A combined approach toward the evaluation of convective momentum fluxes, as derived from Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) and microwave imager data (TMI; TRMM product "2B31"), is being undertaken. The primary aspect of the project involves an estimation of convective momentum fluxes from precipitation (rainfall signature) pattern analysis within TRMM data, employing the technique of Mecikalski (2003). As a means of validating these estimates, cloud resolving model simulations over the Kwajalein Atoll Experiment (KWAJEX) and South China Sea Monsoon Experiment (SCSMEX) domains are being used to estimate the mean momentum flux characteristics over regions that our TRMM data analyses are being performed. Error estimates between the simulated and estimated momentum fluxes are done to assess accuracy (in terms of momentum flux sign and magnitude) and improve our TRMM-based method. Direct data analysis of the convective structures over the KWAJEX and SCSMEX regions, for the assessment of convective qualities, will also be performed as a follow-on to the cloud-resolving simulations.

An additional component of this work will couple the TRMM data to a numerical model through the use of a cumulus momentum parameterization, as a preliminary approach to TRMM data assimilation. Specifically, use and modification of the Wu and Wanai (1994) momentum parameterization scheme will allow us to directly incorporate TRMM and/or TRMM-derived information into numerical simulations by relating these information to model variables. An extension of the Wu and Yanai parameterization development will be to employ updates to this scheme to assess the independent influences of vertical and horizontal wind shear on convective momentum transport (Mecikalski 1999), which can only be reasonably addressed in tropic regions (see Mecikalski and Tripoli 1998; Emanual 1979).