【摘要】 利用南海季风试验所得到的最新资料分析了１９９８年南海夏季风建立前后的突变特征及其爆发过程，初步认定１９９８ 年亚洲夏季风最早（５ 月２３ 日）在南海地区建立，它是亚洲冬季风形势向夏季风形势转换的最早体现。副高从南海地区连续东撤是南海地区夏季风建立的直接过程，它的撤出有利于不稳定能量的释放，形成南海夏季风的爆发性。提出赤道印度洋地区的西风和降水向中南半岛地区扩展、华南静止锋活跃南压，这种形式的中低纬相互作用可能是导致副高东撤、南海夏季风爆发的特征过程和触发机制更多还原

【Abstract】 The latest dataset from the SCS (South China Sea) Monsoon Experiment is used in this paper to study the features of abrupt change in some meteorological elements before, during and after the monsoons establishment in 1998 and to investigate its onset , arriving at preliminary conclusions that the 1998 Asian summer monsoon was established first in the SCS (as early as May 23),and the establishment represented the earliest indicator of conversion from the winter to summer monsoon situation in Asia; the continued eastward retreat of the western Pacific subtropical high from the SCS area had a direct effect on the SCS summer monsoons establishment because the withdrawal favored the release of unstable energy, responsible for the sudden onset of the monsoon. However, why did the subtropical high retreat eastward? This tentative investigation indicates that the interactions between middle and lower latitudes,such as the eastward extension of westerly and rainfall bands from the equatorial Indian ocean to the Indo China and the southward spreading of the active South China stationary front, were likely the characteristic events which contribute to the eastward retreat of the subtropical high and the onset of summer monsoon over the SCS更多还原