Impact of vertical resolution on representing baroclinic modes and water mass distribution in the North Atlantic

•Vertical grids impact the modeling of baroclinic modes and water mass distribution.•32-layer HYCOM is adequate to represent first 5 baroclinic modes in mid-latitudes.•A simulation with 16 layers exhibits no dense overflow water and a shallower AMOC.•Simulations with 24 to 96 layers exhibit overall similar North Atlantic circulation.