Jan. 27, 2005
Dryden Flight Research Center
P.O. Box 273
Edwards, California 93523
NASA Dryden Flight Research Center
Gretchen Cook-Anderson/Dolores Beasley
INTERNATIONAL SCIENCE TEAM MEASURES ARCTIC'S ATMOSPHERE
An international team of scientists has embarked on a journey this
week to improve modeling of global scale air quality and climate
change predictions by conducting high quality measurements of the
arctic region's atmosphere.
The Polar Aura Validation Experiment (PAVE) is gathering information
to validate data from NASA's Aura satellite, launched in July 2004.
PAVE is the third in a series of planned Aura validation and science
missions to help understand the transport and transformation of gases
and aerosols in the lower atmosphere (troposphere) and their exchange
with those in the lower stratosphere. The mission began Jan. 24 and
continues through Feb. 9.
Image Right: NASA's Airborne Science DC-8, displaying new colors in a
check flight Feb. 24, 2004, over the Dryden Flight Research Center.
NASA Photo EC04-0047-04 by Jim Ross.
"In addition to providing important validation for the various Aura
data products, PAVE brings together a full NASA complement of
space-based and suborbital measurements to study the atmospheric
chemistry and transport of gases and aerosols in this sensitive
region of our planet," said Dr. Michael Kurylo, Program Scientist for
PAVE at NASA Headquarters in Washington, DC. "The information
obtained from this campaign will aid in understanding how changing
atmospheric composition associated with climate change might affect
the recovery of the Earth's ozone layer that is anticipated to occur
over the next several decades."
In particular, PAVE is focusing on the high latitude (Arctic) region
of the Northern Hemisphere, where winter chemistry has led to
significant seasonal reduction of the stratospheric ozone layer in
many years over more than a decade. The ozone layer restricts the
amount of the sun's ultraviolet radiation that reaches the Earth.
Depletion of this protective layer can thus have harmful effects on
humans and other ecosystems.
NASA's DC-8 flying laboratory and high-altitude balloons are
collecting valuable science data, especially on ozone and
ozone-destroying chemicals, using a suite of atmospheric remote
sensing and in situ instruments. The aircraft, operated by NASA's
Dryden Flight Research Center at Edwards, Calif., is flying the PAVE
mission from Pease International Tradeport, Portsmouth, N. H.
Balloons are being launched from the European Sounding Rocket Range
(ESRANGE) facility in Sweden.
The study is focusing on obtaining in situ and remote sensing
measurements of the Arctic region for validation of the Aura
satellite. Information gathered during PAVE will be combined with
data from Aura to improve modeling of global scale air quality, ozone
and climate change predictions.
Instruments onboard the DC-8 are characterizing upper tropospheric and
stratospheric gases inside and outside the Arctic polar region to
study ozone depletion chemistry. Such flights will also permit
measurement of the outflow of gases from the North American continent
thereby contributing to an understanding of how regional pollutants
are distributed on a hemispheric basis. Scientists will make remote
sensing measurements (extending many kilometers away from the
aircraft) of tropospheric and stratospheric ozone, aerosols,
temperature, nitric acid, HCl, ClO and other ozone-related chemicals.
These are complemented by measurements (such as ozone, methane, water
vapor, carbon monoxide, nitric acid, and nitrous oxide) in the
atmosphere immediately surrounding the aircraft.
"The DC-8 will perform a number of specialized maneuvers to permit
concurrent flights under the path of the Aura satellite and to sample
the concentration of ozone at very high latitudes," said Walter
Klein, Dryden's mission manager for the project. "The aircraft is
carrying 13 instruments, weighing more than 20,000 pounds, and a
complement of 40 scientists, engineers and technicians in support of
"PAVE is designed to validate satellite data from the newly launched
Aura mission," added Mark Schoeberl, PAVE co-project scientist and
Aura project scientist at NASA's Goddard Space Flight Center,
Greenbelt, Md. "Aura contains four instruments including the Dutch
Ozone Monitoring Instrument and the joint U.S.-U.K. High Resolution
Dynamics Limb Sounder. Both Dutch and U.K. representatives will be in
the field as part of the validation program."
NASA scientists from Dryden, Goddard, Ames Research Center, Moffett
Field, Calif., Langley Research Center, Hampton, Va., and the Jet
Propulsion Laboratory, Pasadena, Calif., are participating in PAVE.
Major PAVE partners include the University of New Hampshire,
University of California-Berkley, University of Bremen, National
Center for Atmospheric Research (NCAR), the U.S. Naval Research
Laboratory, Koninklijk Netherlands Meteorological Institute and Los
Gatos Research Inc.
For more information about PAVE on the Web, visit:
For more information about the Aura mission on the Web, visit:
Photos of NASA's DC-8 are available on the Web at:
Television Editors: A Video File on the PAVE mission incorporating
interview segments and b-roll footage is scheduled to be fed on NASA
Television on Jan. 27 - 28. NASA Television is available in the
continental United States on the AMC-6 satellite, at 72 degrees west
longitude, transponder 9, 3880 MHz, vertical polarization, audio at
6.8 MHz. In Alaska or Hawaii, NASA TV is available on AMC-7, at 137
degrees west longitude, transponder 18, at 4060 MHz, vertical
polarization, audio at 6.8 MHz.