## Mesoscale Typhoon Field Simulation and Analysis
### Simulation Results and Discussions  
To verify the validity of the proposed simulation model of Typhoon \"Nuri\", the typhoon path and minimum sea level pressure throughout the simulation are shown in Figure 3. The simulated path was drawn according to the minimum pressure in the cyclonic center of the WRF model. The measured path was the best path provided by the Typhoon Website of the China Meteorological Administration, and it could also refer to some literature cites [36; 37]. The simulated path and the measured path were stable, and both paths moved toward the northwest. In early simulations, the simulated path was close to the measured path. However, the typhoon path deflected gradually as time went on, which might be caused by the intensifying initial error with the increase of simulation time. The evolution of typhoon intensity was mainly represented by the minimum sea level pressure. The simulated value and measured value of minimum sea level pressure in the simulation period differed slightly, but the distribution trend was basically consistent. Both the simulated value and the measured value increased slowly with time, and increased sharply in the late simulation period. At this moment, the typhoon became weak and disappeared gradually. \begin{table}
\begin{tabular}{c c c c} \hline
**Layers** & **Altitude/m** & **Layers** & **Altitude/m** \\ \hline
0 & 0 & 19 & 997.85 \\
1 & 5.41 & 20 & 1441.03 \\
2 & 21.64 & 21 & 1864.44 \\
3 & 43.28 & 22 & 2383.35 \\
4 & 64.96 & 23 & 2929.90 \\
5  
Simulation results and measured results in the simulation regions at typical height for the landing of the typhoon at 20:00 on 22 August are shown in Figures 4 and 5. These nephograms are conducive to analyzing the wind field information when the Typhoon \"Nuri\" ran through the center of the simulation region. It can be concluded from the analysis that:  
1. The typhoon had a low-pressure center. The land underlying the surface was rougher than the ocean after landing, thus cutting the heat source. Hence, the upflow was weakened, while the surrounding airflows continued radiation toward the typhoon center, which gradually further increased the air pressure. After comparison, it was found that the simulated pressure distribution agreed well with the measured results. 2. Wind speed increased due to the invasion of the peripheral nephsystem of the typhoon. The wind speed increased continuously as the typhoon approached. The wind speed closer to the center was the higher. 3. Influenced by the downward transmission of atmospheric heats, the MYJ boundary layer scheme contributed a high computational accuracy of turbulent fluctuation fluxes, such as heats and momentum in the boundary layer of the region. This implied that the low atmosphere heats were mainly carried into the boundary layer by the upper atmosphere through high temperature, which caused the hybrid heating of the low atmosphere. 4. Cloud precipitation close to the typhoon belongs to the long-term convective precipitation. The large rainfall volume in this region is related to the typhoon strength and the central distance. The Noah pavement scheme can simulate the surface flux and airflow convergence field well. 5. There is a minor difference between the simulation results and the measured results of the typhoon, but the distribution trend is basically consistent. In the central area of the typhoon simulation, the ranges of wind pressure, wind speed, temperature, and rainfall were 860-920 Pa, 22-26 m/s, 294-297 K, and 40-48 mm/h, respectively. These data are close to the measured data on the website of the National Meteorological Center. The maximum error is lower than 15%. Figure 3: Typhoon path and minimum sea level pressure throughout the simulation. (**a**) Typhoon path; (**b**) Minimum sea level pressure. Figure 4: Simulation results for landing of typhoon. (**a**) Air pressure nephogram; (**b**) Wind speed nephogram; (**c**) Temperature nephogram; (**d**) Rainfall nephogram.