Mignot A, Ferrari R, Claustre H
Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
Laboratoire d'Océanographie de Villefranche (LOV), UPMC Univ. Paris 06, CNRS, UMR 7093, Sorbonne Universités, 181 Chemin du Lazaret, 06230, Villefranche-sur-mer, France.
Nat Commun. 2018 Jan 15;9(1):190. doi: 10.1038/s41467-017-02143-6.
The North Atlantic bloom corresponds to a strong seasonal increase in phytoplankton that produces organic carbon through photosynthesis. It is still debated what physical and biological conditions trigger the bloom, because comprehensive time series of the vertical distribution of phytoplankton biomass are lacking. Vertical profiles from nine floats that sampled the waters of the North Atlantic every few days for a couple of years reveal that phytoplankton populations start growing in early winter at very weak rates. A proper bloom with rapidly accelerating population growth rates instead starts only in spring when atmospheric cooling subsides and the mixed layer rapidly shoals. While the weak accumulation of phytoplankton in winter is crucial to maintaining a viable population, the spring bloom dominates the overall seasonal production of organic carbon.
北大西洋水华对应着浮游植物的强劲季节性增长，这些浮游植物通过光合作用产生有机碳。究竟是哪些物理和生物条件引发了水华，目前仍存在争议，因为缺乏浮游植物生物量垂直分布的全面时间序列。九艘浮标每隔几天对北大西洋水域进行数年采样所得到的垂直剖面显示，浮游植物种群在初冬时开始以非常缓慢的速度生长。而真正的水华，即种群增长率迅速加快的情况，要到春季大气冷却消退且混合层迅速变浅时才开始。虽然冬季浮游植物的微弱积累对于维持一个可存活的种群至关重要，但春季水华主导了有机碳的整体季节性产量。
