The evaluation and characteristics of land-surface processes over the Indian Summer Monsoon (ISM) region are studied using Dirmeyer's two-legged land-atmosphere coupling metrics in regional climate modelling system. Different land-atmosphere coupling metrics are used for assessing the “hot-spots” of land atmosphere feedback over the Indian subcontinent. The model simulations are performed using regional climate model (RCM)—RegCMv4.0, 4.2 and 4.4.5.10 at different horizontal resolutions. The monthly soil wetness climatology over India is calculated using European Space Agency (ESA) datasets. Maximum soil moisture(SM) is found over the western part of central India during June–September. The results from RCM simulations (RegCMv4.0, 4.2 and 4.4.5.10) indicate more soil wetness, systematically (over-predicted) over North India, Indo-Gangetic plains and central India during June, July, August and September, implying that model soil wetness is driven by precipitation minus evapotranspiration (P-E). The role of aerosols in land–atmosphere interactions along with the impact of mixed convective parameterization schemes over ocean and land on modelling SM and land–atmosphere interactions is also addressed. The spatial and temporal variation of atmospheric and terrestrial coupling indices during ISM regime concludes that May, June, July and August are the prime months of land–atmosphere interactions over central and north-west India reiterating results from previous GLACE (The Global Land–Atmosphere Coupling Experiment) studies. Model simulations also indicate that during the ISM season the terrestrial segment of land–atmosphere coupling (i.e. terrestrial coupling index of soil moisture, SM) from SM to latent heat flux varies around 35–40 W m⁻², while the atmospheric segment of coupling (i.e. atmospheric coupling index of precipitation) from latent heat flux to precipitation modulates around 4–6 mm/day. Aerosols are found to influence land-atmosphere interactions over north-west India by modulating net radiation. More in-situ observations of land surface variables are required for verification of land-atmospheric interactions (along with impact of aerosols) using RCMs.

在区域气候模拟系统中，使用Dirmeyer的两足土地-大气耦合指标，研究了印度夏季风（ISM）区域的地表过程的评估和特征。不同的陆地-大气耦合度量用于评估印度次大陆上陆地大气反馈的“热点”。使用区域气候模型（RCM）-RegCMv4.0、4.2和4.4.5.10在不同的水平分辨率下进行模型模拟。使用欧洲航天局（ESA）数据集计算了印度整个月的土壤湿度气候。在6月至9月期间，印度中部西部地区发现了最大的土壤湿度（SM）。RCM模拟（RegCMv4.0、4.2和4.4.5.10）的结果表明，在印度北部，系统地（过度预测）的土壤湿度更高，6月，7月，8月和9月，印度—恒河平原和印度中部地区，意味着模型土壤湿度是由降水量减去蒸散量（PE）驱动的。还讨论了气溶胶在陆地-大气相互作用中的作用，以及海洋和陆地混合对流参数化方案对SM和陆地-大气相互作用建模的影响。ISM期间大气和地面耦合指数的时空变化得出结论，5月，6月，7月和8月是印度中部和西北部土地-大气相互作用的主要月份，重申了先前GLACE（全球土地-大气）的结果。耦合实验）研究。模型模拟还表明，在ISM季节，陆地-大气耦合的地面部分（即⁻²，而从潜热通量到降水的大气耦合部分（即降水的大气耦合指数）约为4-6 mm /天。发现气溶胶通过调制净辐射影响印度西北部的土地-大气相互作用。使用RCM验证陆-气相互作用（以及气溶胶的影响）需要对地表变量进行更多的现场观测。