What are solar flares and how does NOAA predict them?


Solar flares are sudden bursts of energy and light from sunspots — the dark spots on the sun that have increased magnetic activity. During a flare, sunspots release energy-emitting particles (photons) that travel at the speed of light to the Earth’s upper atmosphere — 93 million miles away — in just eight minutes.

When these bursts of energy reach the Earth, they can interfere with the operation and use of critical satellites, such as the global positioning system (GPS). For example, they can distort or disrupt GPS radio signals, skewing reported positions by as much as half a football field. These inaccuracies can cause disruptions in transportation, agriculture, military and airline operations, banking transactions, navigation, disaster forecasting and warnings, telecommunications, and other critical functions that rely on GPS accuracy. 

Solar flares and other solar disturbances can also disrupt space and aircraft operations, cause widespread power outages and affect cell phone and radio transmissions.

NOAA scientists currently use NASA’s Solar and Heliospheric Observatory’s Extreme Ultraviolet Imaging Telescope  to forecast solar flares. This telescope locates active solar flare regions by taking images of the sun. Larger and more complex active regions are more likely to produce a flare, so forecasters look closely at each active region in order to make their predictions. 

Recently, NOAA scientist Alysha Reinard and her colleagues have found a more reliable way to predict solar flares. The new method uses a system of instruments called the Global Oscillation Network Group (GONG). By using GONG, scientists can look below the surface of the sun to detect the changes in twisting magnetic fields — the more twisting that occurs, the more likely it is that the active region will produce a solar flare.

The new system is already twice as accurate as current methods; according to the scientists, the accuracy of solar flare forecasts is only expected to improve over the next few years. Their goal is to use the new GONG technique to forecast watches and warnings for the next solar maximum predicted to occur in 2013. During solar maximum, which occurs about every 11 years, all solar activity increases dramatically, including solar flares.   

You can learn more about solar flares by visiting NOAA’s Space Weather Prediction Center at:

This month’s expert: Alysha Reinard, NOAA’s Space Weather Prediction Center. Researched and edited by Kimberly Sarmuksnis, NOAA Communications & External Affairs.

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