to get to journals electronically: -click on letter corresponding to journal name or
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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
QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.
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
QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.
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:
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