HAFRANNSÓKNASTOFNUNIN

Marine Research Institute

Reykjavík, Iceland

HAFRÓ MAIN




HYDROGRAPHIC CRUISE REPORT

CRUISE NUMBER: B10 - 2000
(Aug./Sep. 2000)


















SCIENTIFIC OBJECTIVES

The B10-2000 cruise was carried out by the Marine Research Institute (MRI) on the RV Bjarni Sæmundsson with the following aims:

  1. To carry out long-term hydrographic investigations on standard section in the waters all around Iceland along with the yearly 0-group investigations. The oceanographic investigation were performed by CTD-casts.

  2. Collect water samples for the determination of pCO2, total carbonate, oxygen and nutrients.

  3. Collect continuos underway measurements of surface temperature and salinity.

  4. Collect samples for analysis of Cesium-137 and Technetium-99 (Icelandic Radiation Protection Institute and Risø National Laboratory).

  5. Deploy, recover and service a number of current meter moorings.

  6. Sea-bird ecology

CRUISE NARRATIVE

The RV Bjarni Sæmundsson left Reykjavík harbor at 2000 hours on August the 9th 2000 for the B10-2000 cruise.

The vessel headed for the Faxaflói section ( Figure 1) occupying the first nine stations, from there to the Látrabjarg and Kögur sections in the Denmark Strait, where all planned stations were occupied. During these legs an ADCP current meter mooring was deployed at the sill in the Denmark Strait and a current meter mooring was recovered at the continental slope of the Kögur section. The vessel then headed eastwards into North Icelandic waters to the Hornbanki, Húnaflói, Siglunes, Slétta, Langanes NE and Langanes E sections, during which two current meter moorings were serviced at Hornbanki section. From there the vessel headed for the Krossanes, Stokksnes and Selvogsbanki sections and arrived Reykjavik at 1800 hours on September the 5th 2000. During the cruise exceptional good weather was experienced so only a short stop in Patreksfjörður where needed due to weather and call of ports were limited to three planned stops (Ólafsvík, Akureyri and Vopnafjörður) for scientific crew exchanges.

HYDROGRAPHY

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.

CTD (SBE 911plus CTD System) Sensor Status.

		Temp.		Calibr		Cond.		Calibr.
		sensor		date   		sensor		date

Unit A	       2806	        04-01-00       2341	        31-12-99
Unit B		868	        29-01-00	549	        01-02-00

RESULTS

All of the goals of the cruise were achieved (see list of stations and cruise track-Figure 1).

The main results of the hydrographic conditions in Icelandic waters in August 2000 were the following (see e.g. T - 50m , S - 50m , T - 100m , S - 100m , and T - botm ):

South and west of Iceland temperatures of the Atlantic water were relatively high (6-11°C) with a warming-up in the surface layer. The salinity in this area was high, as it has been since September 1997 (35.1-35.25) after decades of lower salinities.

The flow of Atlantic water into the area north of Iceland was quite pronounced (5-7°C; S>35.0) and was covered by a relative thin low saline but warm surface layer. The Atlantic water reached as far as the waters off the East Coast of Iceland similar to what was observed in August 1999. As in previous years an intrusion of relative cold (3°C) water from the north was observed in the northwestern part of the survey area.

The surface layers in the northeastern and eastern parts of the survey area were in general characterised by high temperatures (7-9°C) with a sharp thermocline in the depth range 20 to 40 metres. The combined effect of the Atlantic inflow and pronounced heating of the surface layer resulted in that the cold East Icelandic Current was found relative far-off the northeastern coast of Iceland and with high surface temperatures. Salinities of the surface layers east of Iceland were found to be higher than those observed in August 1999 which again was more saline than previous years.

It is concluded that in August 2000, temperatures as well as salinities were relatively high in the survey area with a pronounced heating of the surface layer in general. The hydrographic conditions were in many ways similar to those observed in August 1999.

Preliminary TS-diagrams from the Faxaflói , Látrabjarg , Kögur , 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), Siglunes (Fig. 7a and Fig. 7b), Slétta (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.


CONTACT

In case of further information contact:

Héðinn Valdimarsson Email: hv@hafro.is
John Mortensen Email: johnm@hafro.is
Svend-Aage Malmberg Email: svam@hafro.is
Jóhannes Briem Email: briem@hafro.is

or by mail:

Att. name
Hafrannsóknastofnunin
(Marine Research Institute)
P.O. Box 1390
Skúlagata 4
121 Reykjavík
Iceland

or

Tel. (+354) 55 20240
Fax. (+354) 56 23790




Comments and suggestions regarding this page are welcome. Please send email to johnm@hafro.is