While rotating the earth in its orbit, the moon bypasses the sun and the shadow of our natural satellite shades on the sun – that's what we know as the solar eclipse. While a total solar eclipse is not that uncommon a phenomenon as it takes place every 18 months, the Great American Eclipse of August 2017 was particularly special because it was visible to a large population on Earth. Along with some of the most stunning celestial pictures ever, this eclipse opened the horizon for some astonishing new observations, including a never-seen-before phenomenon – "bow waves."
Researchers from Norway's University of Tromso and Haystack Observatory of MIT followed and analyzed mysterious impacts of the eclipse on earth's atmosphere and they discovered something astonishing - atmospheric "bow waves," such as the outlying waves, which occur during a ship's wake. The scientists made use of 2,000 sensors to receive the satellite data. The theorized behavior was so insignificant that it was never detected earlier.
These findings are significant because it "reveals complex interconnections between the Sun, Moon, and Earth's neutral atmosphere and ionosphere, and (it) demonstrates persistent coupling processes between different components of the Earth's atmosphere, a topic of significant community interest," stated the study, published in the Geophysical Research Letters.
"We were looking at some phenomena that were expected but never had the chance to be observed. That was the surprise we found... we had a large coverage and our system is sensitive enough to be able to see these smaller variations. That was really very interesting to us," one of the authors of the study MIT Haystack Observatory's Shun-Rong Zhang told Gizmodo.
Sun's heat supplies earth's energy. So, when the moon passes by the sun it causes a considerable amount of decrease in that energy in the area where the shadow casts. When the shadow moves, it transports quite fast and creates these bow waves in Earth's atmosphere. Bow waves created by solar eclipses were too tiny to be detected until the August solar eclipse happened.
Previous attempts at spotting these waves never bore any fruit, as enough amount of data could not be gathered until the August 21 solar eclipse. With the help of the 2,000 sensors, positioned all across America, this time scientists were able to collect as much information as needed.
These sensors spotted the changes in the ionosphere surrounding the Earth.
However, there is nothing to worry about these bow waves, as they are not as severe as that of the solar weather, which is capable of damaging earth's entire communication system, stated researcher Zhang.
Earth's atmosphere is quite complex and contains both neutral and charged. Scientists are continuously trying to comprehend the nature of it and get to the roots of several unsolved mysteries. Detecting and observing the bow waves would open new avenues for further research.