Departure: Reykjavík, Iceland, November 11th 2000
Arrival: Reykjavík, Iceland, December 2nd 2000
Jóhannes Briem, Chief scientist
Magnús Danielsen, Physical and chemical oceanography
Ólafur Gíslason, Physical oceanography
Sveinn Sveinbjörnsson, Capelin
Björn Sigurðarsson, Capelin
Albert Stefánsson, Capelin
Gisli Ólafsson, Capelin
Sigurður Gunnarsson, Capelin
The B14-2000 cruise was carried out by the Marine Research Institute (MRI) on the RV Bjarni Sæmundsson with the following aims:
The RV Bjarni Sæmundsson left Reykjavík harbor at 1000 hours on November 11th 2000 for the B14-2000 cruise.
The vessel headed first for the Faxaflói section ( Figure 1) completing nine standard CTD stations before proceeding to the Dohrn-bank area. Having surveyed the area for capelin and completed 9 stations of the Látrabjarg CTD section, survey work was continued north along the Denmark Strait until the afternoon of the 14th where work was hindered by weather. The opportunity was taken to go into the port of Ísafjörður to pick up a member of the scientific team.
Capelin survey with intermittent CTD stations was resumed north along the Denmark Strait on the 16th in good weather with the exception of six hours on the 18th when a recess had to be made due to a weather front passing the area. In the afternoon of the 20th a rendezvous was made with RV Árni Friðriksson on the Kögur section for intercalibration of survey equipment. This was completed just before midnight when CTD and survey continued east along the shelf area out to 68°N. A current meter mooring with two current meters was deployed just east of the Hornbanki section.
In the afternoon of the 23rd, having just completed the Siglunes section the ship was diverted to make assessment of herring in Eyjafjörður and Skjálfandaflói. A short stop was made in Akureyri and the work completed in the afternoon of the 25th. Due to a storm in the area north of Iceland it was decided to wait in the lee of Melrakkaslétta for better weather. A short stop was made in Húsavik to pick up spare parts. In the evening of the 26th course was set for Langanes NE section arriving there at 0220 on the 27th and finishing the section at 1930. The course was then set for Langanes E station 7, arriving there at 0830 hours next morning. From Langanes E the vessel headed for the Krossanes, Stokksnes and Selvogsbanki sections and arrived Reykjavik at 1100 hours on December the 2nd 2000.
The hydrographic work was carried out with two independent CTD-water sampling units both equipped with Seabird Inc. SBE 911plus CTD´s. The first unit, a MRI made rosette equipped with 12 modified Hydro-Bios 1.7 liter water bottles and a General Oceanics underwater unit was used for all standard CTD stations. The second unit (referred to as UNIT B), a SBE 32 rosette equipped with 12 Ocean Test Equipment Inc. 10 liter water samplers, was mainly used on few special stations in relation to chemical sampling. Water samples were collected at deepest sampling level on all stations for calibration purposes of salinity.
Temp. Calibr Cond. Calibr. sensor date sensor date Unit A 1428 26-10-2000 861 28-10-2000 Unit B 1172 26-10-2000 1162 28-10-2000
Samples for oxygen measurements were collected in 60 ml bottles, and Winkler reagents added. Samples were then placed in a dark cold storage until the time of analysis. Oxygen concentration was determined using a modified Winkler method.
Samples for nutrient analysis, nitrate, phosphate and silicate, were collected on selected stations, in 250 ml polyethylene bottles. Samples were frozen, for later analysis in land on a ChemLab auto-analyzer.
Samples for pCO2 and total carbonate were collected on 2 stations in 500 and 250 ml bottles, preserved with mercury chloride and placed in cold storage.
All the goals of the hydrographic cruise were achieved (see list of stations and cruise track-Figure 1).
The main results of the hydrographic conditions in Icelandic waters in November 2000 were the following (see e.g. T - 50m , S - 50m , T - 100m , S - 100m , and T - botm ):
Conditions of the Atlantic Water of the Irminger Current south and west of Iceland were very similar to those of 1999 i.e. with relatively high temperature (6-8°C) and salinity (>35.15). This is a continuation of high temperature and salinity year-long observed since 1997. However, compared with the November cruise in 1998 a slight decrease was observed in both temperature and salinity in the Atlantic Water as in November 1999.
On the Látrabjarg and Kögur sections the north flowing warm Atlantic Water which filled the Icelandic shelf area right on to the eastern slope of the Denmark Strait which was quite comparable to that of the period 1997-1999 but out-flowing overflow water occupying the deeper parts of the Strait is more pronounced in 2000 than in previous years (1997-1999).
East of the Hornbanki section conditions can only be described as unusual. Thus, the frequently observed intrusion of cold low saline surface waters from the north was absent and replaced by inflowing Atlantic Water (t >5°C and S >34.90) right up to 67°30'N.
Further east on the Siglunes section the Atlantic inflow was still pronounced. Thus, water with temperature of >5°C and salinity >34.90 was found in a 200 m thick layer as far north as 67° 30'N. This is warmer and saltier than in November-December the three previous years.
On the shelf northeast and east of Iceland still some remains of diluted Atlantic inflow were found, with temperatures as high as above 5°C. Further off-shore in the East Icelandic Current temperatures were also relatively high (1-3°C), but salinities were though relatively low (34.50-34.70) in the upper 50 m but at 34.80 or more deeper.
It is concluded that in November/December 2000 temperatures as well as salinities were generally high in the survey area as had been throughout the years since 1997.
Preliminary TS-diagrams from the Faxaflói , Látrabjarg , Kögur , Hornbanki , Siglunes , Langanes NE , Langanes E , Krossanes , Stokksnes and Selvogsbanki sections show the results above. In addition are preliminary potential temperature and salinity sections shown for Faxaflói (Fig. 3a and Fig. 3b), Látrabjarg (Fig. 4a and Fig. 4b), Kögur (Fig. 5a and Fig. 5b), Hornbanki (Fig. 6a and Fig. 6b), Húnaflói (Fig. 7a and Fig. 7b), Siglunes (Fig. 8a and Fig. 8b), Langanes NE (Fig. 9a and Fig. 9b), Langanes E (Fig. 10a and Fig. 10b), Krossanes (Fig. 11a and Fig. 11b), Stokksnes (Fig. 12a and Fig. 12b) and Selvogsbanki (Fig. 13a and Fig. 13b) sections respectively. For location of the above sections see Figure 1 and the station numbers.
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