Measuring Oceanic Carbon Dioxide

测量海洋二氧化碳

• 批准号: 06044002
• 负责人: TSUNOGAI Shizuo
• 金额: $ 4.16万
• 依托单位: Hokkaido University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06044002/
• 关键词: Ocean; system; Carbon dioxide; Total carbon dioxide; pH; Alkalinity; Analytical chemistry; Earth environment; 全炭素; PH

Te ocean carbon dioxide system is important on the carbon cycle in the earth. It is estimated ocean uptakes about 30% of the anthoropogenic carbon dioxede. However, change of oceanic carbon dioxide system owing to the anthoropogenic carbon dioxede is too small to detect conveniently because the ocean contains more than 50 times as much carbon as the atmosphere. The ocean carbon dioxide system is investigated by the temporal and spatial variations of fugacity of dissolved carbon dioxede [fCCO_2)], total carbon dioxide, pH,alkalinity, ratio of stable carbon isotopes, etc. These data should be highly precise and accurate to detect the change in the earth's environment. Recent developments in analytical chemistry make it possible to reduce the random errors. However, the systematic errors between institutes or scientists are often serious, but not well known. In this study, we discussed most precise and accurate method of oceanic carbon dioxide measurements under any conditions and standar … More d materials to decrease of the systematic errors with the researchers in the world and conducted an intercomparison of analytical works with Institute of Ocean Sciences (IOS) in Canada.The f(CO_2) value of seawater is commonly obtained by the determination of the air equilibrated with sample seawater using the showering type equilibrator and detected with ND= It was known the pressure inside this type equilibrator has to be controlled in order to obtain high accurate f(CO_2) value because the f(CO_2) value is affected by the pressure inside the equilibrate.Standard materials are necessarily for the highly precise measurements of total carbon dioxide, pH,alkalinity and ratio of stable carbon isotopes. The standards for pH and total carbon dioxide developed by Dickson were useful, but standard for alkalinity measurement has been still under the discussion. Intercomparison of stable carbon isotope measurement using the standard for total carbon analysis was conducted by C.S.Wong. However, it was not enough to detect the small change induced anthoropogenic carbon dioxide.Results of the intercomparison with IOS are as follows : (1) the f(CO_2) value obtained by the equilibrator of Hokkaido University was same as that by IOS's equilibrator, (2) difference between amounts of total carbon dioxide measured by Hokkaido University and by IOS was about 10mumole/l, (3) there were systematic errors between pH values obtained by Hokkaido University and these by IOS doe to instrument's standardization and (4) ratios of stable carbon isotopes of bottled Seawater samples and carbonates prepared by Hokkaido University were about 0.7%。 deferent from these analyzed at IOS. Less

海洋二氧化碳系统对地球碳循环非常重要。据估计，海洋吸收了约 30% 的人为二氧化碳。然而，人为二氧化碳引起的海洋二氧化碳系统变化太小，不方便检测，因为海洋中的碳含量是大气的50倍以上。通过溶解二氧化碳的逸度[fCCO_2)]、二氧化碳总量、pH、碱度、稳定碳同位素比等的时空变化来研究海洋二氧化碳系统。这些数据应该高度精确和准确，以检测地球环境的变化。分析化学的最新发展使得减少随机误差成为可能。然而，机构或科学家之间的系统错误往往很严重，但却不为人所知。在这项研究中，我们与世界上的研究人员讨论了在任何条件和标准材料下最精确、最准确的海洋二氧化碳测量方法，以减少系统误差，并与加拿大海洋科学研究所(IOS)进行了分析工作的比对。海水的f(CO_2)值通常是通过使用淋浴式测定与海水样品平衡的空气来获得的。 众所周知，为了获得高精度的f(CO_2)值，必须控制平衡器内的压力，因为f(CO_2)值受平衡器内压力的影响。标准材料是高精度测量总二氧化碳、pH、碱度和稳定碳同位素比值所必需的。 Dickson 制定的 pH 值和总二氧化碳标准很有用，但碱度测量标准仍在讨论中。 C.S.Wong 使用总碳分析标准进行稳定碳同位素测量的相互比较。然而，不足以检测人为二氧化碳引起的微小变化。与IOS比对结果如下：（1）北海道大学平衡器得到的f（CO_2）值与IOS平衡器相同，（2）北海道大学和IOS测量的总二氧化碳量之间的差异约为 10mumole/l，（3）北海道大学获得的pH值与IOS doe对仪器标准化的pH值之间存在系统误差，（4）瓶装海水样品和北海道大学制备的碳酸盐的稳定碳同位素比率约为0.7％。与IOS分析的结果不同。较少的