第四纪北半球冰盖发育与东亚气候的遥相关  

TELECONNECTION BETWEEN NORTHERN HEMISPHERE ICE SHEETS AND EAST ASIAN CLIMATE DURING QUATERNARY

作　　者：张仲石 燕青[2] 张冉[4] 李香钰[4] 戴高文[1] 冷姗 田雨润 

机构地区：[1]中国地质大学(武汉)环境学院大气科学系,武汉430074 [2]中国科学院大气物理研究所竺可桢-南森国际研究中心,北京100029 [3]Uni Research Climate, Bjerknes Centre for Climate Research, Allegaten 70, Bergen 5007, Norway [4]中国科学院气候变化研究中心,北京100029

出　　处：《第四纪研究》2017年第5期1009-1016,共8页Quaternary Sciences

摘　　要：新生代东亚气候演化和北半球冰盖演化具有很好的耦合性。这种耦合性在气候学上可以被称为遥相关。一般认为，北半球冰盖的消长通过影响西伯利亚高压来改变东亚气候。第四纪冰期，北半球冰盖的增长，可以加强西伯利亚高压，从而增强东亚冬季风和加剧亚洲内陆干旱程度；反之，间冰期北半球冰盖的消退，可以减弱西伯利亚高压，并加强东亚夏季风。本文利用通用大气模式CAM4，开展理想试验，模拟了北半球冰盖对东亚气候的影响。模拟结果证实，冰期北半球冰盖消长与东亚地区气候变化存在遥相关，很好地支持了地质记录所反映的东亚气候与冰盖演化之间的耦合性。第四纪冰期，北半球气候变冷和冰盖发育，可以加剧我国北方的干旱程度。北半球北美-欧亚冰盖的发育，尤其是冬季，通过影响北半球的槽脊系统，在北美-欧亚冰盖南侧形成一个气旋式环流异常，这对加强我国西北内陆和黄土高原区西风或西北风至关重要。然而我们的模拟并不支持北美-欧亚冰盖通过加强西伯利亚高压来影响东亚冬季大气环流这一传统认识，第四纪北半球冰盖发育与东亚气候的遥相关可能比我们原有的认识复杂。During the Quaternary, the evolution of East Asian climate was coupled with the development of Northern Hemisphere （NH） ice sheets. This coupled relationship satisfies the definition of teleconnection, a climatology termination, thus can also be called the teleconnection between ice sheets and East Asian climate. It is believed that the wax and wane of Northern Hemisphere ice sheets, modifies the West Siberian high pressure system, thus influencing East Asian climate. In glacial periods, the wax of ice sheets can intensify the West Siberian high pressure, hence enhancing the Asian inland aridity and East Asian winter winds. On the contrary, in interglacial periods, the wane of ice sheets can weaken the West Siberian high pressure, allowing the intensification of East Asian summer winds. Here, using the Community Atmosphere Model version 4 （CAM4） , we carry out idealized experiments to investigate the impacts of NH ice sheets on East Asian climate. Started from a preindustrial control experiment, we decrease obliquity and atmospheric CO2 level to produce an idealized glacial climate. Then we add the American-European ice sheets anomalies in, to investigate the climate responses to the ice sheets in the idealized glacial climate. Our simulations confirm the teleconnection between the NH ice sheets and East Asian climate, giving a strong dynamics support to the coupled relationship revealed by geological evidence. The idealized experiments illustrate that the global cooling and the wax of NH ice sheets can reduce annual precipitation in Northern China, thus enhancing aridity there. Compared to the global cooling, the wax of American-European ice sheets plays a more important role in reshaping atmospheric circulations in winter. It changes the existing trough and ridge systems in the NH. The wax of American-European ice sheets leads to an anomaly cyclonic on the south of the European ice sheets in winter. The anomaly cyclonic is crucial for the strengthened winter westerlies and northwesterlier over inland Ch

关 键 词：遥相关 东亚气候 北半球冰盖 

分 类 号：P534.63[天文地球—第四纪地质学] P532[天文地球—古生物学与地层学]