Southern Ocean Iron Experiment (SOFeX) Cruise
January 5 - February 26, 2002
Skip to Log Entry from the R/V Melville
January 22, 2002: Day 18
Ship: -66 10.9134 -170 22.1694
In North Patch Particle Interceptor Trap: -55.681 S, -171.768 W
Out North Patch Particle Interceptor Trap: -55.635 S -171.963 W
R/V Revelle Log Entry: Whoa, what a day!They dont pay the Chief Scientist enough!We arrived at our initial target of 65S, 170W at 0400 this morning.Water temperature was a chilly -0.2C.Conditions at 65S were a little uncertain for the experiment. It looks like the spring/summer phytoplankton bloom has not occurred yet in the waters south of 62. Large drops in the concentration of carbon dioxide and silicate in surface waters are good indicators of the phytoplankton bloom - diatoms consume Si and CO2 as they grow.The values were high all the way down, CO2 is nearly 400 matm - typical of winter values.Now this is what were looking for: high Si and CO2, but were a little afraid that the normal spring bloom will occur during the middle of our experiment. That would be very confusing, making an experimental bloom in the middle of the spring bloom. The normal bloom would be different because it has much less iron. The main difference is that the normal bloom runs out of iron before much of the nitrate in the water is consumed, so it is much weaker than the bloom we expect. Still, it would be confusing.
Is the spring/summer bloom late, was there just no iron this year or did intense storms mix blooms so deep that they ran out of light before they could grow? Pete Strutton adds that the summer crop is several weeks late at his fathers almond farm in Australia due to unusual cold. We did a CTD cast and found that the mixed layer was two times deeper than that found during the JGOFS expedition. If it warms and the mixed layer shoals, then the bloom might form and wed have a mess.
So we continued south to move into an area where blooms typically dont occur.This was our prime experimental area. But, then the bergs got thick with almost 80 targets on the RADAR at times. At one point we turned back because it didnt seem like it would be feasible to make an iron patch amongst the bergs. We shifted a little further west and, WOW, we got through. Were in relatively open water now.The chemical signals that were monitoring aboard ship look good. Well do a CTD cast shortly to test the mixed layer depth and then start SeaSoaring around midnight if all is well.
Not much else to report. We spoke with MELVILLE by satellite telephone this morning. Theyre stuck in a gale, while we coast along in flat seas.MELVILLE should arrive around midnight at the North Patch when they get going. The big activity on board is e-mail. What a change from the old days of once a week calls to Ham Radio operators that were then patched through on collect phone calls: "Hi Honey, over".
Well this is Kilo Alpha Oscar Uniform (REVELLEs call sign), over and out.
- Ken J.
Ships Position:53 degrees, 53 minutes South, 174 degrees, 38 minutes West
R/V Melville Log Entry: Well, the nice weather we have been enjoying just went south, so to speak. I awoke to a falling barometer and reports of a gale heading our way at 30 kts from the southwest. We have had a pretty impressive following sea but when we turned into it for our test station today, the waves were larger than would allow a safe deployment of all our equipment. In the figure above, the wave you can see over the starboard main deck is well above the crane and the 01 deck. We had to abort the CTD cast and it was too rough for the Trace Metal Rosette deployment, but we did get a full set of Go Flo casts in and the bottles are now soaking with nice clean seawater in them. As the day progressed the swell came around to our starboard and we are now taking pretty big rolls. All weather doors are secure and porthole plates are dogged in place with timbers protecting the hanger doors. Winds are about 40 kts, gusting to 50. So far the lab is in good shape and only minor problems were experienced during the test station (meter block readout on the CTD winch does not work) but these are being solved at the moment. Another problem is that the bow comes out of the water and the seawater intake draws air. When this happens the pump loses its prime and the waterline shuts down. Not a big problem, unless you are trying to cool a laser on a flow cytometer. We have switched to another line and things are rolling along smoothly.
A funny story: Life at sea can be intense. The conditions are severe and the quarters cramped. The bunks dont necessarily allow a person room to sit up and the rooms are very small. As such, one needs to develop a courteous attitude towards ones room mate. As Dr. Mark Brzezinski got up, not wanting to disturb his room mate (Dr. Mike Landry), Mark groped around, quietly in the dark, found his clothes, dressed and went to the main laboratory to work. When Mike got up he asked Mark:"What are you doing wearing my nice pants?"Sure enough Mikes pants fit Mark so perfectly that even Mark didnt know the difference until he recognized that the belt was not his.
- Kenneth Coale