## 3 Validation  
In 2015, five typhoons affected the Taiwan Strait area, four of which were super typhoons. Two of these super typhoons (Soudelor and Dujuan) crossed the Taiwan Strait and twice made landfall (Figure 2). The characteristics of typhoons Soudelor and Dujuan are listed in Table 2. The maximum wind speed recorded at the Suao meteorological station, which lies on the east coast of the island of Taiwan, reached 66.1 and 68.4 m/s during the passage of Soudelor and Dujuan, respectively. In Taiwan, Soudelor and Dujuan caused 6 and 2 fatalities and led to 102 and 324 people being injured, respectively. Both storms caused serious damage and the aquaculture and breakwaters along the west coast were damaged severely by high waves and flooding. To investigate the response of the coastal water of the Taiwan Strait to the passage of these two storms, all available data were collected. Water level observations were obtained using float-type tide gauges at five tide gauge stations (Dongshan, Xiamen, Chongwu, Pingtan, and Sansha, north-to-south along the western bank of the Taiwan Strait) managed by the State Oceanic Administration of China. The measured storm surge was calculated by subtracting the predicted astronomical tide elevation from the water level observations. Significant wave heights were obtained using four float-type wave gauges (No.2, No.3, No.3, and No.4) deployed in the Taiwan Strait and four nearshore gauges (Gulei, Douweigang, Huanqi, Beishuang) along the coast of Fujian Province. The locations of the tidal stations (solid circles) and wave buoys (open circles) are shown in Figure 2.  
The sea surface pressure, wind speed, and significant wave height observations acquired during the passage of both Soudelor and Dujuan are shown in Figures 3 and 4. The recorded wind speed was highest during the time between the two landfalls. Waves are driven by both wind and pressure, i.e., stronger winds and lower pressure generate higher waves. In comparison with Soudelor, Dujuan weakened more after its first landfall, which resulted in comparatively lower wave heights in the Taiwan Strait. Wave height increased rapidly as the typhoons approached and decreased as the typhoons moved away. As the typhoons crossed the area of the Taiwan Strait (11:00 on 8 August to 00:00 on 9 August for Soudelor, and 01:00-09:00 on 29 September for Dujuan), the wave height recorded at the buoys in the Taiwan Strait area peaked and then subsided as the typhoons moved away. Surface pressure decreases as a typhoon approaches and increases as a typhoon moves away. Surface wind speed, which is often nearly zero within the eye of a typhoon, increases rapidly with distance from the eye to reach its highest value at the radius of maximum wind before decreasing \begin{table}
\begin{tabular}{c c c c} \hline \hline \multicolumn{1}{c}{**Name of Typhoon**} & **Soudelor (2015)** & **Dujuan (2015)** \\ \hline \multirow{3}{*}{First landfall} & location & 121.5\({}^{\circ}\) E, 24.2\({}^{\circ}\) N & 121.7\({}^{\circ}\) E, 24.3\({}^{\circ}\) N \\  & time & 05:00, 8 August & 18:00, 28 September \\  & Max Wind Speed (m/s) & 45 & 48 \\  & Central Pressure (hPa) & 950 & 945 \\ \hline \multirow{3}{*}{Second landfall} & location & 119.2\({}^{\circ}\) E, 25.1\({}^{\circ}\) N & 119.1\({}^{\circ}\) E, 25.1\({}^{\circ}\) N \\  & time & 22:00, 8 August & 09:00, 29 September \\ \cline{1-1}  & Max Wind Speed (m/s) & 38 & 33 \\ \cline{1-1}  & Central Pressure (hPa) & 970 & 975 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Characteristics of typhoons Soudelor and Dujuan. Figure 2: Locations of tidal stations (solid circles) and wave buoys (open circles) in the Taiwan Strait, and the tracks of typhoons Soudelor and Dujuan. steadily. Buoys No.2, No.3, and Douweigang were close to the track of both Soudelor and Dujuan (Figure 2). When the typhoons passed by, these three buoys were located in the area between the eye and the radius of maximum wind. As the typhoons approached, the surface pressure would decrease and the surface wind speed would increase.