School of Earth and Environmental Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea.
School of Earth and Environmental Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea.
Sci Total Environ. 2021 Jan 10;751:141678. doi: 10.1016/j.scitotenv.2020.141678. Epub 2020 Aug 18.
Climate change in the Southern Hemisphere has exerted impact on the primary production in the Southern Ocean (SO). Using a recently released reanalysis dataset on global biogeochemistry, a comprehensive analysis was conducted on the complex biogeochemical seasonal cycle and the impact of climate change with a focus in areas within the meridional excursion of the sea ice boundary-coastal and continental shelf zone (CCSZ) and seasonal sea ice zone (SIZ). The seasonal cycles of primary production and related nutrients are closely linked with the seasonal changes in sea ice and sea surface temperatures. As sea ice retreats and allows energy and gas exchange across the sea surface, phytoplankton growth is initiated, consuming accumulated nutrients within the shallow depth of ~40 m. The seasonal evolutions of physical, biological and chemical variables show both spatial and temporal consistency with each other. Climate change has altered the timing and amplitude of the seasonal cycle. While primary production has generally increased along with an intensified uptake of CO, some areas show a reduction in production (e.g., Prydz Bay, eastern Indian Ocean). In the CCSZ, increased iron utilization and light availability allowed production to be increased. However, the mechanism by which these factors are altered varies from one location to another, including changes in sea ice cover, surface stratification, and downwelling/upwelling. In the SIZ, where iron is generally a limiting factor, iron supply is a key driver of changes in primary production regardless of other nutrients. There is a clear influence of climatic change on the biogeochemical cycle although the signal is still weak.
南半球的气候变化对南大洋的初级生产力产生了影响。利用最近发布的全球生物地球化学再分析数据集，对复杂的生物地球化学季节性周期以及气候变化的影响进行了综合分析，重点关注海冰边界纬向摆动的沿海和大陆架区（CCSZ）和季节性海冰区（SIZ）内的区域。初级生产力和相关养分的季节性循环与海冰和海面温度的季节性变化密切相关。随着海冰的消退，能量和气体可以通过海面进行交换，浮游植物的生长就开始了，消耗了浅海深度（~40 米）内积累的养分。物理、生物和化学变量的季节性演变在空间和时间上彼此具有一致性。气候变化改变了季节性周期的时间和幅度。虽然随着 CO2 的吸收增强，初级生产力普遍增加，但一些地区的产量却有所减少（例如，普里兹湾，印度洋东部）。在 CCSZ，铁的利用率增加和光照条件改善使产量增加。然而，这些因素变化的机制因地点而异，包括海冰覆盖、海面分层和下沉/上升流的变化。在 SIZ，铁通常是一个限制因素，无论其他养分如何，铁供应都是初级生产力变化的关键驱动因素。尽管信号仍然很微弱，但气候变化对生物地球化学循环有明显的影响。
