Mesoscale Variability Linked to Interannual Displacement of Gulf Stream

The impacts of interannual oscillations of the Gulf Stream (GS) on oceanic mesoscale variability are investigated using satellite observations of sea surface height (SSH) and sea surface temperature (SST) from 1993 to 2018. We show that variations in GS position, strength, and meandering status are the dominant spatiotemporal modes in regional SSH variability as they explain over 50% of the total variance. In particular, meridional shift of the GS associated with the large-scale wind variation over the North Atlantic contributes to approximately 30% of SSH variability. We further find that this path displacement mode can drive approximately 15% of regional mesoscale variability in eddy kinetic energy and divergent eddy heat flux. This observational-based evidence of ocean mesoscale response to GS shift infers a potentially important forcing mechanism that could drive eddy-scale ocean variability and has far-reaching implications for regional ocean and ecosystem dynamics in response to climate variation.