Welcome to spring! Today is the vernal equinox (aka spring equinox) officially distinguishing March 20, 2015 as the first day of spring. But is it really the first day of spring?

Equinox, Equilux… What?!?!

Let’s back up for a moment. Last September I took a look at the autumnal equinox (aka fall equinox):

[The autumnal equinox is] a bittersweet transition from summer’s generative forces to hibernal barrenness. Metaphorically at least… (Essex on Lake Champlain)

It turns out that much of the fanfare around the fall equinox is anecdotal. Even the science is broadly misconstrued. Part of the trouble is that cool sounding (but pesky) word equinox.

The word itself has several related definitions. The oldest meaning is the day when daytime and night are of approximately equal duration. The word equinox comes from this definition, derived from the Latin aequus (equal) and nox (night). The equinox is not exactly the same as the day when period of daytime and night are of equal length for two reasons. Firstly, sunrise, which begins daytime, occurs when the top of the Sun’s disk rises above the eastern horizon. At that instant, the disk’s center is still below the horizon. Secondly, Earth’s atmosphere refracts sunlight. As a result, an observer sees daylight before the first glimpse of the Sun’s disk above the horizon. To avoid this ambiguity, the word equilux is sometimes used to mean a day on which the periods of daylight and night are equal. (Wikipedia)

Confused? Aggravated? Don’t be. Let’s not get tangled up. Not yet. Let’s see what the astronomers think about the spring equinox.

Astronomically Speaking

Astronomically speaking, the March equinox occurs when the Sun crosses the celestial equator on its way north along the ecliptic. In the Northern Hemisphere, the March equinox is known as the vernal, or spring, equinox, and marks the start of the spring season. (Almanac.com)

Simple. Straightforward. For a fleeting moment each spring (and each autumn) the earth’s orbit is perfectly vertical, not tilting toward or away from the sun. Theoretically the duration of daylight is the same everywhere around the world. And theoretically that fleeting moment of straight up and down terrestrial orbit marks the threshold from winter to spring. Right?

Not so quick. Let’s check what the meteorologists think about the spring equinox.

Meteorologically speaking

Meteorologically speaking… in the Northern Hemisphere the official spring season always begins on March 1 and continues through May 31. Summer begins on June 1; autumn, September 1; and winter, December 1. (Almanac.com)

In other words, the spring equinox is an overly precise pinpoint on a longer, more gradual process of transition from winter meteorological conditions to spring and summer conditions. And while this contradiction seems confusing, it really isn’t at all. After all, everyone I bump into around town has been commenting on the finicky weather. For those of us who have the good fortune of living year round in Essex we know that it takes a goodly while for the weather to make up its mind that winter is really over and spring is here. Early snow drops and late snowfalls vie for the upper hand, and we are buffeted by their scuffles. Soon, we know, the tension will resolve and crocus and daffodils will follow the snow drops.

Spring Equinox + Solar Eclipse + Supermoon

While winter and spring are wrestling for dominance, there’s another twist to our 2015 spring equinox. In addition to the first day of spring, today also afforded some geographically favored folks a chance to witness another astronomical event early this morning, a solar eclipse.

The total eclipse will not be visible anywhere in the USA and will be seen only by folks on some rather remote islands in far northern Europe Friday morning. Residents of the Danish-owned Faroe Islands and the sparsely inhabited Norwegian island group of Svalbard will be the only lucky ones to see the full spectacle. A partial solar eclipse will be visible across all of Europe, northern Africa and much of northern Asia… (USAToday.com)

And if that’s not impressive enough, today is actually an astronomical “triple header.” In addition to the spring equinox and the solar eclipse, if weather permits (unfortunately cloudy forecasts do not bode well) this evening you’ll be able to enjoy a supermoon (sometimes also referred to as a perigee moon).

The Supermoon is a full or new moon that occurs during the moon’s closest approach to Earth on its elliptical orbit… It’s when a full or new moon coincides with perigee — the moon’s closest point to Earth in its orbit. Basically, the moon will appear a bit bigger and brighter than usual in the night sky. (USAToday.com)

Hopefully the overcast and possibly inclement weather will clear up at or before supper time and we can all wander out to watch the superman reflecting across the frozen lake.

Foggy, Groggy Spring Equinox

If all this talk of the spring equinox has failed to excite you about warmer, sunnier days ahead, then perhaps you’ll enjoy revisiting Judith Dow Moore’s poem, “Forced March,” which we published last spring. She opens with Old Spring awakening “in all her glorious squalor” amid the “fog, dank and chill.” Her reference to the ice rotting on the lake seems especially appropriate today. I’ll close with Moore’s final stanzas in which she captured with documentary accuracy the grumpy mood some are feeling despite their optimism that spring will return soon.

“Equinox? Now?” she groans, recalling with a wince
October’s drunken red and orange riot
“Just look at all that slithery mud.
Why me to clean it up? Those noisy birds can do it.

I’ll sleep another week or two. It’s only March.
Some extra rest will make me April lovely.” (Essex on Lake Champlain)

Here’s to all feeling April lovely soon!

Related articles

• Trio of Celestial Events Set for Friday (eastidahonews.com)
• Fall Equinox (www.essexonlakechamplain.com)
• Forced March (www.essexonlakechamplain.com)
• Trio of Celestial Events Set for Friday (abcnews.go.com)
• Freaky Friday: Solar eclipse, Supermoon, spring equinox (usatoday.com)