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This study evaluates the performance of a non-hydrostatic Regional Climate Model (RegCM) with two land surface parameterizations, namely Biosphere-Atmosphere Transfer (BAT) scheme and Community Land Model (CLM) scheme on the simulation of summer monsoon over India. The initial and boundary conditions are taken from ERA-Interim (ERA-I) reanalysis available at a 0.75 spatial grid. The RegCM is designed with 25 km horizontal resolution and 23 vertical levels, and it integrated for the period 1st January 1982 to 30th September 2016. We used the NOAA Optimum Interpolation Weekly sea surface temperatures, the topography and land-use data from the United States Geological Survey, and Global Land Cover Characterization. Our results reveal that the summer monsoon precipitation anomaly is reasonably well simulated with BAT and CLM schemes compared to those of India Meteorological Department (IMD) observations. The spatial distributions of temperature anomaly over India with BAT compared to CRU shows cold bias over most of the Indian sub-continent, whereas the CLM shows large warm bias over central India and monsoon trough region. The low-level and upper-level winds are in good agreement with ERA-I.Further, the analysis of extreme monsoon events (i.e., excess and deficit seasons) reveals that CLM depicts less bias in simulating the excess and deficit precipitation regions as compared to those of BAT. Conversely, BAT simulates temperature well over India in both excess and deficit monsoon seasons. The Taylor's diagram analysis, Added Value Index based on Mean Square Error, and Modified Brier Skill Score are also applied for the extreme rainfall seasons. Our quantitative analysis demonstrates that the CLM have resolved better rainfall features with more skills with respect to that of BAT. The results suggest that CLM have added value in Indian Summer Monsoon (ISM) regional climate simulation than the BAT, particularly on simulation of the rainfall characteristics during extreme rainfall seasons.

Anthropogenic Chlorofluorocarbons (CFCs) compelled stratospheric ozone reduction is one of the significant global environmental issues of this era. Ozone acts as a life saviour in the stratosphere whereas the same plays a role as a secondary air pollutant at tropospheric levels. This review encompasses studies involving the science of ozone destruction with an emphasis on chemical processes involved, minimum ozone features, ozone hole area characteristics, various Ozone Depleting Substances (ODSs), consequences of reduced stratospheric ozone levels, and the different executed international commitments to restrain ozone depletion. It has been perceived that the decrease in stratospheric ozone volume gives away extensively to climate change such as through ozone chemistry fluctuations of polar annular modes and its Greenhouse Gas (GHG) features. Different international ozone layer protection agreements have been performing a major role in limiting stratospheric ozone depletion thereby its adverse effects, and specifically Montreal protocol has been a great success to this point.

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In this study, we examine the sensitivity of the Indian Summer Monsoon (ISM) to runoff parameterizations in a non-hydrostatic Regional Climate Model (RegCM) for the period from 1982 to 2018. The experiments comprise parameterizations namely SIMTOP control (CTL) scheme and Variable Infiltration Capacity (VIC) scheme. Both simulations were forced with ERA interim analysis and evaluated with respect to observation and reanalysis products. The results revealed that the VIC simulated rainfall exhibiting a good agreement with India Meteorological Department (IMD) gridded rainfall as compared to the CTL experiments. The temperature features also were simulated relatively well in VIC than CTL especially over the monsoon core region. Similarly, spatial characteristics of soil moisture, relative humidity, total cloud cover, surface net radiation, sensible heat flux, and latent heat flux were also performing better with VIC with respect to ECMWF Reanalysis fifth version (ERA5) products. Further, the extreme monsoon rainfall seasons are better simulated with VIC driven experiment. The interannual variations of rainfall, soil moisture, sensible heat flux, and latent heat flux explained the dominance of VIC simulations over CTL which further lies in alignment with the aforesaid findings. However, these have been validated with statistical skill score named Nash-Sutcliffe coefficient and mean absolute error. The statistical analyses further corroborated the ISM simulations are better performed with VIC runoff parameterization than the CTL.