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SUMMARY:Relating atmospheric CO2 levels to biogeochemical processes - Phil
  Goodwin\, Earth Sciences\, Cambridge
DTSTART:20111018T153000Z
DTEND:20111018T163000Z
UID:TALK33695@talks.cam.ac.uk
CONTACT:John Maclennan
DESCRIPTION:Atmospheric CO2 is an important greenhouse gas\, with elevated
  atmospheric CO2 levels contributing to anthropogenic climate change in th
 e present day. Changing atmospheric CO2 levels have contributed to natural
  variations in past climate\, such as during the Pleistocene glacial-inter
 glacial cycles. Many geological and biogeochemical processes affect atmosp
 heric CO2 levels over a range of timescales [e.g.1\,2]\, from volcanic out
 gassing and silicate weathering on 106 year timescales to the seasonal bal
 ance between photosynthesis and respiration on sub-annual timescales. Nume
 rical models of the Earth system are used to simulate atmospheric CO2 leve
 ls. However\, the model output is often too complex to gain an understandi
 ng of why the model simulation achieves a particular atmospheric CO2 level
 . In particular\, the non-linearity introduced when CO2 dissolves in seawa
 ter is problematic. Here\, atmospheric CO2 is analytically related to biog
 eochemical processes on 100 to 100\,000 year timescales by approximating a
 spects of ocean carbonate chemistry[3]. These approximate analytical solut
 ions are in good agreement with numerical models\, helping to both predict
  and understand their behaviour. \n\n[1] Ridgwell and Zeebe (2005). Earth 
 Plan. Sci. Letters\, Vol 234 p299-315\n[2] Archer et al (2009). Annu. Rev.
  Earth Planet. Sci. 2009. 37:117–34\n[3] Goodwin et al (2008). Glob. Bio
 geochem. Cycles. doi:10.1029/2008GB003184
LOCATION:Harker 1 seminar room\, Department of Earth Sciences
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