Publication Abstract

Ocean climatic conditions in the ICES North Atlantic region 1996/97

W.R. Turrell, R.R. Dickson, S. Narayanan and A. Lavin

Observations obtained at standard sections and stations maintained by members of the ICES Oceanic Hydrography Working Group have been employed to examine present ocean climate conditions in the North Atlantic region. In the northwest Atlantic, increased air temperatures, reduced incidence of sea ice and warmer sea temperatures have been observed throughout the area since 1991-94. In Icelandic waters again moderate conditions have been experienced with relatively warm temperatures, despite generally lower salinities being observed. A moderating climate has also been observed in waters west of Greenland. Faroese standard sections have revealed that the freshening observed in water originating from the North Atlantic Current since the late 1980s has now stabilised. On the Faroese shelf temperatures have increased since the cold years of 1993, 1994 and 1995. In the Faroe-Shetland Channel, North Atlantic water in the slope current has continued to warm since 1987. Salinity has also increased and is approaching 1960's values. Surface water further offshore, arriving in the area after circulating around the Faroe Islands, has demonstrated a general cooling and freshening, with salinity approaching the minimum values observed in the anomaly years of the mid-1970s. Intermediate and deep waters in the Channel continue to freshen, although the sudden warming experienced in the bottom waters in the mid-1990s has now stopped. Areas inundated with Atlantic water within the northern North Sea reveal a similar trend as observed in the water lying at the shelf edge, with generally warmer conditions. Conditions in the Norwegian Sea and Barents Sea reveal a similar trend as exhibited by the Atlantic water circulating around Faroe, with generally decreasing temperatures and salinities. Increased incidence of sea ice in the Barents Sea also suggests decreasing temperatures. In.the southern Bay of Biscay area air temperatures have become mild after a warm period. The increasing trends of temperature and salinity observed between 1991 and 1995 have stopped. Many of these changes may be the expected accompaniment of an NAO index which switched from its second highest value to its lowest in the available 175 year record.

Reference:

W.R. Turrell, R.R. Dickson, S. Narayanan and A. Lavin, 1997. Ocean climatic conditions in the ICES North Atlantic region 1996/97. ICES CM 1997/EE:9, 6pp, 1 table and 16 Figs mimeo.