A note from Bob Anderson, who forwarded the report from K.Coale
Date: Wed, 14 Jan 1998 13:36:09 -0500 Dear All, Following is the first weekly report from the AESOPS Polar Front Zone Survey-II Cruise aboard the R/V Roger Revelle, Kenneth Coale, Chief Scientist. In addition, I have included a subsequent message from Kenneth, because it provides a further description of the dynamic nature of the APFZ. In response to Kenneth Coale's inquiry about ice, Ken Johnson located a Southern hemisphere sea ice image, at: http://www.fnoc.navy.mil/otis/otis_shem_00_ice.gif Indeed, it appears that the ice at 170 deg W has retreated to 70 deg S, from its position at 64d 40' S where the Revelle was forced to turn back north during Process-I less than a month ago. regards, Bob AndersonThe Weekly Report from Ken Coale, Chief Scientist
January 8 Since the ship first docked at the commercial pier, the winds were from the south and blew the ship away from the dock. All items loaded and unloaded the last few days had to be craned on and off because the loose spring lines left a 10 foot gap and items were too heavy or delicate to toss the distance. The fenders had been craned aboard some time ago. The chandler had mentioned an unusual forecast that Jon Alberts relayed, but no one thought much of it, it was beautiful and in the 80's in Lyttelton. Our departure was set for 1600 and we were still sorting boxes and unloading trash. At 1530 the wind shifted and the ship was tight against the dock, the last few items could be handed directly across. Few noticed the subtle change. At 1600, we could almost slip the mooring lines from on deck and as we made our way out of the harbor and through the channel, our minds and bodies were beginning to relax from the worries and exertion of unloading one cruise and loading another. We were looking forward to the good weather experienced by the Process I cruise, just preceding us. After Survey I, many of us were anticipating far less meteorological excitement, yet had stowed our gear securely. Just after we finished securing mooring bits, the crane on the fantail and installing the boom for underway measurements, I noticed the clouds to the north were towering thousands of feet above us and bearing down on us yet still the weather was mild. I went inside to secure items in the main lab and the IMET readout indicated winds of 40 knots! This couldn't be, I had just been on deck and things were fine. I went up to the bridge to find that, within minutes, the world had changed. The wind was blowing a steady 50 with gusts up to 60 and 70. The chief mate and AB's on the bow were struggling to keep the covers on the crane and anchor capstan from blowing off and were getting hammered by wind and spray. I told the mate to hove to until the decks were secured. Funnel clouds, spun off from the collision of two air masses, touched down to form water spouts. Decks were secured as the sea rose and we headed south, fleeing the mayhem. Sleep was almost impossible as we were tossed from side to side, the ship steaming in the trough of some very large seas. A particularly large wave sent things crashing about at 0300 and several of us were up to clean up the damage. The main science labs, forward and aft holds were remarkably secure with computers on the deck in the lounge and computer lab. Pots, pans, utensils, plates, sugar, jelly beans, coffee, chairs and condiments were, however, all over the galley and mess decks ( I guess that is why they call it that). This was indeed a rude beginning, but we all figure things can't get much worse. January 9 The following day, seas were up to 25 feet and winds still at 45 knots. Boarding waves broke two large 4x10 timbers in the bulwarks under the squirt boom and ripped a 1/4" steel cover half way off the trace metal winch, bending it in half and flooding the motors, solenoids and switches. The sea state has slowed our progress to less than 11 knots and I fear my ambitious cruise plan may now be eroded by bad weather and seasick scientists. Fire and boat drill at 1015. It is now January 13 and after a long transit, the seas have quieted considerably and transit speeds are back above 12 knots. We are finally savoring some of the Process I weather and are very glad for such luck. We have successfully completed a test station at 53 S. The ship's electrician, Jack Healy, was very helpful in getting the trace metal winch up and running again. After several casts at 57 S in preparation for the Sea Soar transect from here to the ice edge, the Sea Soar was deployed at 57S, 170W. The AC9 and subunit on the MODAPS were indicating lots of problems and the fish was recovered about midnight. Eight hours later working in cold drizzle on the fantail, the OSU group put the fish back together without the MODAPS, but sporting a reliable SeaBird 911. All indications are that everything is now working properly and even the AC9 data are being logged. Depending on the location of the ice edge, we will be towing this package for the next couple of days. All aboard are in good spirits and looking forward to the ice and the start of our first full vertical profile stations. Kenneth Coale Bob, Ken, Walker Greetings from 60 south. We are seasoaring successfully and the OSU group is producing beautiful cross sections of temperature, salinity sigma t and the flash packs on the fish are returning fluorescence data. Waiting to fix the fish at 57 proved useful in detecting a large bolus of warm water extending to about 300 m between 57 and 57.75 S. In addition, low salinity pockets within the mixed layer are coincident with areas of high fluorescence, as if spun off from the front. The isopleths of all parameters are beginning to be compressed and shoal as we near the front. All underway measurements are proceeding faithfully and we are taking discrete samples regularly for chlorophyll, nutrients, salts, oxygen, flow cytometry etc... I had requested from the bridge an estimate of the distance to the ice from here. Process I found some very interesting features associated with the melt water, and the evolution of a strong biological signal from the ice edge northwards. It was our hope to be able to follow this evolution during Survey II. This morning the bridge reported ice at 70 S!! To continue to seasoar all the way to the ice at 70 would strongly impact our other ambitious plans and we are in the process of planning our next step. Do you have access to any other imagery from which the position of the ice along 170W could be detected? If so, please e-mail to me the latitude and any general description of its features. The weather continues to hold with seas 8-10 and 20 knots of wind. I hope all is well. Kenneth