Download or read book Improving Our Understanding of the Relationship Between Ocean Heat Uptake and Climate Sensitivity written by Michael Cameron Rencurrel and published by . This book was released on 2020 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ocean Circulation and Climate written by John A. Church and published by Elsevier Inc. Chapters. This book was released on 2013-10-22 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ocean has the largest heat capacity in the climate system and as a result the ocean plays a critical role in the climate. Changes in ocean heat content dominate the Earth’s energy storage; and the ocean’s thermal expansion has been a major contributor to sea-level rise in the twentieth century and likely to be the largest contributor in the twenty-first century. The agreement between changes in ocean heat storage over recent decades and changes in the Earth’s radiative balance, within uncertainties, provides strong support for current understanding of anthropogenic climate change. As a result of improvements in observations and modeling of sea level and components contributing to sea-level change, there is now an improved explanation for twentieth century sea-level rise. Models project a continuing sea-level rise during the twenty-first century and beyond. However, a number of uncertainties remain in our understanding of the global mean and regional distribution of sea-level rise resulting from changes in ocean circulation and changes in the Earth’s gravitational field. Ocean-ice-sheet interactions are important for quantitatively estimating future ice-sheet contributions to sea-level rise.
Download or read book Thriving on Our Changing Planet written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2019-01-20 with total page 717 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 presents prioritized science, applications, and observations, along with related strategic and programmatic guidance, to support the U.S. civil space Earth observation program over the coming decade.
Download or read book Climate Stabilization Targets written by National Research Council and published by National Academies Press. This book was released on 2011-02-11 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emissions of carbon dioxide from the burning of fossil fuels have ushered in a new epoch where human activities will largely determine the evolution of Earth's climate. Because carbon dioxide in the atmosphere is long lived, it can effectively lock the Earth and future generations into a range of impacts, some of which could become very severe. Emissions reductions decisions made today matter in determining impacts experienced not just over the next few decades, but in the coming centuries and millennia. According to Climate Stabilization Targets: Emissions, Concentrations, and Impacts Over Decades to Millennia, important policy decisions can be informed by recent advances in climate science that quantify the relationships between increases in carbon dioxide and global warming, related climate changes, and resulting impacts, such as changes in streamflow, wildfires, crop productivity, extreme hot summers, and sea level rise. One way to inform these choices is to consider the projected climate changes and impacts that would occur if greenhouse gases in the atmosphere were stabilized at a particular concentration level. The book quantifies the outcomes of different stabilization targets for greenhouse gas concentrations using analyses and information drawn from the scientific literature. Although it does not recommend or justify any particular stabilization target, it does provide important scientific insights about the relationships among emissions, greenhouse gas concentrations, temperatures, and impacts. Climate Stabilization Targets emphasizes the importance of 21st century choices regarding long-term climate stabilization. It is a useful resource for scientists, educators and policy makers, among others.
Download or read book Sensitivities of Deep ocean Heat Uptake and Heat Content to Surface Fluxes and Subgrid scale Parameters in an Ocean GCM with Idealized Geometry written by Boyin Huang and published by . This book was released on 2002 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sensitivities of the net heat flux into the deep-ocean (Qnet) and of the deep-ocean heat content (DOC) below 700 m are studied using an ocean general circulation model and its adjoint. Both are found to have very similar sensitivities. The sensitivity to the surface freshwater flux (E-P-R) is positive in the Atlantic, but negative in the Pacific and Southern Ocean. A positive sensitivity to the downward net surface heat flux is found only in the North Atlantic north of 40ʻN and the Southern Ocean. The diapycnal diffusivity of temperature affects Qnet and DOC positively in a large area of the tropics and subtropics in both the Pacific and Atlantic Ocean. The isopycnal diffusivity contributes to Qnet and DOC mainly in the Southern Ocean. Detailed analysis indicates that the surface freshwater flux affects Qnet and DOC by changing vertical velocity, temperature stratification, and overturning circulation. The downward net surface heat flux appears to increase Qnet and DOC by strengthening vertical advection and isopycnal mixing. The contribution of isopycnal diffusivity to Qnet and DOC is largely associated with the vertical heat flux due to isopycnal mixing. Similarly, the diapycnal diffusivity of temperature modulates Qnet and DOC through the downward heat flux due to diapycnal diffusion. The uncertainties of Qnet and DOC are estimated based on the sensitivities and error bars of observed surface forcing and oceanic diffusivities. For DOC, they are about 0.7°K (1°K = 3 x 1024 J) for the isopycnal diffusivity, 0.4°K for the diapycnal diffusivity of temperature, 0.3°K for the surface freshwater flux, and 0.1°K for the net surface heat flux and zonal wind stress. Our results suggest that the heat uptake by ocean GCMs in climate experiments is sensitive to the isopycnal diffusivity as well to the diapycnal thermal diffusivity.
Download or read book Climate Change written by The Royal Society and published by National Academies Press. This book was released on 2014-02-26 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate Change: Evidence and Causes is a jointly produced publication of The US National Academy of Sciences and The Royal Society. Written by a UK-US team of leading climate scientists and reviewed by climate scientists and others, the publication is intended as a brief, readable reference document for decision makers, policy makers, educators, and other individuals seeking authoritative information on the some of the questions that continue to be asked. Climate Change makes clear what is well-established and where understanding is still developing. It echoes and builds upon the long history of climate-related work from both national academies, as well as on the newest climate-change assessment from the United Nations' Intergovernmental Panel on Climate Change. It touches on current areas of active debate and ongoing research, such as the link between ocean heat content and the rate of warming.
Download or read book Sustaining Ocean Observations to Understand Future Changes in Earth s Climate written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2017-12-20 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ocean is an integral component of the Earth's climate system. It covers about 70% of the Earth's surface and acts as its primary reservoir of heat and carbon, absorbing over 90% of the surplus heat and about 30% of the carbon dioxide associated with human activities, and receiving close to 100% of fresh water lost from land ice. With the accumulation of greenhouse gases in the atmosphere, notably carbon dioxide from fossil fuel combustion, the Earth's climate is now changing more rapidly than at any time since the advent of human societies. Society will increasingly face complex decisions about how to mitigate the adverse impacts of climate change such as droughts, sea-level rise, ocean acidification, species loss, changes to growing seasons, and stronger and possibly more frequent storms. Observations play a foundational role in documenting the state and variability of components of the climate system and facilitating climate prediction and scenario development. Regular and consistent collection of ocean observations over decades to centuries would monitor the Earth's main reservoirs of heat, carbon dioxide, and water and provides a critical record of long-term change and variability over multiple time scales. Sustained high-quality observations are also needed to test and improve climate models, which provide insights into the future climate system. Sustaining Ocean Observations to Understand Future Changes in Earth's Climate considers processes for identifying priority ocean observations that will improve understanding of the Earth's climate processes, and the challenges associated with sustaining these observations over long timeframes.
Download or read book Assessment of Approaches to Updating the Social Cost of Carbon written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2016-03-26 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: The social cost of carbon (SCC) for a given year is an estimate, in dollars, of the present discounted value of the damage caused by a 1-metric ton increase in CO2 emissions into the atmosphere in that year; or equivalently, the benefits of reducing CO2 emissions by the same amount in that given year. The SCC is intended to provide a comprehensive measure of the monetized value of the net damages from global climate change from an additional unit of CO2, including, but not limited to, changes in net agricultural productivity, energy use, human health effects, and property damages from increased flood risk. Federal agencies use the SCC to value the CO2 emissions impacts of various policies including emission and fuel economy standards for vehicles, regulations of industrial air pollutants from industrial manufacturing, emission standards for power plants and solid waste incineration, and appliance energy efficiency standards. There are significant challenges to estimating a dollar value that reflects all the physical, human, ecological, and economic impacts of climate change. Recognizing that the models and scientific data underlying the SCC estimates evolve and improve over time, the federal government made a commitment to provide regular updates to the estimates. To assist with future revisions of the SCC, the Interagency Working Group on the Social Cost of Carbon (IWG) requested the National Academies of Sciences, Engineering, and Medicine complete a study that assessed the merits and challenges of a limited near-term update to the SCC and of a comprehensive update of the SCC to ensure that the estimates reflect the best available science. This interim report focuses on near-term updates to the SCC estimates.
Download or read book Climate Change Science written by National Research Council and published by National Academies Press. This book was released on 2001-06-28 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: The warming of the Earth has been the subject of intense debate and concern for many scientists, policy-makers, and citizens for at least the past decade. Climate Change Science: An Analysis of Some Key Questions, a new report by a committee of the National Research Council, characterizes the global warming trend over the last 100 years, and examines what may be in store for the 21st century and the extent to which warming may be attributable to human activity.
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 Ocean Circulation and Climate written by Alison M. Macdonald and published by Elsevier Inc. Chapters. This book was released on 2013-10-22 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ability to ascertain the implications of a changing climate are based first and foremost on our understanding the fundamental balances comprising earth’s climate. The global energy budget is integral to this understanding, and the poleward transport of heat by the oceans is an intrinsic component of the energy balance. In this chapter, we look to describe what is presently known about ocean heat transport and its role in the climate system. At the end of the last century, as part of the World Ocean Circulation Experiment (WOCE) and the Joint Global Ocean Flux Study (JGOFS), the ocean-going research community completed a decade-long international effort to explore the ocean through the acquisition of a single consistent and comparable set of high-quality, full-depth observations. This global-scale field campaign was designed to determine the mean steady-state basin-scale circulation and meridional ocean heat transport. At the time, it was recognized that this mean was unlikely to be stationary. It was also understood that patterns of variability that had yet to be measured would influence our eventual understanding of these one-time “synoptic” observations. A decade later, time series of ocean heat transport (from moorings, repeat XBT and CTD lines and profiling floats), although still quite short and either spatially and/or temporally sparse, are now becoming available. The WOCE/JGOFS programs of the 1990s have been extended through large international efforts first by the Climate Variability and Predictability program and now by the Global Ocean Ship-based Hydrographic Investigations Program. Through these newly acquired time series, improvements in analysis techniques, and recent modeling advances, we are beginning to describe ocean heat transport variability and to understand its possible response to and role in climate change. In this chapter, we focus on what has been learnt about ocean heat transport through in situ observations. We include some history, a detailed description of ocean heat transport computation and decomposition, and a discussion of the present state of the science, seeking to measure ocean heat transport variability.
Download or read book Climate Modulations of Air Sea Oxygen Carbon and Heat Exchange written by Yassir Eddebbar and published by . This book was released on 2018 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt: The exchanges of oxygen (O2), carbon dioxide (CO2), and heat across the air-sea interface have broad and profound implications for climate and marine ecosystems. In this thesis, I use observations and models to improve our process understanding of how natural climate variability modulates these exchanges. In chapter 2, I investigate the impacts of El Niño Southern Oscillation (ENSO) on air-sea O2 exchange. I use atmospheric inversions of global, continuous timeseries of atmospheric O2 and CO2 and ocean models to evaluate links between ENSO and air-sea O2 exchange and explore driving mechanisms using ocean and atmospheric models. I find that El Niño events lead to anomalous outgassing of oceanic O2, a response that is driven primarily by changes in the source and intensity of upwelling in the equatorial Pacific. In Chapter 3, I examine the impacts of tropical volcanic eruptions on air-sea exchanges of O2, CO2 and heat using coupled model simulations and observations. Here, I find that volcanic events lead to substantial oceanic heat loss that is accompanied by large oceanic uptakes of oxygen and carbon. An El Niño-like pattern emerges following tropical eruptions and plays a major role in modulating the oceanic response to volcanic forcing. In Chapter 4, I explore the use of global continuous atmospheric measurements of O2 and CO2 to evaluate claims that enhanced ocean heat uptake caused the recent global surface warming hiatus, based on a potential negative relationship between air-sea heat and gas exchange. Here, I find that the relationship between air-sea oxygen, carbon and heat fluxes due to natural variability is complex; air-sea heat and O2 exchange are positively coupled in the tropical Pacific, but are negatively coupled at higher latitudes. This spatially distinct relationship complicates the attribution of observed decadal trends in atmospheric O2 and CO2 to changes in ocean heat uptake, but may present an opporunitity to develop regional constraints. Collectively, the results of this thesis contribute to a quantitative and mechanistic framework enabling interpretation of O2 and CO2 trends in the context of ongoing ocean warming and deoxygenation.
Download or read book Ocean Mixing written by Michael Meredith and published by Elsevier. This book was released on 2021-09-16 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ocean Mixing: Drivers, Mechanisms and Impacts presents a broad panorama of one of the most rapidly-developing areas of marine science. It highlights the state-of-the-art concerning knowledge of the causes of ocean mixing, and a perspective on the implications for ocean circulation, climate, biogeochemistry and the marine ecosystem. This edited volume places a particular emphasis on elucidating the key future questions relating to ocean mixing, and emerging ideas and activities to address them, including innovative technology developments and advances in methodology. Ocean Mixing is a key reference for those entering the field, and for those seeking a comprehensive overview of how the key current issues are being addressed and what the priorities for future research are. Each chapter is written by established leaders in ocean mixing research; the volume is thus suitable for those seeking specific detailed information on sub-topics, as well as those seeking a broad synopsis of current understanding. It provides useful ammunition for those pursuing funding for specific future research campaigns, by being an authoritative source concerning key scientific goals in the short, medium and long term. Additionally, the chapters contain bespoke and informative graphics that can be used in teaching and science communication to convey the complex concepts and phenomena in easily accessible ways. - Presents a coherent overview of the state-of-the-art research concerning ocean mixing - Provides an in-depth discussion of how ocean mixing impacts all scales of the planetary system - Includes elucidation of the grand challenges in ocean mixing, and how they might be addressed
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 NASA Reference Publication written by and published by . This book was released on 1977 with total page 818 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Long Term Climate Monitoring by the Global Climate Observing System written by Thomas R. Karl and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 513 pages. Available in PDF, EPUB and Kindle. Book excerpt: Is the climate warming? Is the hydrological cycle intensifying? Is the climate becoming more variable or extreme? Is the chemical composition of the atmosphere changing? Is the solar irradiance constant? Answers to these questions are fundamental to understanding, predicting, and assessing climate on time scales ranging from weeks to a century. Atmospheric, oceanic, and environmental scientists have primarily relied on an ad-hoc collection of disparate environmental observational and data management systems to address these problems. But these systems were not designed to measure climate variations and, as a result, changes and variations of the earth system during the instrumental climate record is far from unequivocal. This book develops a framework from which a Global Climate Observing System, currently being discussed in international forums, can be implemented to monitor changes and variations of climate. Audience: Administrators, policy makers, professionals, graduate students, and others interested in learning how we can ensure a long-term climate record for application to national economic development and understanding ecosystem dynamics.
Download or read book Effects of Variable Wind Stress on Ocean Heat Content written by Kelly Klima and published by . This book was released on 2008 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ocean heat content change (ocean heat uptake) has an important role in variability of the Earth's heat balance. The understanding of which methods and physical processes control ocean heat uptake needs improvement in order to better understand variability in the Earth's heat balance, improve the simulation of present-day climate, and improve the understanding and projection of future climate. Wind stress can play a strong role in ocean heat uptake on all timescales, and short timescale wind stress effects have not been well studied in the literature. This study for the first time examines short timescale spatial and temporal patterns of global variable wind stress datasets in a coupled atmosphere-ocean climate model. NCEP wind stress dataset was characterized for years 1978 to 2007. NCEP monthly means and monthly standard deviations are of the same magnitude, and strong wind stress events (tropical cyclones) are observed. A variety of metrics cannot reliably identify significant timescales or spatial patterns of the variable wind stress. Model behavior with and without variable wind stress is studied. This study uses the MIT IGSM, a 4°x 11 vertical level zonal atmospheric model coupled at the four hour timestep to a 20x2.50x22 vertical level ocean model with the K profile parameterization. Ocean properties in a no forcing scenario are sensitive to variable wind stress. In a weak forcing scenario (observed forcing over the last century), ocean properties are sensitive to variable wind stress, and internal modes of variability (such as an equatorial Pacific oscillation) are observed. In a global warming scenario (1% CO2 rise per year or a business as usual emissions scenario), the strong forcing overwhelms the more subtle responses due to the differences in variable wind stress forcing. Regardless of forcing, the high frequency variable wind stress (monthly or less) variable wind stresses can force a low frequency response. Hence the major source of annual variability of the MOC in this coarse resolution model is surface wind variability.
