Diagnosing decadal changes in the thermodynamic structure of the North Atlantic

Abstract

We examine the skill of a polynomial fit to detect temporal changes in the thermodynamic structure of the ocean in the North Atlantic. We do so by adjusting the observed neutral density with a polynomial function in terms of observed potential temperature, pressure and salinity, for five different cruises carried out during the last fifty years. This analysis results in five sets of coefjicients whose longitudinal distribution helps to identify spatial and temporal e han ges, revealing interdecadal changes in the thermodynamic structure of the ocean.