Brief Cruise Summary
The CGC92 expedition was carried out on the U.S. registered R/V John V. Vickers. This vessel was operated by the University of Southern California together with officers from the NOAA corps.
The goal of the cruise was to carry out a WOCE one-time hydrographic measurement along section P13 which runs along longitude 165° E from the Kamchatka peninsula to New Caledonia. The cruise was split into three legs for logistical regions.
Leg 0: Expedition Code 3220CGC92/0
Leg 0 of the CGC92 expedition consisted of a transit from Los Angeles, California, to Dutch Harbor, Alaska, with 4 stations occupied along the cruise track to test the CTD/rosette system (stations 1 - 4 are not included in the data set). One of these stations was a re-occupation of Station "P" (50° N, 145° W). Scientists from SIO tested an underway ADCP system along the cruise track.
Leg 1: Expedition Code 3220CGC92/1
The chief scientist for Leg 1 of the cruise was Dr. John Bullister of NOAA/PMEL. The R/V John V. Vickers left Dutch Harbor on August 16, 1992, to carry out the sampling along the cruise track, and arrived at Kwajalein, Marshall Islands, on September 15, 1992.
Leg 1 consisted of 51 stations (Nos. 5 - 55). The first station on this leg (No. 5) was a CTD/rosette cast test (not included in the data set) made in the Bering Sea, along the transit from Dutch Harbor to the start of the P13 line near the Kamchatka Peninsula. Sampling of the P13 section began with occupation of station No. 6 on August 21, 1992, near the 200-meter isobath off Kamchatka. A series of stations were occupied on a southeastward transit down the continental slope and across the Kamchatka trench. The section turned directly southward at about 51° 30' N and 165° 00' E and continued along the 165° E meridian for the remainder of Leg 1. Nominal station spacing was 30 nautical miles (nm) from the start of the section to about 40° N. Because of a series of delays during the first part of Leg 1, a decision was made to stretch nominal station spacing for the remainder of Leg 1 to 40 nm.
Because of concerns about possible structural deformation to the ship and concern over the failure of a watertight door to close properly, work on the P13 CTD/rosette section was halted on September 9, 1992, at about 30° N, and R/V John V. Vickers was ordered to steam directly to Kwajalein.
Leg 2: Expedition Code 3220CGC92/2
The chief scientist for the second leg of the cruise was Dr. Bruce Taft from NOAA/PMEL. The R/V John V. Vickers remained at the dock in Kwajalein for an extended period of time for evaluation of structural integrity by two marine architects and for repair. The ship left Kwajalein on September 26, 1992, and began steaming back to the break-off point to continue work on the P13 section.
Despite the delay caused by these repairs, the R/V John V. Vickers had to arrive in Noumea, New Caledonia in time for its subsequent use by Tropical Ocean Global Atmosphere/Coupled Ocean-Atmosphere Response Experiment (TOGA/COARE) investigators. This schedule did not allow enough time to complete the WOCE Section P13 to even minimum WOCE Hydrographic Program (WHPO) specifications.
With the remaining time, R/V John V. Vickers occupied CTD/rosette stations at a nominal spacing of about 60 nm from 28° N to 4° N, and closer spacing from 4° N to 4° 30' S. Lowered ADCP measurements were made on stations between 4° N and 4° S. The section was terminated on October 17, 1992, at 4° 45' S and 164° 00' E in order to arrive in Noumea by the October 21 deadline. A total of 32 stations (Nos. 56 - 88) were occupied during Leg 2 (station No. 60 was aborted and not included in the listings).
Throughout the cruise along WOCE Section P13, samples for shipboard analysis of TCO2 and TALK were collected from 10-L Niskin bottles on the 36-position small-volume rosette water sampling system. Of the total of 88 stations on the three legs, CO2 samples were collected from all Niskin bottles throughout the water column on 39 stations. On an additional 41 stations CO2 samples were collected from surface bottles only (Fig. 2).