The collision of three weather systems and increased levels of global warming have led Northwest India drowned by an unprecedented deluge.
Be it landslides and flash floods across Himachal Pradesh or Delhi’s heaviest monsoon in 40 years; meteorologists and climate scientists are unanimous that extreme weather events are here to stay.
Mahesh Palawat, vice-president, Meteorology and Climate Change at Skymet Weather (the first private Indian company to provide weather forecasting services) said that the western disturbance over the western Himalayas, cyclonic circulation over the northwestern plains, and the axis of monsoon trough running across Indo-Gangetic Plains was responsible for the brutal rains.
“This alignment is not happening for the first time and is the usual pattern during the monsoon. However, global warming-led changes in monsoon patterns have made a difference. There has been a constant rise in both land and sea temperatures, which has increased the capacity of the air to hold moisture for a longer time”, he said.
Extreme weather events have been unceasing since the start of the year.
In February, temperatures smashed a 123-year old record. In April and June, humid heat waves over east and central India were made 30 times more probable, while cyclone Biparjoy that lasted for 13 days in the Arabian Sea- the longest-duration since 1977.
Raghu Murtugudde, Earth System Scientist and visiting professor at IIT-Mumbai said that other factors too were contributing to the unique events of 2023.
“El Nino has taken shape, which is amplifying global temperatures. Secondly, wildfires have been in three times larger areas, releasing three times of carbon into the atmosphere, and increasing greenhouse gases. Thirdly, North Atlantic Ocean is in a warmer phase. Fourth, the Arabian Sea has warmed unexceptionally since January, infusing more moisture over North-Northwest India. And lastly, the upper-level circulation pattern is also unusual, which forces local surface circulations, bringing rains like the one we are witnessing across north and central India,” he said.
Krishnan Raghavan, Director of the Indian Institute of Tropical Metrology said that rising global surface and ocean temperatures were leading to more evaporation aggravating the rain. “Indo-Gangetic plains have been receiving lots of moisture from the Bay of Bengal as well as from the Arabian Sea. This continuous supply of moisture feed to the weather systems leads to increased rains, which also results in extreme weather events,” he said.
Report after report has concluded that extreme weather conditions are the new normal. The Intergovernmental Panel on Climate Change has warned of a 20 per cent surge in extreme rainfall events in India.
Another report by the Ministry of Earth Sciences concludes that monsoonal rainfall is projected to become more intense in future, and will affect larger areas. Greenhouse gas based warming, aerosols and increasing urbanization are only some of the causes for this.
