Sunday, March 01, 2009

New month, new season

Today is the first of March, which means we’re sliding into autumn. March is roughly the equivalent of September in the Northern Hemisphere.

I grew up hearing the classical names “Vernal Equinox” in March and “Autumnal Equinox” in September, but those terms—with their Northern Hemisphere bias—are now being replaced by the more season and hemisphere neutral terms “March Equinox” and “September Equinox”.

In any event, the astronomical equinoxes mark the point when the sun is directly over the equator (from earth’s perspective) and the day and night are equal. “Equinox” comes from the Latin aequus (equal) and nox (night). The exact moment varies from year to year, but this year the March Equinox will occur at 11:44 UTC on March 20 (00:44—12:44am—March 21 in New Zealand). From then on, the Northern Hemisphere is officially in Spring and we’re officially in autumn.

There are some who claim that New Zealand—by which they really mean Auckland—doesn’t have seasons, which is nonsense, of course. It’s true that Auckland is pretty mild all year (at least by Chicago standards), but there are seasonal variations and even some changing leaves.

English immigrants planted the deciduous tree species they were used to in their homeland, but without frosts in Auckland, the leaf colours aren’t too exciting and make more of a mess than pretty display. New Zealand doesn’t have many native species with leaves that change colour or drop, so Auckland and other regions are green all year (barring droughts, of course).

Fall, however, doesn’t exist in New Zealand: The word is “autumn”. That took me a while to get used to, especially because the old phrase “Spring ahead, Fall back” was such a useful way to remember which way the clocks go. As it happens, New Zealand’s Daylight Savings has been extended and this year won’t end until April 5, after autumn has already begun.

Many places don’t experience seasonal changes—whatever they are—on the Equinox: Some change earlier, some later. We’ll have some nice weather this month before the cooler temperatures start settling in, but the change doesn’t really happen until around the Equinox or later. In Chicago, the changes always started closer to the first day of the Equinox month.

I’ll try and remember to talk a bit more this year about the seasonal changes, since I really haven’t before. But for right now, it’s still summery outside, which is fine with me.


Nik said...

We enjoyed a fine beach today after starting to fear summer was actually DONE. Give us another month or so at least!

d said...

I hear the colors change down in Queenstown, so we are headed down next month to enjoy one of the weekends of the Autumn Festival there. I really miss seeing the colors of Fall!

That's right, Fall. I'm not giving it up just yet. :)

Roger Owen Green said...

It's been snowing from Tennessee to Maine the last couple days. IT'S WINTER!

Arthur Schenck said...

Nik: You probably will get some more beach time yet—past couple days notwithstanding.

D: There are a few places in the North Island where leaves can change (I have no idea if they do) because their climate is right. The trees in Northern Illinois never changed a lot of colours (some), so I don't miss them. Mostly, I definitely don't miss what falls when the leaves are all down, on those cold wintry days.

Roger: THAT is what I definitely don't miss.

Anonymous said...

autumn leaf colours are undoubtedly beautiful...but quite frankly, i can live without them for no frosts!

i'll be coming to NZ from the NW of england, where it is frequently rainy and cold...so you can see where my priorities lie :-)