Presented at the 2014 Aquarius/SAC-D Science Team MeetingThe first Salinity Processes in the Upper Ocean Regional Study (SPURS) I field campaign took place in the approximate center of the north Atlantic surface salinity maximum (~25°N, 38°W). During SPURS I 16 Argo-type profiling floats were deployed in a high-density, 4 by 4 grid surrounding the central mooring with approximate 0.5 degree spacing. The floats were programmed to profile from 2000 meters to the surface every 5 days and remained remarkably close to the heavily instrumented central mooring for the duration of the primary study period from October 2012 to October 2013. Mixed layer salinity was at a maximum when the floats were deployed and the depth of the maximum slowly increased through early spring. Multi year observations display variability in both the mixed layer depth and salinity. We present observations of the formation, evolution, and erosion of the mixed layer in time and space.