Indo-Gangetic Plain ‘high in atmospheric ammonia’

The Indo-Gangetic Plain is the global hotspot of atmospheric ammonia (NH3) due to intense agricultural activities and fertiliser production. Atmospheric ammonia is typically generated due to agricultural activities including the use of nitrogenous fertilisers, manure management, soil and water management practices and animal husbandry.

The study done jointly by IIT-Kharagpur in collaboration with IITM Pune and European researchers and called “Record high levels of atmospheric ammonia over India: Spatial and temporal analyses” has also confirmed a direct correlation between atmospheric ammonia emissions and fire counts. Atmospheric ammonia is growing rapidly at a rate of 0.08 per cent annually during the summer-monsoon covering the June to August period.

“The satellite data we collected for agricultural emissions show a positive correlation of atmospheric ammonia with total fertiliser consumption and temperature since high temperature favours volatilization and is negatively correlated with total precipitation as wet deposition helps removal of atmospheric ammonia,” said Jayanarayanan Kuttippurath, a professor at IIT Kharagpur’s Centre for Oceans, Rivers, Atmosphere.

However, the general trend in atmospheric ammonia over India is negative in most seasons, the study revealed. The report further adds that in India, there has been lack of detailed information about atmospheric ammonia, which is a significant contributor to atmospheric pollution and deterioration of air quality.

Apart from Indo-Gangetic Plain, data from across the country show some regional hotspots in northwest and southeast India. The study also mentions that there are positive trends in atmospheric NH3 over the agricultural areas of the United States, China and Europe, about 1.8 - 2.61 per cent annually, depending on regions.

This study published recently in Elsevier journal “Science of the Total Environment”, is pioneering research from India in measuring the dynamics of atmospheric ammonia over the region and validated the data supporting India’s commitment to reduce atmospheric pollution and development of global pollution control initiatives, the IIT-Kharagpur release said.