Upper atmosphere tidal variability due to latent heat release in the tropical troposphere

The effects of latent heat release due to deep tropical convection on solar tidal variability in the 80 - 150 km altitude region are examined. The latent heating estimates are based on 7-year mean monthly 3-hourly rainfall rates obtained through the Global Precipitation Climatology Project. The latent heating rates are used to force the Global Scale Wave Model (GSWM) to obtain monthly estimates of the migrating diurnal (zonal wavenumber s = 1), migrating semidiurnal (s = 2) and standing (s = 0) diurnal tidal oscillations. It is demonstrated that monthly variations of up to 20 ms(-1) and 10 K are attributable to this excitation source, as well as longitudinal variations in the diurnal tide of order 15 - 25 ms(-1) at peak amplitudes. Higher-order zonal wavenumber contributions are expected to be as important, but are not considered within the scope of the present work. (C) 1999 COSPAR. Published by Elsevier Science Ltd.