将Holland风场与ERA5风场相结合,通过引入一个随风速半径变化的权重系数,构建了混合风场,进而利用MIKE21 SW建立了浙江海域台风浪模型。使用Holland风场、ERA5风场、混合风场作为输入风场模拟1918号台风“米娜”期间的风速和有效波高,...将Holland风场与ERA5风场相结合,通过引入一个随风速半径变化的权重系数,构建了混合风场,进而利用MIKE21 SW建立了浙江海域台风浪模型。使用Holland风场、ERA5风场、混合风场作为输入风场模拟1918号台风“米娜”期间的风速和有效波高,验证结果说明Holland风场和ERA5风场均无法准确反映真实风场和有效波高,而本文构建的混合风场弥补了两种风场的不足。为验证混合风场在浙江海域是否具有普适性,选取近5年影响浙江海域最为严重的5个典型台风进行台风浪数值模拟实验,并开展误差统计分析。结果表明:Holland风场在台风中心周围的风速模拟表现较好,最大风速的平均相对误差为8.62%~10.19%,但10 m s以下风速的平均相对误差较大,为29.76%~44.29%;ERA5风场在台风中心周围的风速偏小,最大风速的平均相对误差为17.64%~25.77%,但10 m s以下风速的平均相对误差比Holland风场小,为19.64%~32.00%。对5个台风的模拟中,由Holland风场、ERA5风场和混合风场驱动得到的台风浪有效波高平均相对误差的平均值分别为29.92%、25.62%和22.82%,均方根误差的平均值分别为0.46 m、0.42 m和0.39 m,一致性指数分别为0.94、0.95和0.96。上述结果说明本文构建的混合风场在浙江海域具有普适性,能够提高台风浪的模拟准确度。展开更多
A numerical model of the couphng between astronomical tide and storm surge based on Mike 21 is applied to the coastal regions of Zhejiang Province. The model is used to simulate high tide levels combined with storm su...A numerical model of the couphng between astronomical tide and storm surge based on Mike 21 is applied to the coastal regions of Zhejiang Province. The model is used to simulate high tide levels combined with storm surge during 5 typhoons, including two super typhoons, that landed in the Province. In the model, the atmospheric forcing fields are calculated with parametric wind and pressure models. The computational results, with average computed errors of 13 cm for the high astronomical tide levels and 20 cm for the high storm-tide levels, show that the model yields good simulations. Typhoon No. 5612, the most intense to land in China since 1949, is taken as the typical super typhoon for the de- sign of 5 typhoon routes, each landing at a different location along the coast. The possible extreme storm-tide levels along the coast are calculated by the model under the conditions of the 5 designed typhoon routes when they coincide with the spring tide. Results are compared with the high storm-tide levels due to the increase of the central atmospheric pressure at the base of a typical super typhoon, the change of tidal type, and the behavior of a Saomai-type typhoon. The results have practical significance for forecasting and minimization of damage during super typhoons.展开更多
文摘将Holland风场与ERA5风场相结合,通过引入一个随风速半径变化的权重系数,构建了混合风场,进而利用MIKE21 SW建立了浙江海域台风浪模型。使用Holland风场、ERA5风场、混合风场作为输入风场模拟1918号台风“米娜”期间的风速和有效波高,验证结果说明Holland风场和ERA5风场均无法准确反映真实风场和有效波高,而本文构建的混合风场弥补了两种风场的不足。为验证混合风场在浙江海域是否具有普适性,选取近5年影响浙江海域最为严重的5个典型台风进行台风浪数值模拟实验,并开展误差统计分析。结果表明:Holland风场在台风中心周围的风速模拟表现较好,最大风速的平均相对误差为8.62%~10.19%,但10 m s以下风速的平均相对误差较大,为29.76%~44.29%;ERA5风场在台风中心周围的风速偏小,最大风速的平均相对误差为17.64%~25.77%,但10 m s以下风速的平均相对误差比Holland风场小,为19.64%~32.00%。对5个台风的模拟中,由Holland风场、ERA5风场和混合风场驱动得到的台风浪有效波高平均相对误差的平均值分别为29.92%、25.62%和22.82%,均方根误差的平均值分别为0.46 m、0.42 m和0.39 m,一致性指数分别为0.94、0.95和0.96。上述结果说明本文构建的混合风场在浙江海域具有普适性,能够提高台风浪的模拟准确度。
基金This Paper is supported by Zhejiang Provincial Science and Technology Plan Project (Grant No2006F12013)
文摘A numerical model of the couphng between astronomical tide and storm surge based on Mike 21 is applied to the coastal regions of Zhejiang Province. The model is used to simulate high tide levels combined with storm surge during 5 typhoons, including two super typhoons, that landed in the Province. In the model, the atmospheric forcing fields are calculated with parametric wind and pressure models. The computational results, with average computed errors of 13 cm for the high astronomical tide levels and 20 cm for the high storm-tide levels, show that the model yields good simulations. Typhoon No. 5612, the most intense to land in China since 1949, is taken as the typical super typhoon for the de- sign of 5 typhoon routes, each landing at a different location along the coast. The possible extreme storm-tide levels along the coast are calculated by the model under the conditions of the 5 designed typhoon routes when they coincide with the spring tide. Results are compared with the high storm-tide levels due to the increase of the central atmospheric pressure at the base of a typical super typhoon, the change of tidal type, and the behavior of a Saomai-type typhoon. The results have practical significance for forecasting and minimization of damage during super typhoons.
