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 How is climate change affecting fauna in the Arctic?
22.05.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

nachricht Sea level as a metronome of Earth's history
19.05.2017 | Université de Genève

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

Im Focus: Bacteria harness the lotus effect to protect themselves

Biofilms: Researchers find the causes of water-repelling properties

Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...

Im Focus: Hydrogen Bonds Directly Detected for the First Time

For the first time, scientists have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope. Researchers from the University of Basel’s Swiss Nanoscience Institute network have reported the results in the journal Science Advances.

Hydrogen is the most common element in the universe and is an integral part of almost all organic compounds. Molecules and sections of macromolecules are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

Innovation 4.0: Shaping a humane fourth industrial revolution

17.05.2017 | Event News

Media accreditation opens for historic year at European Health Forum Gastein

16.05.2017 | Event News

 
Latest News

New approach to revolutionize the production of molecular hydrogen

22.05.2017 | Materials Sciences

Scientists enlist engineered protein to battle the MERS virus

22.05.2017 | Life Sciences

Experts explain origins of topographic relief on Earth, Mars and Titan

22.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>