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Photochemical Oxygen Consumption in Marine Waters

海水中的光化学耗氧量

基本信息

批准号：
9115608
负责人：
Oliver Zafiriou
金额：
$ 30.14万
依托单位：
Woods Hole Oceanographic Institution
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
1992
资助国家：
美国
起止时间：
1992-01-01 至 1994-12-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=9115608&HistoricalAwards=false
关键词：
Photochemical Oxygen Consumption Marine Waters

项目摘要

Oxidative marine photochemical reactions are an important step in modifying and remineralizing terrestrially-derived DOM, as shown in individual examples and indirect mechanistic evidence. Important classes of marine-derived DOM probably also enter this cycle. This project will quantify total photooxidative processes as oxygen consumption, by (1) direct O2 uptake measurements where sensitivity permits, and (2) using an indirect method sensitive enough for "blue water" and for low-reactivity coastal water studies. The results will provide much-needed quantitative evaluation of the role of photooxidation in oceanic carbon and oxygen cycles. Oxygen consumption, closely related to DOM oxidation, will be measured in coastal and estuarine waters and in organic matter concentrated by hydrophobic adsorption. Direct O2 uptake will be measured using pulsed polarographic electrodes with automated data acquisition. A sensitive new indirect technique, calibrated empirically against direct measurements, will quantify fluxes of the primary O2 -consuming species in "blue" and low-activity coastal waters. Effects of variables such as wavelength, light intensity, temperature, oxygen concentration, and prolonged photolysis on O2 consumption rates will be investigated to understand their (bio) geochemical significance and to identify the major mechanisms involved in O2 uptake/C remineralization.

海洋氧化光化学反应是海洋生物化学研究的重要步骤，修改和本地化源自地面的DOM，如个别的例子和间接的机械证据。重要海洋衍生DOM的类可能也进入这个循环。这该项目将量化总的光氧化过程作为氧气消耗，通过（1）直接O2吸收测量，（2）使用足够敏感的间接方法， “蓝水”和低反应性沿海水域研究。的结果将提供急需的定量评价，光氧化在海洋碳和氧循环中的作用。与DOM氧化密切相关的耗氧量，在沿海和河口沃茨和有机物中测量通过疏水吸附浓缩。直接O2摄入量将是使用脉冲极谱电极自动数据测量采集一种灵敏的新型间接技术，根据经验，对直接测量，将量化通量的主要耗氧物种为“蓝色”和低活性沿海沃茨。波长、光线等变量的影响强度、温度、氧浓度和长时间将研究光解对O2消耗率的影响，了解它们的（生物）地球化学意义，并确定 O2吸收/C矿化的主要机制。