Sea smoke

Sea smoke, frost smoke,^[1] or steam fog^[2] is fog which is formed when very cold air moves over warmer water. Arctic sea smoke^[3] is sea smoke forming over small patches of open water in sea ice.^[4]

Sea smoke on the Atlantic Ocean

Steam fog over a small lake on an early summer morning in June 2014 in Bergen, Norway.

Sea smoke over Lake Superior, Duluth, Minnesota. 5 January 2017

External videos
Sea smoke and steam devil over the Sea of Japan on December 25, 2021, on the south of Primorsky Krai of Russia, from Yuzhno-Morskoy (near Nakhodka).

It forms when a light wind of very cold air mixes with a shallow layer of saturated warm air immediately above the warmer water. The warmer air is cooled beyond the dew point and can no longer hold as much water vapor, so the excess condenses out. The effect is similar to the "steam" produced over a hot bath or a hot drink, or even an exercising person.^[2][3]

Sea smoke has a turbulent appearance and may form spiraling columns.^[5] It is usually not very high and lookouts on ships can usually see over it (but small boats may have very poor visibility)^[6] because the fog is confined to the layer of warm air above the sea. However, sea smoke columns 20–30 m (70–100 ft) high have been observed.^[5] Because this type of fog requires very low air temperatures, it is uncommon in temperate climates, but is common in the Arctic and Antarctic.^[3]

See also

• Steam devil

References

1. Bowditch (1962). The American Practical Navigator. U.S. Navy Hydrographic Office. p. 614.
2. MacDonald, Edwin A., Captain, USN (Retired) (1969). Polar Operations. Annapolis: United States Naval Institute. p. 31.{{cite book}}: CS1 maint: multiple names: authors list (link)
3. Ministry of Defense (Navy) (1973). Admiralty Manual of Navigation, Volume II. London: Her Majesty's Stationery Office. p. 188.
4. Nuttall, Mark, ed. (2005). Encyclopedia of the Arctic. New York: Routledge. ISBN 978-1-57958-436-8. OCLC 56012002.
5. Roll, H. U. (1965). Physics of the marine atmosphere. New York: Academic Press. ISBN 978-0-08-095444-8. OCLC 316566885.
6. Halsted, Hank (August 1982). "Fog". Motorboating and Sailing. pp. 41–42. OCLC 46773002.

Further reading

• Sea Smoke and Steam Fog, by P. M. Saunders (Woods Hole Oceanographic Institution, Massachusetts (Manuscript received 9 July 1963: in revised form 29 January 1964), 551.551.8:551.575.1