Download or read book Dissolved Organic Matter Discharge in the Six Largest Arctic Rivers chemical Composition and Seasonal Variability written by Amanda J. Rinehart and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The vulnerability of the Arctic to climate change has been realized due to disproportionately large increases in surface air temperatures which are not uniformly distributed over the seasonal cycle. Effects of this temperature shift are widespread in the Arctic but likely include changes to the hydrological cycle and permafrost thaw, which have implications for the mobilization of organic carbon into rivers. The focus of this research was to describe the seasonal variability of the chemical composition of dissolved organic matter (DOM) in the six largest Arctic rivers (Yukon, Mackenzie, Ob, Yenisei, Lena and Kolyma) using optical properties (UV-Vis Absorbance and Fluorescence) and lignin phenol analysis. We also investigated differences between rivers and how watershed characteristics influence DOM composition. Dissolved organic carbon (DOC) concentrations followed the hydrograph with highest concentrations measured during peak river flow. The chemical composition of peak-flow DOM indicates a dominance of freshly leached material with elevated aromaticity, larger molecular weight, and elevated lignin yields relative to base-flow DOM. During peak flow, soils in the watershed are still frozen and snowmelt water follows a lateral flow path to the river channels. As the soils thaw, surface water penetrates deeper into the soil horizons leading to lower DOC concentrations and likely altered composition of DOM due to sorption and microbial degradation processes. The six rivers studied here shared a similar seasonal pattern and chemical composition. There were, however, large differences between rivers in terms of total carbon discharge reflecting the differences in watershed characteristics such as climate, catchment size, river discharge, soil types, and permafrost distribution. The large rivers (Lena, Yenisei), with a greater proportion of permafrost, exported the greatest amount of carbon. The Kolyma and Mackenzie exported the smallest amount of carbon annually, however, the discharge weighted mean DOC concentration was almost 2-fold higher in the Kolyma, again, indicating the importance of continuous permafrost. The quality and quantity of DOM mobilized into Arctic rivers appears to depend on the relative importance of surface run-off and extent of soil percolation. The relative importance of these is ultimately determined by watershed characteristics.

Download or read book Dissolved Organic Matter in Major Rivers Across the Pan Arctic from Remote Sensing written by Claire Genevieve Griffin and published by . This book was released on 2016 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate-driven changes in Arctic hydrology and biogeochemistry are impacting transport of water and water-borne material from land to ocean. This includes massive amounts of organic matter that are mobilized and exported from the pan-Arctic watershed via rivers each year. Dissolved organic matter (DOM), an important part of the Arctic carbon cycle, has received growing attention in recent years, yet long-term studies of riverine biogeochemistry remain rare in these remote and logistically challenging regions. Remote sensing of chromophoric dissolved organic matter (CDOM, the portion of the DOM pool that absorbs light), provides a unique opportunity to investigate variations in DOM in major Arctic rivers over multiple decades. CDOM is a useful proxy for dissolved organic carbon (DOC) and is essential to photochemical processes in surface waters. This dissertation presents the development and application of remote sensing regression models across six major Arctic rivers: the Kolyma, Lena, Mackenzie, Ob’, Yenisey and Yukon. Frozen, archival samples of CDOM were used to develop calibration data for remote sensing regressions. Remote sensing methods estimated CDOM with R2 of 85% across all rivers, although individual rivers varied in their predictability in association with sediment loading and hydrology. As with previous studies of Arctic systems, concentrations and export of CDOM and DOC were highest during spring freshet in most of these rivers. Interannual variability in DOM export may be linked to the Arctic Oscillation. Within the Mackenzie, Ob’, and Yenisey rivers, observations of DOM concentration and export were extended back to the 1980s, the first known empirical records of this length for Arctic rivers that span both continents. Although no pan-Arctic trends in CDOM export were detected, there is some evidence of long-term changes in riverine DOM. For example, discharge-specific CDOM concentrations decreased in the Yenisey River and increased in the Ob’ River. Additionally, CDOM concentrations increased over the past ~30 years within the Mackenzie River. This dissertation also includes results from experiments used to quantify the effects of cryopreservation on CDOM analyses, and potential approaches for ameliorating freezing effects. These experiments showed that freezing for preservation introduces some error into CDOM measurements, although these effects vary between river systems. Sonication may improve CDOM measurements in some river systems, but the effects of both cryopreservation and sonication should be quantified on a case-by-case basis. Overall, this dissertation work demonstrates that 1) remote sensing of CDOM is a viable tool for tracking fluvial DOM in the major Arctic rivers, 2) only the Mackenzie River showed significant increases in CDOM concentration from the 1980s to present and 3) long-term changes in discharge-specific CDOM concentrations have occurred in the Yenisey and Ob’ rivers. These long-term trends cannot be definitively linked to climate change, but may be related to effects of warming on permafrost, hydrology, and biogeochemistry within in Arctic watersheds with consequences for carbon cycling on both regional and global scales.

Download or read book Climatic Change and Global Warming of Inland Waters written by Charles R. Goldman and published by John Wiley & Sons. This book was released on 2012-11-20 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: Effects of global warming on the physical, chemical, ecological structure and function and biodiversity of freshwater ecosystems are not well understood and there are many opinions on how to adapt aquatic environments to global warming in order to minimize the negative effects of climate change. Climatic Change and Global Warming of Inland Waters presents a synthesis of the latest research on a whole range of inland water habitats – lakes, running water, wetlands – and offers novel and timely suggestions for future research, monitoring and adaptation strategies. A global approach, offered in this book, encompasses systems from the arctic to the Antarctic, including warm-water systems in the tropics and subtropics and presents a unique and useful source for all those looking for contemporary case studies and presentation of the latest research findings and discussion of mitigation and adaptation throughout the world. Edited by three of the leading limnologists in the field this book represents the latest developments with a focus not only on the impact of climate change on freshwater ecosystems but also offers a framework and suggestions for future management strategies and how these can be implemented in the future. Limnologists, Climate change biologists, fresh water ecologists, palaeoclimatologists and students taking relevant courses within the earth and environmental sciences will find this book invaluable. The book will also be of interest to planners, catchment managers and engineers looking for solutions to broader environmental problems but who need to consider freshwater ecology.

Download or read book Influence of Climate Change on the Changing Arctic and Sub Arctic Conditions written by Jacques Nihoul and published by Springer. This book was released on 2009-01-25 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: The current warming trends in the Arctic may shove the Arctic system into a seasonally ice-free state not seen for more than one million years. The melting is accelerating, and researchers were unable to identify natural processes that might slow the deicing of the Arctic. Such substantial additional melting of Arctic and Antarctic glaciers and ice sheets would raise the sea level worldwide, flooding the coastal areas where many of the world's population lives. Studies, led by scientists at the National Center for Atmospheric Research (NCAR) and the University of Arizona, show that greenhouse gas increases over the next century could warm the Arctic by 3-5°C in summertime. Thus, Arctic summers by 2100 may be as warm as they were nearly 130,000 years ago, when sea levels eventually rose up to 6 m higher than today.

Download or read book Aquatic Organic Matter Fluorescence written by Paula G. Coble and published by Cambridge University Press. This book was released on 2014-07-14 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: A core text on principles, laboratory/field methodologies, and data interpretation for fluorescence applications in aquatic science, for advanced students and researchers.

Download or read book The Organic Carbon Cycle in the Arctic Ocean written by Rüdiger Stein and published by Springer Science & Business Media. This book was released on 2011-06-27 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: The flux, preservation, and accumulation of organic carbon in marine systems are controlled by various mechanisms including primary p- duction of the surface water, supply of terrigenous organic matter from the surrounding continents, biogeochemical processes in the water column and at the seafloor, and sedimentation rate. For the world's oceans, phytoplankton productivity is by far the largest organic carbon 9 source, estimated to be about 30 to 50 Gt (10 tonnes) per year (Berger et al. 1989; Hedges and Keil 1995). By comparison, rivers contribute -1 about 0. 15 to 0. 23 Gt y of particulate organi.

Download or read book Biogeochemical Dynamics at Major River Coastal Interfaces written by Thomas Bianchi and published by Cambridge University Press. This book was released on 2014 with total page 673 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive, state-of-the-art synthesis of biogeochemical dynamics and the impact of human alterations at major river-coastal interfaces for advanced students and researchers.

Download or read book Linking Optical and Chemical Properties of Dissolved Organic Matter in Natural Waters written by Christopher L. Osburn and published by Frontiers Media SA. This book was released on 2017-01-17 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: A substantial increase in the number of studies using the optical properties (absorbance and fluorescence) of dissolved organic matter (DOM) as a proxy for its chemical properties in estuaries and the coastal and open ocean has occurred during the last decade. We are making progress on finding the actual chemical compounds or phenomena responsible for DOM’s optical properties. Ultrahigh resolution mass spectrometry, in particular, has made important progress in making the key connections between optics and chemistry. But serious questions remain and the last major special issue on DOM optics and chemistry occurred nearly 10 years ago. Controversies remain from the non-specific optical properties of DOM that are not linked to discrete sources, and sometimes provide conflicting information. The use of optics, which is relatively easier to employ in synoptic and high resolution sampling to determine chemistry, is a critical connection to make and can lead to major advances in our understanding of organic matter cycling in all aquatic ecosystems. The contentions and controversies raised by our poor understanding of the linkages between optics and chemistry of DOM are bottlenecks that need to be addressed and overcome.

Download or read book Biogeochemistry of Marine Dissolved Organic Matter written by Dennis A. Hansell and published by Academic Press. This book was released on 2014-10-02 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine dissolved organic matter (DOM) is a complex mixture of molecules found throughout the world's oceans. It plays a key role in the export, distribution, and sequestration of carbon in the oceanic water column, posited to be a source of atmospheric climate regulation. Biogeochemistry of Marine Dissolved Organic Matter, Second Edition, focuses on the chemical constituents of DOM and its biogeochemical, biological, and ecological significance in the global ocean, and provides a single, unique source for the references, information, and informed judgments of the community of marine biogeochemists. Presented by some of the world's leading scientists, this revised edition reports on the major advances in this area and includes new chapters covering the role of DOM in ancient ocean carbon cycles, the long term stability of marine DOM, the biophysical dynamics of DOM, fluvial DOM qualities and fate, and the Mediterranean Sea. Biogeochemistry of Marine Dissolved Organic Matter, Second Edition, is an extremely useful resource that helps people interested in the largest pool of active carbon on the planet (DOC) get a firm grounding on the general paradigms and many of the relevant references on this topic. Features up-to-date knowledge of DOM, including five new chapters The only published work to synthesize recent research on dissolved organic carbon in the Mediterranean Sea Includes chapters that address inputs from freshwater terrestrial DOM

Download or read book Water Quality Assessments written by Deborah V Chapman and published by CRC Press. This book was released on 1996-08-22 with total page 658 pages. Available in PDF, EPUB and Kindle. Book excerpt: This guidebook, now thoroughly updated and revised in its second edition, gives comprehensive advice on the designing and setting up of monitoring programmes for the purpose of providing valid data for water quality assessments in all types of freshwater bodies. It is clearly and concisely written in order to provide the essential information for all agencies and individuals responsible for the water quality.

Download or read book Second Assessment of Climate Change for the Baltic Sea Basin written by The BACC II Author Team and published by Springer. This book was released on 2015-04-03 with total page 515 pages. Available in PDF, EPUB and Kindle. Book excerpt: ​This book is an update of the first BACC assessment, published in 2008. It offers new and updated scientific findings in regional climate research for the Baltic Sea basin. These include climate changes since the last glaciation (approx. 12,000 years ago), changes in the recent past (the last 200 years), climate projections up until 2100 using state-of-the-art regional climate models and an assessment of climate-change impacts on terrestrial, freshwater and marine ecosystems. There are dedicated new chapters on sea-level rise, coastal erosion and impacts on urban areas. A new set of chapters deals with possible causes of regional climate change along with the global effects of increased greenhouse gas concentrations, namely atmospheric aerosols and land-cover change. The evidence collected and presented in this book shows that the regional climate has already started to change and this is expected to continue. Projections of potential future climates show that the region will probably become considerably warmer and wetter in some parts, but dryer in others. Terrestrial and aquatic ecosystems have already shown adjustments to increased temperatures and are expected to undergo further changes in the near future. The BACC II Author Team consists of 141 scientists from 12 countries, covering various disciplines related to climate research and related impacts. BACC II is a project of the Baltic Earth research network and contributes to the World Climate Research Programme.

Download or read book Chemical Biomarkers in Aquatic Ecosystems written by Thomas S. Bianchi and published by Princeton University Press. This book was released on 2011-02-28 with total page 417 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook provides a unique and thorough look at the application of chemical biomarkers to aquatic ecosystems. Defining a chemical biomarker as a compound that can be linked to particular sources of organic matter identified in the sediment record, the book indicates that the application of these biomarkers for an understanding of aquatic ecosystems consists of a biogeochemical approach that has been quite successful but underused. This book offers a wide-ranging guide to the broad diversity of these chemical biomarkers, is the first to be structured around the compounds themselves, and examines them in a connected and comprehensive way. This timely book is appropriate for advanced undergraduate and graduate students seeking training in this area; researchers in biochemistry, organic geochemistry, and biogeochemistry; researchers working on aspects of organic cycling in aquatic ecosystems; and paleoceanographers, petroleum geologists, and ecologists. Provides a guide to the broad diversity of chemical biomarkers in aquatic environments The first textbook to be structured around the compounds themselves Describes the structure, biochemical synthesis, analysis, and reactivity of each class of biomarkers Offers a selection of relevant applications to aquatic systems, including lakes, rivers, estuaries, oceans, and paleoenvironments Demonstrates the utility of using organic molecules as tracers of processes occurring in aquatic ecosystems, both modern and ancient

Download or read book Deep Carbon written by Beth N. Orcutt and published by Cambridge University Press. This book was released on 2019-10-17 with total page 687 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive guide to carbon inside Earth - its quantities, movements, forms, origins, changes over time and impact on planetary processes. This title is also available as Open Access on Cambridge Core.

Download or read book Submarine Groundwater Discharge Impacts on Coastal Ecosystem by Hidden Water and Dissolved Materials written by Makoto Taniguchi and published by Frontiers Media SA. This book was released on 2021-03-03 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Land Ocean Systems in the Siberian Arctic written by Heidemarie Kassens and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 850 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Arctic and its surrounding marginal seas are considered some of the most sensitive elements of the global environment, which may respond rapidly to climate change. However, due to various reasons, our knowledge of the processes which drive the Arctic system today and in the past is still relatively sparse. Based on a multidisciplinary approach, German and Russian scientists describe in this book the natural paleorecords and modern data which were collected over the past 6 years. These marine and terrestrial datasets provide important new insights into the causes, impacts, and feedback mechanisms of this extreme Arctic environment.

Download or read book Arctic Hydrology Permafrost and Ecosystems written by Daqing Yang and published by Springer Nature. This book was released on 2020-08-28 with total page 914 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive, up-to-date assessment of the key terrestrial components of the Arctic system, i.e., its hydrology, permafrost, and ecology, drawing on the latest research results from across the circumpolar regions. The Arctic is an integrated system, the elements of which are closely linked by the atmosphere, ocean, and land. Using an integrated system approach, the book’s 30 chapters, written by a diverse team of leading scholars, carefully examine Arctic climate variability/change, large river hydrology, lakes and wetlands, snow cover and ice processes, permafrost characteristics, vegetation/landscape changes, and the future trajectory of Arctic system evolution. The discussions cover the fundamental features of and processes in the Arctic system, with a special focus on critical knowledge gaps, i.e., the interactions and feedbacks between water, permafrost, and ecosystem, such as snow pack and permafrost changes and their impacts on basin hydrology and ecology, river flow, geochemistry, and energy fluxes to the Arctic Ocean, and the structure and function of the Arctic ecosystem in response to past/future changes in climate, hydrology, and permafrost conditions. Given its scope, the book offers a valuable resource for researchers, graduate students, environmentalists, managers, and administrators who are concerned with the northern environment and resources.

Download or read book River Discharge to the Coastal Ocean written by John D. Milliman and published by Cambridge University Press. This book was released on 2013-03-28 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rivers provide the primary link between land and sea. Utilizing the world's largest database, this book presents a detailed analysis and synthesis of the processes affecting fluvial discharge of water, sediment and dissolved solids. The ways in which climatic variation, episodic events, and anthropogenic activities - past, present and future - affect the quantity and quality of river discharge are discussed in the final two chapters. The book contains 26 tables and more than 165 figures - many in full color - including global and regional maps. The book's extensive appendix presents the 1534-river database as a series of 44 tables and 132 maps that provide quantitative data regarding the discharge of water, sediment and dissolved solids. The complete database is also presented within a GIS-based package available online at www.cambridge.org/milliman. River Discharge to the Coastal Ocean provides an invaluable resource for researchers, professionals and graduate students in hydrology, oceanography, geology, geomorphology and environmental policy.