Biogenic particle fluxes at the 34°N 21°W and 48°N 21°W stations, 1989-1990 : methods and analytical data compilation

Abstract

This technical report presents the results of analyses on opal, organic carbon, nitrogen and phosphorus content in each of 156 specimen samples collected from the moored sediment trap experiment that was a part of JGOFS North Atlantic Bloom Experiment. The analyzed samples represent a spatio-temporal matrix formed by 6 time-series sediment traps that provided 26 periods of uniform and synchronized periods of 14 days, except for one longer and one shorter period. Traps were deployed at 3 depths, 1 km, 2 km and 0.7 km above the bottom, and at 2 stations, 34°N 21°W and 48°N 21°W from April 4, 1989 to April 17, 1990, as shown in Tables 1 and 2. There was an 20-day hiatus in September /October 1989 for changeover of the trap moorings. Some samples were unusable because of the in trusion of fish. Samples were separated into several aliquots by wet-splitting, then water sieved into larger-than- and smaller-than-1-mm sizes. The fluxes of biogeochemical elements and constituents were determined on these aliquots and size fractions for: carbonate by vacuum gasometric method; opal by selective leaching method; reactive phosphorus by high temperature oxidation hydrolysis method; and organic carbon and nitrogen by applying an elementary analyzer. The annual fluxes, fluxes during the bloom, pre- and post-bloom episodes were normalized to a 365-day calendar year (Table 6) and are summarized in Tables 7 to 12. Variabilty of particle fluxes by each period at the two stations in terms of size fractions, sedimentary constituents and elements are shown in Tables 13 and 14. The molar ratios between pairs of critical biogeochemical elements during each episode and annually, shown at various depths and stations, are included in Tables 10 through 14.