The number of foggy days in the capital has doubled in recent years than what was experienced three decades ago, a study has found.
The study, carried out under the Winter Fog Experiment (WIFEX), initiated by the Ministry of Earth Science (MoES), took into account the observations taken during winter of 2015 and 2016. Experts suggest that surging moisture and increase in air pollution levels, triggered by excessive use of vehicles, along with anthropogenic activities, are major factors triggering frequent and severe fog over north India.
As per the joint study, headed by Pune-based Indian Institute of Tropical Meteorology, fog was reported for 74 days from November to February, as against only 38 days in the season in 1981. The experiment results, published in Current Science in February this year, also highlighted that 20 days in December and January reported dense fog, when the visibility dropped below 50 metres.
The transport sector — road, rail and air — was affected across north India. Scientists claim the region as one of the largest fog-covered zones in the world.
M Rajeevan, Secretary, MoES, told The Indian Express, “Though we could could predict most of the fog events accurately this year, fog prediction remains a challenge given there are both local and external weather conditions that influence fog.”
Senior IITM researcher Thara Prabhakaran said the region provides very little scope for the escape of suspended particles, unless removed by drizzle or rain.