The cool and comfortable afternoon air, the cool and crisp nights, pumpkin spice and apple cider all conjure up images of autumn. It is that time of year again. Astronomically and meteorologically it is the Autumnal Equinox, which means that there is no tilt to the earth. If you’ll recall, summer is when one hemisphere is tilted toward the sun and winter is when that hemisphere is tilted away from the sun. Also recall that the days are longer in summer and shorter in winter. With the fall and spring equinoxes, we have roughly twelve hours of daylight and twelve hours of night.
Beyond meteorology, here are some fun facts about the season. Did you know that the British generally use the term “Autumn” while North Americans use the term “Fall” to refer to the falling of the leaves. This time of the year is generally better for viewing the aurora borealis, better known as the “northern lights”. Since the earth is made up of a northern hemisphere and a southern hemisphere, each hemisphere has the reverse seasons, so as the northern hemisphere is cooling off and welcoming Fall, the southern hemisphere is warming up and welcoming spring.
Fall is also peak time for many species of birds to fly to more hospitable climates. The Arctic tern’s journey is 11,000 miles each way annually to reach its migrating location. The Autumnal equinox date is not set, in can shift by a couple of days. This year it is the 22nd, next year, it will be the 23rd.