最近21 ka以来“神秘时段”的地质记录

The geological records of“Mystery Interval" in the last 21 ka

通过对我国黄土高原^(10)Be和磁化率的高分辨率研究,我们提取了"神秘时段"地质记录,将它与葫芦-董哥洞石笋记录、以及南、北半球高纬地区地质记录进行了空间对比。对比表明亚洲记录的"神秘时段"气候特征不同于其他地区气候记录,表现出空间上的不同步性。由于北半球高纬地区的寒冷气候对亚洲大陆冰雪覆盖期的延长,使得温暖季节对大陆的加热效果降低而导致夏季风减弱,同时由于南半球的温度升高有利于穿越赤道的水汽传输。我们的记录所示出的夏季风先减弱后增强的趋势反映了北半球高纬冷空气活动与南半球低纬水循环的遥相关关系。

Through the high resolution study of the magnetic susceptibility and 10^Be from the Loess Plateau, we extracted the geological records of the ＂Mystery Interval＂. By comparing our records with records of Hulu-Dongge cave and the high latitudes, we discovered that the climate pattern of Asian ＂Mystery Interval＂ is different from the other records. The pattern can be broadly summarized as asynchronization in the space. The severe cold conditions in the northern high latitudes increased the duration of Asian snow cover, and lessened the effectiveness of the summer warm season in heating the continent, hence weaken summer monsoons. The rising of southern temperature is beneficial to the crossing equatorial vapor transmission. The trend of the Asian Monsoon intensity which was weakened at the beginning and increased gradually in our records may basically reflects the teleconnection between the coht air activity of the Northern high-latitude and hydrological cycle from the Southern low latitude.