Lamont Pumping SeaSoar Methodology

This data report documents the methodology used to measure various biogeochemical parameters in the Ross Sea during the AESOPS project of the U.S. JGOFS program using the Lamont Pumping SeaSoar (LPSS) in the period November 25 through December 8, 1997.  Spatially high resolution data were obtained in the upper 200 meters of water during the early stages of phytoplankton blooms in the Ross Sea.  Over the two week period, a total of 4 successful "tows" were made near and along the line 76°30' S, near 175°E in order to document the initiation and progression of the blooms.  During each "tow" which lasted for about 24 hours covering a distance of about 275 km, the following properties were measured in seawater: temperature, salinity, pressure, PAR, chlorophyll-a, oxygen, pCO₂, (nitrate+nitrite), phosphate and silicate.  Of these properties, the temperature, pressure, PAR, chlorophyll-a and oxygen were measured using in situ sensors aboard the SeaSoar fish; pCO₂, and the concentrations of (nitrate+nitrite), phosphate and silicate were determined in the seawater pumped continuously (~ 7 liters/min) aboard the ship from the fish, using respective analyzers located in the ship's laboratories.  The salinity was determined at two places using identical sensors; one aboard the fish and the other aboard the ship for the pumped water.  A comparison of these salinity data allowed us to determine the location of the pumped water accurately.  Tows 3, 4 and 6 were run along an east-west transect located along the 76°30' S latitude over a distance of about 275 km, and the data files are organized according to the "tow" number.  Each file contains data from the time the system was stable until it was shut down for retrieval, and the start time and the end time for each tow are listed in Table 1. The measurements have been interpolated and gridded, and each parameter is contained in a file for each tow.  There is no dissolved oxygen data in Tow 3 due to sensor malfunction. Tow 5, unlike others, was run along five short north-south lines in order to document the meridional distribution of the properties. The data consist of five gridded north-south sections connected by short east-west ones, and each of these sections is contained in a separate file.