Alkenone distributions in the North Atlantic and Nordic sea surface waters

Abstract

The C37–C39 alkenones were quantified in suspended particulate matter obtained from the surface waters of the North Atlantic, including the Nordic seas, over a temperature range of 4°–20°C. U37K′ values were linearly correlated to temperature over the entire range covered by our data set, i.e., 4°–20°C (U37K′ = 0.027T + 0.036, r2 = 0.97). The compilation of water column data from the Atlantic, Pacific, and Southern Ocean and Mediterranean Sea suggests that the linear model may not be the best function for fitting U37K′ and in situ temperature values. It also shows that suspended matter data from warm waters (T > 20°C) are still needed to constrain the equation of the global curve. High abundances of C37:4 were found in the coldest polar waters. Around 4°C, %C37:4 represented up to 35%, a value that dropped to zero at temperatures above 10°C. Values of %C37:4 were linearly correlated to temperature (%C37:4 = −3.7T + 43.7, r2 = 0.50) and salinity (%C37:4 = −48.1S‰ + 1691, r2 = 0.78). Further investigations from other oceanic basins are necessary to confirm these findings.