Air

Scientists at the British Halley station - here in Dronning Maud Land - discovered the ozone hole in 1985. More precisely, what they discovered was a severe drop in stratospheric concentrations of ozone in the antarctic spring.

Further research revealed the likely mechanisms involved - in the cold antarctic winter so-called "polar stratospheric clouds" form. These clouds often look eerily reddish/blue in colour at dawn and dusk, and are familiar to most norwegians by appearance if not by name. They are packed with tiny, crisp ice crystals. These ice crystals act as catalysts and surface for the chemical reactions breaking down ozone in the upper atmosphere.

Three factors then combine to cause the formation of the ozone hole in springtime.
I wouldn't bother to explain this if it didn't sound like something out of Star Trek:

1. Massive anthropogenic release of CFC's and halocarbons into the atmosphere. CFC's last for ca 100 years. Although a huge victory for international environmentalism back in 1989, the Montreal protocol was too late.

2. The formation of the Polar Vortex (told you!). This is a permanent anticyclone around Antarctica, formed by air spiralling around the polar high pressure cell caused by supercold and dense air. The Vortex basically shuts down the continent for incoming ozone and warmer air.

3. Sunlight. The reactions breaking down ozone require UV-radiation. When the sun returns in springtime, the ozone-eaters awake from their stratospheric slumber.

After this breakthrough discovery, ozone monitoring specifically, and air surveillance in general, has been a significant part of Antarctic research. At Troll we have a small monitoring station run by the Norwegian Institute for Air research (NILU). As I find it much easier to get to grips with birds and fuel drums than atmospheric chemistry and radiometers, I asked Chris Lunder, our resident NILU scientist, to show me around the compund.

The gas containers outside feed the different monitors and intruments inside. Lots of contraptions with funny names growing out of the roof.

Chris patiently trying to explain the mysteries of the "PFR Sun Photometer". It indirectly measures the amount of aerosols (particles and droplets) in the atmosphere. Other instruments sample and filter the air directly, to say more about the composition of the aerosols. This is important, because understanding particles in the athmosphere means understanding cloud formation and cooling effects, and understanding those means better and more accurate climate models, which again means less ammo for politicians using every minor scientific uncertainty as an excuse for doing nothing about the major certainties.

There's something alluring about instruments that look like they were built in a garage. Air intakes and outflows everywhere, calibration solutions, mp3's. Chris' speciality is inventing, tinkering with, and maintaining these gadgets. They measure carbon monoxide, soot, surface ozone, mercury, PCB's, UV-light, and a battery of organic and inorganic pollutants.

This is not a new line of Robotniks - but an ongoing experiment in cheap collection of pollutants. The Collectors sit there patiently, without any active air intake or gas flows, waiting for particles to get blown into the bowl where they might get stuck and eaten. The digesting filters will provide hours of analytic fun for Chris and his colleagues when back at the lab in Norway.