Susan Harrison (University of South Carolina, USA); Corinne Trott (Naval Research Laboratory, Mississippi, USA)

Satellite altimetry has been a useful tool for calculating ocean heat content as sea surface height correlates strongly with thermocline depth. Energetic mesoscale ocean eddies contribute to vertical mixing within a water column through the upwelling and downwelling from cyclonic and anticyclonic circulation. Yet, properties from the constituent water-mass first entrained during an eddy’s formation are retained due to negligible horizontal mixing with surrounding waters during the energetic phase of their lifecycles. Changes in water properties, such as sea surface temperatures, in the northwest Atlantic Ocean are modulated by energetics of the eddy field across the Gulf Stream (GS). This makes eddies a principal contributor to the transport of heat across the ocean surface as well as vertically in the water column. GS eddies have been detected within the region of 81°W to 52°W and 28°N to 42°N using an eddy tracking algorithm and assimilated altimetry data from the Nucleus for European Modeling of the Ocean (NEMO) 1/12° resolution modeling framework. This eddy tracking algorithm uses altimetry to resolve principal eddy characteristics such as their abundance, size and intensity. By utilizing altimetry to infer changes in thermocline depth in response to variability in the GS eddy field, the impact from the local eddy field on the expression of heat can be measured. Identifying the impact that eddy generated heat distribution has on marine heatwaves thus provides a mechanism to analyze marine heatwave tendencies using altimetry.