Abstract
<jats:p> Continental shelves challenge satellite altimetry. Over the macrotidal Argentine Continental Shelf, SWOT's unprecedented 1-day CalVal phase enables assessing the mission; using five in situ records, we present the first validation of its L3 sea surface height anomalies. KaRIn sensor noise is low, so residual accuracy is set by the corrections, not the instrument—the tides, best removed by FES2022b, and the dynamic atmospheric correction (DAC), the inverted-barometer (IB) response plus a wind-driven component. Assessing five DACs by cross-spectral coherence (2—10 day band) and isolating that dynamic component against the in situ data, we find none preserves shelf dynamics cleanly; each shifts the signal in time or alters its variance. Only under IB alone does SWOT cleanly resolve regional processes such as northward coastally trapped waves (~4.6-day period; 12.9 ± 3.5 m s <jats:sup>-1</jats:sup> ), which every DAC degrades. For now, IB-only fields are the safer choice to preserve high-frequency shelf dynamics. </jats:p>