I resisted as long as I could. I’ve been driving through a pervasive layer of ghostly ground fog, which hovers like thin smoke over farm
Yet only certain environmental and atmospheric conditions produce ground fog. Aside from radiative cooling, the critical factors are clear and windless skies. On cloudy nights, a larger percentage of outgoing longwave (infrared) radiation is held close to the surface. The air stays warm, so fog can't form. A clear sky allows radiation to escape the atmosphere unimpeded. When breezes whip up, they push water droplets aloft to mix in the atmosphere. On still nights water droplets huddle into mini-clouds that remain close to earth. Ground fog usually evaporates as air warms in the hours after sunrise.
Back on the road, orange light floods my car through the passenger window. On either side of the highway fingers of fog swirl upward, waking at the touch of the sun. A new day has begun. Autumn approaches.