Carbon dioxide and carbon monoxide photoproduction quantum yields in the Delaware Estuary
Carbon dioxide and carbon monoxide photoproduction quantum yields in the Delaware Estuary
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DOI：
10.1016/j.marchem.2009.10.001
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发表时间：
2010-01
期刊：
影响因子：
3
通讯作者：
E. White;D. Kieber;Jane C Sherrard;W. Miller;K. Mopper
中科院分区：
文献类型：
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作者：
E. White;D. Kieber;Jane C Sherrard;W. Miller;K. Mopper
溶解有机质（DOM）的光化学矿化作用在河口生态系统碳循环中起着重要作用。模拟这一过程的关键是了解光化学产物的表观量子产率（AQY）。在这里，我们确定了光谱AQY的二氧化碳（CO2）和一氧化碳（CO），DOM光矿化的主要产品，沿着主轴的特拉华州河口。使用多光谱照射系统在船上测定了CO2光产生的表观量子产率。采用窄带光谱照射系统测定了储存样品中的一氧化碳AQY。一个单一的AQY光谱描述的二氧化碳光化学生产在河口，而CO AQY光谱随盐度变化，这两个物种的生产表明不同的前体和机制。沿着使用CO2 AQY与船上测量的DOM吸收率和太阳辐照度来计算光生速率。在实验误差范围内，计算的CO2光生速率与直接测量的速率（2至4μM CO2d−1）一致，支持进一步开发和使用AQY来计算区域尺度的光化学通量。
Photochemical mineralization of dissolved organic matter (DOM) plays an important role in the cycling of carbon in estuarine systems. A key to modeling this process is knowledge of apparent quantum yields (AQYs) for the photochemical products. Here we determined spectral AQYs for carbon dioxide (CO2) and carbon monoxide (CO), the main products of DOM photomineralization, along the main axis of the Delaware Estuary. Apparent quantum yields for CO2photoproduction were determined shipboard using a multi-spectral irradiation system. Carbon monoxide AQYs were determined in stored samples by employing a narrow band spectral irradiation system. A single AQY spectrum described carbon dioxide photochemical production within the estuary whereas CO AQY spectra varied with salinity, suggesting different precursors and mechanisms for the production of these two species. CO2AQYs were used along with shipboard measurements of DOM absorbance and solar irradiance to calculate photoproduction rates. Calculated CO2photoproduction rates agreed with directly measured rates (2 to 4μM CO2d−1) within experimental error, supporting the further development and use of AQYs to calculate regional-scale photochemical fluxes.