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Identifying the Molecular Origin of Global WarmingWe have investigated the physical characteristics of greenhouse gases (GHGs) to assess which properties are most important in determining the efficiency of a GHG. Chlorofluorcarbons (CFCs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), nitrogen fluorides, and various other known atmospheric trace molecules have been included in this study. Compounds containing the halogens F or Cl have in common very polar X-F or X-Cl bonds, particularly the X-F bonds. It is shown that as more F atoms bond to the same central atom, the bond dipoles become larger as a result of the central atom becoming more positive. This leads to a linear increase in the total or integrated XF bond dipole derivatives for the molecule, which leads to a non-linear (quadratic) increase in infrared (IR) intensity. Moreover, virtually all of the X-F bond stretches occur in the atmospheric IR window as opposed to X-H stretches, which do not occur in the atmospheric window. It is concluded that molecules possessing several F atoms will always have a large radiative forcing parameter in the calculation of their global warming potential. Some of the implications for global warming and climate change are discussed.
Document ID
20110023746
Acquisition Source
Ames Research Center
Document Type
Preprint (Draft being sent to journal)
Authors
Bera, Partha P.
(Oak Ridge Associated Universities, Inc. TN, United States)
Francisco, Joseph S.
(Purdue Univ. West Lafayette, IN, United States)
Lee, Timothy J.
(NASA Ames Research Center Moffett Field, CA, United States)
Date Acquired
August 25, 2013
Publication Date
January 1, 2009
Subject Category
Meteorology And Climatology
Report/Patent Number
ARC-E-DAA-TN706
Funding Number(s)
CONTRACT_GRANT: NNX09AI49A
Distribution Limits
Public
Copyright
Public Use Permitted.
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