The Erratic behavior of monsoon rainfall, including the phenomenon of concentrated heavy rainfall on a small number of days, could, at least in part, be attributed to the rising air pollution, especially the increase in suspended particles in the atmosphere, a new study
The study, published in the prestigious journal, Nature Communications, has shown how excess aerosols, suspended solid particles like dust, smoke, and industrial effluents, in the atmosphere is changing cloud patterns, its shape, size and other properties like temperature, which in turn is resulting in variability in rainfall over the Indian sub-continent during the monsoon season.
The group analyzed satellite data and data from atmospheric computer models from the last 16 years to make an assessment of the likely impacts of changes in cloud behavior over the land area of about 16 lakh square kilometers.
The linkage of air pollution to rainfall activity is not new and has been established in many earlier studies as well. Tripathi’s team, however, has, for the first time, given details of the exact changes that take place in the clouds over India as a result of an increase in aerosols, and how this was leading to a reduction in the difference in day and night temperatures, and also impacting rainfall activity.
Since the Uttarakhand tragedy in 2013, India has had an unusually extreme rainfall event every year. Long-term rainfall data also shows that rainfall activity is getting increasingly concentrated to a few extremely wet days during the season, while most of the other days remain relatively dry.