Spectral Retrieval of Latent Heating Profiles from TRMM PR data.: Version-7 Heating Products

The first satellite mission dedicated to measure rainfall, the Tropical Rainfall Measuring Mission (TRMM), was launched in the late November 1997 and greatly has been providing a wealth of information related to precipitation in the Tropics. The TRMM standard products have version numbers that are incremented each time the data are reprocessed to reflect an advancement of the TRMM standard products (Kummerow et al. 2000). Recently, version 7 of the TRMM standard products has been published by NASA and JAXA. The differences between version 7 of the Precipitation Radar (PR) and the TRMM Microwave Imager (TMI) standard rainfall products have narrowed compared to prior products (version 5 and 6). The primary goal of TRMM is to use this precipitation information to determine the four-dimensional (i.e., temporal and spatial) patterns of latent heating over the whole tropical region. In version 7 of the TRMM standard products, latent heating estimates was introduced. The Spectral Latent Heating algorithm (SLH; Shige et al. 2004, 2007, 2008, 2009) is employed to obtain latent heating from the PR rainfall product (TRMM product 2A25; Iguchi et al. 2009), while the Convective Stratiform Heating algorithm (CSH; Tao et al. 1993, 2010) employed to obtain latent heating from the TRMM Combined Instrument product, which employs data from both PR and TMI (TRMM product 2B31; Haddad et al. 1997). This paper describes the revised SLH for the version 7 of PR heating products. Less agreement between SLH-retrieved heating and sounding-based heating for the South China Sea Monsoon Experiment (SCSMEX) was found when the SLH algorithm was applied to the version 7 of PR rainfall products than the version 6 of PR rainfall products. This problem was caused by the fact that the algorithm did not estimate lower-level cooling of deep stratiform rain when the rain intensity below the melting level increases downward. Stratiform heating retrieval is now separated into downward decrease and downward increase of the rain intensity below the melting level, resulting in the better agreement. Revised procedure for heating retrieval over mountainous regions and region with low melting level height is also described.