Abstract

The article presents the data of an comprehensive expedition of the Pacific Oceanological Institute, Far East Branch, Russian Academy of Sciences, performed in the mixing zones of the Uda and Usalgin rivers in July 2016. During the flood period, they occupy most of the catchment basins: Udskaya Bay and Nikolaya Bay. The estimated discharge of the Uda and Usalgin rivers was 4390 and 173 m³/s, respectively, and estuarine waters with salinity to 8‰ spread from their mouths to a distance of 25 km in Udskaya Bay and 2.5 km in Nikolaya Bay. The boundary of the estuarine seashore distinguished by the isohaline 30‰ was at a distance of 85 km from the river mouths in the both mixing zones. River runoff—the main supplier of suspended particulate matter and silicates—limited the thickness of the photic layer and photosynthesis at the early stage of mixing zones to the salinity of ~24‰, where water was a source of CO₂ for the atmosphere. At the later stage of the mixing zones, under the conditions of a greater thickness of the photic layer, production dominated, and the water area was a sink for atmospheric CO₂. Mineralization of autochthonous organic matter on the bottom of the receiving basins was the main source of inorganic forms of nutrients. The lack of silicates (DISi/DIN < 1 and the relatively low DIN/DIP ratio in the range of 1.8–8) was a limiting factor of photosynthesis at the late stage of the mixing zone.

中文翻译：

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夏季河流径流对乌兹卡亚湾和尼古拉亚湾（鄂霍次克海）水化学特征的影响

摘要

文章介绍了俄罗斯科学院远东分院太平洋海洋研究所于 2016 年 7 月在乌达河和乌萨尔金河混合带进行的综合考察数据。在洪水期间，它们占据了大部分流域盆地：乌兹卡亚湾和尼古拉亚湾。乌达河和乌萨尔金河的估计流量分别为 4390 和 173 m ³/s，盐度为 8‰ 的河口水域从他们的嘴里扩散到 Udskaya 湾 25 公里和尼古拉湾 2.5 公里处。以等盐度30‰为特征的河口海滨边界距离两个混合带的河口85公里。河流径流 - 悬浮颗粒物和硅酸盐的主要供应商 - 将光层的厚度和混合区早期的光合作用限制在约 24‰ 的盐度，其中水是大气CO ₂的来源。混合区后期，在光层较厚的条件下，产量占主导地位，水域是大气CO ₂的汇. 接收盆地底部原生有机质的矿化是无机形式养分的主要来源。缺乏硅酸盐（DISi/DIN < 1 和相对较低的 DIN/DIP 比率在 1.8-8 范围内）是混合区后期光合作用的限制因素。