Colloquium: James Carton

In the second part of the talk I will discuss a scientific problem that has been engaging my research group for a number of years, which is the role that the global oceans play in storing, transporting, and releasing excess heat.  The historical network of ocean observations changes in time, is sparse, and is inhomogeneously distributed.  These limitations mean that we cannot estimate the changing heat content of the oceans based solely on historical observations.  Instead, we must use ocean observations to constrain numerical simulations of ocean circulation driven by historical estimates of surface heat, freshwater, and momentum fluxes (a process known as data assimilation).  Previous studies have left a somewhat confused picture of the time history of the ocean’s ability to store and transport the <1Wm-2 excess heat being added to the ocean due to anthropogenic greenhouse gasses.  How much is being stored?  How/where is it getting into the ocean?  How does storage relate to natural variability such as El Nino?  Was the hiatus something unusual? Here I describe our latest version, just about to be released, of the Simple Ocean Data Assimilation reanalysis (SODA version 3) and present some early results addressing these issues.