Production pattern of alkenones in the Mediterranean Sea

Yann Ternois (1) , Marie-Alexandrine Sicre (2) , Anne Boireau (1) , Jean-Claude Marty (1) , Juan-Carlos Miquel (3) , Jean-Claude Marty

1 LPCM - Laboratoire de Physique et Chimie Marines
2 Centre des Faibles Radioactivités
3 IAEA Marine Environment Laboratory

Time-series of downward alkenone fluxes have been investigated at 200 m depth over a one year sediment trap experiment, in the Northwestern Mediterranean Sea. Alkenone flux maxima occurred in autumn and to a lesser extent in May, during the Sly.ring bloom. Temperature estimates calculated from the U'3 index revealed that alkenone producers preferentially develop in subsurface waters (at about 50 m) in spring, whereas the autumn alkenone production occurred upper in the water column (around 30 m). Examination of the core-top U• index values at various sites of the Northwestern Mediterranean basin, suggested that the spring bloom period do not significantly imprint the temperatures recorded in the sediments. The sedimentary temperature estimates would rather reflect annually integrated SST, with a major influence of the autumnal post-bloom development of the coccolithophores in the euphotic zone.

Domaines: Océan, Atmosphère; Interfaces continentales, environnement

Yann Ternois, Marie-Alexandrine Sicre, Anne Boireau, Jean-Claude Marty, Juan-Carlos Miquel, et al.. Production pattern of alkenones in the Mediterranean Sea. Geophysical Research Letters, 1996, 23 (22), pp.3171-3174. ⟨10.1029/96GL02910⟩. ⟨hal-03594483⟩