Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Atmospheric water clusters provide evidence of global warming

25.02.2004


Hamilton College professor/students publish findings in JACS



Researchers at Hamilton College have identified several methods for successfully determining the structures and thermodynamic values for the formation of atmospheric water clusters, which scientists have speculated may accelerate global warming. The Hamilton team’s findings were published in the March 3 issue of the Journal of the American Chemical Society.

The greenhouse effect is caused by molecules that absorb infrared radiation released from the Earth’s surface, trapping heat in the atmosphere. Water acts as a greenhouse gas because it is one of the molecules that can absorb infrared radiation and cause warming. "Our research supports the suggestion that in a global warming scenario higher temperatures will lead to increased absorption of solar radiation by water clusters," said lead author, George Shields, the Winslow Professor of Chemistry at Hamilton College. "The prediction that higher order water clusters (trimers, tetramers, and pentamers) are present in the atmosphere is significant because it shows that these entities must be considered as key players in atmospheric processes."


Previous research has hypothesized that water clusters (two or more water molecules held together by hydrogen bonds) could catalyze acid rain or the formation of aerosol in the atmosphere, and even lead to acceleration of the Greenhouse effect. All of these ideas depend on the presence of water clusters in the troposphere, the region of the atmosphere that is directly heated by the Earth’s surface. The Hamilton group can now predict the concentration of water clusters present in the troposphere. Large water clusters have for some time been thought to catalyze reactions which have implications for the chemistry that takes place in the atmosphere. A paper in the June 27, 2003 issue of Science documented the first detection of a water dimer (two hydrogen bonded water molecules) in the troposphere.

Shields said, "Once we knew the dimers were present, we investigated whether larger water clusters might also be involved in a variety of atmospheric chemistry processes. We started by using high level quantum chemistry methods to predict dimer concentrations that would be found on a warm, humid day. The accuracy of our dimer calculation, which matched the experimentalists’ detection of water dimer concentrations under the same conditions, led us to calculate the concentration of other water clusters in the troposphere." The researchers found that water clusters consisting of cyclic trimers, cyclic tetramers, and cyclic pentamers should all be detectable in the lower troposphere.

The Hamilton researchers used the documented information on water cluster structures to investigate the effectiveness of various model chemistries in modeling gas-phase water cluster formation. The performance of these chemistries was compared against previous calculations, and the Hamilton team found that thermodynamic calculations by Gaussian-2, Gaussian-3 and Complete Basis Set-APNO chemistries compared quite well to the prior calculations. (Experimentalists reported a value of 6 x 10^14 dimers per cubic centimeter at 292 K on a 100% humid day. The Hamilton study predicted a value of 4 x 10^14 dimers per cubic centimeter at 292 K.)


George Shields conducted the research with two undergraduate students, Meghan Dunn and Emma Pokon. The research was made possible through funding from the American Chemical Society/Petroleum Research Fund, Merck/AAAS, the Camille and Henry Dreyfus Foundation, and from NSF Grant CHE-0116435 for supercomputer instrumentation as part of the MERCURY supercomputer consortium (http://mars.hamilton.edu).

Sharon Rippey | EurekAlert!
Further information:
http://mars.hamilton.edu
http://www.hamilton.edu/

More articles from Earth Sciences:

nachricht Predicting unpredictability: Information theory offers new way to read ice cores
07.12.2016 | Santa Fe Institute

nachricht Sea ice hit record lows in November
07.12.2016 | University of Colorado at Boulder

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>