| 摘要: | 本研究使用WRF 4.5.1版探討不同地表層物理方案對熱帶氣旋強度和結構的影響，並以高解析度模擬了颱風Rai（2021）。研究設計了三種不同地表層物理方案的數值實驗，包括修訂的MM5方案（MM5）、擬Eta方案（CTL）和Mellor–Yamada-Nakanishi-Niino方案（MYNN）。通過模擬的表層、行星邊界層和颱風環流特徵來調查地表層物理方案的影響。結果顯示表層物理方案對颱風強度有很大影響，但對颱風路徑的影響較小。CTL的模擬結果和最佳路徑具有最高的相關係數和最小的偏差及方均根誤差，表示CTL的強度最接近JMA。在表層中，CTL的地表風速、摩擦速度、焓交換係數、地表熱通量和水氣通量以及水汽混合比相對較高，其次是MM5和MYNN。研究結果還表明，地表層物理方案對模擬結構如主環流和次環流、位溫、邊界層高度、暖芯結構和角動量有重要的影響，CTL產生的數量值大於MM5和MYNN。透過Sawyer-Eliassen方程式來分析貢獻的各項分量，表明非絕熱加熱在Rai的次環流發展中起到明顯作用。;The influences of surface layer physics schemes on tropical cyclone intensity and structure are investigated using the WRF 4.5.1 model with high resolution to simulate Typhoon Rai (2021). Numerical experiments are designed with three surface layer physics schemes including revised MM5 Scheme (MM5), Eta similarity scheme (CTL), and Mellor–Yamada-Nakanishi-Niino scheme (MYNN). The impact of surface layer physics schemes has been investigated through the simulated characteristics of the surface layer, planetary boundary layer, and typhoon circulation. The results show that surface layer physics schemes strongly affected typhoon intensity but barely affected typhoon track. With the highest correlation coefficient and smallest bias and root mean square error between the simulated CTL and best track compared to MM5 and MYNN, the intensity of CTL is closest to JMA. At the surface layer, relatively higher surface wind speed, friction velocity, enthalpy exchange coefficients, surface fluxes of heat and moisture, and water vapor mixing ratio are found in CTL, followed by MM5 and MYNN. The findings also demonstrate that simulated structures, such as primary and secondary circulation, potential temperature, boundary layer heights, warm-core structure, and angular momentum are substantially impacted by surface layer physics schemes, and CTL produces larger magnitudes than MM5 and MYNN. By using the Sawyer-Eliassen equation to analyze the contributing forcing components, it is shown that diabatic heating plays a major role in the induced secondary circulation associated with Rai. |
