Venus' surface temperature controlled by a coupled mechanism of chemical and albedo feedback
G. L. Hashimoto, Y. Abe (University of Tokyo)
The abundance of Venus' CO atmosphere was suggested to be
controlled or buffered by carbonation reaction on the surface
(carbonate buffer), since the Venus' surface condition is so
close to the equilibria over the calcite-quartz-wollastonite
assemblage (CO (gas) + CaSiO = SiO + CaCO ).
However, Bullock and Grinspoon  and Hashimoto et al.
 pointed out that the atmosphere buffered by a carbonation
reaction is not stable. Then, which mechanism control the Venus'
atmosphere? Here we propose an alternative idea of regulating
Venus' climate. Our new mechanism regulates the surface
temperature to the present value for a given amount of CO
in the atmosphere. This mechanism may be considered just
opposite to the carbonate buffer, which tries to regulate
the surface pressure for a given surface temperature. We
construct a coupled model of the cloud albedo and the chemical
interaction between the atmosphere and surface rocks. Our
model shows that the coupled effect of chemical reaction
and albedo buffers the surface temperature change against
variation in the solar constant and atmospheric CO abundance.
Our model shows that Venus' surface temperature is kept to be
about 735 K throughout the Venus' history.