Variability in near-surface salinity: From hours to decades in the Eastern North Atlantic: The SPURS region

Abstract

We examine the variability of near-surface salinity in a 10° × 10° region of the eastern North Atlantic, the location of the first part of the Salinity Processes in the Upper-ocean Regional Study (SPURS-1). The data used were collected over a twoyear period, largely by a group of two types of profiling floats equipped with sensors that record high-resolution temperature and salinity measurements in the upper few meters of the water column. By comparing the SPURS-1 measurements to observations in the area from previous decades, we examine variability at time scales ranging from a few hours (mostly consisting of rainfall-driven decreases in salinity) to diurnal cycles in temperature and salinity, seasonal variability and the annual cycle, and finally to decadal-scale changes. The relationship of near-surface salinity to the hydrological cycle suggests a continuous spectrum of variability in this cycle from hours to decades.