Water chemistry from the North Atlantic Bloom Experiment

Primary production was measured every other day towards the end (18-31 May) of the 1989 North Atlantic spring bloom. Rates varied with light and averaged 90.4 mmol C/m**2 day at the 47°N, 20°W station. Productivities measured south of Iceland (59°30N, 20°45W) were somewhat lower, averaging 83.6 mmol C/m**2 day. Carbon and nitrogen fluxes were estimated using free-floating, VERTEX type particle trap arrays. To obtain mean rates representative of the North Atlantic spring bloom, flux data from three trap deployments were combined and fitted to normalized power functions:
mmol C/m**2 day = 14.35 (z/100)**-0.946, mmol N/m**2 day = 2.34(z/100)**-1.02, with depth z in meters. Regeneration rates were:
mmol C/m**2 day = 0.136(z/100)**-1.946, mmol N/m**2 day = 0.0239(z/100)**-2.02. The carbon export rate from the upper 35 m for the entire NABE study period (24 April to 1 June) was 39 mmol/m**2 day. This value divided by the averaged productivity for the entire study (86 mmol N/m**2 day) gave an F-ratio of 0.45.
Concentrations of Cu, Fe, Ni, Pb and Zn were determined in water samples provided by JGOFS NABE scientists involved with primary productivity measurements. Although little contamination was observed for Cu, Ni and Pb, relatively large amounts of Zn (10 nmol/kg) were found in some cases. In subsequent studies it was learned that this quantity of Zn can depress productivity rates by 25%.
North Atlantic dissolved Fe concentrations were similar to those occurring in the Pacific (surface = 0.07; deep = 0.5-0.6 nmolP/kg). Although no evidence of Fe deficiency was found in enrichment experiments, the addition of nmol amounts of Fe did increase CO2 uptake and POC formation by factors of 1.3-1.7. In this region, most of the phytoplankton's Fe requirement is probably met via the lateral transport of Fe from distant continental margins.

1989年北大西洋春季水华末期（5月18日至31日），研究人员每隔一日测定初级生产力（primary production）。生产力速率随光照条件发生变化，在47°N、20°W站位的平均速率为90.4 mmol C/m²·d。冰岛以南海域（59°30′N，20°45′W）的生产力水平略低，平均为83.6 mmol C/m²·d。
碳、氮通量采用悬浮式VERTEX型颗粒捕集器阵列（VERTEX type particle trap arrays）进行估算。为获取能够代表北大西洋春季水华的平均通量速率，研究人员整合了3组捕集器布设的通量数据，并拟合得到归一化幂函数：
mmol C/m²·d = 14.35 (z/100)^-0.946，mmol N/m²·d = 2.34(z/100)^-1.02，其中深度z的单位为米。再生速率（regeneration rate）的拟合公式为：
mmol C/m²·d = 0.136(z/100)^-1.946，mmol N/m²·d = 0.0239(z/100)^-2.02。
整个NABE研究周期（4月24日至6月1日）内，上层35 m的碳输出速率为39 mmol/m²·d。将该值除以整个研究周期的平均生产力（86 mmol N/m²·d），得到F比（F-ratio）为0.45。
研究人员对参与初级生产力测定的JGOFS NABE科学家提供的水样，开展了铜（Cu）、铁（Fe）、镍（Ni）、铅（Pb）及锌（Zn）的浓度测定。尽管铜、镍和铅未观测到明显污染，但部分样本中锌的含量较高（达10 nmol/kg）。后续研究发现，该浓度的锌可使生产力速率降低25%。
北大西洋溶解态铁浓度与太平洋相近（表层为0.07；深层为0.5~0.6 nmolP/kg）。尽管富集实验未发现铁限制的迹象，但添加纳摩尔级的铁可使二氧化碳吸收速率和颗粒有机碳（POC，particulate organic carbon）形成量提升1.3~1.7倍。该区域浮游植物的铁需求，大概率通过远距离大陆边缘的铁横向输运得以满足。