The analysis of synoptic satellite data of total chlorophyll-a (Chl-a) and the environmental drivers that influence nutrient and light availability for phytoplankton growth allows us to understand the spatio-temporal variability of phytoplankton biomass. In the Panama Bight Tropical region (PB; 1–9°N, 79–84°W), the spatial distribution of Chl-a is mostly related to the seasonal wind patterns and the intensity of localized upwelling centers. However, the association between the Chl-a and different physical variables and nutrient availability is still not fully assessed. In this study, we evaluate the relationship between the Chl-a and multiple physical (wind, Ekman pumping, geostrophic circulation, mixed layer depth, sea level anomalies, river discharges, sea surface temperature, and photosynthetically available radiation) and chemical (nutrients) drivers in order to explain the spatio-temporal Chl-a variability in the PB. We used satellite data of Chl-a and physical variables, and a re-analysis of a biogeochemical product for nutrients (2002–2016). Our results show that at the regional scale, the Chl-a varies seasonally in response to the wind forcing and sea surface temperature. However, in the coastal areas (mainly Gulf of Panama and off central-southern Colombia), the maximum non-seasonal Chl-a values are found in association with the availability of nutrients by river discharges, localized upwelling centers and the geostrophic circulation field. From this study, we infer that the interplay among these physical-chemical drivers is crucial for supporting the phytoplankton growth and the high biodiversity of the PB region.

中文翻译：

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巴拿马湾中叶绿素-A的时空变异和环境变量

对总叶绿素-a（Chl-a）的天气卫星数据以及影响浮游植物生长的养分和光利用率的环境驱动因素的分析，使我们能够了解浮游植物生物量的时空变异性。在巴拿马湾热带地区（PB； 1–9°N，79–84°W），Chl-a的空间分布主要与季节性风型和局部上升流中心的强度有关。但是，Chl-a与不同物理变量和养分利用率之间的关联仍未得到充分评估。在这项研究中，我们评估了Chl-a与多种物理因素（风，埃克曼抽水，地转环流，混合层深度，海平面异常，河流流量，海面温度，以及光合作用的辐射）和化学（营养物）驱动因素，以解释PB中的时空Chl-a变异性。我们使用了Chl-a和物理变量的卫星数据，并对生物地球化学产品的营养成分进行了重新分析（2002-2016年）。我们的结果表明，在区域尺度上，Chl-a随风力和海表温度的变化而季节性变化。但是，在沿海地区（主要是巴拿马湾和中南部哥伦比亚以外的沿海地区），发现最大的非季节性Chl-a值与河流排泄物，局部上升流中心和地转环流场的养分供应有关。根据这项研究，