Image of high aerosol optical thickness (or aerosol optical depth) due to agricultural burning in India on November 15, 2023. The base true-color corrected reflectance image was acquired by the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the joint NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) satellite and is overlaid with aerosol optical thickness values. The colors range from yellow to orange to red; where red shows the highest aerosol optical depth values. View the aerosol optical thickness over India in Worldview.
Aerosol optical depth (AOD) (or aerosol optical thickness) indicates the level at which particles in the air (aerosols) prevent light from traveling through the atmosphere. Aerosols scatter and absorb incoming sunlight, which reduces visibility. From an observer on the ground, an AOD of less than 0.1 is “clean” and characteristic of clear blue sky and maximum visibility. As AOD increases to 0.5, 1.0, and greater than 3.0, aerosols become so dense that the Sun is obscured.