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The Measure of Water: NASA Creates New Map for the Atmosphere

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  • npat1@juno.com
    December 05, 2003 NASA scientists have opened a new window for understanding atmospheric water vapor, its implications for climate change and ozone depletion.
    Message 1 of 2 , Dec 17, 2003
    • 0 Attachment
      December 05, 2003
      NASA scientists have opened a new window for understanding atmospheric
      water vapor, its implications for climate change and ozone depletion.

      Scientists have created the first detailed map of water, containing heavy
      hydrogen and heavy oxygen atoms, in and out of clouds, from the surface
      to some 25 miles above the Earth, to better understand the dynamics of
      how water gets into the stratosphere.

      Only small amounts of water reach the arid stratosphere, 10 to 50
      kilometers (6 to 25 miles) above Earth, so any increase in the water
      content could potentially lead to destruction of some ozone-shielding
      capability in this part of the atmosphere. This
      could produce larger ozone depletions over the North and South Poles as
      well as at mid-latitudes.

      Water shapes Earth's climate. The large amount of it in the lower
      atmosphere, the troposphere, controls how much sunlight gets through to
      the planet, how much is trapped in our skies, and how much goes back out
      to space. Higher in the stratosphere, where most of the Earth's ozone
      shield protects the surface from harmful
      ultraviolet rays, there is very little water (less than .001 the surface
      concentration). Scientists don't fully understand how air is dried before
      it gets to this region.

      In the troposphere, water exists as vapor in air, as liquid droplets in
      clouds, and as frozen ice particles in high altitude cirrus clouds. Since
      there is so much water closer to Earth and so little miles above, it is
      important to understand how water enters and leaves the stratosphere. The
      "isotopic content," the natural fingerprint left by the heavy forms of
      water, is key to understanding the process. An isotope is any of two or
      more forms of an element having the same or very closely related chemical
      properties and the same atomic number, but different atomic weights. An
      example is oxygen 16 versus oxygen 18, both are oxygen, but one is
      heavier than the other.

      Heavy water is more readily condensed or frozen out from its vapor,
      causing the nature of its distribution to differ somewhat from the usual
      isotopic form of water. A measurement of the isotopic make-up of water
      vapor enables scientists to determine how water gets into the
      stratosphere.

      "For the first time, we have water isotope content mapped in incredible
      detail," said Dr. Christopher R. Webster, a senior research scientist at
      NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif. Webster is
      principal author of a scientific paper
      announcing the new findings in Science Magazine today. Dr. Andrew J.
      Heymsfield, of the National Center for Atmospheric Research, Boulder,
      Colo., is co-author.

      Measuring water isotopes is extremely challenging, because they represent
      only a small fraction, less than one percent, of the total water in the
      atmosphere. Detailed measurements were made using an Aircraft laser
      Infrared absorption spectrometer (Alias) flying aboard NASA's WB-57F
      high-altitude jet aircraft in July 2002. This new laser technique enables
      mapping of water isotopes with sufficient resolution to help researchers
      understand both water transport and the detailed microphysics of clouds,
      key parameters for understanding atmospheric composition, storm
      development and weather prediction.

      "The laser technique gives us the ability to measure the different types
      of isotopes found in all water," said Webster. "With the isotopic
      fingerprint, we discovered the ice particles found under the stratosphere
      were lofted from below, and some were grown there in place."

      The data help explain how the water content of air entering the
      stratosphere is reduced, and show that gradual ascent and rapid upward
      motion associated with tall cloud systems (convective lofting) both play
      roles in establishing the dryness of the stratosphere.

      The purpose of the aircraft mission was to understand the formation,
      extent and processes associated with cirrus clouds. The mission used
      six aircraft from NASA and other federal agencies to make observations
      above, in and below the clouds. By combining aircraft data with
      ground-based data and satellites, scientists have a better picture of
      the relationship between clouds, water vapor and atmospheric dynamics
      than previously. They also can better interpret satellite measurements
      routinely made by NASA.
      ******************************
      The mission was funded by NASA's Earth Science Enterprise. The 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 more
      information about Alias, visit: http://laserweb.jpl.nasa.gov For
      Information about NASA and JPL programs, visit:
      http://www.nasa.gov and http://www.jpl.nasa.gov
      ###
      Contacts:
      David E. Steitz
      Headquarters, Washington
      (Phone: 202/358-1730)
      Alan Buis
      Jet Propulsion Laboratory, Pasadena, Calif.
      (Phone: 818/354-0474)
      This text derived from http://www.jpl.nasa.gov/releases/2003/164.cfm
      --
      Fwded from a post by Lance Olsen from another group.

      Pat

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    • P. Neuman self only
      December 5, 2003 The Measure of Water: NASA Creates New Map for the Atmosphere NASA scientists have opened a new window for understanding atmospheric water
      Message 2 of 2 , Jul 1, 2004
      • 0 Attachment
        December 5, 2003
        The Measure of Water: NASA Creates New Map for the Atmosphere

        NASA scientists have opened a new window for understanding atmospheric
        water vapor, its implications for climate change, and ozone depletion.

        The scientists have created the first detailed map of water containing
        heavy hydrogen and heavy oxygen atoms in and out of clouds, from the
        surface of Earth to some 25 miles upward, to better understand the
        dynamics of how water gets into the stratosphere.

        Only small amounts of water reach the arid stratosphere, 10 to 50
        kilometers (6 to 25 miles) above Earth, so any increase in the water
        content could potentially lead to destruction of some ozone-shielding
        capability in this part of the atmosphere. This could produce larger
        ozone depletions over the North and South Poles as well as at
        mid-latitudes.

        Water shapes Earth's climate. The large amount of it in the lower
        atmosphere, the troposphere, controls how much sunlight gets through to
        the planet, how much is trapped in our skies, and how much goes back out
        to space. Higher in the stratosphere, where most of the Earth's ozone
        shield protects the surface from harmful ultraviolet rays, there is very
        little water (less than .001 of the surface concentration). Scientists
        don't fully understand how air is dried before it gets to this region.

        In the troposphere, water exists as vapor in air, as liquid droplets in
        clouds, and as frozen ice particles in high altitude cirrus clouds. Since
        there is so much water closer to Earth and so few miles above, it is
        important to understand how water enters and leaves the stratosphere.

        The "isotopic content," the natural fingerprint left by the heavy forms
        of water, is key to understanding the process. An isotope is any of two
        or more forms of an element having the same or very closely related
        chemical properties and the same atomic number, but different atomic
        weights. An example is oxygen 16 versus oxygen 18-- both are oxygen, but
        one is heavier than the other.

        Heavy water is more readily condensed or frozen out from its vapor,
        causing the nature of its distribution to differ somewhat from the usual
        isotopic form of water. A measurement of the isotopic make-up of water
        vapor enables scientists to determine how water gets into the
        stratosphere.

        "For the first time, we have water isotope content mapped in incredible
        detail," said Dr. Christopher R. Webster, a senior research scientist at
        NASA's Jet Propulsion Laboratory, Pasadena, Calif. Webster is principal
        author of a scientific paper announcing the new findings in the journal
        Science. Dr. Andrew J. Heymsfield, of the National Center for Atmospheric
        Research, Boulder, Colo., is co-author.

        Measuring water isotopes is extremely challenging, because they represent
        only a small fraction, less than one percent, of the total water in the
        atmosphere. Detailed measurements were made using an Aircraft laser
        infrared absorption spectrometer (Alias) flying aboard
        NASA's WB-57F high- altitude jet aircraft in July 2002. This new laser
        technique enables mapping of water isotopes with sufficient resolution to
        help researchers understand both water transport and the detailed
        microphysics of clouds, key parameters for understanding
        atmospheric composition, storm development and weather prediction.

        "The laser technique gives us the ability to measure the different types
        of isotopes found in all water," said Webster. "With the isotopic
        fingerprint, we discovered the ice particles found under the stratosphere
        were lofted from below, and some were grown there in place."

        The data help explain how the water content of air entering the
        stratosphere is reduced, and show that gradual ascent and rapid upward
        motion associated with tall cloud systems (convective lofting) both play
        roles in establishing the dryness of the stratosphere.

        The purpose of the aircraft mission was to understand the formation,
        extent and processes associated with cirrus clouds. The mission used six
        aircraft from NASA and other federal agencies to make observations above,
        in and below the clouds. By combining aircraft
        data with ground-based data and satellites, scientists have a better
        picture of the relationship between clouds, water vapor and atmospheric
        dynamics than previously. They also can better interpret satellite
        measurements routinely made by NASA.

        The mission was funded by NASA's Earth Science Enterprise. The 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 more information about Alias, visit:
        http://laserweb.jpl.nasa.gov
        For information about NASA, visit: http://www.nasa.gov
        JPL is managed for NASA by the California Institute of Technology in
        Pasadena
        Contact: Alan Buis (818) 354-0474
        JPL
        David E. Steitz (202) 358-1730
        NASA Headquarter, Washington
        2003-164
        http://www.jpl.nasa.gov/releases/2003/164.cfm




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