南海土台风和非局地台风的对比研究

利用1951—2012年日本气象厅(JMA)热带气旋(TC)最佳路径资料,分析了影响南海的土台风和非局地台风62 a间的时空分布特征,比较了二者在时空分布上的差异性,得到以下主要结果:土台风源地位置与热带季风性气候有关,夏季风时主要在15°N以北,冬季风时向15°N以南移动;土台风与非局地台风相比,活动范围更广,但强度比后者弱;土台风在南海的强度发展过程呈对称曲线形式,非局地台风则是一条递减曲线;土台风和非局地台风的登陆位置都具有季风期规律,夏季风时登陆的TC比冬季风时登陆的多得多,同纬度的非局地台风比土台风移动速度大。

Temporal and spatial distribution of local typhoon and non-local typhoon in the South China Sea

The best track data of tropical cyclones (TC) for 62 years (1951-2012) obtained from Japan Meteorological Agency (JMA) were used to make an analysis on the temporal and spatial distribution of two kinds of tropical cyclones, i. e. entitled local typhoon and non-local typhoon which have impact on the South China Sea (SCS). The result suggests that local typhoon’s sources are associated with the monsoon period. In summer monsoon, the sources mainly located on the north of 15°N, and in winter monsoon, it moved to the south of 15°N. Compared with non-local typhoon, local typhoon’s activity is broader in space, but weaker in intensity in commonly. In the intensity development process, the time-intensisy curve of local typhoon is almost symmetrical, but that of non-local typhoon is a decline curve. The two kinds of TC’s landing positions are also associated with the monsoon. In summer monsoon, local typhoon and non-local typhoon make landfall more frequently than those in winter monsoon. And in the same latitude, non-local typhoon moves faster than local typhoon.