Ahhh, Spring is finally in the air! We are about to experience the Vernal, or Spring Equinox. This is the time when the sun makes its transition from South of the Equator into the Northern Hemisphere. The exact time of this is 1:48AM EDT on March 20th.
To understand how this works, lets take a look at a globe. After this look, you will never view the globe the same way again!.
Notice that this, and every other globe is tilted. This is not a defective globe, but a representation of the Earth's axis, which is tilted 23.5 degrees. This tilt is very important when it comes to our weather and our seasons.
When we are tilted away from the sun, at 23.5 degrees, we experience the start of our Winter. When our tilt is towards the sun at 23.5 degrees, we have the start of our Summer.
Now, there are two times during the year when the Earth is perpendicular with the Sun's radiaition (the Sun's radiation hits us at a right angle, or straight on). These times are our Vernal (Spring) and Autumnal (Fall) Equinoxes. Many believe that the Earth is no longer tilted at this point. That is not true, though. The Earth is ALWAYS tilted at 23.5 degrees. Only from the sun's perspective we are not tilted towards or away at this time! These are the Equinoxes. One happens to start Spring, the other to start Fall.
This brings me to my next point. Every year the Storm Team is asked, "Can you balance an egg on it's end during the equinox?" The answer is YES. Keep in mind, however, that you can balance an egg on its end every other day of the year too, even with the 23.5 degree tilt! It just takes gravity, a steady hand, and excellent egg-balancing skills. The equinox will have no bearing on the egg's ability to stand on its end, so you should save the balancing act for your checkbook!
To see why we don't have 12 hours of daylight and 12 hours of darkness on our equinox, see my previous post by clicking here.
Ray Petelin,
WSEE Storm Team Meteorologist