WASHINGTON, Oct. 10 (Xinhua) -- A team of U.S.
researchers published the first global satellite maps of the key greenhouse gas
carbon dioxide in Earth's mid-troposphere, an area about 8 kms above Earth, the
U.S. space agency NASA reported Friday.
The team's study reveals new information on how
carbon dioxide, which directly contributes to climate change, is distributed in
Earth's atmosphere and moves around our world.
The team, led by Moustafa Chahine of NASA's Jet
Propulsion Laboratory, found the distribution of carbon dioxide in the
mid-troposphere is strongly influenced by major surface sources of carbon
dioxide and by large-scale atmospheric circulation patterns, such as the jet
streams and weather systems in Earth's mid-latitudes.
The new maps reveal enhanced concentrations of carbon
dioxide south of the northern hemisphere jet stream, in a band between 30 and 40
degrees north latitude. These enhanced concentrations correspond to a
well-documented belt of pollution in the northern hemisphere mid-latitudes.
Patterns of carbon dioxide distribution were also
found to differ significantly between the northern hemisphere, with its many
land masses, and the southern hemisphere, which is largely covered by ocean.
The findings are based on data collected from the
Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua spacecraft between
September 2002 and July 2008. The research products will be used by scientists
to refine models of the processes that transport carbon dioxide within Earth's
atmosphere.
Chahine said the AIRS data will complement existing
and planned ground and aircraft measurements of carbon dioxide, as well as
upcoming satellite missions to study Earth's carbon cycle and climate.