A detrended fluctuation analysis to examine the pollutant pattern over Gangetic West Bengal of India

In this paper, we present the results of a careful investigation into the correlational pattern of various pollutants over Kolkata during the months before to the monsoon, which correspond to the pre-lockdown (2019) and lockdown (2020) periods. When Ozone, NO x , SO 2 , and surface temperature were subjected to detrended fluctuation analysis, we found that the SO 2 exhibits long-term positive autocorrelation in the 2019 pre-monsoon. However, during the lockdown, the Hurst exponent (H) dropped below 0.5, which led to the interpretation that the lockdown caused neighbouring pairs to transition between long-term high and low autocorrelation coefficients. Additionally, although the autocorrelation function for NO x resembles a roughly sinusoidal pattern, lockdown has caused a change in H. Using H, fractal dimension and climate predictability, we have analysed the predictability behaviour of the pollutants and temperature under consideration.