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The winter mixed layer depth was variable in the Irminger and Iceland Seas in the period 1990-2000, but reached much deeper in the Irminger Sea as a halocline limits vertical convection in the Iceland Sea. The ranges of the related variations in salinity, density, and nutrient concentrations were similar in both regions. The nutrient variations were proportionately greater in the Iceland Sea. Statistical relationships between mixed layer depth and surface water properties were stronger for the Iceland Sea. but interannual variations in advection had more effects in the Irminger Sea. Article from Marine Science Symposia Vol. 219 - "Hydrobiological variability in the ICES Area, 1990-1999", symposium held in Edinburgh, 8-10 August 2001. To access the remaining articles please click on the keyword "MSS Vol. 219".

The Marine Research Institute in Iceland has been monitoring the inflow of Atlantic Water onto the north Icelandic Shelf using Aanderaa current meters on one mooring since 1985. In August 1999 three moorings were deployed along the Hornbanki section and recovered a year later, and these data are used along with CTD data from the section to estimate the flow of Atlantic Water to the north Icelandic Shelf. The mean transport during this period was found to be 0.95 Sv. This is lower than a pre­vious estimate using a single mooring from the Kogur section. No clear seasonal variations were found in the transport. Interannual variations were studied using data from the single mooring at the Hornbanki section for the period 1994-2000. There are no significant variations in the velocity, but the temperature shows interannual vari­ability. The year 1995 stands out with extremely low temperatures and during that year an anomalously small amount of Atlantic Water was found over the north Ice­landic Shelf. This may show that current measurements alone do not indicate the flow of Atlantic Water, and measurements of the water properties are needed to distinguish what kind of water is flowing along the Shelf.Article from Marine Science Symposia Vol. 219 - "Hydrobiological variability in the ICES Area, 1990-1999", symposium held in Edinburgh, 8-10 August 2001. To access the remaining articles please click on the keyword "MSS Vol. 219".

The overflow of cold water from the Arctic Mediterranean (Arctic Ocean and Nordic Seas) across the Greenland-Scotland Ridge into the Atlantic is a key process in the form ation of North Atlantic Deep Water (NADW ) and a driving mechanism for the Atlantic inflow to the Nordic Seas. About half the overflow flux passes east of Iceland, carried by three separate branches. Previous investigations have shown that the branch that flows through the Faroe Bank Channel decreased in flux from 1950 to 2000. We argue that the same conclusion can be drawn for the cold com ponent of the overflow across the southern part of the Iceland-Faroe Ridge and for the cold com ponent of the overflow across the Wyville-Thomson Ridge. If not compensated by unobserved increases in other sources, the results imply a reduced production of NADW and reduced inflow of Atlantic Water to the Nordic Seas. We briefly discuss the potential biological consequences of the changing transport of organisms by overflow currents, changing bottom temperature regimes in areas affected by overflow water, and changing Atlantic inflow. Article from Marine Science Symposia Vol. 219 - "Hydrobiological variability in the ICES Area, 1990-1999", symposium held in Edinburgh, 8-10 August 2001. To access the remaining articles please click on the keyword "MSS Vol. 219".

The surface circulation of the Nordic Seas and its variability during the 1990s is investigated using current data obtained from satellite-tracked drifters. We find a seasonal intensification of the circulation during winter and during the first half of the 1990s, both due to the enhanced atmospheric momentum forcing. Article from Marine Science Symposia Vol. 219 - "Hydrobiological variability in the ICES Area, 1990-1999", symposium held in Edinburgh, 8-10 August 2001. To access the remaining articles please click on the keyword "MSS Vol. 219".

The main results of the hydrographic conditions in Icelandic waters in the 1990s reveal the same variability from year to year observed since the 1950s, including Atlantic, Polar, and Arctic periods in North Icelandic waters. Attention is paid to the hydro- graphic conditions in the warm water from the south (Inninger Current) which developed at the end of the 1990s into high saline conditions comparable with the period prior to the 1960s. This includes the northern component flowing into North Icelandic waters. The conditions in the East Icelandic Current also improved at the end of the 1990s with relatively high salinities. Thus the hydrobiological conditions in Icelandic waters were favourable at the end of the 1990s with regard to the various fish stocks. Article from Marine Science Symposia Vol. 219 - "Hydrobiological variability in the ICES Area, 1990-1999", symposium held in Edinburgh, 8-10 August 2001. To access the remaining articles please click on the keyword "MSS Vol. 219".

The Denmark Strait overflow water derives from several distinct sources. Arctic Intermediate Water from the Iceland Sea, Atlantic Water of the West Spitsbergen Current recirculating in the Fram Strait, and Arctic Atlantic Water returning from the different circulation loops in the Arctic Ocean all take part in the overflow. Denser water masses, such as the upper Polar Deep Water and the Canadian Basin Deep Water from the Arctic Ocean and Arctic Intermediate Water from the Greenland Sea, are occasionally present at the sill and could contribute the deepest part of the overflow plume. A comparison between hydrographic observations made during the Greenland Sea Project in the late 1980s and early 1990s and during the European Sub Polar Ocean Programme (ESOP) and Variability of Exchanges in the Northern Seas (VEINS) programmes in the late 1990s shows that the Greenland Sea Arctic Intermediate Water has largely replaced the Arctic Ocean deep waters. In the less dense fraction of the overflow the Recirculating Atlantic Water and Arctic Atlantic Water carried by the East Greenland Current have become more prominent than the Iceland Sea Arctic Intermediate Water. If the Denmark Strait overflow were to switch between different sources, it would lead to changes in the characteristics of the overflow water that add to the variations caused by the variability of the source waters. Article from Marine Science Symposia Vol. 219 - "Hydrobiological variability in the ICES Area, 1990-1999", symposium held in Edinburgh, 8-10 August 2001. To access the remaining articles please click on the keyword "MSS Vol. 219".