1 October, 2003

UV light

Well today was very sunny and warm. We took a walk out to the other side of the helicopter pad around Ob hill. There is a tiny glacier that "talks" as it warms and cools. While we were waiting I took a picture of the next plane coming in. It first made a pass on the runway and then headed off into the distance. I thought it was not going to land. But later it turned around the opposite way for a perfect landing.

We have to be careful of sunburn now. Not only because the sun is out but also because the ozone above us is gone. In Antarctica there is a large portion of the sky that has no ozone molecules in it because the chlorine (which our refrigerators released long ago) has attacked it during the last month. This is what we have measured, the destruction of the ozone, we actually count the ozone molecules as the balloon goes up through the atmosphere. And there are not very many left right now. We collected the data that proves this.

This means that the ultraviolet light from the sun can reach the surface of the earth here. Normally the ozone molecules will absorb them. Without the ozone, our faces now are subject to direct UV. Welders know exactly what this feels like. Without protection the light from an arc welder emits UV and burns a welder's face. Perhaps you have seen their funny tan marks when they take off their goggles. Tanning salons are simply large sources of UV light which people absorb by their skin. These salons have to carefully regulate the intensity and duration of exposure so that a person is not burned. I attach a picture of a UV meter used for this that I brought with me here. When I first arrived we had zero UV light, but now as you can see the number has risen.

UV light is very dangerous. The funny tan could easily be a severe burn that can develop into skin cancer. In Argentina and New Zealand, which are close to the Antarctic ozone hole, the weather forecast includes the UV index so people know whether to cover up. It is thought that UV can cause DNA changes in sea life too. Had the United States not stopped producing CFC's, it is likely that the entire earth would have no ozone protection. This would mean that everyday you would have to completely cover your skin. Imagine having to wear a hat and gloves and skin cream all the time.

So why do we only have an ozone hole in the Antarctic? Why not up north? Stay tuned.

I am only briefly exposed to the UV light, later I cover up my face. You can tell things have really warmed up.

UV Beads change color when any ultraviolet light is present.

Another plane arriving with Discovery in the background.

A UVB meter measures a portion of UV light that is parcticularly dangerous to humans. The meter was reading zero just a month ago.

Go to this website to find out how much UV light is hitting your area: http://jwocky.gsfc.nasa.gov/news/press_release_2003.html. The ozone hole you see here is the second largest on record.