Snakes on a Ship: First Results from SPURS SSS
[14-Nov-2013] Schanze, J.J., Lagerloef, G., Schmitt, R.W., and Hodges, B.A.
Presented at the 2013 Aquarius/SAC-D Science Team Meeting
Observations of open ocean surface salinity are generally made at a depth of 5 m. While diurnal variations in temperature are well documented, observations of salinity changes at the air-sea interface are sparse. As part of the Salinity Processes in the Upper Ocean Regional Study (SPURS), a novel sea surface salinity sampling apparatus was deployed aboard the R/V Endeavor
. This apparatus (termed the "sea snake") consists of a reinforced hose that is stoppered at the end and has two small intake holes. This hose is towed from a boom mounted in such a way to ensure the sampling of undisturbed water outside of the ship's wake. A self-priming pump is used to suck in seawater that is then pumped into a de-bubbler before being measured in a Seabird SBE45 thermosalinograph. During the March 2013 SPURS cruise, we found diurnal salinity enhancements exceeding 0.1 psu during calm, sunny days. The uppermost 5 m appeared to be statically stable due to concurrent temperature increases of approximately 2-3°C at the surface. These events are also present in the preliminary record from the September 2013 SPURS cruise. Moreover, freshwater intrusions with changes of up to -2 psu are evident from these data.