Dynamic Sea Level Variability Due to Seasonal River Discharge: A Preliminary Global Ocean Model Study

River discharge R is an important driver of the coastal ocean circulation. However, the influence of variable R effects on large‐scale sea level ζ related to ocean dynamics is not well understood. We perform numerical experiments using a coarse ( ∼ 1 °) global ocean state estimate to quantify R effects on the seasonal cycle in dynamic ζ over the global ocean. Forcing by R drives substantial dynamic ζ signals ( ≳ 1  cm) on regional scales around major rivers (e.g., Amazon, Ganges, Brahmaputra, Irrawaddy, Ob, Lena, and Yenisei). Modeled ζ changes largely reflect halosteric (salinity) effects, which are partly affected by transport processes involving planetary waves and advection. The modeled ζ response to R is informative for interpreting ζ observations from satellite altimetry and tide gauges, explaining 10–20% of the regional‐scale seasonal data variance around some major rivers. Future ζ studies should consider finer‐resolution models and R forcing on nonseasonal time scales of relevance to climate.