Seasonality of particle-associated trace element fluxes in the deep northeast Atlantic Ocean

• Published in: Deep Sea Research Part I: Oceanographic Research Papers
• Main Authors: Kuss, J., Waniek, J.J., Kremling, K., Schulz-Bull, D. E.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2010
• Subjects: Arctic; Atlantic Arctic; Atlantic-Arctic; North Atlantic; Northeast Atlantic
• Online Access: https://oceanrep.geomar.de/id/eprint/13361/; https://oceanrep.geomar.de/id/eprint/13361/1/1-s2.0-S0967063710000701-main.pdf; https://doi.org/10.1016/j.dsr.2010.04.002

In the framework of the German contribution to the Joint Global Ocean Flux Study (JGOFS), deep-water fluxes of particle-associated trace elements were measured in the northeast Atlantic Ocean. The sinking particles were collected almost continuously from 1992 to 1996 at three time-series stations, L1 (33 degrees N/22 degrees W), L2 (47 degrees N/20 degrees W), and L3 (54 degrees N/21 degrees W), using sediment traps. The focus of the present study is the temporal variability of the particle-associated elemental fluxes of Al, Ca, Cd, Co, Cu, Fe, Mn, Ni, P, Pb, Ti, V, and Zn at a depth of 2000 m. A clear seasonality of the fluxes that persisted for several years was documented for the southernmost station (L1) at stable oligotrophic conditions in the area of the North Atlantic Subtropical Gyre East (NASTE). At L2 and L3, an episodic nature of the elemental fluxes was determined. Mesoscale eddies are known to frequently cause temporal and spatial variability in the flux of biogenic components in that area. These events modified the simple seasonal pattern controlled by the annual cycle at L2, in the North Atlantic Drift Region (NADR), and at L3, which was influenced by the Atlantic Arctic province (ARCT). All stations were characterized by an additional episodic lithogenic atmospheric supply reaching the deep sea. The integrated annual fluxes during the multi-year study revealed similar flux magnitudes for lithogenic elements (Al, Co, Fe, Ti, and V) at L2 and L3 and roughly twofold fluxes at L1. Biogenic elements (Cd, P, and Zn) showed the opposite trend, i.e., two to fourfold higher values at L2 and L3 than at L1. For Mn, Ni, and Cu, the spatial differences were smaller, perhaps because of the intermediate behavior, between lithogenic and biogenic, of these elements. Similarly, among the three study sites, there were no noticeable differences in the total annual flux of Pb. The respective lithogenic fractions of the deep-sea fluxes of Cd, Co, Cu, Mn, Ni, V. and Zn were subtracted based on the amount of Al, with ...