Ocean physics and the global carbon cycle: A highly non-linear problem
- 28 Sep 2011
- 17:00 – 19:00 U.K. - England - London
- What time is this for me?
- Virtual
- Speaker details
- Kevin Oliver (K.Oliver@noc.soton.ac.uk) University of Southampton (NOCS)
Event resources
If you are watching the seminar in video streaming and you want to participate to the discussion please email your question to Heiko Palike (heiko@noc.soton.ac.uk)
Abstract:
The Earth System model GENIE is used to explore a range of mechanisms hypothesised to contribute to glacial-interglacial cycles in atmospheric pCO2, by means of a hypercube ensemble experiment whereby parameters representing climate forcing and internal processes are varied simultaneously. It is found that increasing the value of many parameters - including those governing Southern Ocean upwelling, the Atlantic meridional overturning circulation, diapycnal mixing, and air-sea gas exchange - will increase pCO2 in some underlying climate states but decrease pCO2 in other states. This suggests that the traditional approach of examining no more than a few mechanisms at a time is unlikely to be sufficient. Paleo-proxy data are used to further constrain plausible causes of glacial-interglacial cycles: several hypotheses are consistent with observed changes in d13C, but marine-pore salinity data is only consistent with an increase in brine rejection in the Southern Ocean, contributing up to about 50 ppm towards glacial-interglacial changes.