Interannual Salinity North of the Gulf Stream
[24-Feb-2016] Grodsky, S., Reul, N., Chapron, B., Bryan, F., and Carton, J.
Presented at the 2016 Ocean Sciences Meeting
Aquarius observations indicate that SSS in the shelf water north of the Gulf Stream (between 35N and 45N) experiences interannual variations with more than 1 psu difference between salty and fresh events. Longer JAMSTEC records confirm these SSS variations and show that they are positively correlated with interannual SST. This positive correlation suggests the dominant role of horizontal salt and heat advection. In contrast, the vertical advection would have resulted in the negative correlation. Joint analysis of interannual SSS and winds shows that salty/fresh events are produced by easterly/westerly wind anomalies, respectively. Thus, anomalous advection is dominated by anomalous Ekman transport acting on mean salinity and temperature gradient. Finally we use the mesoscale ocean model to examine the salt budget and relative roles of mean and eddy fluxes.