Oceanography and fluorescence at the shelf break off the north Norwegian coast (69 degrees 20 ' N-70 degrees 30 ' N) during the main productive period in 1994

Data on hydrography, fluorescence, wind and currents from shelf studies on the Norwegian shelf between 69 degrees 30'N and 70 degrees 30'N are present ed. The sampling was performed along five transects, covering a narrow shel f break site, a trench, and a bank. The sampling programme was conducted du ring cruises of 4-5 days duration each month from March until October 1994. Three distinct water masses were identified: 1) Coastal Water (S < 35; 4 < T > 12 degrees C) above the shelf and the shelf break (0-300 m depth), 2) Atlantic Water (S > 35; 5 < T > 10 degrees C) off shelf (0-400 m depth) and below the Coastal Water in the trenches (300-400 m depth), and 3) Norwegia n Sea Deep Water (S < 35; T < 0 degrees C) off the shelf break, below 700 m depth. Wind direction between southeast and northwest prevailed during all cruises, except in May, when northeasterly wind was most frequent. Typical wind speeds were in the order of 7-12 m s(-1), bur the wind exceeded 15 m s(-1) frequently during the whole investigation period, Current regime abov e the shelf, as obtained by Acoustic Doppler Current Profiler (ADCP) in Apr il, June and September, demonstrated a strong off-shelf flow along the nort hern side of the trench Malangsdjupet, while a more irregular pattern was f ound along the southern margin of this trench, Above the bank area Nordvest banken a clockwise turn in the flow field from east to west was found. This clockwise turn in flow field coincided with modelled flow fields of the ma jor tidal component during most of the cruises. Residual currents were dete rmined subtracting the modelled M2 from the ADCP-measurements. Fluorescence profiles indicated a higher standing crop of phytoplankton above the trenc h area than above the bank area. No distinct spring bloom was found, but a seasonal maximum in June in surface integrated fluorescence was detected, I n June highest values were recorded in shelf waters (34.2 < S > 34.4) when the pycnocline was about to be established, while the August and September maxima were found in more saline waters (34.8 < S > 35.1) often below the p ycnocline in off-shelf waters.