American scientists today swooped over New Zealand to take
measurements of greenhouse gas levels in its atmosphere.
The data will be used to calibrate past and future
measurements by the National Institute of Water and
Atmospheric Research's (Niwa) Lauder site in Central Otago.
Measurements from the ground will eventually be able to be
compared with satellite data covering huge areas, as well as
recordings from the research flights.
The Lauder site is part of the global total carbon column
observing network of 14 key sites worldwide, helping
scientists better understand the global carbon cycle.
A specially-modified Gulfstream V executive jet today
descended from 14,000m to just 300m above Lauder about 4pm,
making the most extensive airborne measurement so far of
greenhouse gases in the atmosphere.
"The purpose is to find out how the atmosphere is structured,
and the distribution of greenhouse gases," said Harvard
professor Steve Wofsy, one of the project's primary
As the USA National Science Centre-owned plane descended over
Otago, it was recording a profile of greenhouse gases from
the stratosphere down to the Earth's surface.
At the same time, Niwa scientists at Lauder measured the
concentration of these gases at the earth's surface and in
the air column overhead.
The aircraft was making the second of five trips travelling
from pole to pole. Tomorrow it will stop over at
Christchurch, then fly a loop over the Southern Ocean before
returning to New Zealand.
It climbs and dives in a saw-tooth pattern, between 300m and
14,000m, so researchers sample virtually the entire height of
"This is the first time that anyone has systematically tried
to map the distribution of carbon dioxide and related gases
from the Arctic to the Antarctic and from near sea level to
the upper atmosphere," said Vidal Salazar, a project manager
at the US National Centre for Atmospheric Research (NCAR).
"We're taking a slice of the atmosphere to see what is in
it," he said.
Five pole-to-pole flights over three years were giving a
picture of how carbon dioxide was distributed globally at
different altitudes and during different seasons.
The information will help climate modellers trying to
understand Earth's future climates.