On June 27, 2013 the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this true-color image of smoke plumes hovering over Spain and the western Mediterranean Sea. The smoke has a faintly yellow-tan or milky gray color compared with brighter white clouds. The plume seen in this image is an extension of a broad river of smoke which extends over Canada and the open water of the Atlantic Ocean.
Data from NASA and other satellites suggests that the smoke originated from wildfires in Canada. It is less likely, but possible, that part of the smoke also came from wildfires in Colorado and other parts of the southwestern United States.