This book was released on 1997 with total page 56 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 Earth s Climate Response to a Changing Sun written by Katja Matthes and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: For centuries, scientists have been fascinated by the role of the Sun in the Earth's climate system. Recent discoveries, outlined in this book, have gradually unveiled a complex picture, in which our variable Sun affects the climate variability via a number of subtle pathways, the implications of which are only now becoming clear. This handbook provides the scientifically curious, from undergraduate students to policy makers with a complete and accessible panorama of our present understanding of the Sun-climate connection. 61 experts from different communities have contributed to it, which reflects the highly multidisciplinary nature of this topic. The handbook is organised as a mosaic of short chapters, each of which addresses a specific aspect, and can be read independently. The reader will learn about the assumptions, the data, the models, and the unknowns behind each mechanism by which solar variability may impact climate variability. None of these mechanisms can adequately explain global warming observed since the 1950s. However, several of them do impact climate variability, in particular on a regional level. This handbook aims at addressing these issues in a factual way, and thereby challenge the reader to sharpen his/her critical thinking in a debate that is frequently distorted by unfounded claims.

Download or read book The Sun the Earth and Near earth Space written by John A. Eddy and published by Government Printing Office. This book was released on 2009 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: " ... Concise explanations and descriptions - easily read and readily understood - of what we know of the chain of events and processes that connect the Sun to the Earth, with special emphasis on space weather and Sun-Climate."--Dear Reader.

Download or read book Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation written by Intergovernmental Panel on Climate Change and published by Cambridge University Press. This book was released on 2012-05-28 with total page 593 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extreme weather and climate events, interacting with exposed and vulnerable human and natural systems, can lead to disasters. This Special Report explores the social as well as physical dimensions of weather- and climate-related disasters, considering opportunities for managing risks at local to international scales. SREX was approved and accepted by the Intergovernmental Panel on Climate Change (IPCC) on 18 November 2011 in Kampala, Uganda.

Download or read book Cumulus Dynamics written by Chao Jih-Ping and published by . This book was released on 1969 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Weather Prediction by Numerical Process written by Lewis F. Richardson and published by . This book was released on 1922 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Methods for Wave Equations in Geophysical Fluid Dynamics written by Dale R. Durran and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering a wide range of techniques, this book describes methods for the solution of partial differential equations which govern wave propagation and are used in modeling atmospheric and oceanic flows. The presentation establishes a concrete link between theory and practice.

Download or read book Eco2 Cities written by Hiroaki Suzuki and published by World Bank Publications. This book was released on 2010-05-07 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a point of departure for cities that would like to reap the many benefits of ecological and economic sustainability. It provides an analytical and operational framework that offers strategic guidance to cities on sustainable and integrated urban development.