Role of iron as a regulator of nitrogen cycle in the subsurface ocean

作为次表层亚硝酸盐最大值(SNM)的形成机制，通过测量次表层叶绿素最大层附近铁和营养物质的详细分布，验证了铁限制刺激浮游植物细胞向周围水域释放亚硝酸盐的假说。尽管东中国海的浮游植物组合不受铁的限制，但在SNM附近观测到的极低浓度的溶解铁似乎支持西北太平洋的这一假说。然而，在北太平洋的亚北极水域，古细菌的氨氧化也可能有助于SNM的形成，因为环境中的氨浓度很高

As a mechanism for the formation of the subsurface nitrite maximum (SNM), a hypothesis that iron limitation stimulates nitrite release from phytoplankton cells to the surrounding water, was examined in the oceanic waters, by measuring detailed distributions of iron and nutrients near the subsurface chlorophyll maximum layer. Although phytoplankton assemblage in the East China Sea was not under iron-limitation, extremely low concentration of dissolved iron observed near the SNMseems to support the hypothesis in the western North Pacific. In the subarctic waters of the North Pacific, however, archaeal ammonia oxidation may also contribute to the formation of the SNM, because of the high ambient ammonium concentrations