Trend and variability analysis of long-term meteorological parameters for detecting climate change in Kolkata District, India

Abstract Assessing the temporal dynamics of weather parameters in the perspective of climate change, especially in an urban space characterized by tremendous demographic pressure, various anthropogenic activities, is imperative to examine climatological changes and recommend fruitful policies. Hence, trend and variability analysis wasapplied to examine the change of temperature and rainfall in Kolkata district applying the data of “climate Research Unit (CRU TS 4.04with 0.5° by 0.5° resolution)” and “NASA data access viewer” from 1902 to 2021. Data has been examined using “kurtosis”, “skewness”, and “coefficient of variation”, “anomaly index”, “precipitation concentration index. Furthermore, Spearman’s Rho test, Mann-Kendall test and Innovative trend analysis methods has been applied to detect the trend and variability. Both“Mann-Kendall and spearman’s Rho test”shown that the seasonal (summer and winter) and annual temperature is increasing significantly (P < 0.01), whereas the monthly data record revealed a significant (P < 0.01 and 0.05) rising trend of temperature in all months. The annual and monsoonal rainfall increased significantly. Innovative trend analysis slope recorded rising trend of temperature (+ 0.10) and rainfall (+ 1.67). Study does not found any uniform year (PCI = < 10) of precipitation, however, high (79years) and very high (25years) concentration of precipitation was observed. The variability of temperature implies high and positive outlier frequencies in January (+ 5.31), March (+ 33.5), April (+ 21.83), May (+ 46.00), September (+ 2.94), and seasonally in summer (+ 6.57) and winter (+ 7.89). Present study suggests the need tackle the rising temperature by making awareness about the global warming and its consequences on climate change.