To get to journals electronically:

http://findit.library.miami.edu/ejournal.php -click on letter corresponding to journal name

Orhttp://www.rsmas.miami.edu/support/lib-click on web resources-click on IBISWEB-click on E-Journals tag at top

$$$1.00$$$ to Alex -

p.37, exercise 1.6 (a)

“globally averaged surface pressure is 16 hPalower than globally averaged sea-level pressureof 1013 hPa”

p. 11, exercise 1.1 states,

Globally averaged surface pressure is 985 hPa

Renee

Alex

Patrick

Mehmet

Andrew

Ocean structure definitions

The Carbon Cycle:

Water cycle -> phase changes

Carbon cycle -> chemical changes

Why do we care ?

Regulates 2 important greenhouse gases:Carbon dioxide CO2, and methane CH4

12 years6,500 yrs

200,000 yrs

Units in kg m-2

Increased evidence of human impact: Greenhouse Warming

Monthly-mean C02 concentrations, 1958-2002

Carbon Dioxide

Monthly-mean C02 concentrations, 1958-2002

Carbon Dioxide increase only 1/2 of that predictedFrom fossil fuel consumption and forest burning

Where is the missing carbon ?

Oceans appear to uptake more than they expend.

Units in gigatons of carbon or Gt C

Carbon Exchange:CO2 + H2O -> CH2O + O2 photosynthesisCH2O + O2 -> CO2 + H2O respiration

Rxn uses visibleLight wavelengthsOf 0.43 (blue) and0.66 (orange)Micron. PlantsReflective in Near-IR

Euphotic zone takes up carbon dioxide, decaying matterSinks it deeper.

Carbon in the Oceans:

1. CO2 + H2O -> H2CO3 carbonic acid2. H2CO3 -> H+ + HCO3 bicarbonate ion3. HCO3 -> H+ + CO3

2-

Net: CO2 + CO32- + H2O -> 2HCO3

This is connected to Calcium from the Earth’s mantle:

Ca + 2HCO3 -> CaCO3 + H2CO3 coral

Where the Ca derived from the weathering ofRocks containing Ca-Si.

Sedimentation,Weathering,Metamorphosis

Weathering increases with temperature

Oxygen:

Unique component of Earth’s atmosphere

Increasing with time:

Photosynthesis creates oxygen- and -Reduction of water (H2O -> H2 + O) via mineralization,with hydrogen escaping to space.

Oxygen in carbonates estimated from carbon mass.

Early Earth’s History, in brief:

1. ~ 4.5 billion years ago (bya): accretion fromplanetesimals, evidence is lack of noble gases relativeto cosmos.

2. 1st ~750 millions years, named Hadean Epoch: morebombardment, early atmosphere, moon

3. 1st production of O2, 3.0-3.8 bya. Low atmos. conc., but ozone layer

4. Increased O2, 2 bya. -> 1st glaciation

Sudbury

Shatter conesK-T extinction-> nuclear winter

Sun’s luminosity increases w/ time as core contracts.

Why wasn’t Earth’s surface frozen ?

Initial high methane conc. gives way to oxygen ->

3 major glaciations. First is ~ 2.3 bya

2nd glaciation: ~ 2.5 million years ago.•Reduced plate tectonics -> reduced volcanic emission of CO2. +•Increased sink of CO2 in oceans through increasedAtmospheric carbon

•Movement of Antarctica to SP -> increased albedo

• Drake Passage opens, Panama Isthmus closes-> Changing thermohaline circulation -> less poleward heat transport ->colder Arctic

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3rd glaciation, within last million years

Temperature, CO2, CH4 vary coherently.

Antarctica ice core

Decrease is quick, rise less rapid

QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.

Last glacial maximum 20,000 years ago

Global sea level ~ 125 m lower

CO2 levels ~ 180 ppm

Snow/ice extent preceeds CO2 changes

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Venus Mars Jupiter

Hot: No oceans:No hydrogen or water

Atmosphere all carbon

“runaway greenhouseEffect”

Cold & small:No (liquid) waterNo vulcanism

No atmosphere

WHY LIFE ON EARTH ?

ROLE OF OCEANS:

ROLE OF CHEMICAL PHYSICS:

ROLE OF TECTONICS

ROLE OF OTHER PLANETS: