1:30 PM | *The next “Great American" Total Solar Eclipse now just 4 years away*
Paul Dorian
The next total solar eclipse in the US will be April 8th, 2024. Image credit NASA
Overview
It was just a few years ago when the nation went crazy for the first coast-to-coast total solar eclipse on US soil since 1918 and it provided a great opportunity for scientists and sky observers. What became known as “The Great American Solar Eclipse” took place on August 21st, 2017 when the moon passed between the sun and earth resulting in a 67-mile wide shadow that crossed the country from Oregon-to-South Carolina. If you happened to miss the last total solar eclipse or if it was cloudy in your part of the country then you’ll be happy to know there will be another opportunity exactly 4 years from today.
The “totality zone” path for the 2024 total solar eclipse will extend from Texas to northern New England. Map courtesy AccuWeather
Looking ahead to the 2024 total solar eclipse
The next “Great American” total solar eclipse is now just 4 years away as it’ll take place on April 8th, 2024. While the last total solar eclipse was visible on a path from Oregon-to-South Carolina, this next one in 2024 will extend from Texas to northern New England. Some of the cities that will be in the “totality zone” for the April 2024 eclipse include Buffalo, Cleveland, Indianapolis, Little Rock and Dallas. And if you happen to live in southern Illinois or southeastern Missouri then you will be lucky enough to be in the “totality zone” for a second time during the upcoming April 2024 event. In terms of cloud cover from a climatological point-of-view, the odds are certainly better to the south and west on this path and less favorable to the north and east.
Climatological cloud cover for the US in early April shows more favorable conditions to the south and west and less favorable to the north and east in the “totality zone” path. Map courtesy NOAA, ERA
Looking back and some findings from the 2017 total solar eclipse
The total solar eclipse of 2017 provided a rare opportunity to gather information for many scientific disciplines including solar dynamics, heliophysics and atmospheric science. For example, this was a great chance to study the sun’s wispy outer atmosphere called the corona as its overwhelming brightness usually drowns out the faint corona and not even a 99 percent eclipse will reveal the sun’s corona. Temperatures in the corona can reach 1 million °C, making the region much hotter than the solar surface, which is “just” 6,000°C or so. How the corona gets so hot has puzzled scientists for decades and solar scientists continue to analyze data from the 2017 event.
The “totality zone” in August 2017 extended from Oregon-to-South Carolina.
In one project, the National Solar Observatory deployed 68 small telescopes to amateur astronomers across the path of the eclipse so that at all times at least one telescope was in the shadow looking at the sun’s corona. This resulted in a ton of data with more than 45,000 images and plenty left to analyze in months and years to come. One of the early findings was somewhat of a surprise as there are indications of a more complex interaction than previously thought between the “cold” lower atmosphere of the sun known as the chromosphere and the hot outer atmosphere layer (corona). A relatively narrow area called the transition region separates the corona from the chromosphere. Temperatures rise sharply in the transition region, from thousands of degrees in the chromosphere to more than a million degrees in the corona. The density of plasma falls rapidly through the transition region moving upward from the chromosphere to the corona.
Another area of particular interest to atmospheric scientists was how the total solar eclipse would affect the ionosphere which is the barrier region between the atmosphere and what we think of as outer space. It is in the ionosphere where auroras occur and where the International Space Station and low Earth orbit satellites are found. The ionosphere is affected by radiation from the sun above and by weather systems below. The eclipse gave researchers the chance to study what happens to the ionosphere when solar radiation drops suddenly, as opposed to the gradual changes of the day-night cycle. In essence, a total solar eclipse essentially creates a “hole” in the ionosphere and most models predicted beforehand that this would allow radio waves to travel much farther and faster than usual. As it turns out, preliminary findings from the 2017 total solar eclipse suggest the models are correct in their predictions. Finally, in many regions, scientists meticulously mapped responses by the atmosphere to the total eclipse by measuring ambient temperature, humidity, winds and changes in carbon dioxide. There were several teams that launched numerous weather balloons to take measurements from the surface to way up in the atmosphere around 100,000 feet high and this data is still under analysis today.
Meteorologist Paul Dorian
Perspecta, Inc.
perspectaweather.com
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For a video discussion on the August 2017 “Great American” Total Solar Eclipse visit out “Meteorology 101” page.