Sunday, January 6, 2013

BRRRRR - Sea Smoke

Fog in winter, definitely, but it is usually called sea smoke, sea vapour, vapour, ice fog, steam fog and probably several others. The condition occurs when the air temperature is lower than the water temperature and the water evaporating from the ocean surface can’t be absorbed by the cold air (cold air holds less moisture than warm air) and accumulates in droplets that create fog, often sen in convective currents or wispy tendrils. If the air temperature is significantly colder than the sea surface temperature, the sea smoke can be so dense that as it rises, it can create cloud cover and fine snow.

Grand Manan Adventure ferry in sea smoke
These conditions will cause the fog detector to start the fog horn because of the limited visibility. It is also an excellent warning to mariners that sea water hitting their vessels may freeze instantly, accumulating enough that it can compromise the stability of the vessel. Chipping ice can reduce the top heaviness of the vessel but is labour intensive and not all areas can be reached safely on a vessel. Freezing spray warnings are issued when these conditions are likely.  In any event, the air temperature will be very cold and if windy as well, the wind chill can be significant and frost bite may be an issue.

Sea smoke can be incredibly complex and amazing to photograph. Here are a few taken on January 3.
Swallow Tail lighthouse with sea smoke.

Swallow Tail peninsula and the Grand Manan Adventure ferry with wispy sea smoke.
Swallow Tail lighthouse and the Grand Manan Adventure ferry.

Swallow Tail at Night

Visitors to Swallow Tail primarily arrive in the day time, however, some people do go out after darkness. When it was an active light station, the keepers lived on site and had to negotiate the stairs, bridge and footpath in darkness. The rails and cables along these were helpful, not only in stormy conditions but also at night.
Illuminated foot bridge with reflective tape.  Photo courtesy Larry Small.
At the request of the herring weir operators, no dusk to dawn lights are to be used on the property and although shielded low voltage lights can be positioned to provide light and not affect the herring weirs, we chose to use reflective tape to mark the trails, steps, bridge and buildings for now. Just as reflective tape is useful along roadways, it is very useful at Swallow Tail as long as you have a flashlight.
Illuminated path with reflective tape on the trail stanchions.  Photo courtesy Larry Small.
With only the light from the lighthouse, the property is fairly dark and a great place to watch the stars on cloudless nights.