The Organic Carbon Cycle In The Arctic Ocean

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.

This study analyzes carbon-cycle conditions controlling the state of the Arctic ecosystem and their seasonal variations. Territory covered includes the Barents, White, Kara, Laptev, East-Siberian and Chukchi Seas, considering inter-correlations between sources of organic carbon, their fluxes, recycling and burial in bottom sediments. All biological communities (phythoplankton, macrophythobenthos, microphythobentos, bacterioplankton, zooplankton and zoobenthos) are taken into account regarding their participation in the carbon cycle.

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

This book is divided in two sections. Several chapters in the first section provide a state-of-the-art review of various carbon sinks for CO2 sequestration such as soil and oceans. Other chapters discuss the carbon sequestration achieved by storage in kerogen nanopores, CO2 miscible flooding and generation of energy efficient solvents for postcombustion CO2 capture. The chapters in the second section focus on monitoring and tracking of CO2 migration in various types of storage sites, as well as important physical parameters relevant to sequestration. Both researchers and students should find the material useful in their work.

Our desire to understand the global carbon cycle and its link to the climate system represents a huge challenge. These overarching questions have driven a great deal of scientific endeavour in recent years: What are the basic oceanic mechanisms which control the oceanic carbon reservoirs and the partitioning of carbon between ocean and atmosphere? How do these mechanisms depend on the state of the climate system and how does the carbon cycle feed back on climate? What is the current rate at which fossil fuel carbon dioxide is absorbed by the oceans and how might this change in the future? To begin to answer these questions we must first understand the distribution of carbon in the ocean, its partitioning between different ocean reservoirs (the "solubility" and "biological" pumps of carbon), the mechanisms controlling these reservoirs, and the relationship of the significant physical and biological processes to the physical environment. The recent surveys from the JGOFS and WOCE (Joint Global Ocean Flux Study and World Ocean Circulation Ex periment) programs have given us a first truly global survey of the physical and biogeochemical properties of the ocean. These new, high quality data provide the opportunity to better quantify the present oceans reservoirs of carbon and the changes due to fossil fuel burning. In addition, diverse process studies and time-series observations have clearly revealed the complexity of interactions between nutrient cycles, ecosystems, the carbon-cycle and the physical envi ronment.

Oceans account for 50% of the anthropogenic CO2 released into the atmosphere. During the past 15 years an international programme, the Joint Global Ocean Flux Study (JGOFS), has been studying the ocean carbon cycle to quantify and model the biological and physical processes whereby CO2 is pumped from the ocean's surface to the depths of the ocean, where it can remain for hundreds of years. This project is one of the largest multi-disciplinary studies of the oceans ever carried out and this book synthesises the results. It covers all aspects of the topic ranging from air-sea exchange with CO2, the role of physical mixing, the uptake of CO2 by marine algae, the fluxes of carbon and nitrogen through the marine food chain to the subsequent export of carbon to the depths of the ocean. Special emphasis is laid on predicting future climatic change.

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.

This book provides a cross-disciplinary overview of permafrost and the carbon cycle by providing an introduction into the geographical distribution of permafrost, with a focus on the distribution of permafrost and its soil carbon reservoirs. The chapters explain the basic physical properties and processes of permafrost soils: ice, mineral and organic components, and how these interact with climate, vegetation and geomorphological processes. In particular, the book covers the role of the large quantities of ice in many permafrost soils which are crucial to understanding carbon cycle processes. An explanation is given on how permafrost becomes loaded with ice and carbon. Gas hydrates are also introduced. Structures and processes formed by the intense freeze-thaw action in the active layer are considered (e.g. ice wedging, cryoturbation), and the processes that occur as the permafrost thaws, (pond and lake formation, erosion). The book introduces soil carbon accumulation and decomposition mechanisms and how these are modified in a permafrost environment. A separate chapter deals with deep permafrost carbon, gas reservoirs and recently discovered methane emission phenomena from regions such as Northwest Siberia and the Siberian yedoma permafrost.