Temporal and spatial variability of precipitation extremes across India

The occurrence of extreme precipitation events is a matter of concern for any nation because a slight change to it can have a devastating effect on the socio-economic condition for the state. To assess the temporal and spatial variability of precipitation extremes, extreme rainfall data over India (except Island part) have analyzed using quantile perturbation method. The data used in the study is taken from the Climate Research Unit, University of East Anglia (UK). It is a gridded data of 0.5^o × 0.5^o resolution. The analysis showed that different part of the studied area had varying perturbations in the precipitation extremes. The study found a significant anomaly in precipitation extreme for all the periods but the 1910s, 1920s, 1930s, 1940s, 1990s, and 2000s decades had covered wide area as compared to the remaining periods with reference to the long period of 1901-2017. In the 1910s, the positive anomaly was found near most of North East India, while negative anomaly was found in central and north India. In 1930-1940s, the central part had a positive anomaly, and the north part had a negative anomaly. Negative perturbation is present in the most of east region (the Gangetic plain) in 1990-2000s. A positive anomaly found on the west side. But in the recent decade very few anomaly present in the whole region. To partially address the reason behind the perturbation correlation analysis has been done between extreme precipitation anomaly and Indian Ocean Dipole. The result shows most of the part of East, North East side of India are having moderately negative correlation while some of the South and North India are having moderately positive correlation. The sea surface temperature over the Indian Ocean might be the main driver for the decadal perturbations in precipitation extremes.