3. Before 1950, atm. CO 2 values come from ice cores. Scholander made first measurements of gases in icebergs in Baffin Bay in 1950’s.

5. The National Ice Core Laboratory in Denver, Colorado

6. Depth Bubble Close- Off Region Free Atmosphere Glacier Surface 0 115 123 Issues: 1)Ice age - gas age 2)Trapped gases are ave. 3) Gravity and thermal frac.

7. Depth Bubble Close- Off Region Free Atmosphere Glacier Surface 0 115 123 Convection Zone Static-Air Column Non-diffusive Zone Depth N (‰) 15  0.0 Barometric Equation: Pz = Po(e (mgz/RT))

8. 0.35 0.50 0.35 0.50 0.80 0.83 Bubble close- off region To Waste Density (g/cc) Depth Rubber Bladder Firn Air Sampling Device To Inflate bladder To Flasks Bender Baffle

12. Using  15 N to assess the depth of bubble close-off in the past Bubble close off is primarily a function of temperature (colder temps -> deeper close off depths). Gravitational fractionation is also a function of temp. Pz = Po(e (mgz/RT)) Age difference between bubbles and surrounding ice is proportional to accumulation rate which is also tied to surface temperature

14.  T=10.4±2 o C

15. Dry Extraction technique only Numerous labs using different techniques Numerous Antarctic ice cores drilled differently

18. IPCC 2007 Synthesis report

21. Sources of CO 2 to atmosphere Weathering reactions H 2 SO 4 + CaCO 3 → CaSO 4 + H 2 CO 3 Fossil Fuel Burning CH 4 + 2 O 2 → CO 2 + 2 H 2 O Respiration C 6 H 12 O 6 → 2 CO 2 + 2 C 2 H 5 OH O Volcanoes emit CO 2 from subducted oceanic sediment

22. Sinks of Atmospheric CO 2 Increase C org reservoir Increase CaCO 3 reservoir (coral reefs) Store CO 2 in deep ocean Sequestration