Weather reprise 2014

This is a reprise of my favourite weather images from 2014. Tomorrow, I will treat the year’s mammals, and on new-year’s eve, birds.

Maybe once every winter or two, I get a decent shot of a steam devil. It can be thought of as a dust devil where the dust has been replaced by steam fog. The contrast in this scene is greatly improved by being able to shoot across the Lake towards a mountainside hidden from the winter sun.

Seen less often than steam devils are frost flowers. Unlike hoar frost which requires a cold surface (vapour cooling), frost flowers require a warm surface (vapour mixing—the same process involved in producing steam fog and contrails). As a result they grow above the surface as individual flowers. The petals point into a gentle katabatic flow of vapour.

Frazil is a collection of loose flakes of ice in water. Although the air temperature is well below 0C and ice is forming along the shore, waves have prevented the individual flakes from sintering.

Anchor ice forms on the base of a creek or river. We normally think that ice should form at the top of a water column, but that is only true when the water body is stratified. In a turbulent stream, it can form throughout the depth and then adhere to the bottom. Here, the (white) border ice is on the top of the more gently flowing sides of the stream, while the (green) anchor ice is on the bottom in the turbulent central flow. 

Then there is my perpetual favourite: a rainbow. This is a shot that I had sought for many years. A low-sun rainbow with the circle completed by a reflection in the calm waters of the Lake (normally a storm leaves the water too rough).

Perhaps my most unexpected weather shot of the year is of the total lunar eclipse of October 8th. Why do I claim that it is a weather shot? The Moon is in the Earth’s umbra so the red colouring is from light that passed through the Earth’s atmosphere after much of the blue had been scattered out. Even more interesting is the blueish rim. This is only seen as the Moon enters or leaves the umbra and is the result of light that passed through the Earth’s ozone layer (ozone absorbs reddish light but allows bluish light to pass through).