While satellite data has shown aerosols — tiny polluting particles in the air — to be rising over India, a new study based on primary data gathered from measuring instruments installed in a network of stations confirms the trend. The study, by a team from the Vikram Sarabhai Space Centre, Thiruvananthapuram, and Indian Institute of Science (IISc), Bangalore, published online in Geophysical Research Letters last month (14 March), is based on the principle that aerosols absorb the sun’s rays as they reach the earth’s surface.