Uptake by the Ocean Estimated Using Transit-Time
Samar Khatiwala, Associate Research Scientist,Lamont-Doherty Earth Observatory
The ocean is considered to be a major sink of CO2 produced by industrial activity. Much progress has been made in recent years in understanding and quantifying this sink. However, many uncertainties remains as to the distribution of anthropogenic CO2 in the ocean, and its precise rate of uptake over the industrial era. To address this important issue in climate science, we have recently developed a new technique for inferring the distribution of anthropogenic CO2 in the ocean from measurements of transient tracers. Our method is based on the recognition that the transport of tracers in the ocean is described by a Green's function or ``transit-time distribution'' (TTD) which may be parameterically estimated from tracer data. The TTD technique allows us to account for both the ocean's complex transport, and the time-varying air-sea disequilbrium of CO2 over the industrial era. In this talk, I will discuss the ideas underlying the TTD technique, and describe their application using global ocean measurements of CFC12.