BY HANNES THUM
Spring is here. Or is it? Should it be simple to say? Perhaps, not.
Let’s start with what happens tomorrow. Thursday, March 19, is the vernal equinox this year, which generally marks the first day of spring in the Northern Hemisphere. The vernal equinox is that beautiful moment that occurs once per year when the sun is lined up directly over Earth’s equator, on its way from the Southern Hemisphere to the Northern Hemisphere.
While the sun has been shining primarily on the Southern Hemisphere for the past six months, we’ve been experiencing both fall and winter, but that all changes tomorrow. From March 19 on through September 22 (which is the autumnal equinox, when the sun crosses the equator heading the other direction), the sun will be over the Northern Hemisphere and us northern folks will experience spring and then summer.
Most people and most calendars state that the vernal equinox marks the first day of spring. So, fair enough. Spring starts tomorrow.
But, is it the most accurate thing to say that spring starts tomorrow? How should the calendar know? Should the changing of the seasons not be dictated by something more natural or more connected to the weather? Something more ecological, perhaps?
It makes me wonder, once again, about the natural time cues that our local environment gives us.
As I write this, only a few stray and wispy snow patches remain on the south face of Carbonate. I have been watching the face melt out and dry out, daily, for weeks now. It certainly seems earlier than normal, this “browning up” of Carbonate. But, it’s something that happens every spring, sooner or later, and it seems to be a turning point for many local human residents—I can see them now, scampering up and down like tiny ants. I even saw one of them go up wearing shorts. Would all those hikers not agree that spring is here, and before March 19?
I have also been searching, daily, with my students for the first buds to show on the aspen and cottonwood trees around our classroom. Maybe we’re a bit early to be looking—they’re not showing themselves yet. But, buds aside, there are some shoots of green grass starting to show themselves from the melted-out yards around town, and I’ve even heard rumor of some gardens in the south valley that have already started to show flowers.
Who’s to say? If you want to believe the calendar and that the tangible, predictable equinox should be the start of spring, fair enough. But I imagine that there are many folks in this valley who measure the changing of the seasons by their own yardsticks.
Maybe the start of spring is when the Big Wood starts to rise and churn with runoff. Maybe it’s when the first kestrel is spotted (one of my favorite yardsticks, although I haven’t seen one with my own eyes yet). Maybe it’s the first day one feels ready to wear shorts outside for a hike after work.
In any case, happy springtime.
Hannes Thum is a Wood River Valley native and has spent most of his life exploring what our local ecosystems have to offer. He currently teaches science at Sun Valley Community School.