Download or read book Mechanisms and Implications of Changes in the Timing of Ocean Freeze up written by Rebecca J. Rolph and published by . This book was released on 2018 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: The shift to an Arctic seasonal sea ice cover in recent years motivates a deeper understanding of freeze-up processes and implications of a lengthened open water season. As the sea ice boundary between the Arctic ocean and atmosphere covers a smaller area, the effects of enhanced wind mixing become more pronounced. Winds are important for ocean circulation and heat exchange. Ultimately, they can influence when freeze-up can occur, or can break up new ice as it forms. The chapters of this thesis are motivated by the substantial social and geophysical consequences of a lengthening open water season and linked through discussion of what controls freeze-up timing. Implications of a declining sea ice cover as it pertains to the three Arctic Alaska coastal communities of Kotzebue, Shishmaref, and Utqiaġvik are explored in depth. Indices of locally-relevant metrics are developed by using physical climate-related thresholds found by other studies to impact Alaska communities and coastal erosion rates. This allows for a large-scale climate dataset to be used to define a timeseries of these indices for each community. We found a marked increase in the number of false freeze-ups and break-ups, the number of days too windy to hunt via subsistence boat, and in Utqiaġvik, an approximate tripling of erosion-capable wind events from 1979-2014. The WRF-downscaled ERA-Interim dataset (ERA-Interim for sea ice) was also used in the analysis of all chapters. The cumulative wind energy input into the upper ocean was calculated for the Chukchi, southern Beaufort, and northeast Bering Seas at time periods up to three months prior to freeze-up, and then correlated with the timing of freeze-up. We have found that increased wind energy input into the upper ocean 2-3 months prior to freeze-up is positively and most strongly correlated with the date of freeze-up in the Chukchi Sea. Analysis of wind climatology shows winds are increasing in the period prior to freeze-up as a delayed freeze-up moves into the fall storm season. A negative correlation is found in the Bering Sea over shorter timescales, suggesting that storms promote the arrival of sea ice there. Case studies are evaluated for the Chukchi Sea and Bering Sea, to illustrate mechanisms at play that cause the positive and negative correlations in these seas, respectively. Ice advection and high winds from northerly directions are shown to hasten the timing of freeze-up in the Bering Sea. In the Chukchi Sea, higher winds from the dominant northeasterly direction promote upwelling of warm and salty water up onto the shelf, which suggests a mechanism for why high winds are associated with a delayed freeze-up there. We next examine the effect of winds on freeze-up timing by using a 1-D vertical column model of the mixed layer. The model is initialized using temperature and salinity profiles obtained from a freeze-up buoy deployed in 2015 in the north-east part of the Chukchi Sea. The meteorological forcing used to drive the model experiments comes from a WRF-downscaled ERA-Interim Reanalysis dataset. Our results show that vertical wind-driven mixing leads to enhanced heat loss. In light of the previously found positive correlation between wind energy input and freeze-up timing, the mixing model results suggest horizontal advection not captured by the 1-D column model can dominate wind-driven vertical mixing to promote freeze-up.
Download or read book Arctic Subarctic Ocean Fluxes written by Robert R. Dickson and published by Springer Science & Business Media. This book was released on 2008-03-03 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt: We are only now beginning to understand the climatic impact of the remarkable events that are now occurring in subarctic waters. Researchers, however, have yet to agree upon a predictive model that links change in our northern seas to climate. This volume brings together the body of evidence needed to develop climate models that quantify the ocean exchanges through subarctic seas, measure their variability, and gauge their impact on climate.
Download or read book The Ocean and Cryosphere in a Changing Climate written by Intergovernmental Panel on Climate Change (IPCC) and published by Cambridge University Press. This book was released on 2022-04-30 with total page 755 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Intergovernmental Panel on Climate Change (IPCC) is the leading international body for assessing the science related to climate change. It provides policymakers with regular assessments of the scientific basis of human-induced climate change, its impacts and future risks, and options for adaptation and mitigation. This IPCC Special Report on the Ocean and Cryosphere in a Changing Climate is the most comprehensive and up-to-date assessment of the observed and projected changes to the ocean and cryosphere and their associated impacts and risks, with a focus on resilience, risk management response options, and adaptation measures, considering both their potential and limitations. It brings together knowledge on physical and biogeochemical changes, the interplay with ecosystem changes, and the implications for human communities. It serves policymakers, decision makers, stakeholders, and all interested parties with unbiased, up-to-date, policy-relevant information. This title is also available as Open Access on Cambridge Core.
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.
Download or read book Changes in The Seasonality of Sea Ice and The Underlying Mechanisms Across Hudson Bay HB from 1979 2018 written by Ratiba Munir and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sea ice in Hudson Bay (HB) holds great importance ecologically, climatologically, economically, and for the Inuit culture. It has been widely established that sea ice seasons: Break-Up (BU), Ice-Free (IF), Freeze-Up (FU) and Ice-Covered (IC) have been shifting, but the underlying mechanisms remain unknown. Energy and Radiation Budget data-set was downloaded from North American Regional Reanalysis (NARR). The analysis has revealed that over the past 40 years, ocean energy exchange is sensitive to astronomical cycles. As the timing of the BU season shifts away from the summer solstice toward the spring equinox the strength of the ice-albedo feedback weakens, slowing the melt of ice. As the IF season is lengthening primarily into the fall/winter, the benefits of low albedo are diminished and the trend is toward net energy loss. Overall, this research fills important gaps in understanding the duration and energetics of each ice season. It also addresses the limitations of NARR albedo data in studying sea ice.
Download or read book Oil in the Sea III written by National Research Council and published by National Academies Press. This book was released on 2003-03-14 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the early 1970s, experts have recognized that petroleum pollutants were being discharged in marine waters worldwide, from oil spills, vessel operations, and land-based sources. Public attention to oil spills has forced improvements. Still, a considerable amount of oil is discharged yearly into sensitive coastal environments. Oil in the Sea provides the best available estimate of oil pollutant discharge into marine waters, including an evaluation of the methods for assessing petroleum load and a discussion about the concerns these loads represent. Featuring close-up looks at the Exxon Valdez spill and other notable events, the book identifies important research questions and makes recommendations for better analysis ofâ€"and more effective measures againstâ€"pollutant discharge. The book discusses: Inputâ€"where the discharges come from, including the role of two-stroke engines used on recreational craft. Behavior or fateâ€"how oil is affected by processes such as evaporation as it moves through the marine environment. Effectsâ€"what we know about the effects of petroleum hydrocarbons on marine organisms and ecosystems. Providing a needed update on a problem of international importance, this book will be of interest to energy policy makers, industry officials and managers, engineers and researchers, and advocates for the marine environment.
Download or read book Frozen in Time written by Michael Oard and published by New Leaf Publishing Group. This book was released on 2004 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earth's past is littered with the mysterious and unexplained: the pyramids, Easter Island, Stonehenge, dinosaurs, and the list goes on and on as science looks for clues to decipher these puzzles.One such mystery surrounds the now-extinct creature called the woolly mammoth. Author and meteorologist Michael Oard has studied the mammoth and its equally mysterious time period, the Ice Age, for many years and has come to some fascinating conclusions to help lift the fog engulfing the facts. Some of the questions he addresses include:What would cause the summer temperatures of the northern United States and European to plummet more than 50 degrees Fahrenheit?Why did mammoths become extinct across the entire earth at the same time as many other large mammals?Why are the mammoth carcasses found generally in standing positions?How could large lakes exist in what are today very dry, desert-like places?What was the source of the abnormal of moisture necessary for heavy snow?What caused the cold summer temperatures and heavy snowfall to persist for hundreds of years?In logical progression many other Ice Age topics are explained including super Ice Age floods, ice cores, man in the Ice Age, and the number of ice ages. This is one of the most difficult eras in geological history for a uniformitarian scientist (one who believes the earth evolved by slow processes over millions of years) to explain, simply because long ages of evolution cannot explain it. Provided here are plausible explanations of the seemingly unsolvable mysterious about the Ice Age and the woolly mammoths - Frozen in Time.
Download or read book Arctic Sea Ice Decline written by Eric T. DeWeaver and published by John Wiley & Sons. This book was released on 2013-05-28 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 180. This volume addresses the rapid decline of Arctic sea ice, placing recent sea ice decline in the context of past observations, climate model simulations and projections, and simple models of the climate sensitivity of sea ice. Highlights of the work presented here include An appraisal of the role played by wind forcing in driving the decline; A reconstruction of Arctic sea ice conditions prior to human observations, based on proxy data from sediments; A modeling approach for assessing the impact of sea ice decline on polar bears, used as input to the U.S. Fish and Wildlife Service's decision to list the polar bear as a threatened species under the Endangered Species Act; Contrasting studies on the existence of a "tipping point," beyond which Arctic sea ice decline will become (or has already become) irreversible, including an examination of the role of the small ice cap instability in global warming simulations; A significant summertime atmospheric response to sea ice reduction in an atmospheric general circulation model, suggesting a positive feedback and the potential for short-term climate prediction. The book will be of interest to researchers attempting to understand the recent behavior of Arctic sea ice, model projections of future sea ice loss, and the consequences of sea ice loss for the natural and human systems of the Arctic.
Download or read book Abrupt Impacts of Climate Change written by National Research Council and published by National Academies Press. This book was released on 2013-12-31 with total page 281 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate is changing, forced out of the range of the past million years by levels of carbon dioxide and other greenhouse gases not seen in the Earth's atmosphere for a very, very long time. Lacking action by the world's nations, it is clear that the planet will be warmer, sea level will rise, and patterns of rainfall will change. But the future is also partly uncertain-there is considerable uncertainty about how we will arrive at that different climate. Will the changes be gradual, allowing natural systems and societal infrastructure to adjust in a timely fashion? Or will some of the changes be more abrupt, crossing some threshold or "tipping point" to change so fast that the time between when a problem is recognized and when action is required shrinks to the point where orderly adaptation is not possible? Abrupt Impacts of Climate Change is an updated look at the issue of abrupt climate change and its potential impacts. This study differs from previous treatments of abrupt changes by focusing on abrupt climate changes and also abrupt climate impacts that have the potential to severely affect the physical climate system, natural systems, or human systems, often affecting multiple interconnected areas of concern. The primary timescale of concern is years to decades. A key characteristic of these changes is that they can come faster than expected, planned, or budgeted for, forcing more reactive, rather than proactive, modes of behavior. Abrupt Impacts of Climate Change summarizes the state of our knowledge about potential abrupt changes and abrupt climate impacts and categorizes changes that are already occurring, have a high probability of occurrence, or are unlikely to occur. Because of the substantial risks to society and nature posed by abrupt changes, this report recommends the development of an Abrupt Change Early Warning System that would allow for the prediction and possible mitigation of such changes before their societal impacts are severe. Identifying key vulnerabilities can help guide efforts to increase resiliency and avoid large damages from abrupt change in the climate system, or in abrupt impacts of gradual changes in the climate system, and facilitate more informed decisions on the proper balance between mitigation and adaptation. Although there is still much to learn about abrupt climate change and abrupt climate impacts, to willfully ignore the threat of abrupt change could lead to more costs, loss of life, suffering, and environmental degradation. Abrupt Impacts of Climate Change makes the case that the time is here to be serious about the threat of tipping points so as to better anticipate and prepare ourselves for the inevitable surprises.
Download or read book Polar Environments and Global Change written by Roger G. Barry and published by Cambridge University Press. This book was released on 2018-08-09 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: The polar regions are the 'canary in the coal mine' of climate change: they are likely to be hit the hardest and fastest. This comprehensive textbook provides an accessible introduction to the scientific study of polar environments against a backdrop of climate change and the wider global environment. The book assembles diverse information on polar environmental characteristics in terrestrial and oceanic domains, and describes the ongoing changes in climate, the oceans, and components of the cryosphere. Recent significant changes in the polar region caused by global warming are explored: shrinking Arctic sea ice, thawing permafrost, accelerating loss of mass from glaciers and ice sheets, and rising ocean temperatures. These rapidly changing conditions are discussed in the context of the paleoclimatic history of the polar regions from the Eocene to the Anthropocene. Future projections for these regions during the twenty-first century are discussed. The text is illustrated with many color figures and tables, and includes further reading lists, review questions for each chapter, and a glossary.
Download or read book A Little Less Arctic written by Steven H. Ferguson and published by Springer Science & Business Media. This book was released on 2010-05-30 with total page 313 pages. Available in PDF, EPUB and Kindle. Book excerpt: In Arctic Canada, Hudson Bay is a site of great exploration history, aboriginal culture, and a vast marine wilderness supporting large populations of marine mammals and birds. These include some of the most iconic Arctic animals like beluga, narwhal, bowhead whales, and polar bears. Due to the challenges of conducting field research in this region, some of the mysteries of where these animals move, and how they are able to survive in such seemingly inhospitable, ice-choked habitats are just now being unlocked. For example, are polar bears being replaced by killer whales? This new information could not be more salient, as the Hudson Bay Region is undergoing rapid environmental change due to global warming, as well as increased pressures from industrial development interests. A Little Less Arctic brings together some of the world’s leading Arctic scientists to present the current state of knowledge on the physical and biological characteristics of Hudson Bay.
Download or read book Arctic and Antarctic Sea Ice 1978 1987 written by Per Gloersen and published by . This book was released on 1992 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Discrete Inverse and State Estimation Problems written by Carl Wunsch and published by Cambridge University Press. This book was released on 2006-06-29 with total page 357 pages. Available in PDF, EPUB and Kindle. Book excerpt: Addressing the problems of making inferences from noisy observations and imperfect theories, this 2006 book introduces many inference tools and practical applications. Starting with fundamental algebraic and statistical ideas, it is ideal for graduate students and researchers in oceanography, climate science, and geophysical fluid dynamics.
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.
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.
Download or read book Extreme Environmental Events written by Robert A. Meyers and published by Springer Science & Business Media. This book was released on 2010-11-03 with total page 1273 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extreme Environmental Events is an authoritative single source for understanding and applying the basic tenets of complexity and systems theory, as well as the tools and measures for analyzing complex systems, to the prediction, monitoring, and evaluation of major natural phenomena affecting life on earth. These phenomena are often highly destructive, and include earthquakes, tsunamis, volcanoes, climate change,, and weather. Early warning, damage, and the immediate response of human populations to these phenomena are also covered from the point of view of complexity and nonlinear systems. In 61 authoritative, state-of-the art articles, world experts in each field apply such tools and concepts as fractals, cellular automata, solitons game theory, network theory, and statistical physics to an understanding of these complex geophysical phenomena.
