摘要:
本文利用中国近五百年旱涝等级资料,用典型相关的方法重建了15世纪以来的南方涛动指数(SOI)和北太平洋海温(SST)场。在SOI的重建中校准了1913—1973年校准期方差的40%,在1852—1912年的独立验证期验证了方差的20%;在北太平洋SST的重建中校准的方差较高,其中赤道东太平洋SST的校准方差达60%,在近100年的定性检验中效果也很好。说明用中国历史时期的旱涝资料能够在一定程度上重建出历史时期的ENSO事件。通过对15世纪以来SO和SST重建值的分析发现,ENSO事件不但具有明显的周期性,而且还有250年左右的阶段性变化。SO和SST不仅存在2—7年公认的周期,而且历史上SO还有10.6年、赤道东太平洋SST还有25—28.5年及100年左右与太阳活动有关的周期、进一步分析还得出,18,19世纪及20世纪前期SO低指数事件发生相对较少,15世纪后期、16、17世纪及20世纪后期SO低指数事件发生较多;且历史上的低指数多发期与气候上的冷期一致,而低指数少发期则与气候上的暖期一致;气候上的干旱(湿润)期则与东太平洋长期偏冷(暖)、西太平洋长期偏暖(冷)相对应。
Abstract:
In this paper, a canonical correlation technique has been used to reconstruct the seasonal index of the Southern Oscillation and seasonal Pacific SST from the dryness/wetness in China for the last 500 years. About 40 percent of the SO variance during the calibration period of 1913—1973, and about 20 percent of the variance for an independent period of 1852—1912 have been caliberated and verified, respectively. In the reconstrucion of the Pacific SST, about 60 percent SST variance has been caliberated in the equatorial eastern Pacific areas and the estimate value has been efficiently verified over 100 years. It shows that the past ENSO events can be reconstructed in certain extent by using dryness/wetness data in China. It is found that ENSO events not only has apparent periodicity, but also has about 250 years stage change. Both SO and SST have the well-known 2—7 year periodicities, besides, SO has 10.6 year period and SST has 25—28.5 and 100 year periods which related with the solar activities. It is also found that the low SOI events are estimated to be less frequency during the 18th, 19th and the early 20th centuries than the later 15th, 16th, 17th and later 20th centuries, and that the frequent (rare) occurrence of the low SOI events mentioned above corresponds with the climatic cold (warm) period, and that the dryness (wetness) period in China is related to the cold (warm) East Pacific and warm (cold) West Pacific