Carbon Cycle in the Russian Arctic Seas


Book Description

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.







The Organic Carbon Cycle in the Arctic Ocean


Book Description

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.




The Ocean Carbon Cycle and Climate


Book Description

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.




Siberian River Run-off in the Kara Sea


Book Description

Within the joint German-Russian research project Siberian River Run-off (SIRRO) multidisciplinary studies were carried out in the Ob and Yenisei estuaries and adjacent southern Kara Sea (Arctic Ocean). The overall goal of the project was to extend knowledge on understanding the freshwater and sediment input by the major Siberian rivers, and its impact on the environments of the inner Kara Sea. The main results of oceanographical, biological, geochemical, geological and modelling studies are presented in four main chapters.




Influence of Climate Change on the Changing Arctic and Sub-Arctic Conditions


Book Description

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.




Thawing Permafrost


Book Description

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.







Sedimentation History in the Arctic Ocean and Subarctic Seas for the Last 130 kyr


Book Description

The book reflects the results of the study of sedimentation history, paleoclimatology, and paleoceanography of the Arctic and Subarctic during the last 130 ka. The main objects under consideration are marine basins of the West Subarctic (Iceland, Norwegian, and Greenland Seas), the Arctic Ocean (Barents, Pechora, Kara, Laptev, East Siberian, Chukchi Seas and deep-sea Arctic Ocean proper), East Subarctic (Bering and Okhotsk Seas). The modern environment and geological history of water- (ice-) sheds and marine basins have been studied for each region, using different sedimentological and geochemical proxies. Mainly results of the authors' own studies are represented, with special emphasis on glacial/interglacial variability and land-ocean interaction. The book is aimed at sedimentologists, quaternary and marine geologists, paleoclimatologists and paleoceanographers, as well as being of great interest to students in the related fields.




Carbon Cycling in the Baltic Sea


Book Description

The Baltic Sea is an area extensively explored by the oceanographers. Hence it is one of the most often described marine areas in the scientific literature. However, there are still several fields which are poorly investigated and reported by scientists. One of them is the carbon cycle of the Baltic Sea. Although it is believed the shelf seas are responsible for about 20% of all marine carbon dioxide uptake, while they constitute only 7% of the whole sea surface, still a scientific debate exists on the role of the Baltic Sea in the global carbon cycle. “Carbon cycle of the Baltic Sea” is intended to be a comprehensive presentation and discussion of state of the art research by biogeochemists involved in the Baltic Sea carbon cycle research. This work presents both qualitative and quantitative descriptions of the main carbon flows in the Baltic Sea as well as their possible shifts induced by climatic and global change.