Meridional Heat and Salinity Transport Anomalies in the Atlantic Ocean

Kathryn Kelly (University of Washington, United States)

Event: 2014 Ocean Surface Topography Science Team Meeting

Session: Science Results from Satellite Altimetry: Regional and basin-scale processes and sea level rise

Presentation type: Type Poster

Transport anomalies of salt and heat have been linked in models to stability of the Atlantic Meridional Overturning Circulation (AMOC). However, few direct measurements of these transports are available. Here we assimilate observations of thermosteric (TSL) and halosteric (HSL) sea level, equivalent water thickness (EWT) from GRACE, and sea surface height (SSH) into a simple model forced by surface heat and freshwater fluxes to construct a heat and salt anomaly budget for the Atlantic for 1993-2011. Heat and salt transport convergence (HTC) anomalies are estimated as a residual of the budget using a Kalman filter. Anomalies of HTC are combined with direct estimates of meridional transport at 41N from Willis (2010) to estimate transport anomalies throughout the Atlantic. The monthly MHT anomalies agree well with MHT from the RAPID/MOCHA program at 26.5N (the RAPID line). The relationship of salt transport anomalies with AMOC is less clear and we compare our estimates with the few high quality salt transport observations available and with results from climate models.
Kathryn Kelly
University of Washington
United States