Formation of HNLC region in the subarctic Pacific

2016 Fiscal Year Final Research Report

• Project/Area Number: 26281002
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Environmental dynamic analysis
• Research Institution: Hokkaido University
• Principal Investigator: Nishioka Jun 北海道大学, 低温科学研究所, 准教授 (90371533)
• Co-Investigator(Kenkyū-buntansha): 三寺 史夫 北海道大学, 低温科学研究所, 教授 (20360943)
• Co-Investigator(Renkei-kenkyūsha): YASUDA Ichro 東京大学, 大気海洋研究所, 教授 (80270792)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 北太平洋 / 鉄 / HNLC海域 / 植物プランクトン

Outline of Final Research Achievements

To investigate iron (Fe) sources controlling the seasonal variation in biogeochemical parameters in the subarctic Pacific, where phytoplankton growth is broadly limited by Fe availability, we examined the spatial variation in the distribution of dissolved Fe in the whole subarctic Pacific. Our results indicated that Fe-rich intermediate water is transported laterally and distributed across the western subarctic gyre. Spatial pattern of Fe to nutrient ratio supplied from the intermediate water to surface in comparison with Fe and nutrient demand in surface phytoplankton, and the analysis of dissolved Fe and nutrient fractionation in upper 200 m shallow water, quantitatively explains the differences in surface macronutrient consumption between the western and eastern gyre as well as the formation of the high nutrient and low chlorophyll region in the whole subarctic Pacific.

Free Research Field

化学海洋学