Particle flux in the NE Atlantic as recorded by sediment traps

Downward particle flux was measured using sediment traps at various depths over the Porcupine Abyssal Plain (water depth ab. 4850 m) for prolonged periods from 1989 to 1999. A strong seasonal pattern of flux was evident reaching a maximum in mid-summer. The composition of the material changed with depth, reflecting the processes of remineralisation and dissolution as the material sank through the water column. However, there was surprisingly little seasonal variation in its composition to reflect changes in the biology of the euphotic zone. Currents at the site have a strong tidal component with speeds almost always less than 15 cm/sec. In the deeper part of the water column they tend to be northerly in direction, when averaged over periods of several months. […]

1989年至1999年间，研究团队采用沉积物捕集器（sediment traps），在水深约4850米的豪猪深渊平原（Porcupine Abyssal Plain）的不同深度开展了长期颗粒向下通量观测。观测结果表明，通量呈现显著的季节变化模式，于仲夏时节达到峰值。沉降物质的组分随深度发生改变，反映了其在水柱沉降过程中经历的再矿化与溶解过程。但令人意外的是，其组分的季节变化极不显著，未能反映真光层（euphotic zone）的生物活动变化。该站位的海流具有显著的潮汐分量，流速几乎始终低于15厘米/秒。若以数月为周期取平均值，深水层的海流整体呈北向。[…]