4/9/2023 0 Comments Aurora definition![]() 'Aurora australis' means 'dawn of the south'. 'Aurora borealis', the lights of the northern hemisphere, means 'dawn of the north'. Usually the best time of night (on clear nights) to watch for auroral displays is local midnight (adjust for differences caused by daylight savings time). The long periods of darkness and the frequency of clear nights provide many good opportunities to watch the auroral displays. Winter in the north is generally a good season to view lights. Researchers have also discovered that auroral activity is cyclic, peaking roughly every 11 years. When is the best time to watch for auroral displays? Areas in the north, in smaller communities, tend to be best. Southern auroras are not often seen as they are concentrated in a ring around Antarctica and the southern Indian Ocean.Īreas that are not subject to 'light pollution' are the best places to watch for the lights. Auroral displays can also be seen over the southern tip of Greenland and Iceland, the northern coast of Norway and over the coastal waters north of Siberia. However the best places to watch the lights (in North America) are in the northwestern parts of Canada, particularly the Yukon, Nunavut, Northwest Territories and Alaska. Scientists have learned that in most instances northern and southern auroras are mirror-like images that occur at the same time, with similar shapes and colors.īecause the phenomena occurs near the magnetic poles, northern lights have been seen as far south as New Orleans in the western hemisphere, while similar locations in the east never experience the mysterious lights. The lights are known as 'Aurora borealis' in the north and 'Aurora australis' in the south. Northern Lights can be seen in the northern or southern hemisphere, in an irregularly shaped oval centred over each magnetic pole. Where is the best place to watch the Northern Lights? The lights of the Aurora generally extend from 80 kilometres (50 miles) to as high as 640 kilometres (400 miles) above the earth's surface. These collisions emit light that we perceive as the dancing lights of the north (and the south). However, the earth's magnetic field is weaker at either pole and therefore some particles enter the earth's atmosphere and collide with gas particles. Blown towards the earth by the solar wind, the charged particles are largely deflected by the earth's magnetic field. Free electrons and protons are thrown from the sun's atmosphere by the rotation of the sun and escape through holes in the magnetic field. At this temperature, collisions between gas molecules are frequent and explosive. The temperature above the surface of the sun is millions of degrees Celsius. Rocket research is still conducted by scientists at Poker Flats, a facility under the direction of the University of Alaska at Fairbanks - see web page (Note: 1957-58 was International Geophysical Year and the atmosphere was studied extensively with balloons, radar, rockets and satellites. Thanks to research conducted since the 1950's, we now know that electrons and protons from the sun are blown towards the earth on the 'solar wind'. ![]() The connection between the Northern Lights and sunspot activity has been suspected since about 1880. Nitrogen produces blue or purplish-red aurora. Rare, all-red auroras are produced by high-altitude oxygen, at heights of up to 200 miles. The most common auroral color, a pale yellowish-green, is produced by oxygen molecules located about 60 miles above the earth. Variations in colour are due to the type of gas particles that are colliding. The Northern Lights are actually the result of collisions between gaseous particles in the Earth's atmosphere with charged particles released from the sun's atmosphere. The lights appear in many forms from patches or scattered clouds of light to streamers, arcs, rippling curtains or shooting rays that light up the sky with an eerie glow. ![]() Shades of red, yellow, green, blue, and violet have been reported. They are known as 'Aurora borealis' in the north and 'Aurora australis' in the south.Īuroral displays appear in many colours although pale green and pink are the most common. The lights are seen above the magnetic poles of the northern and southern hemispheres. ![]() The bright dancing lights of the aurora are actually collisions between electrically charged particles from the sun that enter the earth's atmosphere. ![]()
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