The data set comprises measurements on several stations in the following regions: - The main area comprising: the Arctic Seas (the Greenland, Iceland and Norwegian Seas) between latitudes 70° N - 77° N, longitudes 12° E - 17° E and the Arctic Front delimited by longitudes 2° 41'W - 3° 05'E and latitudes 70° 54'N - 72° 32'N. - Spitsbergen's fjords (since 1989-1995). - The profile between latitudes 74° 30'N - 77° N and longitudes 1° E - 15° E (1988, 1989, 1991). - The profile along longitude 0° E and latitudes 65° N - 74° N (1988, 1989, 1991). - The profile on the Norwegian Sea between latitudes 63° N - 69° N and longitudes 3° 24'45W - 13° 40'E (1988, 1989). - The profile between Faroe and Shetland Islands (1988, 1989, 1991).

Light absorption in the water column

Optical data were collected as auxiliary data to observe optical water properties determining photosynthetic conditions of the water and affecting primary production processes. The main measurement sites were two polygons (repeated over the years) in the northern part of the North Sea, and in Hornsund Fjord on Spitzbergen. The data set includes: 1987 - 76 stations ('c') 1988 - 35 stations ('c') 1989 - 49 stations ('c') 1991 - 122 stations ('c') 1992 - 16 stations ('c') 1993 - --- 1994 - 105 stations ('Kd') 1995 - 161 stations ('c'), 68 ('Kd') Downwelling irradiance at the sea surface was measured every day during those periods. This forms the daily time series, averaging every 30 seconds, recorded from dusk to dawn, or 24h at high latitudes, which are stored as compressed ASCII files. Data of 'c' and 'Kd' are stored as ASCII files of profiles of parameters, paired with depth and temperature readings, with a header containing information clearly identifying the data set (date, time, latitude, longitude, station number). All stored data are interpolated to full metres. All data are quality controlled.

Institute of Oceanology, Polish Academy of Sciences
Powstancow Warszawy 55
Sopot

81-712
Poland