不同强度El Nio事件长期变化规律的若干统计特征

Some Statistical Characteristics of the Long-Term Variation Pattern for Different Strengths of EI Nio Events

本文对1763～1987年间历次强、中、弱El Nio事件的发生频率、各次事件的间隔年数,以及当某类强度事件发生后下一次事件的强度级别与发生时间的概率等做了统计分析。结果表明,El Ni(?)o事件的长期变化具有一定的规律性。这些规律可作为预测El Ni(?)o事件的参考。

In this paper, some statistical characteristics of the long-term variation pattern for all the strong, moderate, weak and very weak E1 Nino events during 1763-1987 are analysed. The main results are as follows: 1. The intervals of the occurrence of E1 Nino events are 1-7 years, in which 2-4 years' intervals are the most remarkable, amounting to about 75% of the total. 2. For strong events the intervals are 7-21 years, for moderate events 2-15 years and for weak events 2-44 years. And in the last seventy years the intervals for strong and moderate events were both 10-15 years. 3. Following a strong event, a moderate event is most probable (its probability is about 77%) and occurs in about 3-4 years. But it would not be followed immediately by another strong event. Following a moderate event, a strong event is most probable (54%) and occurs in 2-6 years. And following a weak event, a strong event is most probable (50%) and occurs in 1-7 years. 4. It is predicted that the last decade of this century will have more events (3-4 events) than normal. The results in the present paper can be used in prediction of El Nino event.