NASA Launches Airborne Study of Arctic Atmosphere, Air Pollution

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Alan Buis 818-354-0474
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Steve Cole 202-358-0918
NASA Headquarters, Washington
Stephen.e.cole@nasa.gov

NEWS RELEASE: 2008-051 April 1, 2008

NASA Launches Airborne Study of Arctic Atmosphere, Air Pollution

PASADENA, Calif. -- This month, NASA begins the most extensive field campaign ever to
investigate the chemistry of the Arctic's lower atmosphere. The mission is poised to help scientists
identify how air pollution contributes to climate changes in the Arctic.

The recent decline of sea ice is one indication the Arctic is undergoing significant environmental
changes related to climate warming. NASA and its partners plan to investigate the atmosphere's
role in this climate-sensitive region with the Arctic Research of the Composition of the
Troposphere from Aircraft and Satellites (ARCTAS) field campaign.

"It's important that we go to the Arctic to understand the atmospheric contribution to warming in a
place that's rapidly changing," said Jim Crawford, manager of the Tropospheric Chemistry
Program at NASA Headquarters in Washington. "We are in a position to provide the most
complete characterization to date for a region that is seldom observed but critical to understanding
climate change."

The campaign begins this week in Fairbanks, Alaska. NASA's DC-8, P-3 and B-200 aircraft will
serve as airborne laboratories for the next three weeks, carrying instruments to measure air
pollution gases and aerosols and solar radiation. Of particular interest is the formation of the
springtime "arctic haze." The return of sunlight to the Arctic in the spring fuels chemical reactions
of pollutants that have accumulated over the winter after traveling long distances from lower
latitudes.

"The Arctic is a poster child of global change and we don't understand the processes that are
driving that rapid change," said Daniel Jacob, an ARCTAS project scientist at Harvard University,
Cambridge, Mass. "We need to understand it better and that's why we're going."

ARCTAS is NASA's contribution to an international series of Arctic field experiments that is part
of the International Polar Year, a two-year event focusing science and education on Earth's remote
polar regions. The National Oceanic and Atmospheric Administration and the Department of
Energy also are sponsoring research flights from Fairbanks this month in collaboration with
NASA.
The wealth of data collected also will improve computer models used to study global atmospheric
chemistry and climate. This ultimately will provide scientists with a better idea of how pollutants
are transported to and around the Arctic and their impact on the environment and climate.

"We haven't looked at pollution transport in a comprehensive fashion," said Hanwant Singh, an
ARCTAS project scientist at NASA Ames Research Center, Moffett Field, Calif. "We can see
Arctic haze coming in but we don't know its composition or how it got there. One goal of
ARCTAS is to provide a comprehensive understanding of the aerosol composition, chemistry and
climate effects in the Arctic region."

The aircraft observations also will help researchers interpret data from NASA satellites orbiting
over the Arctic, such as Aura and its Tropospheric Emission Spectrometer instrument, developed
and managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif.; Terra; and Cloud-Aerosol
Lidar and Infrared Pathfinder Satellite Observation. Interpreting satellite data can be difficult in the
Arctic because of extensive cloud cover, bright reflective surfaces from snow and ice, and cold
surface temperatures. For example, it's difficult for researchers to look at satellite data and
distinguish between light reflected by clouds and light reflected from white ice cover.

"NASA has invested a lot of resources in satellites that can be of value for diagnosing effects of
climate change," Jacob said. "Satellites orbit over poles with good coverage and good opportunity,
but you really need to have aircraft observations supporting those to make good interpretations of
what satellites are telling you."

The new airborne view of the Arctic atmosphere combined with satellite data will provide
scientists with a better understanding of the atmospheric side of the climate question.

"We're interested in data that will help models better characterize the current state of the
atmosphere, to set a benchmark for them so we can gain confidence in their ability to predict future
warming in the Arctic," Crawford said.

A second phase of the ARCTAS campaign, involving JPL scientists using data from the
Tropospheric Emission Spectrometer on Aura, takes place this summer from Cold Lake in Alberta,
Canada, where flights will focus on measurements of emissions from forest fires. Researchers
want to know how the impact of naturally occurring fires in the region compares to the pollution
associated with human activity at lower latitudes. Understanding the relative influence of each is
important to predictions of the Arctic's future climate.

"What we've found before is that there's sometimes a significant amount of ozone produced from
these fires and sometimes there's not," said John Worden, an ARCTAS project scientist at JPL.
"We need to understand that, because ozone in the Arctic region is a significant greenhouse gas,
where it will be involved in part of the warming of the Arctic region. Because the plumes from
these fires can stretch across the globe, the ozone and other pollutants they produce such as
aerosols and carbon monoxide can have an impact on local pollution in higher latitude cities."

For more on ARCTAS on the Web, visit: http://www.nasa.gov/mission_pages/arctas . For more on
the Tropospheric Emission Spectrometer on the Web, visit: http://tes.jpl.nasa.gov/ .

JPL is managed for NASA by the California Institute of Technology in Pasadena.

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