The proposed research focuses on determining water budgets and the key elements of water cycling over the Gulf of Mexico and Caribbean Sea basins based on a new approach of obtaining retrievals of the principal water variables, i.e., precipitation (P), cloud water path [CWP = liquid water path (lwp) + ice water path (iwp)], precipitable water (PW), and surface evaporation (E). The retrieval system is based on a combination of TRMM, AMSR, and GOES measurements, an active-passive microwave radiative transfer model (MW RTE model), and a nonhydrostatic mesoscale model operated as a cloud-resolving model (CRM). The research will emphasize the role of tropical storms and hurricanes on water budgets and water cycle processes.
The innovative aspects of the water budget retrieval system stem from how the CRM is used to establish a unified database of dynamic, thermodynamic, hydrological, and microphysical parameters associated to RTE model calculations of multispectral/multipolarization upwelling passive microwave (PMW) TRMM Microwave Imager (TMI) and Advanced Microwave Scanning Radiometer (AMSR) brightness temperatures (TBfps), TRMM Precipitation Radar (PR) Ku-band reflectivities (ZKUs), and optical / infrared GOES radiometer quantities [reflectances (Rs)/ equivalent black body temperatures (EBBTs)] that can be associated to satellite measurements of the equivalent radiative quantities. From this unified database, subsets of the model-radiation quantities are selected based on their radiative-dynamic-thermodynamic-hydrological proximity to a measurement set based on TMI and AMSR PMW TBfps, TRMM PR ZKUs, GOES Rs/ EBBTs, and atmospheric variables obtained from either operational analyses (e.g., from NCEP or ECMWF) or field experiment weather data, all for use in a Bayesian retrieval scheme that simultaneously retrieves P, CWP, PW, and E. [Here, proximity is defined by a Euclidian Norm metric.] With this approach, the dynamic-thermodynamic-hydrological parameters bound the appropriate weather regime, while the radiative parameters bound the appropriate column microphysics.
Time derivatives of the PW and CWP terms establish the vapor-cloud water storage, which in combination with the E - P term, dictates the convergence of water flux Qsat into a selected region as a residue term (where Q = vertically integrated water quantities). Since the CRM is also calculating convergence of water flux (Qmod), the retrieval system has a means of cross-checking the derived convergence of Qsat, i.e., the satellite residue term.
With this water budget retrieval system, we will analyze the interannual variability water cycling within the Gulf of Mexico and Caribbean Sea basins, at high resolution space and time scales, since the advent of TRMM measurements. In so doing, we will focus attention on the role of tropical storms and hurricanes that frequent these two basins, insofar as the water budgets and the water cycle processes.
