하구및 연안생태학 Estuarine and coastal ecology 2015 년 가을 학기

생지화학 Biogeochemisty 생태계에 존재하는 다양한 물질의 양과 성분에 영향을 미치는 화학, 물리, 지질, 생물학적 과정의 연구 주요 관심사는 탄소(C), 질소(N), 인(P); 유기물의 구성성분 생물학적 과정에 의해 이루어지거나 영향을 받는 chemical cycle 에 초점을 맞춤. 생물학의 한 분야인 system ecology 와 연관성이 많음 지구 온난화와 이산화 탄소의 거동, 부영양화 등의 연구의 주요 관점

The Crustal-Ocean Atmosphere Factory The ocean is a place where biological, physical, geological, and chemical processes interact, making the study of marine chemistry very “interdisciplinary” and more appropriately termed marine “biogeochemistry “

THE CRUSTAL-OCEAN-ATMOSPHERE FACTORY AND GLOBAL BIOGEOCHEMICAL CYCLES  

WHY THE STUDY OF MARINE BIOGEOCHEMISTRY IS IMPORTANT? Water: Excellent solvent; increase reactions ability to absorb a great deal of heat without undergoing much of an increase in temperature; weather life first evolved in a wet environment ! biological activity and chemical evolution of the planet.; photosynthesis and O2 CO2, O2, organic matter (CH2O)n

WHY THE STUDY OF MARINE BIOGEOCHEMISTRY IS IMPORTANT? Study on marine biogeochemistry focus on exchanges of energy and material between the crust, atmosphere, and ocean. CO2 and climate, role of Ocean Productivity of coastal ocean ; transport of nutrients; altered by human activity

BIOGEOCHEMICAL CYCLES promoted by the liquid water, which is also the most important transporting agent on Earth’s surface dissolved and particulate chemicals from the land and the inner earth into the ocean via rivers and hydrothermal vents. buried as sediments or diffuse across the sea surface to accumulate in the atmosphere. Uplift marine sediments; terrestrial weathering followed by river transport

Ocean in the biogeochemical cycle the ocean acts as a giant stirred flow-through reactor in which solutes and solids are added, transformed, and removed.

Example of box model  

Steady State, Residence Times, and Turnover Times Steady state; input=output dM/dt=0=Jin-Jout Residence time = Total amount of a substance in a reservoir /Total rate of supply to or removal of the substance from the reservoir - the average molecule of water spends 3800 years in the ocean before being removed, mostly via the process of evaporation - steady-state concentration of a chemical Jout = kM = kCSSWV SW = Jin = QRWC RW [C]SSW= [C]RW/(RT x k)

Steady State, Residence Times, and Turnover Times fractional residence time or turnover time of a material in a reservoir. turnover time represents how long it would take for that subset of processes by itself to either supply or remove all of the material from the reservoir. turnover time of marine sediment: reservoir (1.0 × 1024 g) / the annual rate of river input of particles(1.4 × 1016 g /y) = 71 × 106 y.

CONSIDERATION OF TIME AND SPACE SCALES Steady state is time dependent Examples of catastrophic events that can perturb global biogeochemical cycles include: (1) meteorite impacts, (2) changes in the rate and pattern of plate tectonic activity, and (3) climate change induced by fluctuations in delivery of solar radiation. Negative feed back; gaia hypothesis Positive feed back

THE HISTORY OF THE STUDY OF MARINE BIOGEOCHEMISTRY Marine chemistry: 1900: Before 1900, salt composition by Robert Boyle (1674) Antoine Lavoisier (1772); published the first analysis of seawater (evaporation followed by solvent extraction) Olaf Bergman (1784) analysis of seawater by weighing precipitated salts. Joseph Louis Gay-Lussa (1824 and 1836); volumetric titrimetry determined that the salt content of open-ocean seawater is nearly geographically constant. Alexander Marcet (1819–1822)seawater contained small quantities of all soluble substances, the relative abundances of some were constant. This hypothesis is now known as Marcet’s principle.

THE HISTORY OF THE STUDY OF MARINE BIOGEOCHEMISTRY Georg Forchhamme (1865) ; The concept of salinity was introduced. demonstrate the validity of Marcet’s Principle And built a base for the salinity to chlorinity (S‰ = 1.805 Cl‰ + 0.030) calculations A slight revision in this equation (S‰ = 1.80655 Cl‰) was made in 1962 by international agreement The modern era of oceanography began in 1876 with the Challenger Expedition. 77 seawater samples ; supported Marcet’s principle. 19th century, progress was made in the development of analytical methods for the measurement of trace constituents, such as dissolved oxygen (O2) and nutrients.

THE HISTORY OF THE STUDY OF MARINE BIOGEOCHEMISTRY R / V Meteor (1925 to 1940); systematic and dynamic surveys. echo sounding was first used to map seafloor topography submarine activity during World War II. : rapid development in technology and instrumentation The salinity and temperature of seawater became recognized as a powerful tracer of large-scale water movements, including surface and d Modern oceanography is presently characterized by multidisciplinary research projects conducted collaboratively by large groups of scientists often from different research institutions. global scales, like climate change.

THE HISTORY OF THE STUDY OF MARINE BIOGEOCHEMISTRY Modern oceanography is presently characterized by multidisciplinary research projects conducted collaboratively by large groups of scientists often from different research institutions. global scales, like climate change. 1958 with the International Geophysical Year, which was organized by the United Nations’ UNESCO General Assembly. Geochemical Ocean Sections Study (GEOSECS) that ran from 1968 to 1978: to determine the pathway of deep-ocean circulation using radioisotopes, Transient Tracers in the Ocean (TTO) program,(1980~ 1983). Trace the radioisotopes from nuclear weapons testing conducted in the 1950s and 1960s. Joint Global Ocean Flux Study (JGOFS; 1987~2003): fluxes of chemicals (carbon and other biogenically controlled elements; , to better understand linkages to global climate change.; HOTS, BATS