Influence of climatic variability on rainfall of western region of Haryana

Climate variability refers to the variation or deviation in the weather variables for a short period of time, such as months or years. This can be influenced by phenomena such as El Niño, La Niña, and IOD. Haryana, a north-western region of India, predominantly falls under the arid or semi-arid climatic type and mainly depends on rainfall for its kharif crop production. The influence of El Niño, La Niña, and IOD phases on the rainfall variability was studied based on calculating the percent deviation of rainfall observed during the years from the normal rainfall of the locations. The results for the western region of Haryana showed that the surplus rainfall effect of La Niña was more pronounced than deficit El Niño years. The El Niño effect is stronger for SWM and winter season causing below normal rainfall and weak in the pre-monsoon, and the post-monsoon (drier seasons) resulted in above-normal rainfall. Specifically, during the pre-monsoon season, the usual pattern of El Niño and La Niña is reversed, resulting in above-normal rain during El Niño years and below-normal rain during La Niña years for the season. In case of positive IOD, the predominant locations received excess rain during the pre-monsoon and post-monsoon, and contrary to its typical effect positive IOD years, caused below-average rain during the winter and SWM seasons. The negative IOD event caused above-normal rainfall in post-monsoon and SWM but below-normal rain in winter and pre-monsoon. In mean annual rain, El Niño and positive IOD resulted in deficit rain while La Niña event and negative IOD resulted in surplus rain. The six of the negative IOD events were associated with La Niña, and three of the El Niño events were associated with positive IOD. The El Niño and La Niña events nullified the typical effect of IOD events.