Pictures of Weather phenomena

Distant Ridge

Despite most of the photographs that you see of the place, much of Antarctica is actually very flat and boring. It's just that flat boring places don't photograph very well and once you've seen a couple of shots, that's about as much as you need to see.

Most of continental Antarctica is taken up with a vast high ice plateau that part from undulations due to crevassing and ridges of blown snow, is largely featureless. Most of the photographs therefore are of coastal regions that present much more interesting landscapes.

Sunbeam

Picked out by a shaft of sunlight. Robin Peak glows in a dusting of early winter snow.

Berg Wash

Ice bergs are eroded by a combination of temperatures above freezing and the effects of wave action. Here in a fairly rough sea, waves are washing up the side of this berg to a point about 2 metres above sea level and will probably make two separate upright areas that are divided by the developing trough. We did for a short time consider trying to speed through the gap when it was awash in our small powerfully driven zodiac boat, but decided against it - probably for the best!

Raspberry ripple snow

OK not an iceberg at all, but part of a land-based snow slope. In the spring when the winters snow begins to melt, water flows across the top of glaciers and snow slopes carrying with it dissolved nutrients in the melt water. In these conditions, algae grows within the top layer of the ice or snow catching the goodies as they flow by and taking advantage of the extra energy from the longer days and stronger sunshine.

In this case the algae is predominantly a red-coloured species, but further down the slope, green and blue-green colours are discernable. This is relatively short-lived spring phenomena as soon the very snow and ice layer that the algae are living in will melt and the algae will flow down to the sea with the water that provides them with their nourishment. It is not unusual to see distinctly red, green or blue-green topped ice bergs in the spring as a result of the growth of such algae.

There are over 300 species of such algae that live in such harsh and cold conditions. The red colour is a protective chemical (carotenoids such as astaxanthin) that the alga produces against exceptionally high concentrations of visible and ultra violet light that bounces off the snow and ice surfaces and so saturates them to a point where it become harmful and destructive. Such algae are also found in other parts of the world, often in high mountains where extra u-v light due to the thinner atmosphere and again increased light scattering by ice and snow requires protection by similar pigments.

Large grounded ice-berg

Icebergs are made of freshwater ice and not of frozen sea water. They form from the edge of glaciers when the glacier reaches the sea and either break off in pieces to form an iceberg, or in the case of an ice shelf, begin to float on the sea and then break off from the rest of the glacier as a large slab.

Icebergs are made up of snow that has fallen over many hundreds or even thousands of years. The stripes and different coloured layers in icebergs represent different layers of snowfall and the weather conditions under which the snow fell. If it is very cold then a light open layer with much air included will be formed, this gives a paler or white layer. The darker, bluer layers come from snow fall in relatively warm, maybe even wet conditions when little or no air is trapped in the layer.

In addition to this, air is squeezed out of the lower layers of a glacier as more and more snow falls and so the weight of snow builds up

Temperature dropping, sea-ice begins to form

Sea ice in the process of forming, the shore of the island in the distance is about 5 miles (8 kilometers) away and the whole of the sea surface in-between is made of forming fast ice. Notice how the slabs of forming ice become larger further out to sea as there are less undulations of the coast to push the slabs together as the tide falls.

Temperature dropping, sea-ice begins to form

This is sea-ice in the very early stages of formation. Sea-ice that forms in situ and is attached to the coast is called "fast-ice", it is stuck fast. In this picture the surface of the sea is beginning to freeze as the temperature is dropping to -20C and below. Pack ice has come near to the shore and so all movement of the sea has been killed completely allowing low temperatures to freeze the sea water. At this stage the ice is around an inch (2.5cm) thick but it has a spongy texture, you could poke a finger or certainly a fist through it relatively easily. The patterned effect comes from the rise and fall of the tides. As the tide rises, so the surface of the sea enlarges slightly and so the ice cracks apart, as the tide falls, so the surface of the sea decreases slightly and so the slabs of ice overlap at the edges.