# Measuring Albedo

In my book, The Tree Rings’ Tale, in addition to sharing the stories of scientists I tried to give young readers examples of science they can do themselves. As a science journalist, I got hooked on weather years ago because the sciency bits connect so nicely to readers’ everyday experience. It’s just one short step, I hope, to teaching young people how they can use the weather as an introduction to the act of measuring and recording their world.

If you live in a snowy place, it’s the perfect time of year for one of the book’s experiments: albedo. From the book:

When the sun comes out after a snowstorm, go out with your shovel and cut a hole in the snow so the sunlight can reach the pavement on a sidewalk or driveway. Watch how the snow warms up the pavement and being melting the surrounding snow. Compare that area to one where there are no holes in the snow. The snow there will melt much more slowly.

To collect data, I recommend a little handheld infrared thermometer.

infrared thermometer

A science teacher friend of mine turned me on to the little gizmos, which he said are one of the best science teaching tools he’s ever run across. You can use them to compare the temperature of the snow to the warming patch of exposed pavement. Again, from the book:

One of the most important effects of albedo on weather happens when snow is covering the ground. Snow is white and reflects 75 to 95 percent of the sun’s light. By comparison, a dry dirt field reflects anywhere from 5 to 20 percent of the sun’s light. That means much more of the sun’s energy is absorbed by the dry field, heating up the ground more.

1. Cool.
Another possibly interesting experiment is to put snow into a beaker in the shade and weigh it at different times. The weight will decrease even though the snow does not melt.

Sublimation in action.

2. Thank you! I was going to wander downtown and see if I could find an infrared thermometer, but wasn’t quite sure what I would be looking for.

3. Dano

I shovel the driveway out into the blacktop street – this little action starts the street melting sooner. A couple neighbors have picked up on this and our street is clear first around here. I guess paying for all those physics classes has finally paid off after all.

:o)

Best,

D