The modulation of Madden-Julian oscillation (MJO) pattern evolution over the Maritime Continent (MC) by El Niño-Southern Oscillation (ENSO) was investigated through a combined observational and modeling study. MJO convective branches shifted south of the equator over the MC during eastern Pacific (EP) El Niño winters, while it became relatively symmetric about the equator during La Niña winters. The impact of central Pacific (CP) El Niños to MJO pattern, on the other hand, is not statistically significant. The cause of the distinctive MJO pattern evolutions is likely attributed to the ENSO-induced changes of the background moisture and vertical shear over the MC. Idealized numerical experiments with a 2.5-layer model were carried out, and the result revealed that the background moisture change played a dominant role. An observational diagnosis of column-integrated moist static energy (MSE) budgets was further conducted. The result indicated that the MJO pattern difference was attributed to the MSE tendency asymmetry in front of MJO convection between EP El Niño and La Niña, caused by the advection of the mean MSE by anomalous meridional wind. The difference in the MJO-scale anomalous meridional wind was ultimately controlled by the change of the background meridional moisture gradient associated with EP El Niño and La Niña.

通过结合观测和模型研究，研究了厄尔尼诺-南方涛动（ENSO）对海洋大陆（MC）上马登-朱利安振荡（MJO）模式演变的调制。在东太平洋（El）厄尔尼诺冬季，MJO对流分支在MC上移至赤道南侧，而在LaNiña冬季，MJO对流分支相对于赤道相对对称。另一方面，中部太平洋（CP）厄尔尼诺现象对MJO模式的影响在统计上并不显着。MJO模式发生明显变化的原因很可能归因于ENSO引起的MC背景湿度和垂直剪切的变化。用2.5层模型进行了理想化的数值实验，结果表明背景水分变化起主要作用。进一步进行了柱综合湿静态能量（MSE）预算的观察性诊断。结果表明，MJO型态差异是由于异常子午风对流平均MSE对流造成的，EP ElNiño和LaNiña之间的MJO对流前的MSE趋势不对称。MJO尺度异常子午风的差异最终由与EP ElNiño和LaNiña相关的本底子午水分梯度变化控制。