Cleanest air in the world
South Pole observatory provides baseline for detecting pollution
Posted January 4, 2004
It takes the cleanest air in the world to tell us just how dirty our planet is.
Once a week at the National Oceanic and Atmospheric Administration's (NOAA) South Pole research site, Station Chief Jason Seifert or technician Glen Kinoshita walk into an area called the Clean Air Sector with a suitcase of glass bottles. Extending a black rod into the sky, they fish for the cleanest air in the world.
Inside the nearby research facility, instruments are continuously recording the levels of carbon dioxide and a range of other chemicals in the air.
The South Pole observatory is one of four baseline observatories operated by NOAA's worldwide Climate Measuring and Diagnostic Laboratory. Combined with information from Hawaii, Samoa, Alaska and the South Pole, it provides comparison points for the network of air sampling sites around the world.
"It's like checking a person's blood pressure. We are measuring the health of the world on a daily basis," said Russell Schnell, director of observatory operations for the laboratory.
Schnell describes the South Pole observatory as the "baseline of baselines."
"You've got to set standards from somewhere and we set ours from the South Pole," he said.
Air sampling has been done at the South Pole since 1957, when the International Geophysical Year kicked off the modern era of Antarctic research.
The current observatory, first occupied in 1997, is about 500 meters upwind of Amundsen-Scott South Pole Station at the edge of the clean air sector, an area kept free from human activities. Even foot access to the clean air sector is strictly limited. Aircraft flight paths traversing the sector are discouraged and a 100-meter vehicle exclusion zone exists even downwind of the building.
A tourist flight over the South Pole during November's eclipse strayed into the sector and spikes in carbon dioxide were almost immediately noticed by NOAA's Boulder, Colo. monitoring center. The first floor, part of the second floor and much of the roof of the building are used for the NOAA climate monitoring.
The data collected by NOAA's network of observatories is used to assess climate change, ozone depletion, and helps to develop and test diagnostic and predictive models.
The records show how the atmosphere has been affected by industrial emissions over the past 50 years, revealing general trends, like the 30 percent increase in carbon dioxide.
The data also help explain specifics about the transportation of emissions around the globe. For example, particles from burning in the Northern hemisphere are detected at the Pole about a year later.
Scientists believe carbon dioxide generated by the burning of fossil fuels contributes to the greenhouse effect, which traps the sun's heat in our atmosphere. The atmosphere acts like the glass in a greenhouse, allowing the energy from the sunlight in, but trapping the heat that reflects back into the atmosphere.
The South Pole observatory also looks at solar radiation. Instruments on the roof measure the energy received from the sun as well as the energy emitted from the surface.
Atmospheric studies at the South Pole have also been important for understanding the factors that create a hole in the ozone layer above Antarctica each spring.
Using balloons and ground-based equipment, NOAA measures ozone at the surface and up through the atmosphere. Equipment also monitors ozone-depleting chemicals, called halocarbons, on an hourly basis. Production of many of these halocarbons has been banned by international agreement and the growth rates are decreasing.
From the roof of the Atmospheric Research Observatory, technicians fill containers of different shapes and sizes to send to research institutions around the world.
Recently, new sampling techniques have extended NOAA's atmospheric record back to the early 1900s.
"By drilling down into the snow, we can collect large volumes of trapped air at different depths to 120 meters, where the snow turns to ice. These air samples are analyzed in Boulder and also kept as an archive for future analysis," Schnell said.
The South Pole data record has contributed to a comprehensive catalogue. The operations are expected to continue for at least the next 100 years, Schnell said.
NSF funded research featured in this story: Dave Hofmann, National Oceanic and Atmospheric Administration.
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