Fábio Vargas¹, Gotao Yang¹, Paulo Prado Batista¹, Delano Gobbi¹

¹National Institute for Space Research - INPE

Amplitude growth rates of monochromatic gravity waves were estimated and compared in this study by using multiple instrument measurements carried out in Brazil. Wave dynamic parameters (vertical wavelength, horizontal wavelength, period, and wave amplitude) were obtained from sodium density profiles of lidar observations in São José dos Campos (23ºS, 46ºW), while multiple airglow layer imaging provided brightness fluctuations amplitudes and parameter of waves over Cachoeira Paulista (23ºS, 45ºW). We find the vertical scales of gravity waves to range from 2 to 10 km for lidar measurements, and their amplitude growth rates in this regime are consistent with saturate/damped waves. The same characteristic is observed for waves detected in airglow images, but the vertical scales are larger in this case (λz>15 km). Despite the fact that both instruments show complementary information, the general saturated/damped behavior is consistent with diffusive filtering processes that impose limits on the amplitude growth rate of the observed waves, that is, the atmospheric diffusivity acts on the wave in order to reduce its amplitude.