![]() ![]() Many also believe that sunspots are the only way the solar wind can cause auroras on Earth, also false. In fact, during this last minimum from 2017-2020, we have witnessed some incredible displays of the northern lights over Northern Norway (see figure 4). ![]() Yes, solar maximum will provide many big solar storms, but solar minimum isn’t devoid of northern lights. Many believe that around solar maximum is the best and only time to see the aurora, this is wrong. During each cycle there is a solar maximum (many sunspots) and a solar minimum (few to no sunspots). The next maximum is forecast to come at some point in 2025 © David Hathaway NASA/ARC No sunspots does not equal no northern lightsĪround every 11 years, the magnetic field of the sun flips so the north pole becomes the south and the south becomes the north. There are different mechanisms and features on the sun’s surface which can cause the solar wind to impact Earth and create the northern lights, these are summed up in figure 2.įigure 3: Sunspot cycles since 1870 showing a variable 11 year cycle with peak and troughs right up to the present minimum. The solar wind can blow anywhere from 250 to over 800 kilometres per second depending on the state of the sun. This reaction occurs billions of times over with enough energy produced in 1 second to power modern civilisation for around 500,000 years! This energy makes its way to the surface of the sun and is released in the form of a stream of electrically charged particles, collectively known as, the solar wind. In the dense, hot and deep core of the sun, hydrogen is forced together by gravity to create helium, resulting in a small release of energy. At four and a half billion years old, this giant creates energy on a humongous scale. Figure 1 – A large northern lights swirl over Kirkenes, Northern Norway lighting up the snow laden landscape below © William Copeland We begin our story on the sun While in the northern hemisphere, the lights occur over highly populated areas so are seen more frequently, such as in the northern Norwegian town of Kirkenes seen in figure 1. The reason the southern lights can often be overlooked is due to the fact that the strongest auroras occur on the Antarctic continent itself or over the surrounding oceans and land fringes where few people are located. In this article, the term northern lights will predominantly be used, but the same science applies to the southern lights that are seen around the Antarctic. The technical names for the night time displays are aurora borealis (northern lights) for the northern hemisphere and aurora australis (southern lights) for the southern hemisphere. Therefore, this article aims to make the science a little more digestible, while throwing in some astonishing facts along the way. ![]() What causes this phantom in the night skies over the high latitudes? The story is a complex riddle of scientific discoveries that are still taking place to this day, which can often make it difficult to understand what on Earth is going on. An enigma that draws thousands to the northern polar regions each year, inspiring myth, legend and an incomparable sense of awe. The Northern lights are one of mother nature’s greatest light shows. ![]()
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