The Indian state of Punjab has two growing seasons—one from May to September and another from November to April. In November, Punjab farmers typically sow crops such as wheat and vegetables; but before they do that, farmers often set fire to fields to clear them for planting. Punjab comprises only about 1.6 percent of India’s land surface, but thanks to fertile soils and the adoption of agricultural advances, the state grows about one-fifth of India’s wheat.
The Moderate Resolution Imaging Spectroradiometer (MODIS) flying aboard NASA’s Aqua satellite passed over India on October 18, 2013 and captured this true-color image of fires clustered in the agricultural region. Red hotspots combined with smoke mark actively burning fires. Given the location and the time of the year, these fires are likely agricultural in origin.
Using fire to prepare for planting brings some benefits, such as killing pets that damage drops, and turning crop residue from the previous season into fertilizing ash. However, smoke can be harmful to human health, and can aggravate heart and lung disease. Exposure to high level of smoke, which can contain a variety of compounds including carbon dioxide, carbon monoxide, nitrogen oxides and particulate matter, is particularly difficult for older adults, children and people with chronic health conditions.