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 Technical Report Series on Global Modeling and Data Assimilation Volume 5 Documentation of the AIRES GEOS Dynamical Core Version 2 written by and published by . This book was released on 1995 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Report Series on Global Modeling and Data Assimilation Volume 20 The Climate of the Fvccm 3 Model written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-15 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: This document describes the climate of version 1 of the NASA-NCAR model developed at the Data Assimilation Office (DAO). The model consists of a new finite-volume dynamical core and an implementation of the NCAR climate community model (CCM-3) physical parameterizations. The version of the model examined here was integrated at a resolution of 2 degrees latitude by 2.5 degrees longitude and 32 levels. The results are based on assimilation that was forced with observed sea surface temperature and sea ice for the period 1979-1995, and are compared with NCEP/NCAR reanalyses and various other observational data sets. The results include an assessment of seasonal means, subseasonal transients including the Madden Julian Oscillation, and interannual variability. The quantities include zonal and meridional winds, temperature, specific humidity, geopotential height, stream function, velocity potential, precipitation, sea level pressure, and cloud radiative forcing. Suarez, Max J. (Editor) and Chang, Yehui and Schubert, Siegfried D. and Lin, Shian-Jiann and Nebuda, Sharon and Shen, Bo-Wen Goddard Space Flight Center
Download or read book Technical Report Series on Global Modeling and Data Assimilation Volume 3 An Efficient Thermal Infrared Radiation Parameterization for Use in General Circulation Models written by and published by . This book was released on 1994 with total page 102 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 Technical Report Series on Global Modeling and Data Assimilation Volume 4 Documentation of the Goddard Earth Observing System GEOS Data Assimilation System Version 1 written by and published by . This book was released on 1995 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Report Series on Global Modeling and Data Assimilation written by Max J. Suarez and published by BiblioGov. This book was released on 2013-08 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: This document describes the climate of version 1 of the NASA-NCAR model developed at the Data Assimilation Office (DAO). The model consists of a new finite-volume dynamical core and an implementation of the NCAR climate community model (CCM-3) physical parameterizations. The version of the model examined here was integrated at a resolution of 2 degrees latitude by 2.5 degrees longitude and 32 levels. The results are based on assimilation that was forced with observed sea surface temperature and sea ice for the period 1979-1995, and are compared with NCEP/NCAR reanalyses and various other observational data sets. The results include an assessment of seasonal means, subseasonal transients including the Madden Julian Oscillation, and interannual variability. The quantities include zonal and meridional winds, temperature, specific humidity, geopotential height, stream function, velocity potential, precipitation, sea level pressure, and cloud radiative forcing.
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 2002 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 548 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 610 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Computational Science ICCS 2024 written by Leonardo Franco and published by Springer Nature. This book was released on with total page 511 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 with total page 1450 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Extremes in a Changing Climate written by Amir AghaKouchak and published by Springer Science & Business Media. This book was released on 2012-10-24 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a collection of the state-of-the-art methodologies and approaches suggested for detecting extremes, trend analysis, accounting for nonstationarities, and uncertainties associated with extreme value analysis in a changing climate. This volume is designed so that it can be used as the primary reference on the available methodologies for analysis of climate extremes. Furthermore, the book addresses current hydrometeorologic global data sets and their applications for global scale analysis of extremes. While the main objective is to deliver recent theoretical concepts, several case studies on extreme climate conditions are provided. Audience The book is suitable for teaching in graduate courses in the disciplines of Civil and Environmental Engineering, Earth System Science, Meteorology and Atmospheric Sciences.
Download or read book Food Insecurity Hydroclimate in Greater Horn of Africa written by Joseph Awange and published by Springer Nature. This book was released on 2022-01-25 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book will benefit users in food security, agriculture, water management, and environmental sectors. It provides the first comprehensive analysis of Greater Horn of Africa (GHA)’s food insecurity and hydroclimate using the state-of-the-art Gravity Recovery and Climate Experiment (GRACE) and its Follow-on (GRACE-FO)’s, centennial precipitation, hydrological models’ and reanalysis’ products. It is here opined that GHA is endowed with freshwater (surface and groundwater) being home to the world's second largest freshwater body (Lake Victoria) and the greatest continental water towers (Ethiopian Highlands) that if properly tapped in a sustainable way, will support its irrigated agriculture as well as pastoralism. First, however, the obsolete Nile treaties that hamper the use of Lake Victoria (White Nile) and Ethiopian Highland (Blue Nile) have to be unlocked. Moreover, GHA is bedevilled by poor governance and the ``donor-assistance” syndrome; and in 2020-2021 faced the so-called ``triple threats’’ of desert locust infestation, climate variability/change impacts and COVID-19 pandemic. Besides, climate extremes influence its meagre waters leading to perennial food insecurity. Coupled with frequent regional and local conflicts, high population growth rate, low crop yield, invasion of migratory pests, contagious human and livestock diseases (such as HIV/AIDs, COVID-19 & Rift Valley fever) and poverty, life for more than 310 million of its inhabitants simply becomes unbearable. Alarming also is the fact that drought-like humanitarian crises are increasing in GHA despite recent progress in its monitoring and prediction efforts. Notwithstanding these efforts, there remain challenges stemming from uncertainty in its prediction, and the inflexibility and limited buffering capacity of the recurrent impacted systems. To achieve greater food security, therefore, in addition to boosting GHA's agricultural output, UN Office for the Coordination of Humanitarian Affairs suggest that its “inhabitants must create more diverse and stable means of livelihood to insulate themselves and their households from external shocks”. This is a task that they acknowledge will not be easy as the path ahead is “strewn with obstacles namely; natural hazards and armed conflicts”. Understanding GHA’s food insecurity and its hydroclimate as presented in this book is a good starting point towards managing the impacts of the natural hazards on the one hand while understanding the impacts associated with extreme climate on GHA's available water and assessing the potential of its surface and groundwater to support its irrigated agriculture and pastoralism would be the first step towards “coping with drought” on the other hand. The book represents a significant effort by Prof Awange in trying to offer a comprehensive overview of the hydroclimate in the Greater Horn of Africa (GHA). Prof Eric F. Wood, NAE (USA); FRSC (Canada); Foreign member, ATSE (Australia).
