A. CRUISE NARRATIVE: AR18 (NORDIC WOCE - OVERFLOW THROUGH THE DENMARK STRAIT) A.1. HIGHLIGHTS WHP CRUISE SUMMARY INFORMATION WOCE section designation AR18 Expedition designation (EXPOCODE) Leg 1: 34AR10_1 Leg 2: 34AR10_2 Chief Scientist(s) and their affiliation Jouko Launiainen/FIMR* Dates Leg 1: 1993.AUG.16 to 1993.SEP.10 Leg 2: 1993.SEP.11 to 1993.OCT.05 Ship R/V ARANDA Ports of call Leg 1: Gothenburg, Sweden to Reykjavik, Iceland to Isafjoudur Island Leg 2: Isafjoudur Island to Reykjavik, Iceland to Helsinki, Finland Number of stations 99 67° 23.16 N Geographic boundaries of the stations 29° 47.53 W 22° 52.02 W 65° 22.08 N Floats and drifters deployed two Argos drifters Moorings deployed or recovered 0 Contributing Authors: Jouko Launiainen *Chief Scientist Jouko Launiainen Finnish Institute of Marine Research 3 Lyypekinkukja P.O. Box 33 FIN-00931 Helsinki, Finland Phone: +358-0-331-044 FAX: +358-0-331-376 Telex: 125731 imr sf Email: jouko.launi@fimr.fi A.2. CRUISE SUMMARY Exchange of water and heat between the Atlantic Ocean and the polar seas is one of the key problems in the oceanographic, climatological and environmental change. As a contribution to the WOCE, the Nordic Countries study the question, especially the exchange of water, heat and salt through the Denmark Strait and the Iceland-Faeroe Ridge as the NORDIC WOCE. After a Norwegian pilot expedition in 1992, the Icelandic research vessel Bjarni Saemundsson and the Finnish R/V Aranda (of ice class 1A Super) started in autumn 1993 a set of NORDIC WOCE expeditions. R/V Aranda made in the Denmark Strait Area a CTD and ADCP survey, took samples for tracer studies (freons), released Argos drifters, monitored flow- through surface salinity and fluorescence and, made marine meteorological studies and balloon soundings. The ice conditions in the Denmark Strait were during the late summer and autumn 1993 quite difficult and exceptional. Opposite to the normal situation in this time of the year time, when approximately a fourth of the strait should be covered by ice on the Greenland side, during late August and September on might meet sea ice, growlers and ice bergs on the Icelandic side of the Strait, up to 25 to 30 nautical miles from the coast. During the R/V Aranda expedition some 100 to 150 growlers and ice bergs were seen in the area (Fig.1) and as a top curiosity one might report that 30 nautical miles from north-western Iceland a grounded (at 66o 444 N, 29o 244 W) iceberg was seen the over water part of which was 95 to 100 m high! The thermal front between the Polar and Atlantic water was shifted eastwards as well. In spite of rather difficult navigation and measuring conditions, fog and currents and high winds during the later expedition, in addition to the ice difficulties, a successful CTD- network of 99 station was implemented in the Denmark Strait. Seven transversal sections were taken, four of which were repeated three times during the four weeks (Fig. 1). The data is of high quality and meets the "WOCE" standards. In Fig. 2 is given the density and salinity structure and its time history for one section, the overall structure indicating the northward flow of warm Atlantic water on the eastern side and polar outflow in the west. In each of the sections, both a ship mounted and a CTD mounted acoustic doppler current profiler, ADCP, was used. Although especially the latter techniques turned out to be rather demanding and suffered technical faults, the measurements offer an interesting situation for a methodological comparison study, in addition to getting more insight to the onsite oceanographic processes. Additionally, two Argos drifters were deployed on 28 August 1993. The one, having a sail in the depth of 75 m, was deployed on the eastern warm Atlantic water side of the front. The other, having the sail in 10 m, was deployed on the western cold polar water side, 20 nautical miles from the eastern one. The drifters are still active (15 Nov. 1993) and their trajectories showed the front later to have been shifted back towards the Greenland. Generally, the drift was rather irregular having e.g. tidal and inertial scales of motions. During the first and a half month the eastern buoy showed a net drift of 3 to 4 cm/s northwards in the Irminger Current. The western one drifted a slightly longer distance towards south- southwest, in the East Greenland current, towards which also the eastern drifter turned, finally. For tracer studies, samples for four fluorocarbons (CFCl3, CF2Cl2, CCl2FCClF2) were taken both from water and air samples during the first three weeks of the cruise. Water samples were taken from rosette mounted 10 l Niskin bottles and analysed using a purge-and-trap sample work-up technique based on gas chromatographic separation and very sensitive electron capture detection. A total of 672 water samples from the CTD casts were analysed. Additionally, a continuos flow-trough monitoring of surface salinity and fluorescence was implemented. Especially in the thermal frontal areas, intensive marine meteorological near surface measurements were made from the research vessel for studies of air-sea interaction. These were completed by over 40 aerological balloon soundings (by Vaisala DigiCora). Those give data e.g. for estimating the aerial atmospheric forcing as well as for studies of air - sea exchange during the exceptional ice conditions prevailed. RESEARCH GROUP The institutions involved in the expedition, co-ordinated and financially supported by the NORDIC WOCE read: FIMR Finnish Institute of Marine Research HU University of Helsinki, Department of Geophysics, Finland GU/OI University of Gothenburg, Oceanographic Institute, Sweden GU/CUT Univ. of Gothenburg and Chalmers Univ. of Technol., Department of Anal. and Mar. Chem., Sweden RESPONSIBLE INVESTIGATORS: Name/Institution Parameter -------------------- ------------------- P. Lundberg/GU/OI CTD J. Vainio/FIMR CTD R. Hietala/FIMR ADCP - ship mounted B. Liljeblad/GU/OI ADCP - CTD mounted J. Launiainen/FIMR Drifters T. Vihma/HU Drifters E. Fogelqvist/GU/CUT Chem. tracers J. Launiainen/FIMR Air-sea T. Vihma/HU Air-sea EXPEDITION PARTICIPANTS: Name Institution Leg(s) -------------------------------------------------- Launiainen, Jouko FIMR Chief scientist I Grönvall, Hannu FIMR Chief scientist II Hietala, Riikka FIMR I Kalliosaari, Simo FIMR I II Purokoski, Tero FIMR I II Söderman, Henry FIMR I II Vainio, Jouni FIMR I Vuori, Hannu FIMR I II Vihma, Timo HU I Lundberg, Peter GU/OI I II Fristedt, Tim GU/OI II Liljeblad, Bengt GU/OI I Lindblad, Klas GU/OI I II Fogelqvist, Elisabet GU/CUT I Krysell, Mikael GU/CUT I Tanhua, Toste GU/CUT I Bastürk, Özden GU/CUT/Turkey I CTD MEASUREMENTS EQUIPMENT AND CALIBRATIONS The CTD equipment used on R/V Aranda's cruise was the property of FIMR. The following equipment was deployed on the CTD/multisampler underwater frame: 1. Neil Brown Mk-III CTD, Serial No. 22-1007. 2. General Oceanics 24 bottle rosette, model 1015, with 24 12 liter Niskin- bottles. 3. RD Instruments 600kHz ADCP. Property of University of Gothenburg. The shipboard equipment consisted of system for collecting, displaying and post-prosessing the CTD data as well as controlling the rosette multisampler. The system included the following units: 1. EG&G deck-unit. Model 1401. 2. 386PC system connecting to network for archiving data to DAT-tape. 3. General Oceanics' rosette firing module. Calibration of the Mk-III CTD temperature and pressure sensors and conductivity cell was carried out at the IOS calibration facility. CTD | IOSDL | 13 July | Temperature was calibrated in the ITS90 scale temperature | CT0001 | 1993 | at five temperatures ranging from -2°C to calibration | | | 32°C with uncertainly better than *3m°C. -------------|--------|---------|---------------------------------------------- CTD | IOSDL | 09 July | Pressure was calibrated at five pressures pressure | CP0001 | 1993 | ranging from 0 to 5000 dbar with uncertainly calibration | | | better than *3dbar. -------------|--------|---------|---------------------------------------------- CTD | IOSDL | 15 July | Conductivity was calibrated at five points conductivity | 90233 | 1993 | ranging from 10 to 40 in salinity. Calibration | | | No post-cruise laboratory calibration is available due to bottom-contact of the equipment during return-cruise in the Baltic Sea. SAMPLE SALINITY MEASUREMENTS On R/V Aranda cruise 10/1993 (NordicWOCE cruise) the salinity analysis of collected samples was carried out after cruise in University of Gothenburg, Sweden. TABLE 1 Idx Station name Date UTC Latitude Longitude Depth --- ------------ ----------- ----- -------- --------- ----- 287 WOCE-E2 24-AUG-1993 12:49 66:03:25 -28:40:20 373 288 WOCE-E3 24-AUG-1993 16:03 65:54:48 -28:27:39 494 289 WOCE-E4 24-AUG-1993 19:57 65:46:22 -28:15:14 796 290 WOCE-E3A 24-AUG-1993 22:22 65:50:46 -28:21:43 583 291 WOCE-L1 25-AUG-1993 06:11 66:01:00 -26:48:01 438 292 WOCE-L2 25-AUG-1993 08:11 66:03:02 -26:55:07 571 293 WOCE-L3 25-AUG-1993 10:04 66:05:02 -27:03:11 645 294 WOCE-L4 25-AUG-1993 12:34 66:06:58 -27:09:18 604 295 WOCE-L5A 25-AUG-1993 14:41 66:09:23 -27:13:08 523 296 WOCE-L6A 25-AUG-1993 16:31 66:11:06 -27:17:45 481 297 WOCE-S7 25-AUG-1993 21:15 66:42:06 -27:00:10 445 298 WOCE-S6 26-AUG-1993 05:29 66:37:02 -26:38:04 541 299 WOCE-S5 26-AUG-1993 09:14 66:30:53 -26:15:31 634 300 WOCE-S4 26-AUG-1993 11:20 66:28:00 -26:04:16 652 301 WOCE-S3 26-AUG-1993 13:39 66:25:55 -25:53:15 626 302 WOCE-S2 26-AUG-1993 15:43 66:23:00 -25:42:04 441 303 WOCE-R1 26-AUG-1993 22:50 67:08:08 -26:02:58 753 304 WOCE-R2 27-AUG-1993 02:54 67:03:05 -25:45:04 866 305 WOCE-H4 28-AUG-1993 03:32 67:13:42 -24:05:30 647 306 WOCE-H3 28-AUG-1993 05:57 67:10:29 -23:55:36 457 307 WOCE-H2 28-AUG-1993 08:05 67:07:14 -23:46:22 290 308 WOCE-BENGT 28-AUG-1993 14:03 67:09:01 -22:52:02 256 309 WOCE-BENGT 28-AUG-1993 14:41 67:09:00 -22:52:02 256 310 WOCE-BENGT 28-AUG-1993 16:25 67:09:00 -22:52:05 256 311 WOCE-L1 30-AUG-1993 09:10 66:00:59 -26:48:05 440 312 WOCE-L2 30-AUG-1993 11:15 66:02:57 -26:55:25 571 313 WOCE-L3 30-AUG-1993 13:06 66:05:00 -27:02:53 642 314 WOCE-L4 30-AUG-1993 15:03 66:06:52 -27:09:08 607 315 WOCE-L5 30-AUG-1993 16:58 66:08:04 -27:15:02 526 316 WOCE-L6 30-AUG-1993 18:44 66:11:01 -27:21:09 481 317 WOCE-L8 30-AUG-1993 21:17 66:14:58 -27:32:40 483 318 WOCE-S2 31-AUG-1993 08:25 66:22:58 -25:42:18 447 319 WOCE-S3 31-AUG-1993 10:10 66:25:59 -25:53:30 635 320 WOCE-S5A 31-AUG-1993 14:17 66:33:27 -26:24:41 557 321 WOCE-S6 31-AUG-1993 16:57 66:37:04 -26:38:05 541 322 WOCE-S7A 31-AUG-1993 20:02 66:41:31 -27:01:52 442 323 WOCE-S8 31-AUG-1993 22:20 66:48:05 -27:21:46 365 324 WOCE-R1 01-SEP-1993 13:43 67:08:43 -26:05:56 732 325 WOCE-R2 01-SEP-1993 17:01 67:03:02 -25:44:59 864 326 WOCE-R3 01-SEP-1993 19:33 66:57:12 -25:24:40 1032 327 WOCE-R4 01-SEP-1993 22:15 66:54:16 -25:14:16 969 328 WOCE-H6A 02-SEP-1993 09:27 67:22:32 -24:32:06 1135 329 WOCE-H5A 02-SEP-1993 12:34 67:18:37 -24:20:21 941 330 WOCE-H4A 02-SEP-1993 17:25 67:10:01 -24:09:31 634 331 WOCE-H3 02-SEP-1993 20:55 67:10:37 -23:55:38 462 332 WOCE-H2A 02-SEP-1993 22:40 67:07:50 -23:47:19 317 333 WOCE-R6 03-SEP-1993 09:14 66:48:09 -24:53:20 575 334 WOCE-R5 03-SEP-1993 12:25 66:50:59 -25:02:40 808 335 WOCE-H2A 07-SEP-1993 08:58 67:07:40 -23:47:32 320 336 WOCE-H3 07-SEP-1993 12:06 67:10:31 -23:55:35 459 Idx Station name Date UTC Latitude Longitude Depth --- ------------ ----------- ----- -------- --------- ----- 337 WOCE-H4A 07-SEP-1993 16:01 67:13:05 -24:06:37 654 338 WOCE-H5A 07-SEP-1993 19:42 67:15:13 -24:11:55 776 339 WOCE-H6B 08-SEP-1993 12:07 67:21:25 -24:29:01 1077 340 WOCE-R6 09-SEP-1993 09:05 66:48:19 -24:53:50 585 341 WOCE-R5 09-SEP-1993 10:58 66:51:16 -25:04:11 832 342 WOCE-R4 09-SEP-1993 13:07 66:54:11 -25:13:38 965 343 WOCE-R3 09-SEP-1993 15:53 66:57:10 -25:23:35 1038 344 WOCE-S6A 10-SEP-1993 04:33 66:36:41 -26:39:40 540 345 WOCE-S7 10-SEP-1993 07:28 66:42:05 -27:00:07 445 346 WOCE-S5 10-SEP-1993 11:08 66:30:52 -26:15:17 636 347 WOCE-S4 10-SEP-1993 13:36 66:28:05 -26:04:54 659 348 WOCE-S3 10-SEP-1993 16:37 66:26:02 -25:53:07 636 349 WOCE-S2 10-SEP-1993 18:28 66:22:57 -25:42:04 440 350 WOCE-R6 13-SEP-1993 17:32 66:48:34 -24:53:02 581 351 WOCE-R5 13-SEP-1993 20:09 66:51:19 -25:03:51 830 352 WOCE-R4A 13-SEP-1993 22:54 66:53:56 -25:13:02 956 353 WOCE-R3B 14-SEP-1993 06:07 66:58:10 -25:27:35 1015 354 WOCE-R2A 14-SEP-1993 09:48 67:02:37 -25:43:12 886 355 WOCE-R1 14-SEP-1993 13:39 67:08:53 -26:05:59 732 356 WOCE-S8A 14-SEP-1993 21:53 66:46:40 -27:15:39 371 357 WOCE-S7 15-SEP-1993 00:07 66:42:07 -27:00:33 446 358 WOCE-S6 15-SEP-1993 02:50 66:37:07 -26:38:40 538 359 WOCE-S5A 15-SEP-1993 05:47 66:31:38 -26:18:01 622 360 WOCE-S4 15-SEP-1993 11:00 66:27:58 -26:04:02 658 361 WOCE-S3B 15-SEP-1993 14:21 66:25:02 -25:50:13 601 362 WOCE-S2 15-SEP-1993 15:51 66:23:03 -25:42:32 455 363 WOCE-L2A 16-SEP-1993 11:18 66:05:08 -26:59:30 637 364 WOCE-L3 16-SEP-1993 13:08 66:05:00 -27:03:02 651 365 WOCE-L4 16-SEP-1993 14:45 66:07:02 -27:09:18 605 366 WOCE-L5 16-SEP-1993 16:16 66:08:58 -27:15:07 520 367 WOCE-L6 16-SEP-1993 17:34 66:11:02 -27:21:07 484 368 WOCE-L7 16-SEP-1993 18:39 66:13:00 -27:26:26 486 369 WOCE-L8 16-SEP-1993 19:47 66:15:05 -27:32:43 486 370 WOCE-E4 17-SEP-1993 04:58 65:46:14 -28:15:01 802 371 WOCE-E3A 17-SEP-1993 07:02 65:50:41 -28:22:05 615 372 WOCE-E3 17-SEP-1993 08:30 65:54:57 -28:28:10 493 373 WOCE-E2A 17-SEP-1993 09:46 65:59:00 -28:32:33 444 374 WOCE-E4A 17-SEP-1993 12:53 65:41:59 -28:08:56 882 375 WOCE-E5 17-SEP-1993 14:59 65:37:40 -28:02:36 805 376 WOCE-F7 17-SEP-1993 18:34 65:22:12 -28:40:10 1244 377 WOCE-F6 17-SEP-1993 20:56 65:26:21 -28:45:14 1222 378 WOCE-F5 17-SEP-1993 23:59 65:30:20 -28:50:40 1181 379 WOCE-F4 18-SEP-1993 03:33 65:34:33 -28:56:11 1088 380 WOCE-F3 18-SEP-1993 05:52 65:38:37 -29:01:18 931 381 WOCE-F2 18-SEP-1993 08:40 65:42:52 -29:06:50 733 382 WOCE-F1 18-SEP-1993 10:37 65:47:01 -29:12:06 441 383 WOCE-G1 18-SEP-1993 14:23 65:31:59 -29:47:14 414 384 WOCE-G2 18-SEP-1993 16:00 65:27:20 -29:44:04 834 385 WOCE-G3 18-SEP-1993 17:48 65:22:30 -29:40:52 1147 Fig.1. NORDIC WOCE / R/V Aranda research sections and ice conditions during 30. August to 3. September 1993 in the Denmark Strait. Fig. 2.a. Density structure in the section S during four consecutive weeks during 23. August to 15. September 1993. Fig. 2.b. Salinity structure in the section S during four consecutive weeks during 23. August to 15. September 1993. Fig. 3. Drift trajectories of the Argos buoys during 29 August to 20 October 1993. Six hour positions. W = buoy deployed in the cold polar water side of the NE-SW directional thermal front. E = trajectory of the buoy deployed in the warm water Atlantic side of the front. DATA PROCESSING NOTES Date Contact Data Type Data Status Summary -------- ---------- ----------- -------------------------------------------- 09/24/99 Buck CTD/SUM/DOC Website Updated Files added to website 09/30/99 Bartolacci SUM Update Needed SUM file errors listed below: This sumfile AR18 34AR10_1 had the following errors from sumchk: .SUM header was missing: BOTTOMHT WHEEL_MT sumun1: hour or minute bad= 0 91 main: warning on rec= 53 sumun1: hour or minute bad= 0 83 main: warning on rec= 175 sumun1: hour or minute bad= 0 84 main: warning on rec= 193 10/01/99 Anderson SUM Data Reformatted I reformatted the AR18 .sum file to conform with the "standard" WHP format and put it in my ftp area in the subdir AR18. Error in the time: Sta. 311 the BE was input as 0091. Since this was a 400+ meter cast and the EN time was 0954 I assumed the BE should have been 0910. Sta. 372 the BE was input as 0083 and the EN was 0859. Since this was a shallow cast I assumed the BE should have been 0830. Sta. 381 the BE was input as 0084 and the EN was 0922. Since this was a shallow cast I assumed the BE should have been 0840. If possible these should be checked with the originator. I would guess that the last digit in the minutes should not always be 0. Sta. 331 the EN had 462 for UNC DEPTH, 446 for COR DEPTH and 4440 for WIRE OUT. I changed the WIRE OUT to 444 which is much more reasonable. 10/04/99 Launiainen SUM Data Update Corrections OK'd 12/11/00 Uribe DOC Submitted File contained here is a CRUISE SUMMARY and NOT sumfile. Documentation is online. Files were found in incoming directory under whp_reports. This directory was zipped, files were separated and placed under proper cruise. All of them are sum files. Received 1997 August 15th. 03/26/01 Uribe CTD Website (Expocodes) Updated Expocodes in all ctd files have been editted to match the underscored expocode in the sum file. New files were zipped and replaced existing ctd files online. Old files were moved to original directory. 05/01/02 Bartolacci CTD/BTL Update Needed BOT still with PI CTD needs WOCE frmttng. CTD is NONPUB still. Cruise not linking to table. Email PI for BOT and PUB status. Find out why cruise isn't linking! 07/15/02 Kappa DOC Doc Update: pdf, txt versions compiled Added sections on CTD measurements, Salinity measurements, this List of Data Processing Updates, and cruise participants list. Also added a pdf version of this cruise report which includes everything in the text document as well as figures and links between the table of contents, figures and tables and relevant text passages.