Fun with Aureoles and Aerosols

Earth Science Picture of the Day (EPOD) recently ran a series of photos that illustrates nicely the impact that small airborne particles called aerosols can have on light.

As EPOD notes, the size of an aureole — the halo-like circle that appears around the sun when viewed through a haze or mist — depends on the amount of aerosol in the air. More aerosols mean more light is scattered, which produces larger aureole). Since most aerosols are concentrated near Earth's surface, the aureole at sea level appears much larger than it would high on a mountain peak. You can try this experiment yourself to get a sense of the aerosol load in the air you're breathing.

Aerosols are a major preoccupation for climate scientists as the particles—including dust, ash, sea salt, soot, and industrial pollutants—can scatter light and affect Earth's energy balance. Infusions of ash and sulfate from volcanic eruptions, for example, are capable of cooling global temperatures by 0.3 degrees Celsius. Likewise, sulfate aerosols from factories and power plants can mask global warming somewhat and are often bandied around as possible components of geoengineering schemes.

more

http://blogs.nasa.gov/cm/blog/whatonearth/posts/post_1272658076861.html

never mind.

:)

for my climate and meteorology classes (it's the sort of thing that will fit nicely in our equipment budget... :))

but the field trip to 10,000 feet might be a bit pricey.

Here in the desert at my own 6000 foot level, the sky directly above is a deep blue. On the mountain to the east, at nearly 11,000 feet, the sky darkens to a dark indigo directly overhead. Since this is the desert, the aureoles are small at both levels, although dependent on the angle of the sun and whether or not the wind is tossing grit into the air.

I'm thinking different sun angles, and different days with varying weather conditions. I'm always looking for an excuse to leave the classroom and walk around for a bit...