澳大利亚古季风演化过程、主要控制因素及其海洋生物生产力效应

新生代以来澳大利亚板块向北漂移了～20°,气候也随之发生了明显改变,即其北部逐渐进入了热带辐合带的影响范围,与亚欧大陆间的联系越来越紧密.上新世时印度尼西亚贯穿流的流通性受到限制,这可能直接促成了澳大利亚季风的形成.海洋沉积记录显示,澳大利亚气候的季节性特征最早出现于～3.5Ma,而现代意义上的澳大利亚季风则形成于～2...

EVOLUTION OF AUSTRALIAN PALEOMONSOON AND ITS CONTROLLING FACTORS AND EFFECT ON MARINE PRODUCTIVITY

Since the Cenozoic, the Australian Plate has drifted about 20 latitudes to the north, and its climate also underwent significant changes. When northern Australia was gradually moved into the control of the Intertropical Convergence Zone, its connection with Eurasia also increased. In the Pliocene, the Indonesian Throughflow was limited, which started the Australian paleomonsoon. Marine sedimentary records show that the climate of Australia seasonal character appeared first at ~3.5 Ma. In addition, the Australian monsoon in the present sense had been ultimately built at ~2.4 Ma. The Australian monsoon had obvious orbital cycles in Quaternary. The summer monsoon in the glacial period weakened and the interglacial period strengthened, which was mainly affected by the insolation of the Northern Hemisphere, the transequatorial action of East Asian Winter Monsoon, the surface sea water temperature of the eastern Indian Ocean, and the fluctuation of global sea level. The Australian monsoon had millennium cycles similarly to climatic events in the high latitude of Northern Hemisphere in the last deglaciation. In the Dansgaard/Oeschger event when the Northern Hemisphere was warm, summer monsoon weakened; In the Heinrich Stadials and the Younger Dryas events when the Northern Hemisphere was cool, the Australian summer monsoon strengthened. On the millennium timescales, the change of summer monsoon rainfall was closely related to the position of the Intertropical Convergence Zone. Moreover, the change of Australian monsoon was in anti-phase with the paleomonsoon records in the same latitude of Africa and South America, responding to the Southern Hemisphere insolation. Australian monsoon obviously responded to the insolation of the Northern Hemisphere. This inverse phased relationship might be related to the transequatorial interaction between the Asian monsoon and Australian monsoon. According to the studies on paleoproductivity of the last glacial period, the Australian monsoon played an important role on the marine biological productivity. The Australian monsoon can control the terrigenous input to the ocean, the structural stability of seawater, and the processes occurring at the sea surface by affecting the current patterns, precipitation, and runoff.