Featured Research

from universities, journals, and other organizations

NASA Space Sleuth Hunts The Trail Of Earth's Water

Date:
February 1, 2007
Source:
NASA/Jet Propulsion Laboratory
Summary:
For the first time, NASA scientists have used a shrewd spaceborne detective to track the origin and movement of water vapor throughout Earth's atmosphere. This perspective is vital to improve the understanding of Earth's water cycle and its role in weather and climate.

This view depicts the distribution of "heavy" and "light" water vapor molecules over Earth's tropics. Red illustrates heavy water vapor, which indicates recent evaporation or plant "exhalation." Blue and purple show lighter water vapor that has undergone significant condensation. The data was obtained Oct. 7, 2006, by the Tropospheric Emission Spectrometer on NASA's Aura satellite.
Credit: Image credit: NASA/JPL

For the first time, NASA scientists have used a shrewd spaceborne detective to track the origin and movement of water vapor throughout Earth's atmosphere. This perspective is vital to improve the understanding of Earth's water cycle and its role in weather and climate.

NASA's newest detective in the mysteries of atmospheric water vapor is the Tropospheric Emission Spectrometer instrument on the Aura satellite. A team of scientists from NASA's Jet Propulsion Laboratory, Pasadena, Calif., and the University of Colorado, Boulder, used the instrument's observations of heavy and light water vapor to retrace the "history" of water over oceans and continents, from ice and liquid to vapor and back again. Heavy water vapor molecules have more neutrons than lighter ones do.

By analyzing the distribution of the heavy and light molecules, the team was able to deduce the sources and processes that cycle water vapor, the most abundant greenhouse gas in Earth's atmosphere.

The team found that tropical rainfall evaporation and water "exhaled" by forests are key sources of moisture in the tropical atmosphere. They noted that more water than they had expected is transported over land rather than ocean into the lower troposphere (Earth's lowermost atmosphere), especially over the Amazon River basin and tropical Africa.

"One might expect most of the water to come directly from the wet ocean," said study co-author Dr. David Noone of the University of Colorado. "Instead, it appears that thunderstorm activity over the tropical continents plays a key role in keeping the troposphere hydrated."

The team found that in the tropics and regions of tropical rain clouds, rainfall evaporation significantly adds moisture to the lower troposphere, with typically 20 percent and up to 50 percent of rain there evaporating before it reaches the ground. The atmosphere retains this water, which can be used to make clouds. The strength and location of this evaporation give scientists new insight into how water in Earth's atmosphere helps move energy from Earth's surface upwards. The main role of the atmosphere in Earth's climate system is to take energy deposited by the sun and dispose of it back into space.

The team also found evidence that water transported upwards by thunderstorm activity over land originates from both plant "exhalation" in large forests and evaporation over nearby oceans. The balance between these two different sources tells us how vegetation interacts with climate and helps maintain regional rainfall levels.

"This link between vegetation, hydrology and climate has implications for how societies choose to manage their ecological resources," said Noone. "Our measurements provide a baseline against which future changes in vegetation-climate interactions can be measured."

The details of this journey are critical for understanding clouds and climate, as well as changes in precipitation patterns and water resources, Noone explained. "Our study measures the conditions under which precipitation and evaporation occur, providing insights into the processes responsible. Better knowledge of these processes ultimately leads to a clearer understanding of the factors that drive the global water cycle and its importance in climate and global climate change."

Noone and his co-authors said there has been a general lack of information on the way water moves around in Earth's atmosphere – where it comes from and where it ends up.

"Since we measure the history of water, so to speak, we can tell the difference between air masses that have undergone extensive condensation from those that are more dominated by evaporation from the ocean surface," said study co-author Dr. John Worden of JPL.

"These results also lay the groundwork for research to help interpret the isotopic measurements that scientists use to study Earth's climate in the past," added JPL co-author Dr. Kevin Bowman.

Study results appear in the February 1 issue of the journal Nature.

For more on the Tropospheric Emission Spectrometer, visit: http://www.nasa.gov/aura and http://tes.jpl.nasa.gov/ .

JPL is managed for NASA by the California Institute of Technology in Pasadena.


Story Source:

The above story is based on materials provided by NASA/Jet Propulsion Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

NASA/Jet Propulsion Laboratory. "NASA Space Sleuth Hunts The Trail Of Earth's Water." ScienceDaily. ScienceDaily, 1 February 2007. <www.sciencedaily.com/releases/2007/01/070131204349.htm>.
NASA/Jet Propulsion Laboratory. (2007, February 1). NASA Space Sleuth Hunts The Trail Of Earth's Water. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2007/01/070131204349.htm
NASA/Jet Propulsion Laboratory. "NASA Space Sleuth Hunts The Trail Of Earth's Water." ScienceDaily. www.sciencedaily.com/releases/2007/01/070131204349.htm (accessed July 31, 2014).

Share This




More Earth & Climate News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Big Waves In Arctic Ocean Threaten Polar Ice

Big Waves In Arctic Ocean Threaten Polar Ice

Newsy (July 30, 2014) Big waves in parts of the Arctic Ocean are unprecedented, mainly because they used to be covered in ice. Video provided by Newsy
Powered by NewsLook.com
Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
Powered by NewsLook.com
Amid Drought, UCLA Sees Only Water

Amid Drought, UCLA Sees Only Water

AP (July 30, 2014) A ruptured 93-year-old water main left the UCLA campus awash in 8 million gallons of water in the middle of California's worst drought in decades. (July 30) Video provided by AP
Powered by NewsLook.com
In Virginia, the Rise of a New Space Coast

In Virginia, the Rise of a New Space Coast

AP (July 30, 2014) Every summer, tourists make the pilgrimage to Chincoteague Island, Va. to see wild ponies cross the Assateague Channel. But, it's the rockets sending to supplies to the International Space Station that are making this a year-round destination. (July 30) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins