20 June 2013 Quick- What’s a Pyranometer?

Don’t know? You can get an idea if you go to the trusty (usually trusty) word root method. We could take this a few places. In Greek mythology, Pyrrah was the daughter of Pandora (you know, the one with the box that got opened.) Pyro we associate with fire – pyrotechnics as in fireworks, pyromaniac as in someone associated with fire.

How are Pyrrah and pyro associated? Well, the Latin work pyrrhus means red or flame colored. Pyrrah had red hair so the story goes. Back to the subject Pyranometer. If you speculated that it must have something to do with fire you were on track. Heat, radiation of the sun to be specific. A pyranometer measures the power of electromagnetic radiation from the sun. In other words, how much heat and light from the sun is coming down on the surface that you are measuring. They are also referred to as solarimeters.

As you probably have guessed by now, there is one of these at Palmer Station. It calculates this radiation in watts per square meter and is sensitive to infrared, visible and UV radiation. Remember the spectrum of wavelengths? About 90% of solar energy is concentrated in these three I just listed.

A short history lesson to make you smarter

A pyranometer is considered to be a type of actinometer. What? Well, an actinometer is something that is used to measure the number of photons in a beam of radiated wavelength, its heating power. You mostly associate this with measuring ultraviolet and visible wavelength ranges like I mentioned before. It can be a physical device or a chemical system. Any guesses when it was invented? 2000s? 1900s? Nope, 1825, seriously, by John Herschel. And speaking of word roots, actin or action- can be a word root for radiation/radioactivity or a radial structure, like tentacles in a sea star. You might be more familiar with it as the protein associated with muscle movements. But we are way off topic now, so a quick word on John Herschel. He was one of those amazig multi-talented scientists who made great strides in astronomy, mathematics, botany, chemistry, even early photography!

Your Challenge

Below is a picture of a pyranometer graph. It is a measurement of the sun’s radiation on Logan, Utah on June 21st of last year. My challenge to you is to draw a graph of what you think Palmer Station’s pyranometer will look like tomorrow at high noon. I’ll post it on tomorrow’s blog. Good Luck!!