Large‐scale forcing impact on biomass variability in the South Atlantic Bight

The Gulf Stream western front (GSF) follows the shelf slope topography for a great extent of the South Atlantic Bight (SAB). Sub‐surface intrusions of the Gulf Stream are known to provide nutrient‐rich waters to the outer shelf regions of the SAB and, consequently, promote phytoplankton growth. These intrusions are much more frequent during summer and are responsible for a significant portion of the annual SAB shelf carbon production. Based on the analysis of satellite ocean color data, sea surface temperature (SST), sea surface height (SSH), and climatologic data sets, we present evidence for a connection between these Gulf Stream intrusions and the seasonal variability of the size and strength of the North Atlantic Subtropical Gyre (NASG). The intensity and frequency of intrusions depend on the proximity of the GSF to the shelf, which is modulated by the seasonal expansion and contraction of the NASG.