Download or read book The Impact of Saharan Dust on the North Atlantic Circulation written by Nidia Martínez Avellaneda and published by GRIN Verlag. This book was released on 2010-03-05 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: Doctoral Thesis / Dissertation from the year 2010 in the subject Geography / Earth Science - Meteorology, Aeronomy, Climatology, grade: Sehr Gut, University of Hamburg (Institute of Oceanography), language: English, abstract: The erosion of Saharan soil is the World's largest annual source of mineral dust aerosols, resulting in a deposition of more than 40% of the global atmospheric dust into the North Atlantic (NA). By changing the atmospheric opacity, mineral dust can alter the shortwave radiative forcing at the surface of the ocean, altering the ocean mixed layer heat budget and therefore affecting the sea surface temperature (SST). Moreover, changes of the total amount of energy received at the ocean surface have an impact on the ocean circulation. In this thesis we combine several satellite observations, in-situ radiation measurements, a 1D mixed layer model of the ocean, and various versions of a 3D general ocean circulation model, to study the impact of Saharan dust on the circulation of the NA. A buoyancy source generated by realistic dust-induced shortwave flux anomalies is imposed in the eastern NA and the differences between this simulation and an unperturbed one are investigated in terms of the ocean dynamical adjustment and changes in the Atlantic Meridional Overturning Circulation (AMOC). A joint analysis of aerosol optical depth retrievals from the MODIS sensor and SST from the TMI sensor for the period 2000-2006 shows a decrease in SST of 0.2° to 0.4°C simultaneously with, or shortly after, strong dust outbreaks, which is consistent with an independent estimate of SST decrease simulated by a local 1D mixed layer model. A comparison between observed TMI SST fields and simulated SSTs with an eddy-permitting model of the NA suggests a local cooling of about 0.5°C on sub-seasonal to interannual time-scales. Results of the 3D simulations show that an advection of the ocean properties ocurs in response to the buoyancy source in the eastern subtropical NA. The eddies and baroclinic instabilities present in the ocean advect the signal towards the west and back towards the east. Once they have reached the African coast, they trigger westward propagating Rossby waves. The time-mean differences of AMOC between the perturbed and unperturbed simulations show an increased meridional transport at 38°N and 43°N of 0.55 and 0.45 Sv, respectively, and a decreased AMOC at 40°N and 45°N of 0.2 Sv. We conclude that the effect of Saharan dust should be incorporated in ocean numerical simulations, specially under the frame of climate change studies when a changing dust load of the atmosphere in response to a changing climate could be possible.
Download or read book Saharan Dust Deposition in the Equatorial North Atlantic Ocean and Its Impact on Particle Export Fluxes written by Laura Franziska Korte and published by . This book was released on 2018 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Impact of Desert Dust Across the Mediterranean written by Stefano Guerzoni and published by Springer Science & Business Media. This book was released on 1996-11-30 with total page 415 pages. Available in PDF, EPUB and Kindle. Book excerpt: The atmosphere is an important pathway for the transport of continentally-derived material to the oceans. In this respect the Mediterranean Sea is of special importance because its atmosphere receives inputs of anthropogenic aerosols from the north and desert- derived Saharan dusts from the south. The dusts, much of which is transported in the form of seasonal `pulses', have important effects on climate, marine chemistry and sedimentation in the Mediterranean Sea. This volume brings together reviews and specific-topic papers on the following aspects of Saharan dust transport to the Mediterranean Sea: (i) the modelling of Saharan dust transport, (ii) the chemistry and mineralogy of the dusts and their effect on precipitation, (iii) the contribution of the dusts to marine sedimentation, (iv) the aerobiology of the dusts, and (v) climatic implications of Saharan dust transport. The volume is aimed at students and researchers with an interest in the climate, biogeochemistry and geology of the Mediterranean Sea.
Download or read book Atmospheric Aerosols written by Guillaume A. D'Almeida and published by A. Deepak Publishing. This book was released on 1991 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Saharan Dust Transport Over Ther North Atlantic Ocean written by and published by . This book was released on 1981 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Paleoclimatology and Paleometeorology Modern and Past Patterns of Global Atmospheric Transport written by Margaret Leinen and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 904 pages. Available in PDF, EPUB and Kindle. Book excerpt: The NATO Advanced Research Workshop on "Paleoclimatology and Paleometeorology: Modem and Past Patterns of Global Atmospheric Transport" (held at Oracle, Arizona, USA from November 17-19, 1987) brought together atmospheric chemists, physicists, and meteorologists who study the origin and transport of modem-day mineral and biological aerosols with geologists and paleobotanists who study the sedimentary record of eolian and hydrologic processes along with modelers who study and conceptualize the processes influencing atmospheric transport at present and in the past. Presentations at the workshop provided a guide to our present knowledge of the entire spectrum of processes and phenomena important to the generation, transport, and deposition of eolian terrigenous material that ultimately becomes part of the geologic record and the modeling techniques that used to represent these processes. The presenta tions on the geologic record of eolian deposition documented our present understanding of the na~e and causes of climate change on time scales of the last glacial ages (tens of thousands of years) to time scales over which the arrangement of continents, mountains, and oceans has changed sub stantially (tens of millions of years). There has been a growing recognition of the importance of global climatic changes to the future well-being of humanity. In particular, the climatic response to human alterations to the earth's surface and chemical composition has led to concern over the agricultural, ecological, and societal impacts of such potential global changes.
Download or read book Hydrological Socioeconomic and Ecological Impacts of the North Atlantic Oscillation in the Mediterranean Region written by Sergio M. Vicente-Serrano and published by Springer Science & Business Media. This book was released on 2011-06-17 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Mediterranean basin represents one of the most important “hot spots” of climate change in the world, with recent trends towards a hotter and drier climate being related to changes in atmospheric circulation patterns. Such changes can have significant impacts in the climate of this region but also on the natural environment and several socioeconomic activities. Among these patterns, the North Atlantic Oscillation (NAO) is one of the main forcing factors in the region with impact on extreme events such as droughts, severe precipitations or heat and cold waves, the availability of water resources, the ecological dynamics, the quality and quantity of crops, the migration and welfare of animal populations, the fisheries dynamics, the triggering of landslides and the air pollution and human health, among others. The aim of Hydrological, Socioeconomic and Ecological Impacts of the North Atlantic Oscillation in the Mediterranean Region, is to serve as an updated reference text that covers the wide range of evidences on the NAO impacts in the Mediterranean regions and from a multidisciplinary perspective. This volume constitutes a unique document to present the state of the art of the numerous studies undertaken on the hydrological, socioeconomic and ecological impact of the NAO, collecting the expertise of researchers from several complementary earth science fields (geography, hydrology, remote-sensing, climatology, agriculture, energy), but that have been lacking a common ground.
Download or read book Mineral Dust written by Peter Knippertz and published by Springer. This book was released on 2014-09-01 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents state-of-the-art research about mineral dust, including results from field campaigns, satellite observations, laboratory studies, computer modelling and theoretical studies. Dust research is a new, dynamic and fast-growing area of science and due to its multiple roles in the Earth system, dust has become a fascinating topic for many scientific disciplines. Aspects of dust research covered in this book reach from timescales of minutes (as with dust devils, cloud processes and radiation) to millennia (as with loess formation and oceanic sediments), making dust both a player and recorder of environmental change. The book is structured in four main parts that explore characteristics of dust, the global dust cycle, impacts of dust on the Earth system, and dust as a climate indicator. The chapters in these parts provide a comprehensive, detailed overview of this highly interdisciplinary subject. The contributions presented here cover dust from source to sink and describe all the processes dust particles undergo while travelling through the atmosphere. Chapters explore how dust is lifted and transported, how it affects radiation, clouds, regional circulations, precipitation and chemical processes in the atmosphere and how it deteriorates air quality. The book explores how dust is removed from the atmosphere by gravitational settling, turbulence or precipitation, how iron contained in dust fertilizes terrestrial and marine ecosystems, and about the role that dust plays in human health. We learn how dust is observed, simulated using computer models and forecast. The book also details the role of dust deposits for climate reconstructions. Scientific observations and results are presented, along with numerous illustrations. This work has an interdisciplinary appeal and will engage scholars in geology, geography, chemistry, meteorology and physics, amongst others with an interest in the Earth system and environmental change. body>
Download or read book The Impact of Saharan Dust on Atlantic Convective Systems written by Jianyu Liang and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tropical weather systems such as the African Easterly Waves (AEWs), the African Easterly Jet (AEJ), and tropical cyclones usually interact with the Saharan Air Layer (SAL) and mineral dust aerosols embedded in the SAL. Previous studies have debates about the strength and even the direction of the impact from the dust and SAL on the development of the tropical systems. In this study, the sole impact from the dust on a hurricane is quantified using carefully designed numerical experiments. Hurricane Earl (2010) was originated from an AEW disturbance over Africa. It was influenced by the dusty SAL especially in its early development stage. We conduct numerical experiments using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) to simulate Hurricane Earl (2010) starting from a weak disturbance. Experiments with 36-km resolution show that without moist convection, dust slightly weakens the low-pressure system in North Africa by cooling the atmosphere. This scenario mainly results from a reduction of the boundary layer heating during the daytime and from the enhancement of the outgoing longwave radiative cooling during the nighttime. The zonal mean of the AEJ is intensified slightly (less than 1m/s) in its southern part and weakened in its northern part when dust is included in the model. Adding dust weakens the AEWs at 850 hPa and 600 hPa levels and the tropical cyclone. High-resolution (4-km) cloud-resolving model experiments show that dust deepens the system slightly but does not affect the track. In the tropical low stage, dust increases the low-level cloud at 1-2 km height. It reduces rainfall in the outer edge of SAL region between 250 km to 350 km radii while it increases rainfall in the inner edge at around 200 km. The associated latent heat release shifts the updraft radially inward. The dynamical consequence is the acceleration of the tangential wind and the mid-level circulation. In the tropical depression stage, adding dust increases the number of cloud droplets in most of the regions and enhances the convection around the center, which generates more ice, snow, and rain. Overall, the impact of dust aerosols on Earl is small, the center minimum sea-level pressures only differ by less than 1 hPa at the end of the simulation. This suggests that pure meteorological model may be sufficiently accurate to forecast hurricanes if the dynamical and thermodynamical features of the SAL are properly described. In order to predict aerosols, one can use a simple chemistry model such as GOCART which only has aerosol direct effects. Using the Ensemble Kalman Filter (EnKF) to assimilate conventional observations and MODIS aerosol optical depth (AOD) data, both forecasts of the track of the storm and the aerosol can be improved.
Download or read book Desert Dust in the Global System written by Andrew S. Goudie and published by Springer Science & Business Media. This book was released on 2006-09-05 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dust storms are a vital component of the environment. This book explores and summarises recent research on where dust storms originate, why dust storms are generated, where dust is transported and deposited, the nature of dust deposits and the changing frequency of dust storms over a range of time-scales. It is the first global study of causes and effects of dust storms, which are one of the increasing nature catastrophes.
Download or read book The Impact of Desert Dust Across the Mediterranean written by Stefano Guerzoni and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: The atmosphere is an important pathway for the transport of continentally-derived material to the oceans. In this respect the Mediterranean Sea is of special importance because its atmosphere receives inputs of anthropogenic aerosols from the north and desert- derived Saharan dusts from the south. The dusts, much of which is transported in the form of seasonal `pulses', have important effects on climate, marine chemistry and sedimentation in the Mediterranean Sea. This volume brings together reviews and specific-topic papers on the following aspects of Saharan dust transport to the Mediterranean Sea: (i) the modelling of Saharan dust transport, (ii) the chemistry and mineralogy of the dusts and their effect on precipitation, (iii) the contribution of the dusts to marine sedimentation, (iv) the aerobiology of the dusts, and (v) climatic implications of Saharan dust transport. The volume is aimed at students and researchers with an interest in the climate, biogeochemistry and geology of the Mediterranean Sea.
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 Linking Climate Change to Land Surface Change written by S.J. McLaren and published by Springer Science & Business Media. This book was released on 2000-11-30 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our views and understanding of variations in climate, geomorphological processes and the interrelationships that exist between climatic changes and land surface changes, both now and in the past, have developed greatly over the last decade. This book aims to encapsulate some of these recent advances and focuses on the integration of research that has been conducted by geomorphologists and climatologists on linking climate and land surface changes. This book is divided into two main parts: Section A incorporates research that has concentrated on short-term variations in climate, whilst Section B looks at some of the work on long-term climate variability. The volume concludes with a summary chapter that brings together the various ideas that have been presented in this work and other recent research in this general field. This text will be of interest to upper level students of geomorphology, Quaternary studies, climatology, earth sciences, and environmental studies. It will also be of use to researchers in these fields.
Download or read book Particle Flux in the Ocean written by Venugopalan Ittekkot and published by . This book was released on 1996-08-22 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: Particle flux in the ocean is a major segment linking terrestrial, meteorological and surface ocean processes with those operating in the deep sea. This book describes how wind speeds and dust fallout over the oceans, volcanic eruptions and freshwater and suspended matter inputs from rivers influence material flux to the ocean's interior and its variability. It explores the potential use of deep ocean particle flux studies to record and monitor climatic and environmental changes.
Download or read book Mediterranean Climate Variability written by P. Lionello and published by Elsevier. This book was released on 2006-08-22 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: This multi-authored book provides an updated description of climate variability in the Mediterranean basin, focusing on decadal and centennial time scales and on the results available on the impact of future emission scenarios at regional scale. The authors describs both local physical processes responsible for these variability - such as changes in the surface properties and land use- and globalprocesses - such as changes in the large scale atmospheric circulation associated to global warming, NAO, tropical monsoon and ENSO. Regional climate change issues are also addressed. Mediterranean Climate Variability aims to review the research on this region and to provide at the same time both an introduction and a reference for researchers. It covers topics typical of Climatology, Climate history, Meteorology, Oceanography, Environmental Science but the information here provided would also be useful for research in agriculture, social and economic studies. It is addressed to scientists and students interested in the Mediterranean climate and environment. Some topics have interesting connections to nearby regions: Northern Atlantic, West Africa, central and Eastern Europe. Each chapter will contain a summary meant to provide information to policy makers, researchers from other fields, and in general to a wide audience without a technical expertise on climate. * Provides an updated analysis of the Mediterranean climate features and guidelines for future research * Considers both oceanographic and atmospheric aspects * Analyzes the Mediterranean climate in a global perspective
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.
