Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Global Climate Reconstruction Across Time And Space Using Data Assimilation
Download Global Climate Reconstruction Across Time And Space Using Data Assimilation full books in PDF, epub, and Kindle. Read online Global Climate Reconstruction Across Time And Space Using Data Assimilation ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Global Climate Reconstruction Across Time and Space Using Data Assimilation by : Nathan Steiger
Download or read book Global Climate Reconstruction Across Time and Space Using Data Assimilation written by Nathan Steiger and published by . This book was released on 2015 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: Paleoclimate proxy data span seasonal to millennial time scales, and Earth's climate system has both high- and low-frequency components. Yet it is currently unclear how best to incorporate multiple time scales of proxy data into a single reconstruction framework and to also capture both high- and low-frequency components of reconstructed variables. In the first half of this dissertation we present a data assimilation algorithm that can explicitly incorporate proxy data at arbitrary time scales. Through a series of pseudoproxy experiments, we find that atmosphere--ocean states are most skilfully reconstructed by incorporating proxies across multiple time scales compared to using proxies at short (annual) or long ( ~ decadal) time scales alone. Additionally, reconstructions that incorporate long time-scale pseudoproxies improve the low-frequency components of the reconstructions relative to using only high-resolution pseudoproxies. We argue that this is because time averaging high-resolution observations improves their covariance relationship with the slowly-varying components of the coupled-climate system, which the data assimilation algorithm can exploit. These results are insensitive to the choice of climate model, despite the model variables having very different spectral characteristics. Our results also suggest that it may be possible to reconstruct features of the oceanic meridional overturning circulation based solely on atmospheric surface temperature proxies. Water isotope data from ice cores, particularly [delta scientific symbol][^18]O, has long been used as a paleoclimate proxy. In the past decade or so isotope-enabled climate models have allowed for a more rich understanding of the climate processes that produce the isotopic signals in precipitation. Such modeling-based studies tend to complicate simple temperature-isotope interpretations by pointing to the many non-local influences on isotopic signals at coring locations. Recent observational studies have also linked ice cores to non-local patterns of climate variability, particularly to mid-latitude atmospheric circulation patterns and to variations in tropical climate. However, the full spatial and temporal extent to which ice cores can robustly inform past climate is unknown. In the second half of this dissertation we estimate a realistic upper-bound on what ice cores can tell us about climate at annual and decadal time scales in a paleoclimate reconstruction context. We employ a similar data assimilation-based reconstruction technique that optimally combines isotopic proxy information with the dynamical constraints of climate models. Through several pseudo and real proxy experiments we assess the spatial and temporal extent to which ice cores can reconstruct the key variables of surface temperature, geopotential height at 500 hPa, and precipitation. We find local reconstruction skill to be the most robust across the reconstructions, particularly for temperature and geopotential heights. Non-local skill is also found for these variables in certain locations. For precipitation we find virtually no reconstruction skill outside of coastal and West Antarctica. These results are in agreement with long-held views that isotopes in ice cores have clear value as local climate proxies, particularly for temperature and atmospheric circulation. These results also show that in principle non-local climate information may also be reliably deduced from ice cores, though the spatial range of this information depends on how proxies are modelled within the reconstruction process, is non-uniform, and may not extend into plausible nearby locations: in particular, Greenland ice cores, by their nature, appear to be relatively uninformative for Europe and the British Isles at annual and decadal time scales.
Author :National Academies of Sciences, Engineering, and Medicine Publisher :National Academies Press ISBN 13 :0309444640 Total Pages :92 pages Book Rating :4.3/5 (94 download)
Book Synopsis Frontiers in Decadal Climate Variability by : National Academies of Sciences, Engineering, and Medicine
Download or read book Frontiers in Decadal Climate Variability written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2016-07-22 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many factors contribute to variability in Earth's climate on a range of timescales, from seasons to decades. Natural climate variability arises from two different sources: (1) internal variability from interactions among components of the climate system, for example, between the ocean and the atmosphere, and (2) natural external forcings, such as variations in the amount of radiation from the Sun. External forcings on the climate system also arise from some human activities, such as the emission of greenhouse gases (GHGs) and aerosols. The climate that we experience is a combination of all of these factors. Understanding climate variability on the decadal timescale is important to decision-making. Planners and policy makers want information about decadal variability in order to make decisions in a range of sectors, including for infrastructure, water resources, agriculture, and energy. In September 2015, the National Academies of Sciences, Engineering, and Medicine convened a workshop to examine variability in Earth's climate on decadal timescales, defined as 10 to 30 years. During the workshop, ocean and climate scientists reviewed the state of the science of decadal climate variability and its relationship to rates of human-caused global warming, and they explored opportunities for improvement in modeling and observations and assessing knowledge gaps. Frontiers in Decadal Climate Variability summarizes the presentations and discussions from the workshop.
Book Synopsis Data Assimilation for the Earth System by : Richard Swinbank
Download or read book Data Assimilation for the Earth System written by Richard Swinbank and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: Data assimilation is the combination of information from observations and models of a particular physical system in order to get the best possible estimate of the state of that system. The technique has wide applications across a range of earth sciences, a major application being the production of operational weather forecasts. Others include oceanography, atmospheric chemistry, climate studies, and hydrology. Data Assimilation for the Earth System is a comprehensive survey of both the theory of data assimilation and its application in a range of earth system sciences. Data assimilation is a key technique in the analysis of remote sensing observations and is thus particularly useful for those analysing the wealth of measurements from recent research satellites. This book is suitable for postgraduate students and those working on the application of data assimilation in meteorology, oceanography and other earth sciences.
Author :National Academies of Sciences, Engineering, and Medicine Publisher :National Academies Press ISBN 13 :0309492432 Total Pages :29 pages Book Rating :4.3/5 (94 download)
Book Synopsis Thriving on Our Changing Planet: A Decadal Strategy for Earth Observation from Space by : National Academies of Sciences, Engineering, and Medicine
Download or read book Thriving on Our Changing Planet: A Decadal Strategy for Earth Observation from Space written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2019-06-18 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: We live on a dynamic Earth shaped by both natural processes and the impacts of humans on their environment. It is in our collective interest to observe and understand our planet, and to predict future behavior to the extent possible, in order to effectively manage resources, successfully respond to threats from natural and human-induced environmental change, and capitalize on the opportunities â€" social, economic, security, and more â€" that such knowledge can bring. By continuously monitoring and exploring Earth, developing a deep understanding of its evolving behavior, and characterizing the processes that shape and reshape the environment in which we live, we not only advance knowledge and basic discovery about our planet, but we further develop the foundation upon which benefits to society are built. Thriving on Our Changing Planet: A Decadal Strategy for Earth Observation from Space (National Academies Press, 2018) provides detailed guidance on how relevant federal agencies can ensure that the United States receives the maximum benefit from its investments in Earth observations from space, while operating within realistic cost constraints. This short booklet, designed to be accessible to the general public, provides a summary of the key ideas and recommendations from the full decadal survey report.
Book Synopsis Assimilation of Time-averaged Pseudoproxies for Climate Reconstruction by : Nathan J. Steiger
Download or read book Assimilation of Time-averaged Pseudoproxies for Climate Reconstruction written by Nathan J. Steiger and published by . This book was released on 2013 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: We examine the efficacy of a novel ensemble data assimilation (DA) technique in climate field reconstructions (CFR) of surface temperature. We perform four pseudoproxy experiments with both general circulation model (GCM) and 20th Century Reanalysis (20CR) data by reconstructing surface temperature fields from a sparse network of noisy pseudoproxies. We compare the DA approach to a conventional CFR approach based on Principal Component Analysis (PCA) for experiments on global domains. DA outperforms PCA in reconstructing global-mean temperature in all four experiments, and is more cosistent across experiments, with a range of time-series correlations of 0.69--0.94 compared to 0.19--0.87 for the PCA method. DA improvements are even more evident in spatial reconstruction skill, especially in sparsely sampled pseudoproxy regions and for a 20CR experiment. We hypothesize that DA improves spatial reconstructions because it relies on local temperature correlations. These relationships appear to be more robust than orthogonal patterns of variability, which can be non-stationary. Additionally, comparing results for GCM and 20CR data indicates that pseudoproxy experiments that rely solely on GCM data may give a false impression of reconstruction skill.
Book Synopsis Four-Dimensional Model Assimilation of Data by : National Research Council
Download or read book Four-Dimensional Model Assimilation of Data written by National Research Council and published by National Academies Press. This book was released on 1991-02-01 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume explores and evaluates the development, multiple applications, and usefulness of four-dimensional (space and time) model assimilations of data in the atmospheric and oceanographic sciences and projects their applicability to the earth sciences as a whole. Using the predictive power of geophysical laws incorporated in the general circulation model to produce a background field for comparison with incoming raw observations, the model assimilation process synthesizes diverse, temporarily inconsistent, and spatially incomplete observations from worldwide land, sea, and space data acquisition systems into a coherent representation of an evolving earth system. The book concludes that this subdiscipline is fundamental to the geophysical sciences and presents a basic strategy to extend the application of this subdiscipline to the earth sciences as a whole.
Book Synopsis Interhemispheric Climate Linkages by : Vera Markgraf
Download or read book Interhemispheric Climate Linkages written by Vera Markgraf and published by Elsevier. This book was released on 2001-01-25 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a novel approach in the field of global change by presenting a comprehensive analysis of interhemispheric linkages of climate, present and past, and their effects on human societies. The ultimate goal of this interhemispheric integration is to improve our understanding of causes and mechanisms of climate change to enhance our capability in predicting future changes. Given the societal interest in global change issues this book offers a new approach for the integration of global information. It will provide a reference for professional scientists, researchers and graduate students in the fields of climatology, and the earth and environmental sciences. Chapters analyse instrumental atmospheric and oceanic data to address such phenomena as El Nino/Southern Oscillation variability and other climate anomalies such as the Pacific and North Atlantic Oscillation and polar air outbreaks A new systematic methodology is presented that allows objective and verifiable reconstruction of climate fields from sparse data Especially valuable in the context of climate proxy data
Book Synopsis Abrupt Climate Change by : National Research Council
Download or read book Abrupt Climate Change written by National Research Council and published by National Academies Press. This book was released on 2002-04-23 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: The climate record for the past 100,000 years clearly indicates that the climate system has undergone periodic-and often extreme-shifts, sometimes in as little as a decade or less. The causes of abrupt climate changes have not been clearly established, but the triggering of events is likely to be the result of multiple natural processes. Abrupt climate changes of the magnitude seen in the past would have far-reaching implications for human society and ecosystems, including major impacts on energy consumption and water supply demands. Could such a change happen again? Are human activities exacerbating the likelihood of abrupt climate change? What are the potential societal consequences of such a change? Abrupt Climate Change: Inevitable Surprises looks at the current scientific evidence and theoretical understanding to describe what is currently known about abrupt climate change, including patterns and magnitudes, mechanisms, and probability of occurrence. It identifies critical knowledge gaps concerning the potential for future abrupt changes, including those aspects of change most important to society and economies, and outlines a research strategy to close those gaps. Based on the best and most current research available, this book surveys the history of climate change and makes a series of specific recommendations for the future.
Book Synopsis Advancing the Science of Climate Change by : National Research Council
Download or read book Advancing the Science of Climate Change written by National Research Council and published by National Academies Press. This book was released on 2011-01-10 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate change is occurring, is caused largely by human activities, and poses significant risks for-and in many cases is already affecting-a broad range of human and natural systems. The compelling case for these conclusions is provided in Advancing the Science of Climate Change, part of a congressionally requested suite of studies known as America's Climate Choices. While noting that there is always more to learn and that the scientific process is never closed, the book shows that hypotheses about climate change are supported by multiple lines of evidence and have stood firm in the face of serious debate and careful evaluation of alternative explanations. As decision makers respond to these risks, the nation's scientific enterprise can contribute through research that improves understanding of the causes and consequences of climate change and also is useful to decision makers at the local, regional, national, and international levels. The book identifies decisions being made in 12 sectors, ranging from agriculture to transportation, to identify decisions being made in response to climate change. Advancing the Science of Climate Change calls for a single federal entity or program to coordinate a national, multidisciplinary research effort aimed at improving both understanding and responses to climate change. Seven cross-cutting research themes are identified to support this scientific enterprise. In addition, leaders of federal climate research should redouble efforts to deploy a comprehensive climate observing system, improve climate models and other analytical tools, invest in human capital, and improve linkages between research and decisions by forming partnerships with action-oriented programs.
Book Synopsis Global Environmental Change by : National Research Council
Download or read book Global Environmental Change written by National Research Council and published by National Academies Press. This book was released on 1999-09-14 with total page 621 pages. Available in PDF, EPUB and Kindle. Book excerpt: How can we understand and rise to the environmental challenges of global change? One clear answer is to understand the science of global change, not solely in terms of the processes that control changes in climate and the composition of the atmosphere, but in how ecosystems and human society interact with these changes. In the last two decades of the twentieth century, a number of such research effortsâ€"supported by computer and satellite technologyâ€"have been launched. Yet many opportunities for integration remain unexploited, and many fundamental questions remain about the earth's capacity to support a growing human population. This volume encourages a renewed commitment to understanding global change and sets a direction for research in the decade ahead. Through case studies the book explores what can be learned from the lessons of the past 20 years and what are the outstanding scientific questions. Highlights include: Research imperatives and strategies for investigators in the areas of atmospheric chemistry, climate, ecosystem studies, and human dimensions of global change. The context of climate change, including lessons to be gleaned from paleoclimatology. Human responses toâ€"and forcing ofâ€"projected global change. This book offers a comprehensive overview of global change research to date and provides a framework for answering urgent questions.
Book Synopsis Songs and Sayings of Gowrie by : Adam Philip
Download or read book Songs and Sayings of Gowrie written by Adam Philip and published by . This book was released on 1901 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Data Assimilation for Atmospheric, Oceanic and Hydrologic Applications (Vol. II) by : Seon Ki Park
Download or read book Data Assimilation for Atmospheric, Oceanic and Hydrologic Applications (Vol. II) written by Seon Ki Park and published by Springer Science & Business Media. This book was released on 2013-05-22 with total page 736 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the most recent progress in data assimilation in meteorology, oceanography and hydrology including land surface. It spans both theoretical and applicative aspects with various methodologies such as variational, Kalman filter, ensemble, Monte Carlo and artificial intelligence methods. Besides data assimilation, other important topics are also covered including targeting observation, sensitivity analysis, and parameter estimation. The book will be useful to individual researchers as well as graduate students for a reference in the field of data assimilation.
Book Synopsis Surface Temperature Reconstructions for the Last 2,000 Years by : National Research Council
Download or read book Surface Temperature Reconstructions for the Last 2,000 Years written by National Research Council and published by National Academies Press. This book was released on 2007-01-05 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: In response to a request from Congress, Surface Temperature Reconstructions for the Last 2,000 Years assesses the state of scientific efforts to reconstruct surface temperature records for Earth during approximately the last 2,000 years and the implications of these efforts for our understanding of global climate change. Because widespread, reliable temperature records are available only for the last 150 years, scientists estimate temperatures in the more distant past by analyzing "proxy evidence," which includes tree rings, corals, ocean and lake sediments, cave deposits, ice cores, boreholes, and glaciers. Starting in the late 1990s, scientists began using sophisticated methods to combine proxy evidence from many different locations in an effort to estimate surface temperature changes during the last few hundred to few thousand years. This book is an important resource in helping to understand the intricacies of global climate change.
Book Synopsis Natural Climate Variability on Decade-to-Century Time Scales by : National Research Council
Download or read book Natural Climate Variability on Decade-to-Century Time Scales written by National Research Council and published by National Academies Press. This book was released on 1996-08-30 with total page 645 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume reflects the current state of scientific knowledge about natural climate variability on decade-to-century time scales. It covers a wide range of relevant subjects, including the characteristics of the atmosphere and ocean environments as well as the methods used to describe and analyze them, such as proxy data and numerical models. They clearly demonstrate the range, persistence, and magnitude of climate variability as represented by many different indicators. Not only do natural climate variations have important socioeconomic effects, but they must be better understood before possible anthropogenic effects (from greenhouse gas emissions, for instance) can be evaluated. A topical essay introduces each of the disciplines represented, providing the nonscientist with a perspective on the field and linking the papers to the larger issues in climate research. In its conclusions section, the book evaluates progress in the different areas and makes recommendations for the direction and conduct of future climate research. This book, while consisting of technical papers, is also accessible to the interested layperson.
Book Synopsis Dynamic Data Assimilation by : John M. Lewis
Download or read book Dynamic Data Assimilation written by John M. Lewis and published by Cambridge University Press. This book was released on 2006-08-03 with total page 601 pages. Available in PDF, EPUB and Kindle. Book excerpt: Publisher description
Book Synopsis Reconstructing Past Climate by Using Proxy Data and a Linear Climate Model by : Walter A. Perkins
Download or read book Reconstructing Past Climate by Using Proxy Data and a Linear Climate Model written by Walter A. Perkins and published by . This book was released on 2016 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work we improve the skill of climate field reconstructions (CFRs) through the use of an online paleoclimate data assimilation (PDA) method within the Last Millennium Reanalysis framework (LMR). A computationally cheap forecast model, known as a linear inverse model (LIM), is employed here to provide 1-year forecasts between analysis times of the reconstruction. CFRs of annual mean 2m air temperature are compared between the previous offline and new online method. We test LIMs calibrated on surface temperatures from the Berkeley Earth observational dataset, the 20th Century Reanalysis (20CR), and coupled general circulation model last-millennium simulations (Community Climate System Model v4, CCSM4; Max Planck Institute Earth System Model, MPI). In all cases skill metrics are assessed for both spatial fields and global averages. Generally, we find that the usage of online PDA can increase reconstruction agreement with the instrumental record for both spatial fields and the global mean temperature (GMT). Spatial field skill increases tend to occur over Northern Hemisphere land areas and in the high-latitude North Atlantic - Barents Sea corridor. These regions of increased skill are associated with better agreement in temperature anomaly amplitude or trend, and not associated with changes in anomaly timing. Overall, the CCSM4 LIM provides the best performance when considering both spatial fields and GMT. A comparison with a persistence forecast experiment suggests that the skill of LIM forecasts are associated with the usage of the LIM, rather than simply the persistence of existing temperature anomalies. Results from this study are directly applicable in providing more dynamically consistent CFRs over the past two millennia.
Book Synopsis Predictability of Weather and Climate by : Tim Palmer
Download or read book Predictability of Weather and Climate written by Tim Palmer and published by Cambridge University Press. This book was released on 2014-07-10 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The topic of predictability in weather and climate has advanced significantly in recent years, both in understanding the phenomena that affect weather and climate and in techniques used to model and forecast them. This book, first published in 2006, brings together some of the world's leading experts on predicting weather and climate. It addresses predictability from the theoretical to the practical, on timescales from days to decades. Topics such as the predictability of weather phenomena, coupled ocean-atmosphere systems and anthropogenic climate change are among those included. Ensemble systems for forecasting predictability are discussed extensively. Ed Lorenz, father of chaos theory, makes a contribution to theoretical analysis with a previously unpublished paper. This well-balanced volume will be a valuable resource for many years. High-calibre chapter authors and extensive subject coverage make it valuable to people with an interest in weather and climate forecasting and environmental science, from graduate students to researchers.
