San Francisco Bay (SFB) is a complex ecosystem that has been heavily impacted by human activities. It has experienced strong year-to-year variations in physical, chemical, and biological conditions, due to both natural climate variation and human activities. There is a need to investigate this long-term variation, with a focus on management practices and needs. The study aims to construct a coupled hydrodynamic and ecosystem model SCHISM/CoSiNE, to investigate interannual variability of chlorophyll and nutrient dynamics in SFB over the 10-year period of 2005–2014. The coupled SCHISM/CoSiNE model captures the long-term observations well. It shows that high chlorophyll concentrations in South Bay persist during warm months, while chlorophyll in North Bay is low and has strong interannual variation. Nutrient concentrations are higher in North Bay where large river outflow influences their distribution and interannual variation, and in lower South Bay. The model results show that phytoplankton blooms in Suisun Bay tend to occur when flow rates are between 100 and 250 m³/s and ammonium concentration is in the range of 1–2 mmol/m³. Model sensitivity experiments show that benthic grazing can potentially reduce phytoplankton biomass, and its effect on chlorophyll concentration is modulated by river outflow. We demonstrate the potential of this open-source model for exploring water quality conditions and options for river flow management of SFB.

中文翻译：

---

旧金山湾叶绿素和养分的年际变化：一项模拟研究

旧金山湾（SFB）是一个复杂的生态系统，受到人类活动的严重影响。由于自然气候变化和人类活动的影响，它的物理，化学和生物条件每年都经历着很大的变化。有必要调查这种长期变化，重点是管理实践和需求。该研究旨在构建一个耦合的水动力和生态系统模型SCHISM / CoSiNE，以调查2005-2014年10年间SFB中叶绿素和养分动态的年际变化。耦合的SCHISM / CoSiNE模型可以很好地捕获长期观测结果。结果表明，在温暖的月份中，南湾的叶绿素含量持续较高，而北湾的叶绿素含量较低，并且年际变化很大。在北部湾（河水大量流出影响其分布和年际变化）和下部南部湾的养分浓度较高。模型结果表明，水流在100〜250 m之间时，易孙湾浮游植物大量繁殖。³ / s，铵浓度为1-2 mmol / m ³。模型敏感性实验表明，底栖放牧有可能减少浮游植物的生物量，其对叶绿素浓度的影响受河流流出量的调节。我们展示了这种开源模型在探索水质条件和SFB河流流量管理选择方面的潜力。