This study presents the interannual variation in the summer monsoon rainfall during the El Nino Southern Oscillation (ENSO) phases, that is, El Nino and La Nina throughout the Indian subcontinent and its subregions during 1986–2010. The analysis includes the performance assessments of the regional climate model (RegCM4) in simulating Indian summer monsoon rainfall through comparison with India Meteorological Department rainfall data. Observation clearly demonstrates that the El Nino/La Nina produced weaker/strong monsoon rainfall over India and it increases the interannual variability of the southwest monsoon. The capability and skill of RegCM4's Grell and Mix99 cumulus parameterization scheme in simulating Indian summer monsoon rainfall associated with extreme climate are usually higher in “dry” conditions rather below average for the accurate simulation of “wet” conditions. Also, model performance was good in defining the characteristics, spatial distribution, and trend of a dry spell during ENSO phases with observation. The model‐simulated spatial and temporal value of wet spell during ENSO produces overestimated value over all India.

中文翻译：

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RegCM4对印度及其地区西南季风期间El Nino / La Nina事件动态降尺度的性能

这项研究提出了1986-2010年整个印度次大陆及其次区域的厄尔尼诺南方涛动（ENSO）阶段，夏季季风降水的年际变化。分析包括通过与印度气象部门的降雨数据进行比较，模拟印度夏季风的区域气候模型（RegCM4）的性能评估。观测清楚地表明，厄尔尼诺现象/拉尼娜现象在印度产生了较弱/较强的季风降雨，并增加了西南季风的年际变化。RegCM4'的能力和技能 用于模拟与极端气候相关的印度夏季风降水的Grell和Mix99累积参数化方案通常在“干燥”条件下较高，而对于“湿”条件的精确模拟则低于平均水平。此外，模型性能在定义ENSO阶段的干燥特征，空间分布和趋势方面具有良好的表现，并具有观察性。在ENSO中，模型模拟的湿拼的时空值在整个印度产生了高估的值。