Biogeochemical responses of the surface ocean and the lower atmosphere during the meso-scale iron enrichment experiments

南大洋、东赤道太平洋和亚北极太平洋被公认为HNLC（高营养低叶绿素）海洋，其中铁的消耗是初级生产的限制因素。从1993年开始进行了中尺度铁施肥试验，以检验铁假设和未来的地球工程作为碳封存。在北太平洋，A. Tsuda和他的同事从2001年开始进行了三个实验（SEEDS， SERIES和SEEDS II）。这笔赠款支持SEEDS II巡航，以及其他两个实验的详细分析和综合。此外，在副热带太平洋进行了添加铁和磷酸盐的初步瓶培养实验，以测试未来中尺度实验的可行性。通过国内研讨会、国内研讨会、国际研讨会、国际研讨会、PICES-IFEP会议和solas相关会议，对这些实验进行了数据分析和综合。本实验的主要结论是：施用铁肥可提高高通量水体的初级产量，但浮游植物的积累量、繁殖时间和优势浮游植物种类因铁浓度、表层混合层深度、浮游动物生物量和季节而异。更重要的是，由于微生物的呼吸作用，颗粒物沉降固碳的效率并不像预期的那么高。这些结果对国际共识的形成产生了重要影响，即铁肥作为固碳技术是一种不成熟的技术。另一方面，铁在副热带实验中几乎没有影响，但这些实验有助于积累亚热带生态系统的基础知识，并为solas相关项目（重点领域科学研究资助：表层海洋和低层大气之间生化循环的联系）奠定基础。少

The Southern Ocean, the eastern equatorial Pacific and subarctic Pacific are recognized as HNLC (High Nutrient Low Chlorophyll) oceans, where depletion of iron is an limiting factor of primary production. Mesoscale iron-fertilization experiments have been conducted from 1993 to test the iron hypothesis and for future geoengineering as carbon sequestration. In the North Pacific, three experiments (SEEDS, SERIES and SEEDS II) have been carried out by A. Tsuda and his colleagues from 2001. This Grant-in-Aid supported the SEEDS II cruises, and detailed analysis and synthesis of other two experiments. Furthermore, preliminary bottle incubation experiments in which iron and phosphate were added, were carried out in the subtropical Pacific to test the feasibility of future mesoscale experiments. Data analysis and synthesis of these experiments have been done through a domestic workshop, domestic symposium, international workshop, international symposium, PICES-IFEP meeting and SOLAS-related m … More eetings. The main conclusion of our experiments is iron-fertilization to HNLC waters enhance the primary production but the magnitude of phytoplankton accumulation, the timing of the bloom and dominant phytoplankton species varies depending on the iron concentration, depth of surface mixed layer, zooplankton biomass and the season. More importantly, the efficiency of carbon sequestration by sinking of particulate matter was not high as what have been expected, because of respiration of microbial organisms. These results importantly affect on the formation of the international consensus that iron-fertilization is an immature technology as carbon sequestration. On the other hand, iron had almost no effect in the subtropical experiments, but these experiments contributed for the accumulation of the basic knowledge of the subtropical ecosystems and formed a groundwork of SOLAS-related project (Grant-in-Aid for Scientific Research on Priority Areas: Linkages in Biochemical Cycles between Surface Ocean and Lower Atmosphere). Less