Spectral retrieval of latent heating profiles from TRMM PR data: Comparison of look-up tables

The primary goal of the Tropical Rainfall Measuring Mission (TRMM) is to use the information about distributions of precipitation to determine the four dimensional (i.e., temporal and spatial) patterns of latent heating over the whole tropical region. The Spectral Latent Heating (SLH) algorithm has been developed to estimate latent heating profiles for the TRMM Precipitation Radar (PR) with a cloud-resolving model (CRM) by Shige et al. (2004). The method uses PR information [precipitation top height (PTH), precipitation rate at the melting level, rain rate and type] to select the heating profiles in look-up table. The look-up table is produced from the CRM simulations in which large-scale forcing derived from TOGA-COARE data are used.

For global applications, the universality of the look-up table needs to be examined. We reconstruct heating profiles from CRM-simulated parameters (i.e. PTH, precipitation rate at the melting level, rain rate and type) with the TOGA-COARE table and compare them to CRM-simulated “true” heating profiles, which are computed directly the model thermodynamic equation. CRM-simulated data during the GATE and SCSMEX periods are used for consistency checks. The consistency checks show that SCSMEX convection has more “continental” characteristics than TOGA-COARE convection, while GATE convection has more “oceanic” characteristics than TOGA-COARE convection. Also there are differences in the stratiform heating profiles, almost due to differences in the melting levels. Possible solutions for the algorithm improvement and algorithm applications to TRMM PR data will be presented at the conference.