It's that time of year again when fog becomes a common occurrence in early morning. Fog is a stratus cloud that forms on or near the ground. One type of fog, 'radiation fog', is common in the mornings after heat has radiated into the atmosphere during the night. It normally dissipates after sunrise, often quickly if the wind picks up. It can be a magical time. 'Trees in fog' was captured on the North Shore of Lake Superior.