Date: Sat, 15 Nov 1997 10:22:16 -0500
Science Situation Report for NBP97-08; Friday, November 14, 1997 Science operations for the last Process Cruise of AESOPS (Antarctic Environment Southern Ocean Process Study) aboard the NB Palmer began as we left Lyttleton, NZ at 1700 November 5. The Palmer steered a course to 53 deg. S, 170 deg. W and then proceeded directly south along 170 deg. W. Underway samples were collected for a variety of projects: nutrients (Codispoti, Takahashi), chlorophyll (Smith, Barber, Marra), dissolved carbon dioxide and oxygen (Takahashi), dissolved organic carbon (Carlson/Hansell), and stable isotopes (Altabet). Upon reaching the region of the polar front (ca. 61 deg. S), we rendezvoused with the R. Revelle, which is conducting a survey cruise in the region of the polar front as part of AESOPS. Because of excellent weather, at the end of the SeaSoar activities, we conducted a test station and deployed all instrumentation that we will be using later during the cruise. We also at this time deployed the LDEO pumping SeaSoar as well. The SeaSoar deployment was successful in that some data from the pumping system was obtained, and a test of the control mechanisms was completed. Unfortunately, the pumping line's integrity was breached and further data could not at that time be collected. During the test station we discovered some unexpected problems with the CTD systems; however, water was collected to the bottom to provide dissolved organic carbon concentrations. Deep water DOC levels were found to be 41 uM, consistent with previous cruises in the region. Chlorophyll levels in the frontal region were ca. 0.4 ug/l. After the test station was completed, we resumed our transit south along 170 deg. W, collecting underway data until we passed near the AESOPS sediment trap/current meeting mooring near 65 deg. S. At that time we changed course and are proceeding to Station Sei on the northern portion of the continental shelf, crossing the Antarctic circle on the evening of November 12. The transit has been extremely fast, as the ice we have encountered is thin and broken. The ship's officers and crew have made the transit flow smoothly, and the ASA support personnel have greatly assisted the science party in their equipment preparation and set up. This morning the traditional crossing ceremony was held at breakfast, and the ship is now certified to enter the realm of the Southern Ocean. The scientific party looks forward to beginning sampling in earnest tomorrow. Walker Smith, Chief Scientist