Exploring new radar constraints on cloud microphysical uncertainty Marcus van Lier-Walqui. Cloud microphysical processes remain a large source of uncertainty and error in numerical simulations of weather and climate. This is due to both a lack of theoretical understanding, as well as the approximations employed to simulate these processes with computational tractability. Radar observations, in particular polarimetric radar and vertically profiling radar Doppler spectra, are an ideal source of information capable of constraining cloud microphysical uncertainties. Results are presented from investigation of the polarimetric radar signals associated with deep convection for comparison with detailed microphysical models. Additionally a Bayesian parameter estimation experiment was performed where S-band radar Doppler spectra are used to probabilistically constrain ice particle sticking efficiencies using a Markov chain Monte Carlo (MCMC) sampler.