The variability of the water mass exchange between the Arabian Gulf and the Indian Ocean is investigated using a high-resolution (1/36°) ocean model. We focus on the period from December 1996 to March 1998, having as reference in situ measurements at the Strait of Hormuz. Previous studies, based on models and observations, suggested a perpetual deep outflow, mainly in the southern part of the Strait, and a variable flow in the upper layers. In the present study, we confirm that there is a permanent core of a deep outflow in the Strait at depths greater than 40 m, characterised by high-salinity waters. In addition, we show that there is a seasonal signal in the upper layers net flow in the southern part of the Strait, altering from net inflow during winter/spring to net outflow during summer/fall. The mean annual inflow through the Strait is estimated at 0.22 ± 0.01 Sv and the deep outflow at 0.147 ± 0.01 Sv. The water mass exchange through the Strait is controlled by synoptic processes with high variability net transport fields. These processes characterise the structure and the intensity of the transport patterns, exhibiting 2- to 5-day period. On synoptic time scales, winds drive an immediate baroclinic flow at the Strait of Hormuz, affecting mostly the upper layers, and a quasi-barotropic flow that peaks approximately 2 days later.

中文翻译：

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霍尔木兹海峡的水交换变化

使用高分辨率（1/36°）海洋模型研究了阿拉伯湾和印度洋之间水质交换的变化性。我们将重点放在1996年12月至1998年3月这段时间，作为对霍尔木兹海峡海峡实地测量的参考。先前基于模型和观测的研究表明，永久性的深水流出（主要在海峡南部）和上层的水流可变。在本研究中，我们确认海峡深处有一个永久性岩心，深度大于40 m，以高盐度水为特征。此外，我们发现海峡南部的上层净流量有一个季节性信号，从冬季/春季的净流入变为夏季/秋季的净流出。通过海峡的年平均流入量估计为0.22±0.01 Sv，深部流出量为0.147±0.01 Sv。海峡两岸的水质交换受天气过程控制，其净输送场变化很大。这些过程表征了运输模式的结构和强度，展现了2至5天的时间。在天气尺度上，风在霍尔木兹海峡驱动立即的斜压流，主要影响上层，并在大约2天后达到峰值的准正压流。