Sea Smoke. Have you ever seen it?→[More:]This morning, I had to drop my car off in the shop and walk to work over the bridge. The tidal river below me was breathing sea smoke, a wraithlike, silent form of fog (advection fog) which shows up pretty rarely but is breathtakingly beautiful and mysterious. The conditions have to be just so* to produce it - so I've seen it just once or twice a year in these very, very cold, dry winter days, along the ocean.

"The difference in the temperatures of the air and water must exceed a threshold which is dependent on the humidity of the air and the temperature and salinity of the water: its value, in the range 5·15°C, is a minimum when the air is moist and the water cold and fresh. the liquid water content and vertical extent of steaming increase as the thermal contrast increases. Close agreement is found between observations of the onset of steaming and the computed threshold values."