Haze Over the Midwestern United States

Haze Over the Midwestern United States

High pressure over the central United States led to hot temperatures and an accumulation of pollutants on August 8, 2005. The Environmental Protection Agency warned that air quality index levels could be unhealthy for the Midwest, and western and southern Great Lakes areas. The EPA advised individuals with respiratory sensitivity to avoid outdoor exercise. Meanwhile, as reported by the CBS 2 Chicago Website, Illinois officials designated August 9, 2005, the ninth air pollution action day this summer, and the second air pollution action day in a row. To cut down on ozone accumulation, city officials encouraged Chicago residents to use public transportation.

The Moderate Resolution Imaging Spectroradiometer (MODIS) flying onboard the Terra satellite captured this image on August 8, 2005. In this image, a layer of haze stretches southwards from the Great Lakes through the Midwest. The sharp line running diagonally through the picture is caused by different passes of the Terra satellite. The images from these passes were stitched together to make a complete picture. Because the passes occurred at different times, cloud and aerosol cover differ, but the cloud of haze persists.

NASA image courtesy the MODIS Rapid Response Team at NASA GSFC.