Abstract
The goal of this study is to further investigate the relationship between the microphysical processes of a tropical cyclone and its intensification. Hydrometeors such as rainwater, cloud ice, cloud water, snow, and graupel play a significant role updraft and downdraft characteristics, precipitation, evaporation, ice concentration, and the distribution of latent heat. These processes are the primary heat sources for tropical cyclones. Therefore, it is expected that cloud microphysics may directly or indirectly influence the intensity of the hurricane.
The first objective of this study is to evaluate the impact of different sophisticated explicit cloud microphysics parameterization schemes available in the PSU/NCAR MM5 model, on the hurricane forecast. Of the four microphysical parameterization schemes, the one that exhibited an intensity pattern closely resembling that of the observed values for the hurricane was selected in order to continue onto the next phase of the project.
The second objective is to assess the impact of ice hydrometeors (cloud ice), in the overall performance of the hurricane forecast. This phase further investigates the impact of the selected microphysical processes on the overall forecast of the hurricane, with an emphasis on intensity. This is achieved by suppressing some of the microphysical processes that would allow for ice depletion. By doing so, we indirectly increase the amount of ice in the hurricane. This numerical comparison is done in the selected scheme both before and after ice production terms are modified, in order to substantiate the hypothesis whether or not an increased amount of ice in a tropical cyclone would lead to a more intense storm.
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