热带季节内振荡在印尼海区域东传路径的分布及其机制  

The distribution of eastward propagating pathways of the Tropical Intraseasonal Oscillation and its mechanism in the Maritime Continent

作　　者：张浩睿 周磊[1] Zhang Haorui;Zhou Lei(School of Oceanography,Shanghai Jiao Tong University,Shanghai 200030,China)

机构地区：[1]上海交通大学海洋学院,上海200030

出　　处：《海洋学报》2023年第10期13-30,共18页

基　　金：国家自然基金杰出青年基金项目(42125601);国家自然基金面上项目(42076001)。

摘　　要：本文利用降水数据,从拉格朗日观点追踪了热带季节内振荡(MJO)路径,对其在海洋性大陆(100°~120°E)区域的分布及机制进行了探讨。以24h内超过12mm的降水范围为MJO的对流区域,以该区域的“重心”为MJO的对流中心,追踪MJO的路径,并形成其路径集。由于向东传播的MJO主要发生在北半球冬季,因此我们聚焦于MJO在北半球冬季的路径分布特征。结果表明,以降水量来衡量,MJO事件主要从赤道附近(5°S~5°N)通过印尼海区域。这和前人以对外长波辐射(OLR)为指标得到的MJO在印尼海区域向南偏折有明显的区别。此外,与MJO伴随的降水主要从赤道附近通过的结论不依赖于厄尔尼诺–南方涛动(ENSO)及印度洋偶极子(IOD)等背景气候态。机制分析表明,与MJO伴随的降水通过印尼海区域的路径主要受强的海表热通量异常的调制,而与暖海表温度(SST)异常的区域并不一致,这也造成了从降水和OLR两个不同角度看到的MJO通过印尼海区域的路径不一致。Using Tropical Rainfall Measurement Mission 3B42 rainfall data,this study tracks pathways of Tropical Intraseasonal Oscillations(MJO)from a Lagrange perspective,analyses their distribution in the Maritime Contin-ent(100°-120°E)and further discusses its mechanism.Identifying a raining area with above 12 mm in 24 hours pre-cipitation as a MJO convective region and using its centroid as MJO convective center,pathways of MJO are tracked and a set of pathways is given.Because eastward propagating MJO events happen mostly in boreal winter,this study focuses on the distribution of pathways of MJO events in boreal winter.The results show that if meas-ured by precipitation MJO moves through the Maritime Continent mostly near the equator(5°S-5°N),which is dif-ferent from past research results that MJO detours to the south of the Maritime Continent measured by using outgo-ing long wave radiation(OLR)as a index.Besides,the conclusion that the precipitation associated with MJO moves through the Maritime Continent mostly near the equator is independent of background climate patterns like ENSO or IOD.The analysis of the mechanism shows that pathways of the precipitation associated with MJO through the Maritime Continent are mostly regulated by strong latent heat flux anomalies and are inconsistent with regions with warm sea surface temperature anomalies,which leads to different pathways of MJO moving through the Maritime Continent from different perspectives of precipitation and OLR.

关 键 词：热带季节内振荡 降水追踪 K均值聚类 海表温度 海表热通量 

分 类 号：P732.6[天文地球—海洋科学]