Rainbows and Weather

by / Friday, 25 February 2011 / Published in Blog - Space Log

Have you ever woken up after a stormy night to see a beautiful rainbow stretched across the sky? When the Sun shines on droplets of moisture in the Earth’s atmosphere, it causes us to see a rainbow. These colorful arcs are unusual and remarkable things. Did you know that rainbows caused by sunlight always appear in the section of sky directly opposite from the sun?

Scientists have recently discovered that rainbows could help them to learn more about particles in the air called aerosols which have huge effects on our climate. There are all different kinds of aerosols: small, big, non-spherical, ice particles, and cloud droplets. The way that NASA scientists figure out which kind is present is by using a method called polarization.

Sometimes the reflected light from the Sun is so bright, rainbows just aren’t visible. But thisdoesn’t mean that they aren’t there. Using polarization, scientists can view the sky and actually see a rainbow, in order to measure it. Measuring rainbows can help them to learn exactly how big the water droplets are and how close they are together. Understanding these things will help scientists to better understand how clouds form in the first place and clouds are the building blocks of our weather.