Glasgow Digital Library Voyage of the Scotia BRUCE PEOPLE SHIP ANTARCTIC INDEX
Scotland and the Antarctic

Section 1: Background - Arctic and Antarctic ... The Nature of Antarctica

Why is the atmosphere so clear?

image from Voyage of the Scotia

The Antarctic air is well known for its clarity and sometimes the visibility may be 150 kilometres (95 miles). The main reason is that there is ten times less water in the atmosphere compared with Scotland. There are also far fewer solid particles (usually caused by pollution). Visitors to the Antarctic are amazed at the quality of their photographs - very sharp.

Rain only rarely falls on the Antarctic continent. Most of the precipitation falls as snow. Quite often the blizzards in the Antarctic are of drifting snow and not fresh-falling snow.

Snow may be measured by its depth using a ruler, or melted so that the water that has fallen (as snow) can be compared with rainfall statistics in other parts of the world. Reference to precipitation in the Antarctic uses 'rainfall equivalent'. The average precipitation in the interior of the continent is about 50mm with 70mm at the South Pole. On the coast this increases and in the South Orkney Islands is 405mm. Scotland's average is between 1000mm and 1500mm.

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Glasgow Digital Library Voyage of the Scotia BRUCE PEOPLE SHIP ANTARCTIC INDEX