HAFRANNSÓKNASTOFNUNIN

Marine Research Institute

Reykjavík, Iceland

VEINS@ICES HAFRÓ MAIN










CRUISE REPORT

CRUISE NUMBER: A09 - 98
(August 1998)


















SCIENTIFIC OBJECTIVES

The A09-98 cruise was carried out by the Marine Research Institute (MRI) on the RV Árni Friðriksson with the following aims:

  1. To carry out long-term hydrographic investigations on standard sections in the waters all around Iceland along with yearly 0-group investigations. The oceanographic investigations were performed by CTD-casts. Included in the observation work is MRI's role in VEINS, a program with the objective of measuring and modeling the variability of fluxes between the Arctic Ocean and the Atlantic with view on implementing a longer term system of measurements needed to understand the high-latitude oceans steering role in decadal climate variability. Funding is provided by the EU MAST-III programme and the participants in the project. The work on this cruise was part of the following VEINS tasks:

    1. Determining the water mass properties of the Denmark Strait Overflow. (Task 1.4.2)
    2. Improving estimation of the freshwater flux to the North Atlantic via the East Greenland Current and East Icelandic Current. (Task 1.4.3)
    3. Measuring the inflow of Atlantic Water to the Iceland Sea. (Task 1.4.4)


CRUISE NARRATIVE

The RV Árni Friðriksson left Reykjavík harbor at 2000 hours on the 4th of August 1998 for the A09-98 cruise.

The vessel headed for the Faxaflói section ( Figure 1) occupying the first nine stations. From there the ship headed for the Denmark Strait NW of Iceland (Látrabjarg and Kögur sections) from the Icelandic coast to the ice-limit and eastwards into North Icelandic waters (Húnaflói, Siglunes, Slétta, and Langanes NE sections). After occupying North Icelandic waters the vessel continued eastwards into East Icelandic waters (Langanes E and Krossanes sections) and to South Icelandic waters (Stokksnes, Ingólfshöfði and Selvogsbanki sections). The RV arrived to Reykjavik at 1000 hour on the 28th of August.

Sections confined to VEINS are those of Faxaflói, Látrabjarg, Kögur, Langanes NE and Krossanes. Locations of hydrographic sections and CTD stations are shown in Figure 1.

HYDROGRAPHY

The hydrographic work was carried out with a CTD-water sampling units equipped with Seabird Inc. SBE 911plus CTD's. The unit, a MRI made rosette equipped with 12 modified Hydro-Bios 1.7 liter water bottles and a General Oceanics underwater unit, was used on all CTD stations. The CTD was equipped with newly calibrated temperature and conductivity sensors and water samples were collected at deepest sampling level on all stations for calibration purposes.

CTD (SBE 911plus CTD System) Sensor Status.

	    Temp. Calibr.  Cond. Calibr.
	   sensor date    sensor date

Unit A        868 30-04-98   861 01-05-98

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 1998 were the following:

South and west of Iceland temperatures were relatively high (7-9ºC) with a strong warming-up in the surface layers. The salinity in the Atlantic water was high as since 1997 (35.1-35.2) after decades of lower salinities. The Atlantic inflow into North Icelandic waters was also very pronounced (5-6ºC) with higher salinities (35.0-35.1) than observed for years as far east as off Melrakkaslétta. This inflow of Atlantic water into North Icelandic waters was though overlaid by a warm but low saline surface layer. Noteworthy is the cyclonic distribution of temperature in the western part of North Icelandic waters bringing warm and saline water northwards along the Kolbeinsey Ridge. Thus the cold water masses from the north were quite far off in the area. Off the East coast of Iceland temperatures were also relatively high below the near-surface layer (3-4ºC) with a moderate heating-up to 5-6ºC in the layer itself. In deep waters northeast and east of Iceland the cold East Icelandic Current was as earlier in the year 1998 relatively far off and rather weak both as regards hydrographic conditions and its extension south-eastwards. It is concluded that in August 1998 temperatures as well as salinity, especially in North Icelandic waters, were relatively high in the survey area. Warming-up in the surface layers was quite strong south and west of Iceland but less so north of Iceland, contrary to 1997, reflecting the climatic conditions in Iceland in summer 1998.

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), Húnaflói (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, of which Figures 3, 4, 5, 9 and 11 are part of the VEINS programme. For location of the above sections see Figure 1 and the station numbers.


CONTACT

In case of further information contact:

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




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