HR: 15:15h
AN: A23D-06    [Abstracts]
TI: Indirect Global Warming Potentials of Halons Using Atmospheric Models
AU: Youn, D
EM: ydo88@atmos.uiuc.edu
AF: Department of Atmospheric Sciences, University of Illinois at Urbana-Champaign, 105 S. Gregory St, Urbana, IL 61801, United States
AU: Patten, K O
EM: kpatten@atmos.uiuc.edu
AF: Department of Atmospheric Sciences, University of Illinois at Urbana-Champaign, 105 S. Gregory St, Urbana, IL 61801, United States
AU: * Wuebbles, D J
EM: wuebbles@atmos.uiuc.edu
AF: Department of Atmospheric Sciences, University of Illinois at Urbana-Champaign, 105 S. Gregory St, Urbana, IL 61801, United States
AB: Emission of bromochlorofluorocarbons, or Halons, results in stratospheric ozone depletion. This leads to cooling of the climate system in the opposite direction to direct warming contribution of the Halons as greenhouse gases. This cooling is a key indirect effect of Halons on radiative forcing or climate. The Global Warming Potential (GWP) is a relative index used to compare the climate impact of an emitted greenhouse gas, relative to an equal amount of carbon dioxide. Until now, indirect GWPs have been calculated based on the concept of Equivalent Effective Stratospheric Chlorine (EESC), which oversimplifies the complex processes in the atmosphere. As a step towards obtaining indirect GWPs through a more robust approach, 2-D and 3-D global chemical transport models (CTM) were used as the computational tool to derive more realistic ozone changes caused by pulse perturbation of Halons at the surface. Indirect GWPs of Halon-1211 and -1301 for a 100-year time horizon were explicitly calculated based on the University of Illinois at Urbana-Champaign (UIUC) 2-D global CTM and radiative transport model (RTM) and the 3-D CTM, MOZART-3.1. The 2-D and 3-D model simulations show acceptable temporal variations in the atmosphere as well as derived lifetimes and direct GWP values of the Halons. The 2-D model-based indirect GWPs for a 100-year horizon are -16,294 for Halon-1211 and -33,648 for Halon-1301. 3-D indirect GWP for Halon-1211 is -18,216. The indirect GWPs for Halon-1211 presented here are much smaller than previous published results using the previous simplified appraoch.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0340 Middle atmosphere: composition and chemistry
DE: 0341 Middle atmosphere: constituent transport and chemistry (3334)
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly