Saturday, February 19, 2005

A science geek post -- What do I do?

On Friday at work, a state senator from the great state of Wisconsin came through the office. Why did he stop by? Well, primarily, his intern was married to someone who works in the building. But, in my naive view of the world, I believe he was actually interested in the research we are doing. So, on that naivete, I'll try and talk a little bit about what I do, and how our work fits in to something that, you, as the average citizen, can relate.
I'm sure many of you watch TV weather forecasts without thinking much about them. A good looking man or woman stands in front of a blue screen and shows various of weather maps, radar images, and satellites. It's these latter images that I'm generally concerned with at work: satellites. How do they work? What are they good for? How do they help you?
Satellites work by detecting radiation. If you imagine radiation as being a wave, it would have a certain wavelength (the distance from crest to crest), and a frequency (the time that passes between peaks). The wavelength or frequency (they are inversely related) determines the characteristics of that radiation. We often describe radiation as being of a certain wavelength or frequency, such as: Radiation in the Infra-red frequencies, or of visible wavelengths. Whether you use frequency or wavelength depends on the application.
Your eyes also work by detecting radiation. They are sensitive to radiation that is emitted from the sun, often called visible radiation. It is usually reflected, or scattered off of objects on our planet, and that is how you can see them.
Satellites have instruments that are sensitive to visible radiation. Since thick clouds are highly reflective of solar radiation, they can be detected quite well in the satellites, and are useful to a forecaster. They can also be distinguished from thinner clouds which don't scatter radiation quite as well.
Another typical instrument detects radiation in the infra-red (IR).IR radiation has longer wavelengths than visible radiation. It can't be seen, but it can be felt; it's what makes cloudy nights warmer than clear nights, and is one of the reasons cities are warmer than the countryside. It's also the primary radiation of concern for global warming.
Essentially, infra-red radiation depends on an object's temperature. The warmer it is, the more IR radiation it emits. High clouds in the atmosphere are colder than lower clouds, thus emitting less radiation.
So, how do these images help? A forecaster can use these instruments to see how clouds and weather systems are moving right now, and predict how they'll move in the near future. They can use them to detect hurricanes in the middle of the ocean, something which was impossible before they were used. They can also be used to study land features, and land use. All in all, even with these two types of radiation, they are extremely powerful. And there are thousands more wavelengths that are being studied as we speak.
So, what do I do? Well, the people I work with are interested in improving those satellite images. We are using them , and additional to detect all sorts of natural phenomenon, in hopes that they will help a forecaster or just tell us more about the natural world.

I'll keep it that vague at this point so that I don't bore the 2 readers that have made it this far. Please post if something isn't clear, or if you found it interesting. If it is interesting, I'll post more science geek posts in the future, including some more details about my work.

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