Jet on mission to measure global greenhouse gases

A gulfstream jet flying low over Lauder yesterday was on an international mission, taking a slice of the atmosphere so scientists can learn more about greenhouse gases globally.

The specially modified research jet, operated by the National Centre for Atmospheric Research in the United States, is flying from the Arctic to the Antarctic as part of a three-year project mapping the distribution of carbon dioxide and related gases.

Lauder was the focus of its attention yesterday afternoon, with the jet making a loop around Niwa's atmospheric climate research station, flying as low as 300m.

Lauder is part of the global Total Carbon Column Observing Network and is one of 14 key sites worldwide where data is used to understand the global carbon cycle.

The aircraft records a profile of greenhouse gases from the stratosphere down to the Earth's surface and at same time, scientists on the ground measure the concentration of those gases at the Earth's surface and in the air overhead.

Niwa Lauder consultant Brian Connor said cloudy weather meant the jet's data-gathering flight was in doubt earlier in the day.

"Cloudy weather isn't that wonderful for us.

"It's fine for the plane, but it affects the measurements taken from the ground at the same time.

"We use a spectrometer that looks at the sun and need a clear path to do that," Dr Connor said.

Fortunately, most of the cloud had lifted by the time the jet was due and he was hopeful the mission would be successful.

If the measurements are not good enough because of the cloud, the aircraft will make a return trip tomorrow .

Dr Connor said the jet was geared up to take measurements at the full range of its altitudes and at all latitudes at different times of the year.

"The data it provides is very valuable and on this trip it's flying over two sites in the United States, this one and one in Australia.

"All the data from all the sites is looked at as a whole," he said.

The Lauder team launched a weather balloon immediately after the flight. The balloon will measure the ozone levels and that data will also be used as part of the international project.

Lauder Niwa manager Paul Johnston said the information collected from the balloon would describe the atmosphere, humidity, state of the ozone and pressure at the time of the flight.

The helium-filled balloon with sensors attached was worth about $1600 and blustery weather meant the launch was marginal.

"If it's too windy and the balloon gets battered, or crashes into the ground, then obviously you can't get the information from it, so wind makes the launch much more difficult," Dr Connor said.

The airborne data-gathering exercise is known as the Hippo project - Hiaper pole-to-pole observations (Hippo) of carbon-cycle and greenhouse gases study.

The research jet is called Hiaper - high-performance instrumented airborne platform for environmental research.

- lynda.van.kempen@odt.co.nz [2]