本文分析2010-2014年松山機場低空風切(Low-level Wind Shear;LLWS)與氣壓大波動(Large Pressure Fluctuation ; LPF ;> )發生機率之日變化，研究顯示機場LLWS五年發生次數為LPF的2.5倍，其中， 低空風切發生頻率，夏季大於秋季，秋季大於春季，春季大於冬季，夏季、秋季、和春季分別為冬季的 8、7和2倍，夏秋發生頻率是冬春的4.7倍。跑道LPF四季發生頻率分布相當平均，秋冬發生頻率比春 夏略多。LLWS和LPF年平均日變化，兩者出現較高時段約在上午11點至下午4點、最高時間出現在 下午1〜3點、較低時段約在晚上6點至翌日上午10點以及最低時間出現在清晨4〜5點等時段和時間 大致相當，唯最高時段LPF提早1小時開始；LPF最高時間提早2小時出現，最低時間則提早1小時 出現。四季LLWS與LPF發生機率平均日變化之主要較高和較低時段也都接近一致，唯四季平均發生 機率與年平均日變化相比，提早或落後略有前後之差。四季平均日變化較高時段和最高時間，與年平均 曰變化最接近；四季平均日變化較低時段和最低時間，除了秋季LLWS和LPF兩者較低時段起始時間， 和冬季兩者最低時間與年平均差異較大之外，四季平均與年平均日變化也都相近。

In this paper, we analyzed the diurnal probability changes of low-Level wind shear (LLWS) alert and large pressure fluctuation (LPF ； > a) in Songshan Airport from 2010 to 2014, where a stands for one standard deviation. Results show that the annual frequency of airport LLWS alerts are 2.5 times that of LPF. Among them, the LLWS alert frequency in summer and autumn is 4.7 times higher than that in winter and spring. Due to Songshan Airport is affected by the typhoons and thunderstorms. However, the frequency distribution of the LPF in each season is relatively consistent with each other. Only the frequency of the autumn and winter is less than that of spring and summer. For the annual diurnal variation, the higher period of LLWS alert and LPF are at about 11 am to 4 pm, the peak time at 1~3 pm, the lower period at about 6 pm to 10 am the next day, the lowest time at 4~5 am in the morning. The high or low diurnal variation periods of LLWS alert and LPF are quite consistent with each other, only the higher period of the LPF appears early 1 hour, the peak time is 2 hours earlier, the lowest time is 1 hour earlier. For the seasonal diurnal variation, the main higher or lower probability period of LLWS alert and LPF in each season is quite consistent with each other. The only seasons compared with the annual diurnal variation, the difference between the two is slightly earlier or later in the main higher and lower diurnal variation periods. Among them, in the higher diurnal variation period and the highest time, the four seasons and the annual diurnal variation are the closest. In the lower period and the lowest time, the spring and summer and the annual diurnal variation are the closest, while autumn and winter and the annual diurnal variation is larger. From this study, the large pressure fluctuation can be used as a precursor for monitoring the runway wind shear.