Convective and stratiform heating profiles estimated from TRMM rain rate data for realistic forcing of equatorial atmospheric waves

The latent heat released in tropical convection is the source for a variety of equatorial waves that both influence the formation of cirrus clouds and drive global-scale circulations in the middle atmosphere. Global models used for climate and data assimilation have sufficient resolution to describe many of these waves, yet the realism of the wave modes appearing in these models is not enerally well validated against observations. We have developed a global model for very realistic representation of quatorial waves that can be directly compared to observations. The model is forced with latent heating derived from the Tropical Rainfall Measurement Mission (TRMM) satellite gridded rainfall product (3B42) with .25 x .25 degree and 3-hourly resolution. Convective and stratiform heating profiles are estimated from the TRMM 3B42 data, which is then used as the forcing for equatorial atmospheric waves in a global spectral model. The vertical structure of heating is one of the important factors to impact the characteristic of the waves. Since the stratiform clouds, having relatively shallow heating structures, are widespread in tropics, the stratiform type heating as well as the convective type heating are considered to make the full convective plus stratiform latent heating profile (CSH). For the stratiform heating, the lookup table of the melting level and the precipitation at melting level depending on the surface rain rate and the precipitation top height are made from TRMM instantaneous swath data. The CSH profile is updated every 3 hours from TRMM 3B42 rainrate data and forced in a version of the model with a horizontal resolution of T40 (approximately 3 x 3 degrees). A broad spectrum of Kelvin, mixed-Rossby, equatorial Rossby, and gravity waves are generated in the model. Equatorial inertia-gravity waves with smaller vertical wavelength are enhanced in the stratosphere by using the CSH profile instead of the convective-only heating profile.