The increased frequency of harmful algal blooms (HABs) is a major environmental concern worldwide, resulting not only in increased treatment costs for drinking water but also in impacts on tourism, commercial fishing and aquaculture and risks to human and animal health. Traditional strategies with ship-based approaches based on field sampling and laboratory analysis have been adopted to assess HABs. However, these methods are labour intensive and costly and do not provide synoptic views of the bloom conditions. Here, we show that the Sentinel-2 twin satellite mission of the Copernicus programme, in combination with in situ data, is a powerful tool that can offer valuable spatiotemporal information about a bloom of the dinoflagellate Lingulodinium polyedra that occurred on the SW Iberian Peninsula. Using the robust ACOLITE atmospheric correction processor combined with the normalized difference chlorophyll index (NDCI), the enhanced mapping of small blooms can be performed at a 10 m spatial resolution, revealing surface patches and a heterogeneous distribution. This research also demonstrates the improved capabilities of Sentinel-2 compared to those of Landsat-8 and Sentinel-3 for continuous monitoring. The Sentinel-3 and Sentinel-2 missions provide ecosystem observations that allow the environmental community and water managers to evaluate changes in water quality and bloom distribution and that facilitate field-based measurements. Therefore, the value added by the Copernicus products in terms of frequency and synoptic observations is of paramount importance for ecological and management purposes at regional and national scales.

有害藻华 (HAB) 频率的增加是世界范围内的一个主要环境问题，不仅导致饮用水处理成本增加，而且对旅游业、商业捕鱼和水产养殖产生影响，并对人类和动物健康造成风险。采用基于现场采样和实验室分析的船载方法的传统策略来评估有害细菌。然而，这些方法是劳动密集型且成本高昂，并且不能提供水华条件的概要视图。在这里，我们展示了哥白尼计划的 Sentinel-2 双卫星任务与现场数据相结合，是一个强大的工具，可以提供有关伊比利亚半岛西南部发生的甲藻藻华的宝贵时空信息。使用强大的 ACOLITE 大气校正处理器与归一化叶绿素指数 (NDCI) 相结合，可以在 10 m 空间分辨率下对小水华进行增强测绘，从而揭示表面斑块和异质分布。这项研究还表明，与 Landsat-8 和 Sentinel-3 相比，Sentinel-2 的连续监测能力有所提高。 Sentinel-3 和 Sentinel-2 任务提供生态系统观测，使环境界和水资源管理者能够评估水质和水华分布的变化，并促进实地测量。因此，哥白尼产品在频率和天气观测方面的附加值对于区域和国家尺度的生态和管理目的至关重要。