Presentation on theme: "Final Thoughts LAST TIME...ended here –Turn in Long Lab Field Trip (HW-1) –Please do HW-2 (due July 7 th ) –Wed – Final Chemical Oceanography -CO 2 _The."— Presentation transcript:
Final Thoughts LAST TIME...ended here –Turn in Long Lab Field Trip (HW-1) –Please do HW-2 (due July 7 th ) –Wed – Final Chemical Oceanography -CO 2 _The Oceans & Ocean Physics Fe 2+ NO 3 - Ca 2+
OUTLINE Foundations of Chemical Oceanography Periodic Table – Valence Electrons Water – It’s Unique Properties Dissolved Elements in SeaWater Sources & Sinks Carbon Dioxide & the WORLD Ocean –Intro to Global Warming
Residence Times of Elements REMOVE? –When sources/ sinks in balance – ocean is steady state –At steady state – can define the amt. of time For total mass of an Element (e.g. Na) to be replaced –aka Residence Time (how long it is in the ocean) –Residence Time = mass of element present / rate of input or removal Na –1.472 x kg yr -1 tons/ year / 2 x10 8 tons/yr -1 Na/year = 70 million years!
Recall - Periodic Table _Valence Electrons Outer valence electrons (= e-) participates in bonding of Elements e.g. CO 2 carbon dioxide.... O::C::O ‘‘ ‘’ Covalent bond Sharing e- O=C=O CO 2 4 e- = (.) 6 e- = (.)
CO2 –Aka, dry ice O=C=O –More CO2 you add the more acidic the water MORE acidic
Carbon Dioxide & the WORLD Ocean –Is human released (= anthropogenic) carbon dioxide (CO 2 ) Changing the Earth’s Climate? ? –CO 2 traps heat in earth’s atmosphere as a greenhouse gas »Other gasses: CH4 (methane), CFCs, H2O CO2, CH4 (methane),CFCs, H2O
Who/ where is the real contribution(s) Source: Source: U.S. Energy Information Administration (EIA) Per Capita and Total Carbon Dioxide Emissions, 2005 CO2 emissions in tons per personTotal CO2 emissions in million tons
Two International Research Programs –Joint Global Ocean Flux Study ( ) –World Ocean Circulation Experiment ( ) To estimate oceanic storage of CO2 –Oceans ~could account for 48% CO2 released thru human activity –Greatest CO2 in Deep waters: N. Atlantic & intermediate Atlantic, S. Oceans »` why it this? » to be continued
Carbon Dioxide & the WORLD Ocean –Increase in CO2 in Atmosphere Increase CO2 in World Oceans –Concurrently seen increase in pH (more acidic) surface waters diff of ~ 0.4 pH (not a big deal?) RecaLL 0.4 diff = 4Xs more acidic! Acidic means more H + s donating vs Basic H + accepting...
Marine Carbonate System and pH –Little CO2 exists as gas in Seawater, Mostly in chemical form: Carbonate Buffering System 0.4 pH diff. in Oceans b/c of Carbonate Buffering System –Favors formation of Carbonate and (H+) (see below) This lowering of pH (more acidic) effects dissolution rates of phytoplankton shells?> Shells dissolve shallower recall lysocline calcite Ca 2+ CO 3 2- MORE acidic
Marine Carbonate System and pH
Anthropogenic (Human produced) Carbon Dioxide –2 major sources: Burning of fossil fuels Deforestation How much have atmospheric CO2 levels risen since 1800? Challenge Question Year Amount 1800 – 270 ppb 2004 – 380 ppb (30% increase)
Anthropogenic (Human produced) Carbon Dioxide –1958, David Keeling (Scripps Institute) Mauna Loa Observatory, HI CONTINUOUS (daily) CO 2 measurements, –Sawtooth pattern indicates variation due to: »Warm seasons: plants consume CO2 (drops) » Cold seasons: animals, plants release CO2 (rise) Trend indicates Increased atmospheric CO2 levels b/c ~ burning of fossil fuels..
Anthropogenic (Human produced) Carbon Dioxide –Fate of anthropogenic CO2 in Atm. is uncertain Sources/sinks reveal discrepancy ~ 2 gigatons (Gt) –i.e. there is less CO2 in atmosphere then should be present –Based on what know about SOURCES & Sinks –The MISSING Carbon Problem: addition Puzzle for Climate modeling.
Estimation of the Sources & Sinks of Carbon to the Atm. –Req. understanding of ~ The GLOBAL Carbon Cycle –What is it? The exchange of Carbon b/w various carbon reservoirs via –bio-geo-chemical processes –Amts. in Gigatons (Gt)
The GLOBAL Carbon Cycle –Total Carbon in Earth Reservoirs: Sources 1) mainly stored in Sedimentary rocks –e.g. limestone or dolomite ~82,370,000 Gigatons (Gt) 2) as organic carbon buried in sediments ~15,500,000 Gt 3) CO2 dissolved in world Oceans ~ 36,000 Gt –More then fossil fuels, the atm. Living organism combined CaMg(CO 3 ) 2 Ca 2+ CO
The Global Carbon Cycle –Residence Time also Important Scientists interested in process that move Carbon from reservoir to another Small Changes in Reservoir MAY have profound effects Large Reservoirs may exert disproportionate influence on small reservoirs –Organic carbon as Fossil fuels ~residence time: thousand years LANDOCEAN
The Global Carbon Cycle - Residence Time also Important Temporal scales exist over which Carbon transfer ~ ranges – e.g. Months thousands of years Thus Scientists Recognize 3 diff Carbon Cycles based on their time scales: What are they? –1. Short term Organic carbon cycle »Atm & biosphere (seasonal - Keeling Curve 1958-) –2. Long-term Organic carbon cycle »Formation of fossil fuels (burial of organic carbon (dinosaurs, plants)) –3. Long-term InOrganic carbon cycle »Storage of Carbon in rocks –
Long Term Inorganic cycle – best represented here –From CO2 trapped in Ice Core measurements (Antarctic) –Together all 3 cycles Influ. atm CO2 over –Long Time scales
CO2 vs Temp correlate – Spark a large debate.... CO 2 Avg. Earth TEMP 13*C Varying/time Petit et al., 1999, Nature 399, 429
Summary –No Questions CO2 is on the Rise 300ppm Unlike never before –Leading to Higher temperatures on earth –What will happen? –Major climate changes??? »More hurricanes, storms, floods etc. »Quite possibly – only one way to find out »Wait and see....
SUMMARY- / Confirming your knowledge How does CO2 in the atmosphere influence the Earth’s Climate? –Serves as a Greenhouse gas What holds more CO2 the Oceans or Atm? –Oceans; thus small changes in ocean conditions large effects on atmosphere, warming/cooling (climate change) Where is most of the earths carbon stored? –Rocks (CaCO3) limestone CO 2 & O 2 undergo rapid changes via biological activity in Oceans from –phytoplankton (photosythnesis) & animals (respiration); what do they do? CO 2 is consumed (phytoplankton) O2 released O 2 is comsumed (animals/zooplankton), CO2 is released Storage of Carbon in Oceans~ only understood by quantifying: –The production (photosynthesis), –The sedimentation –Burial/subduction in ocean crusts
SUMMARY –Humans have been adding Considerable CO2 to Atm for 100 years –The world ocean has absorbed 48% of anthropogenic CO2 increasing Ocean acidity (lowered the pH) LONG TERMS RESULTS -- Not Clear? Speculative... But probable – real climate changes How does this CO2/temp. change affect climate? To be continued...
Lets get informed/Involved? –Watch the Movie 90min Inconvenient Truth Trailer Controversial Inflection points Minor issue – does cast doubt on presentation -brought to light by nut jobs Gyre info KQED Will ask 2 basic Questions from about glaciers and worldwide temperature