NASA Plans to Put an Aura Around the Earth
May 17, 2004
On June 19, NASA will launch Aura, a next generation Earth-
observing satellite. Aura will supply the best information
yet about the health of Earth's atmosphere.
Aura will help scientists understand how atmospheric
composition affects and responds to Earth's changing
climate. The satellite will help reveal the processes that
connect
local and global air quality. It will also track the extent
to which Earth's protective ozone layer is recovering.
Aura will carry four instruments designed to survey
different aspects of Earth's atmosphere. The instruments
will provide an unprecedented and complete picture of the
composition of the atmosphere. Aura will survey the
atmosphere from the troposphere, where mankind lives,
through the stratosphere, where the ozone layer resides and
protects
life on Earth.
Aura's space-based view of the atmosphere and its chemistry
will complete the first series of NASA's Earth Observing
System satellites. The other satellites are Terra, which
monitors land; and Aqua, which observes Earth's water cycle.
"Gaining this global view of Earth will certainly reap new
scientific discoveries that will serve as essential stepping
stones to our further exploration of the Moon, Mars and
beyond, the basis of the Vision for Space Exploration," NASA
Administrator Sean O'Keefe said.
Aura will help answer key scientific questions, including
whether the ozone layer is recovering. Aura data may prove
useful in determining the effectiveness of international
agreements that banned ozone-depleting chemicals like
chlorofluorocarbons (CFCs).
Aura will accurately detect global levels of CFCs and their
byproducts, chlorine and bromine, which destroy ozone. Aura
will also track the sources and processes controlling global
and regional air quality. It will help distinguish between
natural and human-caused sources of these gases. When ozone
exists in the troposphere, it acts as an air pollutant.
Tropospheric ozone is linked to high levels of precursors
such as nitrogen dioxide, carbon monoxide and volatile
hydrocarbons. Aura will help scientists follow the sources
of
tropospheric ozone and its precursors.
"Aura, the first comprehensive laboratory in space to help
us better understand the chemistry and composition of the
Earth's atmosphere, is fundamentally a mission to understand
and protect the very air we breathe, " said NASA Associate
Administrator for Earth Science Dr. Ghassem Asrar. "It is
also a perfect complement to our other Earth Observing
System satellites that, together, will aid our nation and
our neighbors by determining the extent, causes, and
regional consequences of global change."
As the composition of Earth's atmosphere changes, so does
its ability to absorb, reflect and retain solar energy.
Greenhouse gases, including water vapor, trap heat in the
atmosphere. Airborne aerosols from human and natural sources
absorb or reflect solar energy based on color, shape, size
and substance. The impact of aerosols, tropospheric ozone
and upper tropospheric water vapor on Earth's climate
remains largely unquantified. Aura's ability to monitor
these agents will help unravel some of their mystery.
Aura's four instruments, the High Resolution Dynamics Limb
Sounder; the Microwave Limb Sounder; the Ozone Monitoring
Instrument; and the Tropospheric Emission Spectrometer will
work together to provide measurements in the troposphere and
stratosphere to help answer important climate questions.
The High Resolution Dynamics Limb Sounder was built by the
United Kingdom and the United States. The Ozone Monitoring
Instrument was built by the Netherlands and Finland in
collaboration with NASA. NASA's Jet Propulsion Laboratory,
Pasadena, Calif., constructed the Tropospheric Emission
Spectromer and Microwave Limb Sounder. NASA's Goddard Space
Flight Center, Greenbelt, Md., manages the Aura mission.
NASA's Earth Science Enterprise is dedicated to
understanding the Earth as an integrated system and applying
Earth System Science to improve prediction of climate,
weather, and
natural hazards using the unique vantage point of space.
For Aura information and images on the Internet, visit
http://www.gsfc.nasa.gov/topstory/2004/0517aura.html or
http://aura.gsfc.nasa.gov/.
