Date: Fri, 09 Jul 1999
Subject: Rougher waters and science: remote sensing/optics group
Pictures: BioOptics Team, Zodiac Ice Sampling , Thin Ice Section

Last night, and extending into today, we had the worst weather so far: the sea was black and malevolent looking, and the waves were huge. Yesterday we worked "down" the 600 line doing four stations 20 km apart (recall the grid system we did 600.200, 600.180, 600.160 & 600.140). As yesterday progressed the wind picked up and the sea conditions worstened, until at the last station conditions were becoming difficult for the CTD, nets, etc. Both satellite imagery and "isobar" weather maps had warned us that a deep low pressure system was approaching and we were racing against time to get in as many stations as possible before the really bad weather hit. Since yesterday the barometer has dropped to 959mb and it is still falling (our charts show the center of this low to be about 948mb). Winds have often been in excess of 50 knotts (50 to 60 mph). Bottom line we're in a big storm.

In an attempt to keep working, during the night we moved closer to the coast - all the way in to 600.040 in the hope that Andvers I would provide some shelter from the large swell. Around ten, this morning, we decided to try to put the CTD in the water, and the big door of the Baltic room was opened. Three people were there to help, whereas usually it only takes two, and Captain Joe himself was in the room, an indication that it was an "iffish" endeavor.

Several of us were very curious to record this event on film, so we gathered on the gallery above the Baltic room. From there it was really impressive to see the waves come crashing against the ship, one of them coming directly in the room and getting the CTD attendants wet...

After that, it was decided that it would not be safe to send the instrument down since the large swell & the rocking of the ship can put great strain on the instrument cable, and the deployment and recovery of the instrument is very difficult under such conditions and could (if the instrument swung against the side of the ship) destroy the various sensors attached to it.

Given the weather, it was useless to try and go further into the open sea than we already were: the storm was still in full force, and would not allow much work to be done if the ship really took a beating: so instead, we went toward land, knowing that the coast would offer shelter from the wind, which was continued blowing at a speed of 40 miles an hour or more.. So as I write this, we are in the Straights of Bismark, watching the barometer still on its way down, but hoping that tomorrow the storm will abate and allow us to go to Palmer station and use the zodiacs to get everybody off the ship for a little while. Actually the objective is to return various equipment and supplies to the station but many are anxious to recall what "solid" land feels like.

Tonight, since it seems fairly obvious that there will be little more chance to do scientific work, the different groups started packing the instruments and other utensils which they will no longer need. It was interesting to hear bits and pieces of comments made as this was going on: most people seem to not believe that the cruise was ending so soon, and expressed their regrets to have to go back to "real life"... I guess there is something a bit addictive in the kind of life that we have been leading for five weeks: the intensity, the friendliness, the hard work, the absence of irrelevent concerns ("I can't think of having to use money again", said Eric), the beauty we saw around us every day, all that is hard to leave behind. But of course, there is also the other side of the coin, the desire to go back to loved ones, family, friends, pets, a garden...

Perhaps I should say a few words about "our" group - Mike, Sharon and Tim, Jinro, David, Ray and myself - as shown in the photo. Our biooptics group with its interest in the relationships between light and biology, remote sensing, atmospheric forcing and ice was fortunate to have Jinro who is from Japan, and he must have the longest commute I know of, since he alternates between New York and Tokyo! Jinro, as I think I mentioned earlier, is an ice specialist, and studies the physical properties of sea ice and its growth processe and he joined Ray's group for this cruise so that, combined, salinity and it's stratographic properties.

We've used different methods to sample the ice, depending on the conditions: when the ice was solid, we drilled cores, which were brought back on the ship and preserved in the cold chamber. These cores were often cut into thin segments (see photo right), and photographed under polarizing light, which shows the different internal structure of the ice. The most common forms seem to be either granular (small crystals) or columnar (long, regular crystals). These differences in structure tell about the environment in which the ice was formed, whether in calm and peaceful conditions or in turbulent waters. And these conditions of formation may make considerable difference for the ecology of the system. The thin sections, so skifully prepared by Jinro & Tim are beautiful to look at and ... When the ice was too thin to walk on, we went out in the zodiac, and brought back ice in various coolers and buckets, to be analysed in the lab. When snow was present, Jinro, Sharon, and Michael (who is a snow pit specialist) would also examine and measure the snow, which has an influence on the growth of the ice underneath: because it acts as a "blanket" it may slow down the ice formation, however, if it gets too thick, it will push the ice below the surface of the water and create snow ice.

We are also interested in studying the optical characteristics of the ice & snow, which complements Ray's interest in the optical characteristics of the water column. In a collaborative effort with the Cold Region Research Electronic Laboratory (CRREL) Jinro brought an instrument designed to be put through a hole in the ice and then to measure the optical properties of the snow & ice. One of Ray's instruments complemented this instrument by we were the sea ice, optics & remote sensing group. Jinro added important experience for our sea ice cruise. The physical characteristics of sea ice Jinro talks about include: temperature (of the surface, internal and basal), the thickness, the measuring similar optical properties below the snow & ice within the water column. Combined use of these instruments allows them to estimate the solar energy, however slight this time of year, which penetrates through the snow & ice cover and enters the water column. This determinens the energy available for photosynthesis and whatever light is available for, for example, penguins to hunt krill.