Newest Site in the USDA UV-B Network Completes its First Full Year of Operation

by Forrest M. Mims III

The sunlight monitors installed on the roof of the Moody Science Building at Texas Lutheran University had their first birthday on March 16.

The instruments form the newest monitoring site of the United States Department of Agriculture’s UVB Monitoring and Research Program. The program is directed by Dr. James Slusser of Colorado State University.

One of the instruments measures the ozone and the sun’s ultraviolet light. Another measures the ultraviolet that causes sunburn and can damage plants.

Three other instruments measure the blue and red colors of sunlight that make plants grow. They also measure the colors of light that can be seen by the eyes of animals and people.

Seguin High School senior Lans Martin did a first class science fair project comparing measurements made by one of the TLU instruments with those he made using a much simpler one I developed for Radio Shack. His measurements agreed closely with those made by the TLU instrument.

Last spring the TLU instruments measured reductions in sunlight caused by smoke from fires half way around the world in Southeast Asia. They also measured smoke from Mexico and the US.

These smoke events might not seem very important in the grand scheme of things. But it has recently been learned that smoke particles falling on snow and ice cause both to melt much faster than normal.

Already this year the instruments have measured smoke from Vietnam and dust from China. As this is written, widespread fires in southern Mexico and Central America are pumping large amounts of smoke over the Gulf of Mexico. Some of that smoke should soon be arriving in Central Texas, and the TLU instruments will detect it when it does.

Later this year I hope to find time to write the first of a series of scientific papers about the new TLU instruments. One of the instruments has helped make an important discovery about how clouds reflect sunlight, and that alone will become the subject of a paper.

Last week Bill Durham of Colorado State University arrived at TLU to conduct the first annual servicing of the sunlight instruments. He exchanged two of the instruments with freshly calibrated ones, something that is not often done in networks that measure sunlight.

You can see the data from the TLU instruments on the Internet. Just visit my web site (see below) and click on the USDA tab for details.

Forrest M. Mims III and his science are featured online at www.forrestmims.org.

This feature was originally published in Forrest Mims's weekly science column in the Seguin Gazette-Enterprise, Seguin, Texas. The column is written for a general audience.