Ongoing cold wave conditions in North India are traced back to the intrusion of cold and dry air from the Siberian high, a revelation from a study conducted by researchers at IISER Mohali. The Siberian High, accumulating cold dry air from November to February, plays a pivotal role in driving severe winter conditions.
The study, published in the Weather and Climate Extremes journal, provided crucial insights into the factors contributing to extreme winter temperatures. Events like cold waves and severe cold waves are identified through the standard deviation of the normalised minimum temperature anomaly for consecutive days.
Delhi and other northern regions experienced severe cold on Wednesday, with areas receiving rainfall and snow, resulting in temperatures below the season's average, according to the India Meteorological Department (IMD).
The research team, including K.S. Athira at IISER Mohali and V. Brahmanada Rao from the National Institute for Space Research, Brazil, emphasised the intensified winter atmospheric blocking this year, extending cold waves from late December to January.
Despite identifying a decline in the number, duration, and intensity of cold wave events from 1982-2020, the study linked this reduction to rising winter minimum temperatures due to global warming and fewer western disturbances (WDs) originating from the Caspian or Mediterranean Sea.
The meticulous methodology used for identifying cold wave events considers factors like the normalised minimum temperature anomaly and standard deviations.
The study identified 509 cold wave days, including 45 days of severe cold wave events, emphasising the broader impact on agriculture, livestock, and transportation disruptions.
The urgency for clear policies at various administrative levels is stressed due to the risk of hypothermia and frostbite, particularly among vulnerable groups.
Prof. Raju Attada underscored the importance of understanding synoptic features and dynamics for accurate prediction of cold wave events, emphasising the need to prioritize actions to save human lives during cold waves.
Also read | Rainfall over northwest during January was second lowest since 1901: IMD amid light rain in Delhi-NCR
