Earlier this week, three powerful solar flares (coronal mass ejections) erupted from the sun and are expected to reach Earth on Thursday and Friday. According to scientists, these solar flares are the most powerful since 2006. Solar flares of this magnitude can disrupt communications systems, satellites, technology, and power grids. BBC news quoted Alan Thomson, head of geomagnetism at the British Geological Survey; "Our current view is that the effect of the solar flare is likely to reach Earth later today (Thursday GMT), possibly tomorrow morning."
Solar Activity
During periods of intense solar activity, immense clouds of radiation and charged particles erupt from the sun’s surface. When massive solar flares, referred to as coronal mass ejections hit Earth, they can disrupt radio communications, GPS systems, overload power grids, and take out satellites.
A massive sunspot, which according to many astronomers say is the size of Jupiter, is the strongest recorded sunspot since December 6, 2006. The Class X flash, the largest categorized flares, can produce long lasting radiation storms.
The China Meteorological Administration reported that this week’s solar flare activity caused sudden ionospheric disturbances in the atmosphere above China and jammed short-wave radio communications in the southern part of the country.
Solar Max
NASA says that this increased solar activity confirms that the sun is on track for solar max, its period of most intense activity. Solar max is the period of greatest solar activity in the solar cycle of the sun. Sunspots appear during solar max periods.
Solar max is when the sun’s magnetic field lines are the most distorted due to the magnetic field on the solar equator. These rotate at the solar equator at a faster pace than at the solar poles. The solar cycle takes about eleven years to go from one solar max to the next. These typically occur every 9 – 14 years.
In 1958, the solar max was so powerful that the northern light could be seen as far south as 42 degrees latitude (northern U.S.). NASA researchers stated in 2006 that the next solar max would equal in strength to the 1958 occurrence. The last solar max occurred in 2000 and the next one is predicted to occur in May 2013.
Northern Lights
Colors and patterns that can be observed in the northern lights are from the various types of ions (or atoms) being energized as they collide with the Earth’s atmosphere and are affected by lines of magnetic force. In the northern hemisphere they are referred to as the aurora borealis and in the southern hemisphere, the aurora australis. These lights may take many forms, including rippling curtains, pulsating globs, traveling pulses, or steady glows and the altitude affects the colors. Blue violet/reds occur below 100 km, with bright green strongest between 100-240 km and above 150 240 km ruby reds appear.
Many people around the world may get to enjoy the northern lights over the next couple of days as a result of this week’s solar activity. The aurora borealis may be visible further south than normal.
Stargazers below the northern U.S. should look for a diffuse reddish glow as the brightness of the moon may interfere with the sharpness of the colors.
Sources:
BBC News: Solar Flare Eruptions Set to Reach Earth. February 17, 2011
New York Daily News: Biggest Solar Flare in Years set to Blast Earth’s Atmosphere. February 17, 2011
News.com.au: Solar Flare Jams Radio, Satellite Signals. February 17, 2011
NASA
Karen Stephenson - Karen has written for several newspapers and print media in addition to many online publications. She holds a B.A. in English and an ...
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