Effects of Drought and Fire Visible on NASA Satellite Map of Aerosols

A NASA map, using data collected from its Terra satellite, illustrates air quality worldwide during the month of August, with the highest concentrations of aerosols occurring when drought conditions in some regions sparked intense wild fires, including across western Russia and over the Amazon basin in South America. Using Moderate Resolution Imaging Spectroradiometer (MODIS) technology — which measures the extent to which aerosols in the atmosphere reflect and absorb light — the agency depicts how large-scale weather patterns influenced air quality. When aerosols are dense, they block light from the Earth’s surface and aerosol optical depth is high, as shown in brown. When aerosol levels are low, light reaches the surface more easily, as shown in yellow. High aerosol levels can result from numerous factors, including winds that kick up sand and dust, high temperatures that turn pollution into thick haze, and thick smoke produced by fires. In Russia, an historic heat wave sparked fires that swathed the western portion of the country in thick smoke, while drought conditions in the Amazon caused the rapid spread of fires set by people burning forest and underbrush to clear land for agriculture. High levels of aerosols over northern Africa, the Arabian peninsula, and southwest Asia came from dust.