黄海溶解无机氮时空变化及其水团对DIN总量的影响

本文根据2013~2016年4个航次调查资料，研究了黄海水体中溶解无机氮（DIN）的时空变化及其总量影响因素.结果表明：春、夏、秋和冬季黄海调查海域DIN平均浓度分别为（5.43±4.02），（4.47±3.16），（7.46±3.56）和（5.09±2.59）μmol/L.其中，秋季浓度最高，夏季最低；黄海调查海域各季节DIN的分布呈现近岸高、外海低的变化规律，近岸高值点多集中在长江口以北、山东半岛和辽东半岛等处.春~秋季影响DIN分布的因素主要是陆源输入和浮游植物的生长繁殖，冬季则主要是河流输入和沉积物再悬浮作用.四季在中央海域底层还存在一个高值区（>6μmol/L），主要受黄海冷水团和黄海暖流等共同影响；通过聚类分析法对黄海四季水团进行了基本划分，调查海域主要包括5个水团：黄海混合水团、黄海冷水团、黄海暖流水、沿岸水团和黄东海混合水团，除黄海混合水团终年存在外，其他水团均为季节性存在；调查海域DIN总量四季差异不大，整体含量介于1.0×10⁶~1.5×10⁶t，春、夏、秋和冬季DIN总量分别约为1.2×10⁶，1.0×10⁶，1.5×10⁶和1.3×10⁶t.春季和夏季受浮游植物吸收影响，DIN总量略低，从水团对DIN总量的贡献上来看，春季以黄海暖流为主，夏季以黄海冷水团为主，秋、冬季以黄海混合水团为主.

Spatial-temporal variation of dissolved inorganic nitrogen (DIN) and impacts of water mass on the reserves estimation of the total DIN content in the Yellow Sea

Based on the data of 4 curies in 2013~2016, the distribution of DIN in the Yellow Sea、nitrogen pool and its influencing factors have been studied. Results showed that the average concentrations of DIN in the Yellow Sea were (5.43±4.02) μmol/L in spring, (4.47±3.16) μmol/L in summer, (7.46±3.56) μmol/L in autumn, and (5.09±2.59) μmol/L in winter, among which DIN contents reached maximum in autumn and minimum in summer, respectively. DIN concentrations declined from coastal zones to the offshore area. The DIN-rich sites near the coast were mostly centralized in the north of the Yangtze River estuary, Shandong Peninsula and Liaodong Peninsula. The main affecting factors all the year except winter were terrigenous input and the growth of phytoplankton, as the resuspension of the riverine input and sediment were the main factors affecting the distribution of DIN in winter. There was an area with high concentration of DIN(>6μmol/L) in the central area, which was co-influenced by the Yellow Sea warm current and the Yellow Sea Cold Water Mass. Cluster analysis has been used to classified the Yellow Sea water into 5 water masses, including the Yellow Sea water masses (Y), Yellow Sea cold water mass (YC), Yellow Sea warm current water (YW), Coastal water mass (CW) and Yellow Sea-East China Sea mixed water mass (YE), which was the main water mass in the researching sea area. All these water masses except for Y were seasonal. The total DIN content in the research field showed no obvious difference in all year, and their range was 1.0×10⁶~1.5×10⁶t. The DIN content was slightly lower in spring and summer under the influence of phytoplankton assimilation. The total DIN contents were about 1.2×10⁶t in spring, 1.0×10⁶t in summer, 1.5×10⁶t in autumn, and 1.3×10⁶t in winter, respectively. The contributions of water masses to the total DIN content were different in the varying season. In autumn and winter, Y was dominant, while in summer and spring, YW and YC played the dominant roles, respectively.