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GEOF236 CHEMICAL OCEANOGRAPHY (HØST 2012) Christoph Heinze University of Bergen, Geophysical Institute and Bjerknes Centre for Climate Research Prof. in Global Carbon Cycle Modelling Allegaten 70, N-5007 Bergen, Norway Phone: +47 55 58 98 44 Fax: +47 55 58 98 83 Mobile phone: +47 975 57 119 Email: [email protected] DEAR STUDENT AND COLLEAGUE: ”This presentation is for teaching/learning purposes only. Do not use any material of this presentation for any purpose outside course GEOF236, ”Chemical Oceanography”, autumn 2012, University of Bergen. Thank you for your attention.” People: Christoph Heinze, professor in chemical oceanography Email:[email protected], phone: 55589844, 97557119 Jörg Schwinger, post-doctoral researcher/researcher (exercises and modelling course) Helene Frigstad, post-doctoral researcher (laboratory course) Students: Name Main topic of studies Knowledge about oceanography in general Knowledge about chemical oceanography/marine biogeochemistry Programming expertise? What is your motivation/expectation? Pensum: 1. Text book: Sarmiento, J.L., and N. Gruber, 2006, Ocean biogeochemical dynamics, Princeton University Press The first 9 chapters will be part of the pensum (not chapter 10). During the lectures, highlights of specifically important issues will be given. 2. Basic findings of the “laboratory course” and the “modeling exercise”. 3. Basic elements of the calculus experiments. Book: Recommended older text books for those interested in the topic: Schedule: (to be updated, see red markings) Exercises/problem solving (for orientation, some changes may occur for the choice of those during the course): chp 1 (p. 16): 1.3 chp 2 (p. 69): 2.3, 2.8, 2.13 chp 3 (p. 100): 3.1, 3.2, 3.3 chp 4 (p. 168): 4.1, 4.3, 4.4, 4.5, 4.7, 4.8, 4.9, 4.12 chp 5 (p. 222): 5.1, 5.2, 5.5, 5.8, 5.9, 5.10 chp 6 (p. 267): 6.1, 6.10 chp 7 (p. 313): 7.1, 7.2, 7.3, 7.16 chp 8 (p. 355): 8.1, 8.2, 8.4, 8.10, 8.12, 8.15, 8.17, 8.18, 8.19 chp 9 (p. 389): 9.1, 9.2, 9.4, 9.7, 9.9, 9.10, 9.13, 9.14 Students have to solve the exercises before the scheduled dates for discussing them. Students will be asked to present the exercises on the black board an will get assistance when they get stuck. For the grade: 100% exam (probably oral exam), the exercises are a very good way to prepare for the exam Timing: 45 min. lecture, 15 min. break, 45 min. lecture Mi Side: Christoph shows this online Definitions: Chemical oceanography Biogeochemistry Geochemistry Aquatic chemistry Earth system science Chemical oceanography: Millero, F., 2006, Chemical Oceanography, 3rd ed., Taylor and Francis: Oceanography is the scientific study of the oceans. 4 major areas: Physical oceanography: the study of the physics of the ocean and their interactions with the atmosphere. Biological oceanography: the study of the biology of the oceans. Geological oceanography: the study of the geology and geophysics of the oceans. Chemical oceanography: the study of the chemistry of the oceans (added by C. Heinze: and their interactions with the atmosphere). Biogeochemistry: Schlesinger, W.H., 1997, Biogeochemistry – an analysis of global change, Academic Press: Chemistry of the surface of the Earth. Libes, S.M., 1992, An introduction to marine biogeochemistry, John Wiley: The study of marine chemistry (add by C. Heinze: = chemical oceanography) encompasses all chemical changes that occur in seawater and the sediments. Since the ocean is a place where biological physical, geological, and chemical processes interact, the study of marine chemistry is very interdisciplinary. As a result, this field is often referred to as marine biogeochemistry. Not only are all fields of marine science interconnected, but the ocean itself cannot be studied without considering interactions with the atmosphere and the crust of the earth… Geochemistry: Schulz, H.D. & M. Zabel, eds., 2000, Marine Geochemistry, Springer: Marine geochemistry is generally integrated into the broad conceptual framework of oceanography which encompasses the study of the oceanic currents, their interactions with the atmosphere, weather and climate; it leads from the substances dissolved in water, to the marine flora and fauna, the process of plate tectonics, the sediments at the bottom of the oceans, and thus o marine geology. Our notion of marine geochemistry is that it is a part of marine geology… (added by C. Heinze: true or subjective?) Aquatic chemistry: Stumm, W. and J.J. Morgan, 1996, 3rd ed., Aquatic chemistry, John Wiley: Aquatic chemistry is concerned with the chemical reactions and processes affecting the distribution and circulation of chemical species in natural waters. The objectives include the development of a theoretical basis for the chemical behavior of ocean waters, estuaries, rivers, lakes, groundwaters, and soil water systems, as well as the description of processes involved in water technoogy. Aquatic chemistry draws primarily on the fundamentals of chemistry, but it is also influenced by other sciences, especially geology and biology. Earth system science Earth System Science is the study of the Earth System, with an emphasis on observing, understanding and predicting global environmental changes involving interactions between land, atmosphere, water, ice, biosphere, societies, technologies and economies. (Bild: Apollo 17, NASA) Earth System Science Partnership (ESSP, International Council of Science ICSU) (www.essp.org) Earth system science in its first step = climate science plus biogeochemistry Bretherton, F.P., Earth System Science and Remote Sensing, Proceedings of the, VOL. 73, NO. 6, 1985: A conceptual model is presented of the Earth System appropriate to global change on timescales of decades to centuries (added by C. Heinze: also longer timescales and shorter timescales should be included). This is used as a framework for discussion of the processes and feedbacks involved in the physical climate system and in biogeochemical cycles, … … to (added by C. Heinze: also) understand … the impact of human activities on the global environment in the context of natural variability. Bretherton, F.P., Earth System Science and Remote Sensing, 1985 Proceedings of the IEEE, 73(6) Bretherton, F.P., Earth System Science and Remote Sensing, 1985 Proceedings of the IEEE, 73(6) Bretherton, F.P., Earth System Science and Remote Sensing, 1985 Proceedings of the IEEE, 73(6) Simplified version! Source for this figure: J.G. Bockheim, and A.N. Gennadiyev, 2010, Soil-factorial models and earth-system science: A review, Geoderma, 159, 243-251. What determines the composition of the Earth’s “surface” and how does biogeochemistry interact with physics? Source: Jacobson et al., Earth System Science, Academic Press, 2000 The ocean as the interface between the atmosphere & land and the lithosphere: Heinze, C., and M. Gehlen, submitted for 2nd ed. of book Ocean Circulation and Climate, edited by G. Siedler et al. Chemical oceanography (Wikipedia) The Chemical oceanography is the study of ocean chemistry: the behavior of the chemical elements within the Earth's oceans. The ocean is unique in that it contains - in greater or lesser quantities - nearly every element in the periodic table. Much of chemical oceanography describes the cycling of these elements both within the ocean and with the other spheres of the Earth system (see biogeochemical cycle). These cycles are usually characterised as quantitative fluxes between constituent reservoirs defined within the ocean system and as residence times within the ocean. Of particular global and climatic significance are the cycles of the biologically active elements such as carbon, nitrogen, and phosphorus as well as those of some important trace elements such as iron. Another important area of study in chemical oceanography is the behaviour of isotopes (see isotope geochemistry) and how they can be used as tracers of past and present oceanographic and climatic processes. For example, the incidence of 18O (the heavy isotope of oxygen) can be used as an indicator of polar ice sheet extent, and boron isotopes are key indicators of the pH and CO2 content of oceans in the geologic past. Geochemistry 1 (Wikipedia) The field of geochemistry involves study of the chemical composition of the Earth and other planets, chemical processes and reactions that govern the composition of rocks, water, and soils, and the cycles of matter and energy that transport the Earth's chemical components in time and space, and their interaction with the hydrosphere and the atmosphere. Some subsets of geochemistry are: 1.Isotope geochemistry :Determination of the relative and absolute concentrations of the elements and their isotopes in the earth and on earth's surface. 2.Examination of the distribution and movements of elements in different parts of the earth (crust, mantle, hydrosphere etc.) and in minerals with the goal to determine the underlying system of distribution and movement. 3.Cosmochemistry: Analysis of the distribution of elements and their isotopes in the cosmos. 4.Biogeochemistry: Field of study focusing on the effect of life on the chemistry of the earth. CONTINUED ON NEXT SLIDE Geochemistry 2 (Wikipedia) CONTINUED FROM PREVIOUS SLIDE 5.Organic geochemistry: A study of the role of processes and compounds that are derived from living or once-living organisms. 6.Aqueous geochemistry: Understanding the role of various elements in watersheds, including copper, sulfur, mercury, and how elemental fluxes are exchanged through atmospheric-terrestrial-aquatic interactions. 7.Regional, environmental and exploration geochemistry: Applications to environmental, hydrological and mineral exploration studies. Victor Goldschmidt is considered by most to be the father of modern geochemistry and the ideas of the subject were formed by him in a series of publications from 1922 under the title ‘Geochemische Verteilungsgesetze der Elemente’ (geochemical laws of distribution of the elements). Earth system science (Wikipedia) Earth system science seeks to integrate various fields of academic study to understand the Earth as a system. It considers interaction between the atmosphere, hydrosphere, lithosphere, biosphere, and heliosphere. In 1996, the American Geophysical Union, in cooperation with the Keck Geology Consortium and with support from five divisions within the National Science Foundation, convened a workshop "to define common educational goals among all disciplines in the Earth sciences." In its report, participants noted that, "The fields that make up the Earth and space sciences are currently undergoing a major advancement that promotes understanding the Earth as a number of interrelated systems." Recognizing the rise of this systems approach, the workshop report recommended that an Earth system science curriculum be developed with support from the National Science Foundation. … The Carleton College, offers the following definition: "Earth system science embraces chemistry, physics, biology, mathematics and applied sciences in transcending disciplinary boundaries to treat the Earth as an integrated system and seeks a deeper understanding of the physical, chemical, biological and human interactions that determine the past, current and future states of the Earth. Earth system science provides a physical basis for understanding the world in which we live and upon which humankind seeks to achieve sustainability." Biogeochemistry (Wikipedia) Biogeochemistry is the scientific discipline that involves the study of the chemical, physical, geological, and biological processes and reactions that govern the composition of the natural environment (including the biosphere, the hydrosphere, the pedosphere, the atmosphere, and the lithosphere). In particular, biogeochemistry is the study of the cycles of chemical elements, such as carbon and nitrogen, and their interactions with and incorporation into living things transported through earth scale biological systems in space through time. The field focuses on chemical cycles which are either driven by or have an impact on biological activity. Particular emphasis is placed on the study of carbon, nitrogen, sulfur, and phosphorus cycles. Biogeochemistry is a systems science closely related to systems ecology. THIS COURSE: Aim and Content This course gives a basic introduction to chemical oceanography and useful methods applied within analytical work and modelling to interpret the distribution of substances and identifying processes causing their distribution. Focus is placed both on the natural and anthropogenic system of the general carbon cycle and other important processes causing changes in biogeochemical cycles and earth systems. Some central topics are the general circulation of the ocean (the thermohaline circulation), biological production, remineralisation and export of organic material. Radiometric and stable isotope distribution used for aging purposes of water masses and to identify source waters, calculation of mixing rates and advection of chemical component etc. Air - Sea gas exchange, the biological pump, nutrient cycles (nitrogen, phosphorous and silica cycle) will also be central topics. Learning Outcomes After completing this subject the student should be able to: - calculate the uptake of carbon both in a natural and anthropogenic air and sea system based upon analytical and model data - work on and systemize chemical oceanographic data in order to identify underlying processes that determine the general distribution of chemical substances - determine how the biological pump influences the distribution of chemical substances in the ocean based on stoichiometry - identify processes that are important for air-sea exchange - measure and interpret experimental data and summarize results in a short laboratory report - interpret results based on modelling in a short report Pre-requirements Principles of oceanography. Principles of chemistry is an advantage. Timescales in the Earth system Gates, W.L.,1979, Dynamics of the Atmosphere and Oceans, 3(2-4) The Open University/Pergamon: Ocean Chemistry and Deep-Sea Sediments, 1989 Chapter 1: Introduction You find practically all elements in seawater Chapter 2: Tracer conservation and ocean transport Broecker&Peng, Tracers in the sea, ELDIGIO press, 1982 An ocean conveyor belt Chapter 3: Air-sea interface Mean annual CO2 flux across the air water interface Takahashi, T., et al., 2009, Climatological mean and decadal change in surface ocean pCO2, and net sea–air CO2 flux over the global oceans, Deep-Sea Research II, 56, 554–577 Chapter 4: Organic matter production Satellite derived estimate (following Carr, 2002) Source: Henson, S., et al., 2012, Global patterns in efficiency of particulate organic carbon export and transfer to the deep ocean, Global Biogeochemical Cycles, 26, GB1028 Chapter 5: Organic matter export and remineralisation GEOSECS Station 214 32º N 176º W North Pacific Broecker&Peng, 1982, Tracers in the Sea, ELDIGIO Press Chapter 6: Remineralisation and burial in the sediments Top sediment distribution of organic carbon Source: Jahnke, R., The global ocean flux of particulate organic carbon: Areal distribution and magnitude, Global Biogeochemical Cycles, 10(1), 71-88. Chapter 7: Silicate cycle Shades: organic carbon primary production. Isolines: Si sediment content in weight-% on calcite free basis Tréguer, P., 2002, Silica and the cycle of carbon in the ocean, C. R. Geoscience 334 (2002) 3–11 Chapter 8: Carbon cycle Column inventory of anthropogenic CO2 Source: Sabine, C., et al., 2004, The Oceanic Sink for Anthropogenic CO2, Science, 305, 367-371. Chapter 9: Calcium carbonate cycle Gridded map of top CaCO3 sediment in weight-% of sediment Source: Archer, D., 1996, An atlas of the distribution of calcium carbonate in sediments of the deep sea, Global Biogeochemical Cycles, 10(1), 159-174