Space weather
When storms in outer space occur near Earth or in Earth's upper atmosphere, we call it space weather. Rather than the more commonly known weather within our atmosphere (rain, snow, heat, wind, etc.), space weather comes in the form of radio blackouts, solar radiation storms, and geomagnetic storms caused by disturbances from the Sun.
NOAA's Space Weather Prediction Center (SWPC) is the official source for space weather forecasts for our nation. They forecast solar storms, much like our National Weather Service offices forecast weather here on Earth. SWPC forecasters use ground-based instruments and satellites to monitor the active regions of the Sun for any changes and issue watches, warnings, and alerts for hazardous space weather events. Just like there are categories used to classify hurricanes, there are also Space Weather Scales for communicating the severity of solar storms. To predict these storms, forecasters watch the Sun for solar flares and coronal mass ejections. Solar flares are massive explosions on the Sun's surface. They often arise near sunspots and release a wide spectrum of photons such as X-Rays, visible light, and ultra-violet light, as well as highly energized protons outward into space. The biggest solar storms arise from coronal mass ejections (CME). A CME is an enormous bubble of plasma expelled by the Sun; it contains billions of tons of fast-moving solar particles as well as the magnetic field that binds them. The velocity of a CME can even exceed 5 million miles per hour!
Earth's magnetic field helps to protect us from the effects of some solar storms, but how can space weather impact the Earth? Strong solar storms can cause fluctuations of electrical currents in space and energize electrons and protons trapped in Earth's varying magnetic field. These disturbances can cause problems with radio communications, Global Positioning Systems (GPS), power grids, and satellites. Imagine all the ways in which we are dependent upon satellites: cell phones, weather prediction, TV, search and rescue, navigation, space travel, military surveillance, credit card and ATM transactions, and more. What if those satellites were damaged? As we become more dependent on technology, the need for space weather monitoring and forecasting becomes more important.
They say every storm cloud has a silver lining. In the case of space weather, that lining is the aurora, commonly known as the Northern or Southern Lights. When electrons and protons around Earth are energized by solar disturbances, they can follow Earth’s magnetic field toward the North and South magnetic poles where they collide with atmospheric molecules, energizing them and causing them to glow. The colors that result depend on the types of nearby atmospheric gases and are most commonly a brilliant yellow-green color.
EDUCATION CONNECTION
To address student's questions, educators can use the background information, multimedia, and career profiles. The lessons and activities link the physical science concepts of the electromagnetic spectrum, Earth-Sun relationships, and energy to the engaging topic of space weather. During space weather events students can also track auroras, space weather alerts, solar wind, and satellite imagery of the Sun using the data resources.
Adapted from materials provided by AMNH Science Bulletinsoffsite link and NOAAWatch Space Weather.Last updated: 4/28/2015.