Comparison of the Structure and Evolution of Intraseasonal Oscillations Before and After Onset of the Asian Summer Monsoon

• Published in: Acta meteorologica Sinica Vol. 27; no. 5; pp. 684 - 700
• Main Author: 齐艳军 张人禾 赵平 翟盘茂
• Format: Journal Article
• Language: English
• Published: Heidelberg The Chinese Meteorological Society 01.10.2013; Chinese Academy of Meteorological Sciences,Beijing,100081
• Subjects: Atmospheric Protection/Air Quality Control/Air Pollution; Atmospheric Sciences; Earth and Environmental Science; Earth Sciences; Geophysics and Environmental Physics; Meteorology; 亚洲夏季风; 国际标准化组织; 大气季节内振荡; 演化; 热带印度洋; 爆发后; 结构; 高分辨率卫星; intraseasonal oscillation; Asian summer monsoon; onset; tropical Indian Ocean
• ISSN: 0894-0525; 2191-4788
• DOI: 10.1007/s13351-013-0511-2

High-resolution satellite-derived data and NCEP-NCAR reanalysis data are used to investigate intraseasonal oscillations （ISO） over the tropical Indian Ocean.A composite evolution of the ISO life cycle is constructed,including the initiation,development,and propagation of rainfall anomalies over the tropical Indian Ocean.The characteristics of ISO over the tropical Indian Ocean are profoundly different before and after the onset of the Indian summer monsoon.Positive precipitation anomalies before monsoon onset appear one phase earlier than those after monsoon onset.Before monsoon onset,precipitation anomalies associated with ISO first initiate in the western tropical Indian Ocean and then propagate eastward along the equator.After monsoon onset,convective anomalies propagate northward over the Indian summer monsoon region after an initial eastward propagation over the equatorial Indian Ocean.Surface wind convergence and air-sea interaction play critical roles in initiating each new cycle of ISO convection.