Southern Ocean Iron Experiment (SOFeX) Cruise
January 5 - February 26, 2002
Skip to Log Entry from the R/V Melville
February 6, 2002: Day 33
Ship @ 2/6/02 0520Z,-62 39.7688, -171 18.9891
No. Patch ARGOS Drifter @2/4/02 0600Z,-54 9.3, -169 37.62
No. Patch SOLO Float @ 2/4/2002 2251Z,-54 23.292, -169 57.048
R/V Revelle Log Entry: Hello again. We left the South Patch last evening under a beautiful sky and one of the few sunsets that weve seen. After floating the sediment trap over last night, we said farewell to MELVILLE over the radio. Kenneth Coale transferred a spectacular photo of REVELLE headed north - thanks Kenneth and good luck with the South Patch.
Never passing up a chance for one last sample, we towed the SeaSoar through the patch until 0100.Were now well on our way to the North Patch, more or less in the middle of nowhere right now.Still plenty of ice around.
The laboratories are pretty empty today as everyone catches up on sleep. Our next major task will be to find the North Patch. Were receiving positions from two sources: a drogued surface drifter with an ARGOS beacon and a profiling SOLO float with a GPS receiver and ORBCOM communications. Both have followed about the same trajectory since they were released in the patch nearly two weeks ago. Weve plotted their latest positions and projected their trajectories out to noon on Friday, when we will arrive in the vicinity. Then the search will begin! A 15x15 km patch is not very large and easy to miss in this ocean. Cross your fingers! We have just two days for work at the North Patch. Well need to be very efficient.
We left the South Patch with quite a bloom developing. Our last samples indicate that the bloom may soon exceed that created in the Equatorial Pacific during IronEx II. The data set that is produced should really help us understand much more about carbon export and the interaction of ocean chemistry, biology and climate. We had a betting pool going on the concentration of chlorophyll that would be produced in the South Patch. Looks like even the wildest guesses will be conservative. Seaman Bubba! Stand by to be impressed. Well, thats it for now.Time to catch up on paper work.
- Ken J.
Position: 66 degrees, 18 minutes south, 171 degrees,26 minutes west.
R/V Melville Log Entry: After a long and productive In Station, at 1700 last night we slipped the sediment trap over the side and set the floats and surface buoy free. Revelle came alongside to recover it for possible deployment at the Northern Patch site. Revelle then got underway and departed yesterday following a crosspatch Seasoar survey. She had been the mapping spreading and reconnaissance vessel providing us with up to date positional data regarding the Patch center. Her crew had been responsible for the site selection, iron deployment and initial tracking. Her other observations and measurements have helped shape our study. Her presence here will be missed as Melville now takes on all navigational and mapping responsibilities for this study in addition to all the station work.Our tasks have just been multiplied at a time when the patch continues to bloom and another doubling of biomass is predicted to occur within the next three days. Some have said that Revelle has made dinner and we get to eat it. Others say that Revelle has set a fire and we get to put it out. From my perspective this has been a first in multiple vessel operations and has benefited the experiment in ways such that the whole is much more than the sum of its parts.
Both the cruises aboard Revelle and Melville are long ones, especially for operations in an area that gets hit by storms every three days or so. Revelle was low on fresh milk, Melville was low on popcorn and CO2 for the soda machine. We had hoped to swap supplies during the sediment trap deployment by bundling them in garbage bags and throwing them over the side with a recovery buoy tied to the package, but time and weather prevented the exchange and this was not a scientific priority (but it would have been fun). Instead we were able to lash some nutrient standards, chlorophyll standards and documentation to the mast of the buoy so that we can intercalibrate our data sets. Revelle will be in good groceries soon enough and the radio messages received last night indicated that they were ready to head north.
The weather here is fickle. While rigging for deployment of the sediment trap array for Revelle last night, a squall came in and reduced visibility to about 30 meters. You could barely see the quarterdeck from the fantail, much less the Revelle holding off our starboard quarter almost 1 kilometer away. Corn snow swirled in thick clouds and still covers the deck in small drifts this morning. Deployment was cancelled and the Revelle said that it would probably head north without the array. Five minutes later we had 20 km visibility and the transfer was again on. The sun broke out as the array was cast off and Revelle moved in for recovery, a hint of green in the waves as she approached.
As we steamed off for the evening survey, we saw the sun set for my first time this trip.At these latitudes, it takes forever. Two successive small green flashes were apparent as the ship rose and set over two large swells and the sun did the same.