Lecture 1: OCN400 Chemical Oceanography

Prof: Jim MurrayTAs: Tessa McGee Susanna Michael1. Introduce Murray2. Who are the Students? 3. Syllabus / Text (Emerson and Hedges)4. Course web site: http://www.ocean.washington.edu/courses/geol330/5. Themes for course6. What do we want students to be able to do?7. How will we know what they can do?

Problem Sets (7), Paper Discussions (5), Mid-Term (1)8. Course Activities / Materials9. Greatest Challenges for Students

Four Main Themes

1.Global Carbon Cycle2.Are humans changing the chemistry of the ocean?3.What are chemical controls and tracers for biological production?4. What is the fate of organic matter made by biological production?

Quantitative Tools to Master

1. Equilibrium Calculations (carbonate system, speciation, solubility, oxidation-reduction reactions)

2. Stable and Radioactive Isotopes (mass balance equations, decay equations, secular equilibrium)

3. Simple Box Model approaches and fluxes (e.g., gas exchange, primary new and export production, sedimentation)4. What controls the global systems of carbon, nitrogen, phosphorus and oxygen.5. Reading and Discussion of the literature

Global Carbon Cycle

Global Carbon Cycle

Sabine et al. (2004) SCOPE

Reservoirs and Fluxes

Mauna Loa CO2 record – Started by David Keeling (SIO)

NOAA-ERL Data

Latest CO2 Reading399.00 ppmJuly, 2014

Source of anthropogenic CO2

Source: C. D. Keeling and T. P. Whorf; Etheridge et.al.; Barnola et.al.; (PAGES / IGBP); IPCC

(BP 1950)

Projected (2100)

Current (2001)

CO

2 Con

cent

ratio

n (p

pmv)

Vostok RecordLaw Dome RecordMauna Loa RecordIPCC IS92a Scenario

Carbon TrackerAtmospheric CO2 from 800,000 years ago to the present

http://www.youtube.com/watch?v=bbgUE04Y-Xg

Are Humans Changing the Compositionof the Ocean?

Yes, in may ways!

Examples include:Ocean AcidificationLead and Mercury distributionsNitrate distributionsFukushima radionuclides

Because the ocean mixes slowly, half of the anthropogenic CO2 stored in the oceans is found in the upper 10% of the ocean.

Sabine et al. Science (2004)

Global Anthropogenic CO2 Inventory = 118±19 Pg C

Rate of Change in Inventory of anthropogenic CO2

Chemistry, Biology and Circulation

Nitrate concentrations High Nutrient-Low Chlorophyll

regions:

Fate of Organic Matter

Source: JGOFS / IGBP

CO2

PreindustrialCO2:

maximumstrength biopump: 160 ppm

PreindustrialCO2:

Physical pumpalone: 400 ppm

Oceanic Primary Production: Sept. 97 – Aug. 98

CO2 CO2

Biological Pump Physical (solubility) Pump