I suppose I should restate that I couldn’t possibly care less which date one chooses for the start of seasons—meteorological or astronomical—however, I’ll continue to use the meteorological dates because the first of the relevant month is always the first, whereas solstices and equinoxes change dates and times with every visit (see the chart above; go to Time and Date dot com for such a chart; I presume it will display your local dates/times). I think most of us find remembering the first of the relevant month is pretty easy to do, and since the weather is so variable until well into each season, picking either date is equally valid if a change in the weather is what we think of (or maybe hope for) at the start of a season: We have pretty much the same chance to be thrilled or disappointed.
Earth’s seasons are mainly determined by axial tilt (also known as obliquity), the degree to which Earth’s axis—what it rotates around—tilts from the plane of its orbit around the sun (usually called the ecliptic plane). Because the earth’s axis tilts in only one direction, that means that at the June Solstice the North Pole is pointed in the direction of the sun, and at the December Solstice its pointed away from the sun. That gives the Northern Hemisphere summer at the June Solstice, and it gives the Southern Hemisphere winter at the same time. At the December Solstice, the seasons are winter and summer, respectively. At each equinox (September and Match) the sun’s apparent position (when viewed from earth) is directly over the equator. So, earth’s wobbly dance around the sun is the reason we have seasons.
However, while it’s absolutely true that the position of the sun relative to the earth’s tilt absolutely influences the weather, it’s not the sole factor. The tilt is why we don’t get blistering hot days in the middle of winter, for example, however, what, specifically, the weather will be during what we call seasons is determined by far more than merely which way the earth’s axis is tilting relative to the ecliptic plane (and so, the latitude the sun appears to be at when viewed from earth). That’s why, for example, we can still get, say, wintry weather in spring.
So, the sun keeps on doing its thing, and the earth’s wobbly circle dance around it will influence the weather we experience, but the sun’s position during earth’s wobbly dance doesn’t, by itself, cause our seasons, nor does it, by itself, determine our weather. Instead, it’s a complicated stew made up of the sun’s position, jet-stream patterns, ocean surface temperatures, and so much more that actually determines what weather we experience, regardless of the official season or what date we choose to mark its beginning.
Because of that complicated reality, I was surprised on September 1 when I read an incredibly odd piece on The Spinoff titled, “Breaking news: It’s still winter”. The author admits that, “we all have those pet peeves we allow to wind us up for no reason,” and her anti-meteorological seasons bias seems to be one of them. Her adamant, absolutist, dare I say, evangelical fervour for astronomical seasons struck me as, well, odd.
I couldn’t easily tell if she was being serious or just trying to tease people, but, either way, I thought the article was silly. She argues that astronomical dates (or astrological, if you prefer) are the only “correct” determiners of the start of seasons, but then makes the same mistake she accuses the meteorological date folks of making: Assuming the weather changes on a given date, when seasons don’t do that—as literally everyone knows. Still, if it makes her happy to stick to solstices and equinoxes, then good for her, but there have got to be far more important things to be rigidly dogmatics about, right?
As it happens. On September 1, I opened up the windows in my house and turned off the heat pump in my bedroom because the weather was so gloriously, well, springlike. I did the same ting the next day, too. On Wednesday, it was at least partly windy and rainy, so the windows remained closed, and that night I needed to turn the heat on again. On Thursday, the windows were open again and I got a load of laundry washed and dried, and the dishwasher was run, all using only solar power. That, and my hot water cylinder was fully heated using solar power on all those open window days.
I’ve had several more days with the windows open, and yesterday I ran the dishwasher and washed and dried three loads of laundry using free electricity from my solar panels. That’s pretty spring-like for a time of year some insist is still winter.
Still, whether Sunday, September first was or was not the “real” start of Spring is—despite what some (apparently) may passionately believe—beside the point. Transition from one season to another is a process, not an event, and the date we pick to mark the start of the journey from one season to the next is pretty unimportant. Still, for me, Sunday, September 1 was absolutely the most Spring-like day yet this year’s edition. If some people have pet peeves around such seasonal beginnings, well, quite frankly that’s about them, not me. I’ll just open the windows, do more loads of washing, and not care in the least whether anyone joins me in beginning seasons at the meteorological start or not.
I’m just glad for nice weather whatever time we get it, and the lengthening days are awesome. So is having hot water and not having to pay to have it.
No comments:
Post a Comment