High-pressure weather systems often bring fair weather and relatively clear skies. On June 5, 2012, a high off the coast of Tasmania (top-right) did just that...and in spectacular fashion. NASA’s Aqua satellite acquired this view of the weather system over the Great Australian Bight, as it cut out an oval-shaped hole from a blanket of marine stratocumulus clouds. The cloud hole, with a diameter that stretched as far as 1,000 km (620 miles) across, was caused by sinking air associated with an area of high pressure near the surface. In general, winds blow outward and away from areas of high pressure. As a result, areas of high pressure pull air downward. As the air sinks, it also warms, increasing the rate of evaporation, making it difficult for the air to sustain clouds. Areas of low pressure, by contrast, pull air upward and generate clouds and stormy weather.
Tasmania, AustraliaCategory: Space