Changes in climate extremes by the use of CMIP5 coupled climate models over eastern Himalayas

Abstract

A great deal of attention has been given to analyze the trends in Himalayan climate changes due to its reflection in local and global climate variability. To study the same, the two significant meteorological parameters such as temperature and precipitation have been downscaled at various locations over the Eastern Himalayas. For the downscaling, the latest Coupled Model Intercomparison Project 5 climate models with Representative Concentration Pathways experiments were utilized. In this article, we have basically emphasized on the temperature extremity in the historical/measured (1979–2005) and twenty-first century projected (2006–2100) time series durations. The precipitation extreme indices have been computed to correlate the effect of temperature extremes. The results showed that there were substantial variations in these two factors, in terms of their rates, intensities and frequencies in intra-decadal (1979–2005, 2006–2030, 2041–2065 and 2076–2100) time durations. A multi-model climatic projection showed a significant increment in the average annual temperature rate across all the climate stations. Analysis results showed that over the period of records: (1) a diurnal variation of temperature is decreasing due to increments in the minimum temperature, especially after the 2030s; (2) extreme indices-based results showed that the frequencies increase for the summer days and tropical nights but decrease for the frost days. Likewise the intensities of warmest nights also increase; (3) a significant geographical heterogeneity was observed in the temperature as per the results from the multi-model projected temperature datasets; and (4) indeed, there were noticeable areas where these datasets differed on both the sign and significance of precipitation and temperature trends.