The saline-warm Mediterranean Outflow Water (MOW) plays a crucial role in Atlantic Ocean circulation dynamics. Although precession-driven MOW strength variability has been documented, its depth variations during northward transport are poorly known. Using terrigenous grain-size sortable silt and benthic foraminiferal carbon isotopes from two depth-strategic sites (U1389: 644 m vs. U1588: 1339 m), we develop a unified framework of hydrodynamic proxies to constrain MOW’s depth and strength fluctuations over the last 250 kyr. Results reveal that MOW gradually deepened from ~100–60 ka and then stabilized, coinciding with the development of millennial-scale climate variability. This deepening results from reduced North-Atlantic water density due to massive Heinrich Stadials meltwater discharges, and/or enhanced production of denser MOW driven by Mediterranean cooling/aridification. During interglacials, MOW shoaled and directly influenced U1588 sediments, while it sank below this site during glacials. MOW’s depth variations closely follow precession cyclicity, being deeper during Northern Hemisphere summer insolation minima when flow intensified. This is because intensified MOW enhances the mixing and dilution as it moves northward, due to increased density contrasts with ambient waters. Our findings highlight precessional control over both the strength and depth of MOW’s northward propagation.

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