The effect of marginal ice-edge dynamics on production and export in the Southern Ocean along 170°W
The effect of marginal ice-edge dynamics on production and export in the Southern Ocean along 170°W
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DOI：
10.1016/s0967-0645(02)00585-4
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发表时间：
2003-01-01
影响因子：
3
通讯作者：
Sambrotto, R
中科院分区：
文献类型：
--
作者：
Buesseler, KO;Barber, RT;Sambrotto, R
我们综合了南大洋沿西经170度的四个航次的总生产量、新生产量、净生产量和初级生产量以及100米处的颗粒有机碳(POC)通量。同时的卫星色素数据、初级生产力模型和硝酸盐质量平衡被用来将空间和时间上的日产量估计值外推到季节性和年率。通过这一分析，我们对该地区浮游植物水华的时间、规模和影响有了更好的了解。浮游生物生物量的主要特征之一是高叶绿素水平与10月份开始的极锋以南的海冰消退有关。我们的初级生产模型和卫星颜料数据表明，边缘冰区的产量和通量水平高于之前的估计。受冰层影响地区新产量的增加仅限于冰缘消退后相对较短的时间内。出口被发现比开始生产晚了1个月。当整个季节平均时，100米处的POC通量与初级生产力的比率相当高，在亚南极地区从15%到25%，增加到极锋附近的35%到40%，在罗斯海环流以北的最南端站高达50%到65%。浮游植物群落结构和铁胁迫指标的比较表明，极锋的水华最初以大型中心硅藻为主，但随着铁水平的降低，被较小的羽状硅藻和非硅藻物种所取代。再往南，铁水平从来没有那么高，也没有发现大型硅藻，我们仍然观察到相对较高的生物量，以及较短的生长季期间较高的生产力和POC通量。(C)2003爱思唯尔科学有限公司。保留所有权利。
We present a synthesis of the rates of gross, new, net and primary production along with particulate organic carbon (POC) flux at 100 m from four cruises along 170degreesW in the Southern Ocean. Concurrent satellite pigment data, a primary productivity model, and a nitrate mass balance are used to extrapolate daily production estimates in space and time to seasonal and annual rates. From this analysis, we gain a better understanding of the timing, magnitude and impact of the phytoplankton blooms in this region. One of the dominant features with respect to plankton biomass is the association of high chlorophyll levels with the retreat of the sea ice which begins in October just south of the Polar Front. Our primary production model and satellite pigment data suggest higher production and flux levels characterize the marginal ice zone than previous estimates. Elevated rates of new production in ice impacted regions are restricted to relatively short periods following retreat of the ice edge. Export is found to lag the onset of production by up to 1 month. The ratio of POC flux at 100 m to primary production when averaged over the entire season is quite high, increasing from 15% to 25% in the Subantarctic zones to 35-40% near the Polar Front and as high as 50-65% in the southernmost stations, just north of the Ross Sea gyre. Comparisons of phytoplankton community structure and Fe stress indicators suggest that blooms at the Polar Front are initially dominated by large centric diatoms, but are replaced by smaller pennate diatom and non-diatom species as Fe levels decrease. Further south, where Fe levels are never as high and large diatoms are not found, we still observe relatively high biomass and elevated production rates and POC fluxes during the short growing season. (C) 2003 Elsevier Science Ltd. All rights reserved.