Thawing sweets

Here's a thing that I didn't even know was a thing to wonder about:

You know the sugar maple, which produces the raw material for maple syrup by dripping sap into a bucket in the spring. Well, it turns out that it's not only a case of the sugar maple's sap being particularly sweet and thus well suited for this use. The sugar maple, along with a couple of other trees, are the only ones which drip their sap out in a way that can be usefully collected, and it is also particularly sweet.

The question, or rather questions, are:

Why only a few types of tree?

Why does this only happen during spring thaw, in certain temperature conditions?

How does this happen at all?

Some mathematicians from SFU on the west coast decided to calculate this east coast phenomenon.

Natural distillation

I was out snowshoeing with a friend not long ago, and ate some snow because I was thirsty. My friend made a comment about the "distilled water" taste of snow, and I suddenly realized something that, really, I've known all along—snow effectively is distilled water.

Water distillation involves vaporizing impure water, then condensing the water vapour back to a liquid. In the case of snow, water vapour in the air freezes directly into snowflake form, making them pure—distilled—water.

Raindrops, on the other hand, while they also condense out of the water vapour in the air, absorb other vapours into the drop. There are some things that absorb more easily than others, SO₂ being one of the well known pollutant related compounds that absorbs easily into water, and which makes acid rain. It's a little harder (but not impossible) to dissolve other stuff into solids.

Airplane-induced snow

An airplane made that hole.

Not by just flying through it and swirling the visible cloud out of the way, that makes a different pattern which doesn't last nearly as long.

It turns out that in certain conditions, airplanes can actually induce rain or snow in a localized region of a cloud, and the precipitation is what clears the hole - the water droplets that make up the cloud fall because of the airplane.

How much does a cloud weigh?

I was chatting with a friend not long ago, and he mentioned that he sometimes pictured clouds as these malevolant, multi-ton monstrosities hovering overhead, just waiting to smash down on us tiny humans. And by the way, how much does a cloud actually weigh?

Clearly, this calls for some math: I decided to calculate how much a cloud actually massed.

I started out by finding a cloud that I could measure reasonably well.

Identified Hovering Objects

Just pretty pictures today; the post I had been planning on for today is turning out a bit more complicated than I had figured. This will probably happen again. That's the thing about learning new stuff... it always takes longer than you think it will.

Sao Paolo

Syria

Snow eater

The Chinook wind is a warm dry wind that comes down from the Rocky Mountains into Alberta, and can turn a winter day into short-sleeve weather in the space of hours. But what heats up the air? It wasn’t that warm on the BC side of the rockies, before it crossed the mountain range. Well, I decided that I was going to calculate it. Let's see if this works.

Let’s say the air comes off the ocean at about 10 degrees Centigrade and 90% relative humidity, which isn't actually typical for a dreary Vancouver winter day—but that's because the Chinook is powered by the Pineapple Express, which is warm, wet air coming inland from Hawaii. It travels inland, raining on Vancouver as it goes, until it hits the coast mountain range, and is forced to rise.

You’ve probably noticed, if you’ve ever changed altitude quickly, that it gets colder the higher you are. Well, that wind from the ocean is going to do exactly that.

To do the math, we’ll look at a small piece of the wind, pretend it stays together to simplify things, and follow it over the mountains.