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Re: solubility pump



Ray,

I suggest using the mean ocean salinity normalized alkalinity for the
solubility simulations, mainly because I think the focus should be
on your point 1.

It is unfortunately not true that the buffer factor is independent of
Alk. In fact it is largely controlled by the ratio of DIC/Alk. It
therefore affects the anthropogenic CO2 uptake simulations. By how
much ?

Rick Murnane run anthropogenic CO2 simulations using both a solubility
pump model (with ocean mean alkalinity) and a combined pump model and
found that the combined pump model takes up about 5% less
anthropogenic CO2 (Murnane and Sarmiento, 1998). This reduction is
mainly a consequence of the carbonate pump driven lowering of surface
alkalinity and hence a lowering of the anthropogenic CO2 uptake
capacity. I conclude on the basis of these experiments, that we can
expect a 5% difference in anthropogenic CO2 uptake between a scenario
using surface mean or global mean alkalinity.

If the focus is on your point #2, then we have to use surface
mean alkalinity. If the focus is more on point #1 (my preference),
then we have to use ocean mean alkalinity. It is up to you to
decide.

- -- Niki

PS: With regard to C14. I agree with Ken that it is best to run
    bomb C14 with both C13 and C12, and not as a perturbation.



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