东亚季风和南亚季风的反相位关系及其与ENSO的联系:年际尺度和轨道尺度

INVERSE PHASE BETWEEN SOUTH ASIAN AND EAST ASIAN SUMMER MONSOONS AND ITS RELATION WITH ENSO:FROM INTERANNUAL TO ORBITAL SCALE

近年来,众多研究表明东亚夏季风和南亚夏季风在年际尺度上存在着一定的反相关系。通过对NCEP/NCAR资料以及GCM长期瞬变模拟结果的分析,进一步揭示除了年际尺度,在轨道尺度上东亚季风同南亚季风依然可能存在类似的反相位关系,而这种反相关系同太平洋热状况的演化及古ENSO状态变化联系密切。在热带太平洋处于类ElNio态时,东亚夏季风变强,南亚夏季风减弱,而处于类LaNia态时,东亚夏季风则减弱,同时南亚夏季风增强。这种不同时间尺度上季风响应的一致性为已发现的地质证据提供了更好的理解。

Recent studies indicate the inverse phase relation between East Asian and South Asian summer monsoons on the interannual scale. In our paper, NCEP/NCAR data and outputs from GCM transient simulation are analyzed to further appeal that the relation might also exist on the orbital scale and it well links with the Paleo-ENSO evolution. During the E1 Nino-like conditions, the East Asian summer monsoon is strengthened but the South Asian one is decreased. However, these responses are distinctly inverse when the La Nina like events occur. The similar responses of monsoon systems on different time scales could provide better explanations for our geological records.