| 渤海和北黄海有色溶解有机物(CDOM)的分布特征和季节变化 |
| 摘要点击 2424 全文点击 679 投稿时间：2018-05-14 修订日期：2018-09-12 |
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| 中文关键词 有色溶解有机物(CDOM) 紫外-可见光吸收光谱 三维荧光光谱(EEM) 平行因子分析 分布特征 季节变化 渤海和北黄海 |
| 英文关键词 chromophoric dissolved organic matter (CDOM) UV-Vis spectral excitation-emission matrix (EEM) parallel factor analysis distribution seasonal variations Bohai Sea and North Yellow Sea |
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| 中文摘要 |
| 采集了2016年的4、8、12月和2017年2月渤海和北黄海表、中、底海水样品，分析了海水中有色溶解有机物（CDOM）的紫外-可见光吸收光谱和三维荧光光谱，探讨了渤海和北黄海海域CDOM的分布特征、影响因素和季节变化.结果表明，不同季节CDOM分布相似，呈近岸高、远海低的分布特征.吸收系数a（355）和光谱斜率S275-295呈显著负相关，说明CDOM受到陆源输入的显著影响.垂直分布上，8月，受强烈的光降解作用影响，表层CDOM含量最低.2月，底层CDOM含量最低，这可能与受光照影响的初级生产力在水下分布不均匀有关.从2016年4月~2017年2月，CDOM含量先上升后下降，12月含量最高，2月含量最低.CDOM的季节变化主要受陆源输入和浮游植物生物量的季节变化控制.以光谱斜率S275-295表征CDOM的平均分子量，2月由于陆源输入最少，CDOM平均分子量最小.夏季光降解强烈，将部分大分子量有机物降解成小分子量有机物，小分子量有机物增加，因此，8月CDOM的平均分子量小于4月和12月. |
| 英文摘要 |
| UV-Vis spectral data and a fluorescence excitation-emission matrix (EEM) was analyzed for the surface, middle, and bottom layer water samples from the Bohai Sea and North Yellow Sea in April, August, and December of 2016 and February of 2017. Distribution characteristics, influencing factors, and seasonal variation of CDOM in the study area were investigated. The results showed that the horizontal distributions of CDOM are similar in different seasons, showing a characteristic of high levels near shore and low levels in the offshore region. Strong correlations were observed between value a (355) and spectral slope S275-295, indicating that CDOM is significantly affected by land input. According to the vertical distribution, the CDOM level is the lowest in surface seawater in summer due to strong photo-degradation. In February, controlled by primary productivity, the lowest level of CDOM was found in the bottom seawater. From April 2016 to February 2017, the content of CDOM first increased and then decreased. Its concentration was highest in December. Seasonal variations are mainly controlled by land input and on-site production. According to analysis of the spectral slope S275-295, the average molecular weight of CDOM in winter was smallest in February, which was mainly related to the drastic reduction of land-based input at that time. The strong photo-degradation in summer resulted in a small average molecular weight of CDOM. |
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