A highly sensitive and detailed vertical distribution of nutrients in surface oceanic waters as a basis for evaluation of carbon dioxide absorption flux

表层海洋水域营养物的高度敏感和详细的垂直分布作为评估二氧化碳吸收通量的基础

• 批准号: 13680600
• 负责人: KANDA Jota
• 金额: $ 1.66万
• 依托单位: Tokyo University of Marine Science and Technology (Tokyo University of Fisheries)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13680600/
• 关键词: Euphotic Zone; Nutrient Phosphate; Nitrate; Carbon dioxide budget; Colorimetric analysis; Primary production; 一次生産

A highly sensitive method was developed for colorimetric analysis of nutrients in seawater by combining a continuous flow analysis system and a long path-length capillary flow cell (LWCC). With a 2-m light path cell, the detection limit of phosphate in seawater was 2.8nM. Interference with silicate and arsenate was examined and arsenate was to found to affect significantly unless a reduction reagent for arsenate was added. During several cruises of R/V Umitaka-maru and R/V Shinyo-maru, detailed vertical distributions of nutrients within surface or euphotic layers were determined. For stratified and oligotrophic waters, the highly sensitive colorimetric method was applied in phospate analysis. Nitrate (+nitrite) was analyzed by a highly sensitive chemiluminescence method. Detailed profiles of nutrients were obtained by conventional colorimetric analysis in the Southern Ocean during a Umitaka-maru cruise in January-February 2003. In these observations, the depth at which nutrient concentration begins to increase (or the depth of top of the nutricline) was found to be shallower for phosphate than for nitrate within the mixed layer. These features may reflect the general pattern of difference between nitrogen and phosphate dynamics in shallow oceanic waters. The highly sensitive colorimetric analysis of these nutrients can be used in high sensitive surface monitoring of nutrients and onboard incubation experiments.

将连续流分析系统与长径毛细管流动池（LWCC）相结合，建立了一种高灵敏度的海水中营养物质比色分析方法。采用2 m光程电池，海水中磷酸盐的检出限为2.8nM。对硅酸盐和砷酸盐的干扰进行了研究，发现除非加入砷酸盐还原剂，否则砷酸盐对干扰的影响是显著的。在R/V Umitaka-maru和R/V Shinyo-maru的几次巡航中，详细地确定了表层或光层内营养物质的垂直分布。对于分层和低营养水体，采用高灵敏度比色法进行磷酸盐分析。采用高灵敏度化学发光法对硝酸盐（+亚硝酸盐）进行了分析。2003年1 - 2月，在Umitaka-maru巡航期间，通过常规比色分析获得了南大洋营养物质的详细剖面。在这些观察中，发现在混合层中，营养物浓度开始增加的深度（或营养线顶部的深度）对磷酸盐的影响要比对硝酸盐的影响浅。这些特征可能反映了浅海水体氮磷动态差异的一般规律。这些营养物质的高灵敏度比色分析可用于营养物质的高灵敏度表面监测和机载孵育实验。