Vertical salinity variance (SV) budgets are derived using the isohaline Total Exchange Flow (TEF) framework, with the advection of vertical SV quantified by the dispersion of salinity classes across sections. A numerical model of the Changjiang Estuary is used to demonstrate the application of this method. The analysis is focused on the North Channel (NC) segment where strong stratification is produced during neap tides. We find that the advection of vertical SV is stronger than that of horizontal SV during early neap due to the landward excursion of stratified water. However, strong northerly winds can significantly decrease the contribution of advection of vertical SV but increase the advection of horizontal SV into the NC due to the landward transport of relatively well-mixed saline water. This process increases the seaward advection of vertical SV in the southern channels. In addition, we highlight that the vertical SV dissipation (mixing) term balances the straining term and peaks at late neap in the NC, coinciding with the maximum volume-integrated vertical SV.

中文翻译：

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使用等盐线坐标计算盐度方差通量

垂直盐度方差 (SV) 预算是使用等盐总交换流 (TEF) 框架得出的，垂直 SV 的平流通过剖面上盐度等级的分散度进行量化。利用长江口数值模型验证了该方法的应用。分析的重点是北海峡 (NC) 部分，该部分在小潮期间会产生强烈的分层。我们发现，由于分层水向陆地移动，在初潮期间，垂直SV的平流比水平SV的平流更强。然而，由于相对充分混合的咸水向陆地输送，强北风可以显着减少垂直SV平流的贡献，但增加进入北卡罗来纳州的水平SV平流的贡献。这一过程增加了南部航道垂直SV的向海平流。此外，我们强调，垂直 SV 耗散（混合）项平衡了应变项，并在北卡罗来纳州晚晚达到峰值，与最大体积积分垂直 SV 一致。