Date: Wed, 24 Dec 1997 08:58:21 -0500
3rd Weekly Progress Report Process 1, Kiwi 07 R/V ROGER REVELLE December 24, 1997 The third week of the Process 1 cruise was extremely productive and at times the weather was even pleasant. After completion of Sta. 6, including a second in situ productivity array, we ran south towards the ice edge. It was foggy, so Capt. Arsenault approached the loose ice zone with great care. The big icebergs show up on radar, but the loose pack ice does not. We encountered loose ice and made a station at 64deg09minS; after a day there the weather cleared and Capt. Arsenault figured out the drift of the pack ice. He conned REVELLE to 64deg40minS. At that latitude we had pack ice on three sides that stretched to the horizon plus a few big bergs. The wind was calm, there was very little sea and it was clear and sunny. The edge of the pack ice gave us the best weather yet. We made Sta. 9 at 0.6 nm from the edge of the ice. The next two stations were on the 170W transect at 63deg08min and at 62deg28min. At these two very long stations everyone got the chance to sample when they needed. The wind came up and we spent 6 hrs at Sta. 9 hove to with operations suspended. At Sta. 10 we launched the in situ productivity array and retrieved it 20 hrs later in a rising sea state. A section of the first nine stations shows the subsurface temperature front (+1.0 to -1.0 degreeC) that characterizes the APFZ. In Ian Walsh's contours of the same stations it appears that the high particle/Chl/diatom water at 40 - 100 m is being advected down to a considerable depth right in the front. We worked out a plan to sample the front with seven closely spaced CTD stations. We are involved in that work now, but the weather is getting bad. The barometer has fallen; wind is rising. It is not clear if we will be able to launch the CTD at the next scheduled station. The hydrographic, chemical and particle coherence is very dramatic. We have been impressed with the amount and rates of production in the low salinity surface layer between the APFZ and the ice edge. There hasn't been much sun this week, but what there was seems to have been enough to keep the surface layer chlorophyll concentrations between 1 and 2 mgChl/m3. The work of the third week has gone very well with no major breakdowns. The CTD and TM rosettes had to be reterminated, but that's to be expected. The Si, N, C, O2, trace metal, Chl, POC and micrograzer people rush the midnight productivity cast ever increasing vigor and enthusiasm. When the CTD lands the same thing happens with O2, nuts, salinity, CO2, DOC, bacteria, POC and trace metals. The lucky people who get to sample both casts have been busy. It's Christmas Eve and we're battening down for a blow. This may be a Christmas to remember. The people of the REVELLE wish everyone Happy Hanukkah and Merry Christmas. Regards, Dick Barber, Chief Scientist 24 December 1997