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NASSAU, BAHAMAS — Today’s autumnal equinox will mark the first day of fall and this astronomical event has a whole lot more to do with the weather and hurricane activity than you may think.
Miami University Professor Emeritus, Dr. Hays Cummins, whose specialty is geography, explained that everything is tied together in the case of solar orbits, seasonal change, and natural disasters.
He spoke to Eyewitness News about how the autumnal equinox works and how it affects The Bahamas in its annual phase.
“The sun would rise and as it tracked across the sky, at its highest point it would be exactly over the equator let’s say you were at the equator, then no shadows would be cast,” Cummins said.
“There’s nowhere in The Bahamas where the sun is going to be on the autumnal equinox.
“The sun will be over 0 degrees latitude and let’s say you’re on San Salvador and the latitude is 25 degrees north. So, what that means is instead of the sun being directly overhead in San Salvador it would be 25 degrees higher on the horizon at local noon.”
Although geographical location plays a major factor in the length of the shadow cast during this seasonal event, the autumnal equinox happens at the same time everywhere. In the northern hemisphere, it will take place at exactly 9.03pm eastern time.
The word equinox describes equal halves of the northern and southern hemispheres receiving the same amount of sunlight, as the solar system’s brightest star aligns with the earth’s equator.
Following this significant shift, the earth, spinning on its axis will begin tilting away from the sun, resulting in shorter days and longer nights until the next major shift in December, the winter solstice.
“That changes where on the earth most of the heat is going, and that’s what makes our seasons. Where the sun’s position is with the earth in the course of a year,” Cummins said.
The movements happen gradually, he said. Day by day, the sun will appear further south after the autumnal equinox.
Cummins explained that as the sun continues shifting southward during the fall and winter, temperatures will drop due to the sun’s distance.
“In the winter, you know, occasionally you get these cold fronts that come through where it cools off a little bit,” he said.
“But that’s all because of the sun, the location where the sun is directly overhead has a huge impact on the Earth’s climate and weather system.”
Hurricane Fiona is now out the way, but weather systems currently continue to form in the Atlantic. Cummins said Fiona and other tropical storms and hurricanes come as a result of the sun having moved north of the equator from the first day of spring.
“The reason we’re getting this is, the hurricane season is, you know, from June through November. It’s that the sun has moved from south of the equator and in our winter and spring to the north of the equator,” he said.
“And now so it’s been north of the equator for six months. And that’s a lot of heat to the Earth’s oceans and the oceans warm up. And that’s the fuel for hurricanes is basically the evacuation of water from the ocean.”
Cummins said: “And so, what will happen is that the oceans gather heat and water can hold heat for a long period of time. And even though the sun’s moving south, the oceans are still warm and the oceans will be warm enough to support hurricane activity through November.”
The Atlantic hurricane season ends on November 30, but the autumnal equinox signals that this stormy period is nearing its end.
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