Brief Cruise Summary
On May 31, 1991, R/V Thomas Washington departed San Diego for the first of its three consecutive TUNES series WOCE legs. Stations were numbered consecutively from the beginning of the R/V Thomas Washington work on Leg 1, TUNES-1 Expedition, starting off the coast of California. The first station (no. 1) was occupied on June 2, 1991, at ~36° 10' N and 121° 44' W. The last station (no. 123) of the TUNES-1 Expedition was occupied on July 7, 1991, at ~5° 58' S and 135° 00' W. On July 11, 1991, R/V Thomas Washington arrived in Papeete, Tahiti.
During the 42-day expedition, 123 hydrographic stations (including 9 large-volume stations) were completed. All stations were sampled to the bottom and consisted of a rosette/CTD cast. Basic station spacing was 30 nautical miles, closing to 10 nautical miles between 3° S and 3° N. Sampling was performed primarily with a 36-place double-ring rosette of 10-L bottles and mounted CTD and transmissometer. CTD data consisted of pressure, temperature, conductivity, oxygen, and transmissometry. Water samples were collected for analyses of salt, oxygen, silicate, phosphate, nitrate, and nitrite at all stations and for CFC-11, CFC-12, helium, tritium, Δ14C, TCO2, and TALK at selected stations. Underway measurements included ADCP, surface temperature, and surface water and atmospheric pCO2 and N2O.