Supplement to: Roether, Wolfgang; Münnich, Karl O; Ribbat, B; Sarmiento, Jorge L (1980): A transatlantic 14C-section near 40°C N. Meteor Forschungsergebnisse, Deutsche Forschungsgemeinschaft, Reihe A Allgemeines, Physik und Chemie des Meeres, Gebrüder Bornträger, Berlin, Stuttgart, A21, 57-70
14C concentrations, as well as 14C, hydrographic and nutrient data are reported for 5 hydrographic stations that form a transatlantic section near 40° N ("Meteor" cruise no. 23, 1971). Precision (for 14C ± 0.3 ‰ or better) and comparability with literature data are specified. A planned intercomparison with the US GEOSECS program within the Newfoundland Basin deep water failed because of variability of water characteristics. The observed 14C values decrease from about Delta 14C = + 80 ‰ at the surface to -70 ‰ at 2000 m depth. Deeper down, the values west of the Midatlantic Ridge remain similar, whereas those east of the ridge decrease further, to about - 110 ‰. It is shown that bomb-14C is prominent down to about 1500 m depth. Beyond this depth the bomb 14C component is small and is negligible in the eastern basin below 2800 m. On the basis of the 14C-tritium correlation, the distribution of natural 14C below about 1500 m depth is derived from the observations. In the deep and bottom water east of the ridge the 14C-salinity relationship seemingly is non-linear. Contrary to expectation, the 14C concentration in the bottom water is not lower than found on an US GEOSECS station near 10° N. Apparently, lateral concentration differences in the Northeast Atlantic bottom water as well as nonlinearity of the 14C-salinity relationship at 40° N do not exceed 10 ‰ in Delta 14C.
application/zip, 5 datasets