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We previously considered various aspects of gravity wave penetration andeffects at mesospheric and thermospheric altitudes, including propagation,viscous effects on wave structure, characteristics, and damping, local bodyforcing, responses to solar cycle temperature variations, and filtering bymean winds. Several of these efforts focused on gravity waves arising fromdeep convection or in situ body forcing accompanying wave dissipation. Herewe generalize these results to a broad range of gravity wave phase speeds,spatial scales, and intrinsic frequencies in order to address all of themajor gravity wave sources in the lower atmosphere potentially impacting thethermosphere. We show how penetration altitudes depend on gravity wave phasespeed, horizontal and vertical wavelengths, and observed frequencies for arange of thermospheric temperatures spanning realistic solar conditions andwinds spanning reasonable mean and tidal amplitudes. Our results emphasizethat independent of gravity wave source, thermospheric temperature, andfiltering conditions, those gravity waves that penetrate to the highestaltitudes have increasing vertical wavelengths and decreasing intrinsicfrequencies with increasing altitude. The spatial scales at thehighest altitudes at which gravity wave perturbations are observed areinevitably horizontal wavelengths of ~150 to 1000 km and verticalwavelengths of ~150 to 500 km or more, with the larger horizontalscales only becoming important for the stronger Doppler-shifting conditions.Observed and intrinsic periods are typically ~10 to 60 min and ~10 to30 min, respectively, with the intrinsic periods shorter at thehighest altitudes because of preferential penetration of GWs that areup-shifted in frequency by thermospheric winds

Gravity wave penetration into the thermosphere: sensitivity to solar cycle variations and mean winds