The smoke from the west coast wild fires has spread rapidly across the United States in a jet stream and has settled down at a low altitude above Philadelphia and the East Coast. (Photo by Daria Devyatkina | CC 2.0)
The smoke from the west coast wild fires has spread rapidly across the United States in a jet stream and has settled down at a low altitude above Philadelphia and the East Coast. (Photo by Daria Devyatkina | CC 2.0)