This visualization shows variations in the three dimensional distribution
of water vapor in the atmosphere during the summer and fall of 2005. Water
vapor at higher altitudes appears brighter.
The visualization highlights an often overlooked but important player in
the climate system: water vapor. Water vapor frequently condenses into
familiar—and visible—clouds and rain. Water vapor is also the
most significant greenhouse gas in the atmosphere, about twice as
important as the more familiar carbon dioxide.
This movie shows the variations in the height of a surface representing a
constant value of water vapor during the summer and fall of 2005. This
water vapor surface is highest in the tropics where vapor amounts are
largest. The greatest heights (about 3.2 km or 2 miles) occur over south
Asia where monsoon thunderstorms carry water vapor high into the
atmosphere. Other thunderstorms over Africa and South America lift water
vapor there. In some regions of the tropics—such as off the west
coast of South America— the height of the surface is lower. This
indicates drier air brought downward to the surface in these regions. The
concentration over the northern hemisphere show tendrils of water vapor
being pulled from tropical storms into higher latitudes. Some of this
water vapor may condense as rain or snow, far from the warm tropics where
it originated.
The Atmospheric Infrared Sounder (AIRS) in conjunction with the Advanced
Microwave Sounding Unit (AMSU) sense emitted infrared and microwave
radiation from the Earth to provide a three-dimensional look at Earth's
weather and climate. Working in tandem, the two instruments can make
simultaneous observations all the way down to the Earth's surface, even
in the presence of heavy clouds. With more than 2,000 channels sensing
different regions of the atmosphere, the system creates a global, 3-D map
of atmospheric temperature and humidity, cloud amounts and heights,
greenhouse gas concentrations, and many other atmospheric phenomena.
The AIRS and AMSU fly onboard NASA's Aqua spacecraft and are managed
by the Jet Propulsion Laboratory, Pasadena, California, under contract to NASA.
JPL is a division of the California Institute of Technology in Pasadena.
The AIRS Public Web site can be found at http://airs.jpl.nasa.gov.