This work is focused on the seasonal and interannual variability of the freshened surface layer (FSL) in the Kara Sea during ice‐free periods. The majority of annual freshwater runoff inflows to the Kara Sea during the freshet period in June–July. As a result, a large low‐salinity and strongly stratified FSL is formed in the central Kara Sea at the beginning of the ice‐free period. Initially, this layer is fresh with salinities of less than 15. Then, in August–October, river discharge steadily decreases, the fresh (<15) and strongly stratified river plume remains limited to the inner part of the FSL adjacent to the Ob and Yenisei gulfs, which receives reduced freshwater discharge. The area of the fresh plume steadily decreases with decreasing of river discharge; in October, it remains only within the Ob and Yenisei gulfs. Area and position of the outer part of the FSL, on the opposite, remain stable until the end of ice‐free period. Salinities in the outer part steadily increase to 20–25, vertical salinity gradients at the boundary with the subjacent sea decrease, albeit remain prominent. Area and position of the FSL also have low interannual variability, because the volume of river runoff during freshet period in June–July is stable on interannual time scale. As a result, downward freshwater transport and the formation of the seasonal halocline occur in August–October at the stable area located in the central Kara Sea.

中文翻译：

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无冰期卡拉海新鲜表层结构

这项工作的重点是在无冰时期卡拉海的新鲜表层（FSL）的季节和年际变化。在六月至七月的淡水期，大部分年度淡水径流流入卡拉海。结果，在无冰期开始时，在卡拉海中部形成了大量的低盐度和强烈分层的FSL。最初，该层是新鲜的，盐度小于15。然后，在8月至10月，河水流量稳定减少，新鲜（<15）且强烈分层的河羽仍然局限于FSL内部与Ob和Ob相邻的区域。叶尼塞湾，淡水排放量减少。随着河道流量的减少，新鲜羽流的面积逐渐减小。在10月，它仅保留在Ob和Yenisei海湾内。相反，FSL外部的面积和位置保持稳定，直到无冰期结束。外部的盐度稳定地增加到20–25，与海底边界的垂直盐度梯度减小，尽管仍然很明显。FSL的面积和位置也具有较低的年际变化性，因为在6月至7月的新生期河水径流量在年际时间尺度上是稳定的。结果，向下的淡水运输和季节性盐湖的形成发生在8月至10月在卡拉海中部的稳定地区。FSL的面积和位置也具有较低的年际变化性，因为在6月至7月的新生期河水径流量在年际时间尺度上是稳定的。结果，在喀拉海中部的稳定地区，八月至十月发生了向下的淡水运输和季节性盐湖的形成。FSL的面积和位置也具有较低的年际变化性，因为在6月至7月的新生期河水径流量在年际时间尺度上是稳定的。结果，向下的淡水运输和季节性盐湖的形成发生在8月至10月在卡拉海中部的稳定地区。