THIS IS A CONTINUATION OF A PROJECT THAT BEGAN IN MARCH 2016 THAT INVOLVES THE USE OF RADIATIVE.TRANSFER MODELING TO SUPPORT A NASA PRECIPITATION SCIENCE PROGRAM PROJECT. THE WORK.DESCRIBED HERE HAS BEEN STARTED BUT FURTHER ANALYSIS AND ADDITIONAL SIMULATIONS AS DESCRIBED.BELOW ARE NECESSARY. ADDITIONAL SIMULATIONS WILL BE CONDUCTED WITH THE ATMOSPHERIC RADIATIVE TRANSFER SIMULATOR TO BETTER UNDERSTAND RELATIONSHIPS BETWEEN HYDROMETEORS' PROPERTIES AND UPWELLING BRIGHTNESS TEMPERATURES. SPECIFICALLY RADIATIVE TRANSFER SIMULATIONS CONSTRAINED BY OBSERVATIONS WILL BE CONDUCTED TO TEST THE SENSITIVITY OF SIMULATED BRIGHTNESS TEMPERATURES TO DIFFERENT PARTICLE SIZE DISTRIBUTIONS PARTICLE SHAPES DENSITIES ASPECT RATIOS ORIENTATIONS ETC. THE ULM PI WILL ALSO TEST DIFFERENT COMBINATIONS OF HYDROMETEOR TYPES TO BETTER UNDERSTAND THE MOST IMPORTANT HYDROMETEOR SPECIES AND ASSOCIATED PROPERTIES FOR GENERATING THE LOWEST OBSERVED BRIGHTNESS TEMPERATURES. FINALLY USING THESE SIMULATIONS AND ONES ALREADY CONDUCTED BRIGHTNESS TEMPERATURE DIFFERENCES WILL BE EXAMINED FOR CLUES THAT MAY IMPROVE OUR UNDERSTANDING OF PRECIPITATION PHYSICS AND ULTIMATELY IMPROVE PRECIPITATION ESTIMATES FROM PASSIVE MICROWAVE SATELLITE INSTRUMENTS. IN ADDITION TO THE RADIATIVE TRANSFER MODELING THE ULM PI WILL ALSO CONTRIBUTE TO THE ANALYSIS OF THE COMBINED RADIOMETER AND GROUND-BASED RADAR DATABASE. HE WILL ALSO CONTRIBUTE TO THE INTERPRETATION AND PUBLICATION OF THE RESULTS FROM THE PROJECT.