Diagnostic Analyses and Numerical Modeling of Explosive Cyclone over Northwestern Pacific on January 11–13, 2012

Abstract

In this paper, we use FNL grid data obtained from the National Centers for Environmental Prediction (NCEP) to analyze an explosive cyclone (EC) that occurred over the northwestern Pacific Ocean from January 11 to 13, 2012. To simulate the EC, we used the Weather Research and Forecasting model (WRFV3.5). The cyclone outbreak occurred east of Japan from January 11 to 12 and weakened near the Kamchatka Peninsula on January 13. The analysis results show a distinct frontal structure, in which the high potential vorticity (PV) of the upper troposphere extends downward to the surface, which can facilitate EC development. A low-level jet stream develops with the EC, which can lead to more distinct convergence. The results of sea surface temperature (SST) sensitivity tests suggest that changes in the SST can affect cyclone intensity, but have little effect on its path. When small changes are made to the SST, the air pressure at the cyclonic center responds more distinctly to an increased SST than a decreased SST. The results of our latent heat release test suggest that diabatic heating processes lead to maximum PV values in the lower troposphere. Latent heat is also one of the important factors influencing EC development.