Abstract :
A nonlinear convolution integral is developed to model the response of the ocean carbon sink
to changes in the atmospheric concentration of CO2 , This model can accurately represent the
atmospheric response of complex ocean carbon cycle models in which the nonlinear behavior
stems from the nonlinear dependence of CO2 solubility in seawater on CO2 partial pressure,
which is often represented by the buffer factor. The kernel of the nonlinear convolution model
can be constructed from a response of such a complex model to an arbitrary change in CO2
emissions, along with the functional dependence of the buffer factor. Once the convolution
kernel has been constructed, either analytically or from a model experiment, the convolution
representation can be used to estimate responses of the ocean carbon sink to other changes
in the atmospheric concentration of CO2 , Thus the method can be used, e.g., to explore
alternative emissions scenarios for assessments of climate change, A derivation for the nonlinear
convolution integral model is given, and the model is used to reproduce the response of two
carbon cycle models: a one-dimensional diffusive ocean model, and a three-dimensional oceangeneral-
circulation tracer model
