The present study explored the influence of different convective parameters such as lower tropospheric stability (LTS), low and medium cloud covers (LCC and MCC), and convective available potential energy (CAPE) on the regional variability of Indian summer monsoon rainfall (ISMR). The variabilities and trends of summer monsoon rainfall over the west coast (WC), central India (CI), northeast (NE) and northwest (NW) regions of India were analyzed during the period 1979–2015. The linkage of convective parameters and ISMR with ENSO were also examined based on spatial and 21-year sliding correlations. The ISMR shows considerable regional variability with maximum (moderate) rainfall in the WC and NE regions (CI) and minimum in the NW regions. The ISMR shows an increasing trend in all four regions, except in the NE region, where the trend is negative. All the convective parameters exhibit significant trends; however, the trend values highly vary from one region to another. A positive correlation is observed between LTS and ISMR in the WC and CI regions. The increase in specific humidity or LTS may cause more moisture to be trapped within the lower levels which increases the low-level clouds and thus rainfall. The rainfall and CAPE are exhibiting an in-phase (out-of-phase) relationship over the WC and NW (WC and CI) regions. The out-of-phase relationship may be due to the high and low orographic influence over the WC and CI regions, respectively. Both the LCC and MCC are positively correlated with ISMR over all regions; however, a robust relationship is observed in the case of LCC. An out-of-phase relationship between Niño 3.4 index with rainfall and LCC is observed over most of the Indian regions during the summer monsoon season. However, an out-of-phase relationship is observed between Niño 3.4 index and LTS over the eastern and southeastern parts of the country. On the other hand, in the case of CAPE, a significant out-of-phase relationship is dominated only over the CI region.

本研究探讨了不同对流参数（如对流层较低稳定性（LTS），中低云量（LCC和MCC）以及对流可用势能（CAPE））对印度夏季风降水（ISMR）区域变化的影响。 。分析了1979-2015年印度西海岸（WC），印度中部（CI），东北（NE）和西北（NW）地区的夏季季风降水的变化和趋势。对流参数和ISMR与ENSO的联系也根据空间和21年滑动相关性进行了检验。ISMR显示了相当大的区域差异性，WC和NE地区（CI）的降雨量最大（中等），而NW地区的降雨量最小。ISMR在所有四个地区都呈上升趋势，但东北地区除外，该地区为负值。所有对流参数都显示出明显的趋势。但是，趋势值在一个地区与另一个地区之间差异很大。在WC和CI地区，LTS和ISMR之间观察到正相关。比湿度或LTS的增加可能导致更多的水分被困在较低的水平内，从而增加了较低水平的云层，从而增加了降雨。降雨和CAPE在WC和NW（WC和CI）区域表现出同相（异相）关系。异相关系可能是由于分别对WC和CI区域的地形影响较高和较低所致。在所有地区，LCC和MCC均与ISMR呈正相关；然而，在LCC的情况下，观察到了牢固的关系。Niño3之间存在异相关系。在夏季风季期间，印度大部分地区都观测到降雨和LCC的4指数。但是，在该国东部和东南部，观察到Niño3.4指数与LTS之间存在异相关系。另一方面，在CAPE的情况下，仅在CI区域内存在明显的异相关系。