Sensitivity of tropospheric oxidants to biomass burning emissions: implications for radiative forcing. Issue 6 (26th March 2013)

• Record Type: Journal Article
• Authors: Mao, Jingqiu; Horowitz, Larry W.; Naik, Vaishali; Fan, Songmiao; Liu, Junfeng; Fiore, Arlene M.
• Is Part Of: Geophysical research letters. Volume 40:Issue 6(2013:Mar.)
• Page Start: 1241
• Page End: 1246
• Publication Date: 2013-03-26
• Subjects: Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/grl.50210
• Languages: English
• ISSNs: 0094-8276

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p>[1] Biomass burning is one of the largest sources of trace gases and aerosols to the atmosphere and has profound influence on tropospheric oxidants and radiative forcing. Using a fully coupled chemistry‐climate model (GFDL AM3), we find that co‐emission of trace gases and aerosol from present‐day biomass burning increases the global tropospheric ozone burden by 5.1% and decreases global mean OH by 6.3%. Gas and aerosol emissions combine to increase CH₄ lifetime nonlinearly. Heterogeneous processes are shown to contribute partly to the observed lower ΔO₃/ΔCO ratios in northern high latitudes versus tropical regions. The radiative forcing from biomass burning is shown to vary nonlinearly with biomass burning strength. At present‐day emission levels, biomass burning produces a net radiative forcing of −0.19 W/m² (−0.29 from short‐lived species, mostly aerosol direct and indirect effects, +0.10 from CH₄‐ and CH₄‐induced changes in O₃ and stratospheric H₂O) but increases emissions to over 5 times present levels would result in a positive net forcing.</p> </abstract>