The release of ammonia into the air poses a serious risk to ecosystems and human health and so it is important to characterise where this polluting gas originates from. It is known that agriculture is an important source of ammonia (e.g. using fertilisers) and that South Asia is a global hotspot of this pollutant. It is, therefore, important to refine methods used to estimate how much ammonia is released in South Asia to be then used in advanced chemistry models for air quality assessments.