On September 18, 1941, the Brooklyn Dodgers were in Pittsburgh to play the Pirates. With the game tied 0-0 in the fourth inning, announcer Red Barber’s radio broadcast was interrupted and listeners suffered 15 minutes of silence. When the broadcast resumed, the Pirates had scored four points. In a close World Series race, Dodgers fans were furious and called radio stations to complain.
Thousands of baseball fans were experiencing the real effects on Earth’s atmosphere of a geomagnetic storm that began with a plasma eruption on the surface of the sun 93 million miles away. However, even excuses such as sunspots and magnetic disturbances did not quell the frustration of Dodgers fans who saw their team lose 5-6 to the Pirates. Nor was there the spectacular red, purple and green light show that lit up the skies from Maine to Florida. Aurora lights and wireless communication power outages are just some of the effects we experience from this phenomenon called space weather.
Sun and Earth interaction
Our sun is a giant ball of gas and plasma that is stirred on its visible surface, much like water boiling in a pot. This rotational motion creates complex magnetic fields that can produce sunspots, areas that are slightly cooler than the sun’s surroundings. These regions of high magnetic activity can also cause solar flares, which are huge explosions that release electromagnetic energy such as radio waves, X-rays, and ultraviolet light into space. The Sun can also eject parts of itself, a phenomenon called coronal mass ejection, and that material can head toward Earth.
The Sun and Earth are constantly interacting. The sun gives us warmth and light, and the earth’s magnetic field protects us from the sun’s more dangerous radiation. But extreme events on the Sun can cause space weather, which can cause major disruptions to the bubble around Earth, which is dominated by Earth’s magnetic field.
On September 10, 1941, a group of sunspots formed near the eastern edge of the Sun and slowly orbited with the Sun until it headed toward Earth. The sunspots were so large that they were visible with just the naked eye (protect your eyes, of course!). These observations led scientists to warn wireless carriers that major disruptions could occur in the coming weeks. A week later, on September 17, scientists observed a solar flare, and less than a day later they reported the arrival of a coronal mass ejection, causing a massive magnetic storm on Earth.
Impact on the Earth
Space weather is always with us, most notably the aurora borealis around the North and South Poles. However, as we become more dependent on electrical systems and electronic devices, we become more vulnerable to what is happening in Earth’s atmosphere and in space.
When material from the Sun approaches Earth, it is pulled along Earth’s magnetic field, causing plasma and charged particles to converge toward the north and south poles. That light and matter interact in Earth’s upper atmosphere, creating an extravagant light show. The aurora borealis is usually only seen near the poles, but the September 1941 storm was so large that people across much of Canada and the United States witnessed the aurora lights. Space weather can also cause power outages. This occurs when geomagnetic activity causes changes in the electric field within the Earth’s crust. Although no power outages were reported in 1941, power companies experienced fluctuations in voltage on power lines as a result of this storm.
The first professional baseball game was shown on television in 1939, but in 1941 fewer than 10,000 households still had a television set. Most Americans still relied on radio to keep up with their favorite baseball teams. Radio used the upper ionosphere of the Earth’s atmosphere as a reflector. Solar activity, such as flares and coronal mass ejections, destroys the reflective layer and causes radio waves to fade out.
predict space weather
The effects of the 1941 storm were minor compared to what could occur with larger geomagnetic storms. Currently, the Space Weather Prediction Center (SWPC) is responsible for monitoring and predicting disturbances in Earth’s space environment and magnetic field. SWPC uses a series of solar observation satellites in space to collect data on the sun’s activity and predict its potential impacts on Earth.
Many organizations rely on SWPC predictions to protect people and equipment. Strong solar storms increase the likelihood that astronauts aboard the International Space Station (ISS) will be exposed to harmful radiation. NASA is monitoring potential radiation exposure and could direct astronauts to hide in areas better shielded from radiation within her ISS. The Federal Aviation Administration (FAA) is monitoring the potential loss of radio communications for commercial aircraft on routes close to the poles. You can instruct the pilot to change the flight if necessary. Space weather can interfere with satellite operations in space, damaging solar panels and degrading electronic equipment. When a geomagnetic storm is predicted, it can alert satellite operators to put their satellites in “safe mode” to avoid the worst potential damage to their systems.
As we become more dependent on space-age technology, the ability to understand and predict space weather will become even more important.