NASA’s Aqua satellite is being applied effectively. Recently a few hours after a fire began at around 10 a.m. Tuesday, July 19, over the Great Lakes region in the U.S., NASA’s Aqua satellite passed over the region and captured an image of the smoke plume. By that time, the plume of smoke extended 93 miles to the southeast, stretching across Milwaukee and over central Lake Michigan. More than 637 square miles were covered by the plume, including 290 square miles of Lake Michigan.
The image was collected by an instrument called MODIS, one of several sensors on the Aqua satellite. While the resolution, or level of detail, in MODIS imagery is coarse, the sensor provides daily coverage of very large areas. This allows scientists to use MODIS to monitor atmospheric and lake-surface conditions across the entire Great Lakes region on a daily basis. Researchers at the UW-Madison Environmental Remote Sensing Center processed the raw image data to enhance the visibility of the smoke plume. While the plume can easily be seen over land, it is more difficult to detect over the dark background of Lake Michigan’s water.