Noaa's South Pole Ozone Update Oct 1, 2012

NARRATOR: As the sun rises over the South Pole in September, it provides a spark of energy for chemistry that eats away at the ozone layer. DR SCHNELL: It's amazing, it's one of the biggest, fastest chemical reactions in the world driven by sunlight. Very high concentrations of ozone in the stratosphere are reduced by half. Within a month, they go to zero in a certain layer of the atmosphere. The ozone layer is so important in protecting us from ultraviolet radiation. If you remove just a small percentage of the ozone around the world, you're going to affect plant life, you're going to cause cancer increases, you're going to affect plankton formation in the oceans. DR PETROPAVLOVSKIKH: So for the ozone hole to form, we need several conditions. We need very cold temperatures, which is what's happening during the wintertime over Antarctica. And those very, very cold temperatures, as low as low as about minus 109 Fahrenheit, they create these special clouds that are called polar stratospheric clouds. These clouds contain small particles, ice crystals, and on the surface of these particles, there is some special chemistry that happens. All of these manmade chemicals that we produce, chlorofluorocarbons, for example, they become activated And with the sunlight, these chemicals become very active and they start to destroy ozone. NARRATOR: The fast, high-altitude winds of the seasonal Antarctic vortex create the perfect environment for those manmade chemicals to destroy ozone. DR SCHNELL: It's like putting a match match in this thousands square mile pool of high volatile gasoline... Wheew. It's gone. Just like that. In 2012 so far, about 20 megatons of ozone have been destroyed. That's about the weight of three Hoover Dams. 2006 was worse. That year, ozone loss totaled 40 megatons, or six Hoover Dams. DR JOHNSON: There's two ways that we measure ozone at the South Pole. One is with ballon-borne ozonesondes, that's what I'm involved with, and then there's also a ground-based instrument that looks up at the sun and moon as well, to get total column ozone. And that's called the Dobson spectrophotometer. NOAA has been measuring ozone with a Dobson spectrophotometer for about 50 years now and the ozonesondes, the ballon-borne ozonesondes, for 25 years, a little more. These balloonsondes go about 10 mph up through the atmosphere. They'll reach about 21 miles altitude and during that two-hour period, they're sending back ozone data at one line every every second or one point every second. NARRATOR: Levels of ozone-depleting chemicals in the atmosphere have plummeted but they can last decades. NOAA's ozone measurements in the Antarctic spring help us understand ozone depletion where it is the most severe and where we could detect signs of early recovery in the next few decades. In 2011, similar conditions formed over the Arctic in the Northern Hemisphere. That year, ozone-depleting conditions persisted much longer than usual up north, and the stratosphere was very cold. SCHNELL: As climate warms up more energy is going to be held near the Earth, so it's going to get colder high up in the atmosphere, the stratosphere. That could cause more of these temperatures getting to minus 80, and bigger holes. So that is a concern so the Arctic is being monitored very carefully because there's a lot of people living at that latitude, there's a lot of fisheries, there's a lot of potential harm that can happen in the Arctic. JOHNSON: NOAA is an organization that is part of a a broad range of governmental and university and academic organizations that are keeping track of the ozone layer, doing measurements all around the globe, from satellite, ground-based, balloon-borne... and all these organizations kind of work together in keeping track of the ozone layer, With all that information coming together, we can get a good idea a good picture of of what we can predict for the future.