Notes from Under Sky

Turn of the Seasons

What tells me the seasons are changing

I live in the Los Angeles area, in the Beach Cities. This means that the leaves don't really turn, and the year-round temperature variation is exceeded by most outdoor swimming pools. It also means that were you to be dropped into Southern California on a random day of the year, in a random place, there'd be no good way for you to tell what season it was.

And yet, when I wake up in the morning, there's something that tells me winter is coming, and all that means. (On one hand, family is gathering. On the other hand, family is gathering…)

Our house is arranged so that the kitchen area faces the south-east. For most of the year, the Sun rises too far north for sunlight to make its way directly into the kitchen. It has to bounce off the dining room wall, or stream in through a narrow crack bounded by a sliding glass door and the roof of the detached garage. (It all sounds much like a troublesome high school geometry problem.)

But for a dozen weeks each year, the Sun's path is far enough south in the sky—its declination is low enough, in other words—for the the rising sunlight to stream in through the kitchen window and illuminate, for instance, the stovetop. It goes through the pretty stained glass window at the top of the breakfast nook, spraying all sorts of blue and green on the opposite wall. And although we've lived here for less than a decade, it's all still enough to evoke memories of the holiday season from even way before that.

Eventually, the Sun's march southward will stop, on the winter solstice—on December 21, this year, for nearly every spot on the globe—and begin its long northward return. Spring will return, the local high will finally climb out of the 60s (!), the kids will smell summer around the corner, …

Long before that, though, the Sun's light will cease to transit my stove top, or send colors against the high wall of the breakfast nook. Those things don't last long. Just a couple of months centered around December 21, a reminder that the solstice used to be celebrated as the middle of winter, not its beginning. There's good reason for the change: the heat capacity of the Earth means that the temperature variation lags the Sun's illumination by several weeks. But our climate is mild, and my house and I still feel the season begin to turn again at the end of the year.

Copyright (c) 2008 Brian Tung