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The slopes of the wavenumber spectra of sea surface height (SSH) and kinetic energy (KE) have been used to infer “interior” or surface quasi‐geostrophic (QG or SQG) dynamics of the ocean. However, inspection of spectral slopes for altimeter SSH in the mesoscale band of 70 to 250 km shows much flatter slopes than the QG or SQG predictions over most of the ocean. Comparison of altimeter wavenumber spectra with spectra from an eddy resolving global ocean circulation model (the HYbrid Coordinate Ocean Model, HYCOM, at 1/12.5° equatorial resolution), which has embedded tides, suggests that the flatter slopes of the altimeter SSH may arise from three possible sources: (1) presence of strong internal tides, (2) shift of the inertial sub‐range to smaller scales and (3) altimeter noise. Artificially adding noise to the model tends to flatten the spectra for low KE regions. Near internal tide generating regions …