1. Title:
Changing marine carbon sources and sinks under climate change and rising atmospheric CO2
Presenter:
Christoph Heinze and the CarboOcean consortium
Acknowledgement: European Commission, FP6 contr GOCE.
air-sea fCO2 difference
Earth system model future scenarios:
Positive C cycle climate feedback until 2100 confirmed – no big surprises so far, attribution still ongoing (stand-alone/coupled to land); N2O, O2?
In-situ observations:
Ocean C sink more variable than expected; transient CO2 sink strength decreases in both deep water source areas North Atlantic and Southern Ocean during mid-1990 – today; monitor this!
Processes:
Mesocosms: pH dependent stoichiometry C:N can possibly provide a non-negligible negative feedback – but add odds with paleosignal; pH dependent decrease in CaCO3 shell formation provides quantitatively small CO2 feedback only
Ocean acidification:
At sea surface, pH decrease directly documented from time series measurements; modelling: vertical transport of acidification to ocean bottom quick - with unknown consequences for deep biosphere (strong relative pH change!)
CarboOcean final meeting:
5-9 October 2009, Solstrand near Bergen, Norway
Contact:
[µatm]
yr 1990
-80
yr 2006
-80
Schuster, U., et al., Deep-Sea Research II (2009) doi: /j.dsr
Session 4: Physical and biogeochemical feedbacks, forcing and climate sensitivity (part 3)
Joint IPCC-WCRP-IGBP Workshop: New Science Directions and Activities Relevant to the IPCC AR5 3-6 March Honolulu, HI