P87 Impact of complexity in cloud microphysics parameterizations ion the development of tropical cyclones

Michelson, Sara, Evelyn D. Grell, Cooperative Institute for Research in Environmental Sciences and National Oceanic and Atmospheric Administration (NOAA), and Jian-Wen Bao, NOAA

Development of tropical cyclones is very sensitive to uncertainties in the physical representation of cloud dynamics. This presentation highlights major results from a series of numerical experiments with the Advanced Research WRF (ARW) model that were carried out for the purpose of comparing and evaluating different types of microphysics parameterization (MP) schemes with increasing complexity. We will first compare the sensitivity of the asymptotic behavior of the ARW-simulated intensification of an idealized tropical cyclone to the three MP schemes representative of the three types that are available and well tested in the WRF model. We will then compare the heating profiles and hydrometeor distributions from the three schemes. Finally, we will compare the assumptions embedded in the formulations of the three schemes. Using the results from the sensitivity experiments and the comparisons of the three schemes, we will discuss the issues and challenges that the research community is facing in improving MP schemes for accurate representation of convection in operational tropical cyclone prediction models.