Solar Eclipse Make Waves Invisibly Ripple Through Earth’s Upper Atmosphere.
When the solar eclipse swept the USA Continental in August, sculpted a subtle but remarkable path through our atmosphere.
For the first time, the researchers confirmed that the shadow of the moon generates a pair of prow waves in the Earth’s ionosphere, similar to the wake a ship leaves while traveling through water. The waves are caused by the sudden fall and rebound in the incoming energy of the sun, and they extend through the atmosphere in front of and behind the shadow. Bow waves are actually a fairly common phenomenon in nature; for a particularly dazzling example, check out the bow waves made by this runaway star.
In this case, it was not a physical object that pushed the air aside and created a wave, it was a gradient of energy. If you have ever been present in a solar eclipse, you probably noticed a chill as the sun disappeared. This is because the Sun’s rays were momentarily blocked, creating a drop in insolation or the amount of solar radiation reaching an area.The lapse leaves a mark in the ionosphere, a region of our atmosphere that begins at about 37 miles high and is filled with charged particles or ions.
It has been theorized that waves have existed for decades, but scientists do not have equipment sensitive enough to confirm their predictions. This time, however, they were ready. Using a network of approximately 2,000 satellite navigation receivers already stationed throughout the country, the researchers isolated the small perturbation of random fluctuations in the atmosphere.
They detected changes in the content of electrons in the ionosphere (waves of the bow) that lasted about an hour and traveled at the same speed as the shadow of the moon on Earth, they write in a research published this month in Geophysical Research Letters.
They are not very energetic, so they pose no danger to us here on the ground, and they probably do not have much effect on the general atmosphere. Finally, observing the bow wave should give researchers a better idea of how the ionosphere behaves, and how it interacts with the rest of the atmosphere. Along with general relativity tests and ideas about the Sun’s corona, it is just one more way that scientists could use the eclipse to perform unique investigations.