Southern Ocean Iron Experiment (SOFeX) Cruise
January 5 - February 26, 2002
January 7, 2002: Day 3
Latitude:46 12 S, Longitude:178 07 E
Ken Johnson writes: Hello.We sailed last evening from Lyttelton, New Zealand at 1800.The weather is beautiful, calm seas and clear skies.Were heading for 52S, 172W to start our survey for the northern iron enrichment experiment. The REVELLE has four main jobs during the SOFeX experiment.We need to find good locations to conduct each experiment, we need to create the iron fertilized patches, we need to create maps of the patch and we need to collect the initial, time=0, samples from each patch since the MELVILLE and POLAR STAR dont arrive until after the iron is added. When MELVILLE arrives in a few weeks, it will focus on monitoring differences in biological processes inside and outside of the patches, but it wont have time to create maps of each patch, thats our job.
Right now were heading to the vicinity of the first patch that we will create.It will be north of the polar front in low Si water.There are two strong fronts near the areas that we will fertilize, the subAntarctic front (SAF) and the Polar Front (PF).These are regions of strong temperature and chemical gradients and high currents.We want to stay well away from them, the current could destroy our patch if it floats into the front.The SAF is near 55S and we need to find it before we begin fertilizing.We will begin the survey at about 2000 (NZ time, 11 hours ahead of GMT) on Jan. 9.
Today, weve had a quiet day - abandon ship drill at 1015. Since were going south of 50, everyone had to try on their survival suits.A science meeting followed at 1330 to discuss the experiment, the work plan for the next week and, most importantly, to determine our water budget for the two rosettes.Water samples are collected from beneath the surface with twelve, 10 liter Niskin bottles that are mounted on the rosette.There is not always enough water for the experiments that are planned.We dont have a lot of time to collect rosette samples because our main job is mapping and adding iron.After several hours of discussion, we came up with a workable budget.
For the rest of the day, people were busy setting up their instruments, debugging hardware and discussing the experiment.Tomorrow we have our first test station to check the hardware out.