The Role of Physical Parameterization Schemes in Capturing the Characteristics of Extratropical Cyclones Over the South Pacific Ocean

Abstract

Abstract The extratropical cyclone (ETC) of August 2015 in central Chile was investigated using the WRF model to analyze the sensitivity of meteorological variables to different physical parameterization schemes. This study assesses the performance of different physical schemes in the simulation of track, core pressure, mean sea level pressure, wind direction and wind speed associated with ETC over the South Pacific. The analysis uses a total of 36 sensitivity experiments, consisting of: two microphysics schemes; three surface layer and planetary boundary layer; two cumulus schemes; two longwave and shortwave radiation; and Noah for land surface. Sensitivity experiments indicate that the cumulus, planetary boundary layer and surface layer scheme have a fundamental role in the characterization of ETC track and intensity, while the microphysics scheme plays a secondary role in determining these variables. On the other hand, long‐ and shortwave radiation do not have a significant impact. The sensitivity experiments indicate that exp24 provides the best results overall. The results of this work allow the selection time of the different physical schemes to be optimized according to the ETC characteristics that are to be simulated