We present the results of measurements of thermohaline and dynamical structures, as well as hydrochemical parameters of near-bottom water in the Western Gap (Azores-Gibraltar Fracture Zone, Northeast Atlantic). The data were collected during cruise 59 of the research vessel Akademik Ioffe in October 2021. The results of the analysis showed that water with potential temperatures lower than 2.00 °C had crossed the Entrance Sill, but was not detected inside the interior basin of the Western Gap. The velocities of currents at the Entrance Sill were high (up to 30 cm/s) leading to mixing of the water overflowing the sill. While Antarctic Bottom Water (AABW) flows from the Entrance Sill to the Exit Sill it is subjected to modification. Bottom water becomes less dense after the sill due to mixing during overflow and in addition not all cold water overflows the sill. The dissolved oxygen concentration in the bottom layer increases from the Entrance Sill (239–242 μmol/kg) to the Exit Sill (241–248 μmol/kg) indicating the transformation of AABW as it circulates in the Western Gap and mixes with North Atlantic Deep Water propagating from the north. All velocity measurements indicate that north velocity component is a characteristic property of the bottom flow. Thus, water with specific chemical composition of AABW is transported to the Iberian Basin despite that its potential temperature becomes higher than 2 °C.

我们介绍了温盐和动力结构的测量结果，以及西峡（东北大西洋亚速尔-直布罗陀断裂带）近底层水的水化学参数。这些数据是在 2021 年 10 月Akademik Ioffe号研究船第 59 次巡航期间收集的。分析结果显示，潜在温度低于 2.00 °C 的水已穿过入口门槛，但在西部内陆盆地内未检测到。差距。入口窗台处的水流速度很高（高达 30 厘米/秒），导致溢出窗台的水混合。当南极底水 (AABW) 从入口坎流向出口坎时，它会受到修改。由于溢流过程中的混合，底水在经过门槛后变得不那么稠密，此外并非所有冷水都会溢出门槛。底层溶解氧浓度从入口窗台 (239–242 μmol/kg) 到出口窗台 (241–248 μmol/kg) 增加，表明 AABW 在西峡循环并与北大西洋混合时发生了转变深水从北方传播。所有速度测量表明北向速度分量是底流的特征属性。因此，尽管潜在温度高于 2 °C，具有 AABW 特定化学成分的水仍然被输送到伊比利亚盆地。