![]() The 'morning glory' is a type of roll cloud which can be many hundreds of kilometres long. Image: Morning glory cloud, near Burketown, Queensland. Read moreĬatching the aurora Curious clouds A magnificent morning glory cloud Oxygen releases greenish-yellow or red light, while nitrogen releases dark red or blue light. The colour emitted depends on how energetic the collisions are, where they occur in the atmosphere and which atoms and molecules are involved. The patterns and shapes of the aurora are determined by the changing flow of charged particles and the varying magnetic fields. Upon entering the atmosphere, they collide with atoms and trigger light emissions. As these charged particles approach Earth, they're directed by the planet's magnetic field towards the north or south poles. The Sun is so hot that high-energy plasma (a gas of electrically charged particles) can escape from its gravitational field-known as solar wind. Auroras are the result of events that begin on the Sun. The swathe of green light shown here is a space weather phenomenon called 'aurora australis' or the southern lights-a common sight in Antarctica but sometimes also visible from southern Australia. ![]() Image: The aurora australis over Prydz Bay, Davis Research Station, Antarctica. Read moreĬolourful weather: blue jets, elves and sprites An awesome aurora This electrically conducting region of the atmosphere is of major importance because it reflects and modifies radio waves used for communication and navigation. The ionosphere is a layer of the earth's atmosphere, from roughly 50 km above the surface, where solar and cosmic radiation ionise atoms and molecules, thus creating a layer of electrons. Like the process that forms an aurora, sprites are formed by charged particles exiting the top of the storm into the ionosphere. ![]() They can occur out of the top of very powerful thunderstorms, and only last for a fraction of a second. Red sprites are a rare phenomenon which is not very well understood. Image: Red sprites above Kununurra, Western Australia. So what's going on behind the scenes in the atmosphere to produce the weather in these striking images? These and another 10 equally amazing photos are the stars of the show in the 2020 Australian Weather Calendar. Rarely photographed red sprites flickering above a thunderstorm. A bird's-eye view of a sublime morning glory cloud rolling out across the sky. A shimmering aurora australis lighting up the 24-hour darkness in Antarctica.
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