厦门能见度的准周期性变化

利用厦门机场2000～2002三年白天（08～20时）逐时能见度及相应的相对湿度、风资料，通过统计方法和小波分析，发现厦门能见度有显著的日变化、季节变化、季节内和准两周等不同尺度的变化，并且分析了这几种变化的基本特征。在每天有记录的时刻08～20时，能见度日变化明显，在清晨、傍晚最低，午后最高；能见度存在季节变化，在一年中3～5月能见度最低，这正对应着厦门的雾季，厦门地区的能见度与当地的雾关系密切；能见度还存在显著的季节内（30～60d）变化和准双周（10～20d）变化，这与东亚季风区内的大气振荡有关。

THE ANALYSIS OF METEOROLOGICAL VISIBILITY OF XIAMEN AIRPORT

Using hourly diurnal visibility, relative humidity and wind of Xiamen airport from 2000 to 2002, we find that there are distinctly daily, seasonal, intraseasonal and quasi-two-week variations of visibility by statistical method and wavelet analysis method, and then study the characters of these variations. In the observed time, from 08UTC to 20UTC, daily data shows that visibility is the lowest in the morning and evening but reaches its maximum in the afternoon. In seasonal variation, visibility is the lowest from March to May, a foggy season in Xiamen. That is to say, the visibility of Xiamen is greatly related with the local fog. Besides oscillations mentioned above, visibility has two other remarkable variations: intraseasonal variability (30~60 days) and quasi-two-week variability (10~20 days). The two variations have the same variability of quasi-two-year period in both summer and winter which relates to oscillation of the monsoon in eastern Asia.