Chemical Reference Materials


Book Description

The accuracy of chemical oceanographic measurements depends on calibration against reference materials to ensure comparability over time and among laboratories. Several key parameters lack reference materials for measurements in seawater, particles in the water column, and sediments. Without reference materials it is difficult to produce the reliable data sets or long-term baseline studies that are essential to verify global change and oceanic stability. Chemical Reference Materials : Setting the Standards for Ocean Science identifies the most urgently required chemical reference materials based on key themes for oceanographic research and provides suggestions as to how they can be developed within realistic cost constraints. Chemical analyses of seawater are uniquely difficult given the poorly known speciation and the low concentration of many of the analytes of interest. Analyses of suspended and sedimentary marine particulate materials present their own distinct challenges, primarily due to potential interference by predominant mineral phases of different types. Of all the analytical methods applied to marine waters and particles, at present only a small fraction can be systematically evaluated via comparison to reference materials that represent the appropriate natural concentrations and matrices. Specifically, the committee was charged with the following tasks: - compile from available sources a list of important oceanographic research questions that may benefit from chemical reference standards; - create a comprehensive list of reference materials currently available for oceanographic studies; - identify and prioritize the reference materials needed to study the identified research questions; - determine for each priority analyte whether reference materials and/or analytic methods should be standardized; and - identify the most appropriate approaches for the development and future production of reference materials for ocean sciences.




CO2 in Seawater: Equilibrium, Kinetics, Isotopes


Book Description

Carbon dioxide is the most important greenhouse gas after water vapor in the atmosphere of the earth. More than 98% of the carbon of the atmosphere-ocean system is stored in the oceans as dissolved inorganic carbon. The key for understanding critical processes of the marine carbon cycle is a sound knowledge of the seawater carbonate chemistry, including equilibrium and nonequilibrium properties as well as stable isotope fractionation.Presenting the first coherent text describing equilibrium and nonequilibrium properties and stable isotope fractionation among the elements of the carbonate system. This volume presents an overview and a synthesis of these subjects which should be useful for graduate students and researchers in various fields such as biogeochemistry, chemical oceanography, paleoceanography, marine biology, marine chemistry, marine geology, and others.The volume includes an introduction to the equilibrium properties of the carbonate system in which basic concepts such as equilibrium constants, alkalinity, pH scales, and buffering are discussed. It also deals with the nonequilibrium properties of the seawater carbonate chemistry. Whereas principle of chemical kinetics are recapitulated, reaction rates and relaxation times of the carbonate system are considered in details. The book also provides a general introduction to stable isotope fractionation and describes the partitioning of carbon, oxygen, and boron isotopes between the species of the carbonate system. The appendix contains formulas for the equilibrium constants of the carbonate system, mathematical expressions to calculate carbonate system parameters, answers to exercises and more.




The Changing Carbon Cycle


Book Description

The United States Government, cognizant of its responsibilities to future generations, has been sponsoring research for nine years into the causes, effects, and potential impacts of increased concentrations of carbon dioxide (C0 ) in the atmosphere. Agencies such as the National Science Foun 2 dation, National Oceanic and Atmospheric Administration, and the U.S. Department of Energy (DOE) cooperatively spent about $100 million from FY 1978 through FY 1984 directly on the study of CO • The DOE, as the 2 lead government agency for coordinating the government' s research ef forts, has been responsible for about 60% of these research efforts. William James succinctly defined our purpose when he stated science must be based upon " ... irreducible and stubborn facts." Scientific knowledge can and will reduce the present significant uncertainty sur rounding our understanding of the causes, effects, and potential impacts of increasing atmospheric CO2• We have come far during the past seven years in resolving some underlyinig doubts and in narrowing the ranges of disagreement. Basic concepts have become less murky. Yet, much more must be accomplished; more irreducible and stubborn facts are needed to reduce the uncertainties so that we can improve our knowledge base. Uncertainty can never be reduced to zero. However, with a much improved knowledge base, we will be able to learn, under stand, and be in a position to make decisions.







Ocean Acidification


Book Description

The ocean has absorbed a significant portion of all human-made carbon dioxide emissions. This benefits human society by moderating the rate of climate change, but also causes unprecedented changes to ocean chemistry. Carbon dioxide taken up by the ocean decreases the pH of the water and leads to a suite of chemical changes collectively known as ocean acidification. The long term consequences of ocean acidification are not known, but are expected to result in changes to many ecosystems and the services they provide to society. Ocean Acidification: A National Strategy to Meet the Challenges of a Changing Ocean reviews the current state of knowledge, explores gaps in understanding, and identifies several key findings. Like climate change, ocean acidification is a growing global problem that will intensify with continued CO2 emissions and has the potential to change marine ecosystems and affect benefits to society. The federal government has taken positive initial steps by developing a national ocean acidification program, but more information is needed to fully understand and address the threat that ocean acidification may pose to marine ecosystems and the services they provide. In addition, a global observation network of chemical and biological sensors is needed to monitor changes in ocean conditions attributable to acidification.




Deep Carbon


Book Description

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.




Research in Progress, FY 1992


Book Description