The Nature of Wind

If you look in practically any high school text book, wind is said to arise from solar heating causing an updraft, which results in convective flow. Other mechanisms may be mentioned in passing, but one that's often overlooked entirely is the coriolis effect, or the differential rotation rates at different latitudes on the surface of the planet.

What's truly odd is that this is not some obscure effect that only generates small localized wind patterns in faraway reaches of the Earth. Coriolis-generated wind patterns are some of the largest on the planet. Better known as the Tradewinds, they are directly responsible for trans-oceanic travel by sail. They are also the major component of the weather patterns on Jupiter, Saturn, Neptune, and Uranus. No small thing.

As it turns out, it's also the main driving force of the wind where I live. Wind can either be described as "blowing trades" or "blowing Konas". The former is the predominant wind pattern, whereas the latter is almost always the case when a storm is involved.

All of this makes kite flying wonderfully predictable, if you're in an area of clear air. If it's blowing trades, it's blowing trades. If you're solid at 200' above ground, you'll be solid at 500' above ground. And unless there's a storm brewing that's likely to change things, you'll still be just as solid six hours later.

Oh what a wonderful place to learn to fly kites!

So when I visited the Mainland in December, I brought my KAP rig, my kites, and everything that goes with them. There was even wind! Heaven! But wait a sec... the wind shifts 90 degrees when I'm 300' above ground, and does another shift 200' above that. Then as I'm winding back in, the ground layer shifts 90 degrees and the uppers don't change at all. WHAT?! Then the uppers die, but the lowers are screaming so hard I can't get the kite down. ARGH!

All this tells me that maybe I should've paid more attention to the description in my high school text book!

Of course I'm over-simplifying the winds where I live, and I'm over-complicating the winds on the Mainland. But not by much. We do get convective wind patterns where I live. (Physics doesn't stop working just because you live on an island.) Those, too, are nicely predictable because the updrafts tend to center around recent lava flows where the ground is a wonderful matte black. If it's party cloudy the patterns can get rough because of the patchy sunlight, but the directions are all predictable.

It's less-so where I flew on the Mainland. In the three weeks I was there, I saw wind come from every point of the compass, sometimes all in the same day. I was afraid to leave a kite unattended, even for a few seconds, and wound up with hands on the line the entire time. I still treed my kite twice. It was a whole different kind of flying.

Today I flew a kite for the first time since getting back. It's blowing Konas, so the winds are backward, but they're predictable. No KAP since the wind wasn't consistent enough for me to hook up my rig. But I spent a really pleasant few hours just flying and feeling the wind out.

It's good to be home.

Tom