Reading University, one of UK’s leading research centres, claims to have solved a riddle that has perplexed scientists since the 19th century. An intensive study carried out by it has reached the conclusion that heavy snowfall over the Himalayas in winter and spring can be the direct cause of drought in India, especially in the early part of the summer monsoon.

Given that last winter was quite severe and mammoth quantities of snow may have fallen on the Himalayan range, all concerned in the Indian agrarian sector need to be vigilant about a delayed monsoon and plan accordingly. This is what the report appears to suggest. Dr Andy Turner, lead author of the research at Walker Institute of the university, said: ‘‘Our work shows how, in the absence of a strong influence from the tropical Pacific, snow conditions over the Himalayas and the Tibetan Plateau could be used to help forecast seasonal monsoon rainfall for India, particularly over northern India during the onset month of June.’’

These findings are highly significant because Indian agriculture is heavily dependent on early rainfall; a lack of this in the crucial growing season tends to have a devastating impact on crops, as was experienced last year. The work is a part of Reading’s Climate Programme of the National Centre for Atmospheric Science (NCAS). Scientists have known since the 1880s that increased snow over the Himalayas can be linked with weaker summer monsoon rains in India. However, according to Reading, the mechanisms explaining this correlation have never been properly understood.

The latest research shows that greater snowfall reflects more sunlight and produces a cooling over the Himalayas. This in turn means a weakening of the monsoon winds that bring rain to India. The relationship is said to be strongest in the absence of warm (El Nino) or cold (La Nina) environments in the tropical Pacific, since these are normally the dominant control factors over the Indian rains. A spokesperson for Reading university said its research is based on extensive experiments with the British Met Office/Hadley Centre climate model.