Preindustrial-to-present-day radiative forcing by tropospheric ozone from improved simulations with the GISS chemistry-climate GCM


Journal Article

Improved estimates of the radiative forcing from tropospheric ozone increases since the preindustrial have been calculated with the tropospheric chemistry model used at the Goddard Institute for Space Studies (GISS) within the GISS general circulation model (GCM). The chemistry in this model has been expanded to include simplified representations of peroxyacetylnitrates and non-methane hydrocarbons in addition to background NOx-HO x-Ox-CO-CH4 chemistry. The GCM has improved resolution and physics in the boundary layer, improved resolution near the tropopause, and now contains a full representation of stratospheric dynamics. Simulations of present-day conditions show that this coupled chemistry-climate model is better able to reproduce observed tropospheric ozone, especially in the tropopause region, which is critical to climate forcing. Comparison with preindustrial simulations gives a global annual average radiative forcing due to tropospheric ozone increases of 0.30 W/m2 with standard assumptions for preindustrial emissions. Locally, the forcing reaches more than 0.8 W/m 2 in parts of the northern subtropics during spring and summer, and is more than 0.6W/m2 through nearly all the Northern subtropics and mid-latitudes during summer. An alternative preindustrial simulation with soil NOx emissions reduced by two-thirds and emissions of isoprene, paraffins and alkenes from vegetation increased by 50% gives a forcing of 0.33 W/m2. Given the large uncertainties in preindustrial ozone amounts, the true value may lie well outside this range. © 2003 European Geosciences Union.

Full Text

Duke Authors

Cited Authors

  • Shindell, DT; Faluvegi, G; Bell, N

Published Date

  • January 1, 2003

Published In

Volume / Issue

  • 3 / 5

Start / End Page

  • 1675 - 1702

Electronic International Standard Serial Number (EISSN)

  • 1680-7324

International Standard Serial Number (ISSN)

  • 1680-7316

Digital Object Identifier (DOI)

  • 10.5194/acp-3-1675-2003

Citation Source

  • Scopus