Thursday, October 02, 2008

Ozone hole - it's for real

Neutrinos and cosmic microwave background radiation aren’t the only things being studied down here at the South Pole.


The NOAA (National Oceanic and Atmospheric Administration) folks get pretty busy this time of winter collecting data to evaluate the ozone hole on top of us. Ozone has been getting depleted from the stratosphere every year for the past few decades, forming an ozone-less hole over Antarctica. Man-made CFCs make their way up there where chlorine atoms eventually destroy the ozone molecules as the sun’s light starts hitting the stratosphere. The Antarctic wind vortex prevents new ozone from moving in and in that area of our atmosphere, the ozone level goes down to zero, allowing harmful UV rays from the sun to reach the earth’s surface.

Ozone levels are studied throughout the world but nowhere on earth are the levels considered so important to watch closely as down here.

Carpenters Andy holding the balloon as Travis watches

How do they do it? A big plastic balloon is used to lift a little disposable instrument as high as 30km into the sky.

The instrument has an intake tube that brings in the surrounding air and measures the ozone molecules as they cause a change in current across a cell and the data is transmitted back to a computer through a radio sonde. The signals are turned into data which measures the ozone in partial pressure. The levels are plotted versus altitude and results in a graph that looks like this:

The blue line shows the baseline ozone at a nice healthy level in August. The red line is what’s going now…zero ozone.

The balloons are being launched every other day right now as the ozone up there is currently bottoming out. The majority of the ozone destruction is taking place between 12 and 23 km above us. The level will eventually rise again back to baseline levels as the vortex eases off and allows more atmospheric particles to circulate into the area of the hole. The whole process repeats every year and will continue to do so until the CFCs up there degrade, which may take decades more.

It was a gorgeous morning for being outside. A crisp -82F temp reminds us that it's not quite spring although the sun is on its way up into the sky. In just 3 weeks the first scheduled Basler plane is due to arrive here with new faces and that will truly mark the end of the winter for us.

2 Comments:

At 7:15 AM, Blogger Michael said...

Heidi-- This is a fantastic blog. I have a couple specific questions I'd like to ask about life at the new station. Is there a way to email you directly?

Mike in Seattle

 
At 12:53 AM, Blogger Neal said...

I'm pretty sure that the hole in the ozone is caused by all of the plastic balloons littering the continent.

 

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