Halogen chemistry reduces tropospheric O<sub>3</sub> radiative forcing

doi:10.5194/acp-17-1557-2017

GSTDTAP > 地球科学

DOI	10.5194/acp-17-1557-2017
	Halogen chemistry reduces tropospheric O₃ radiative forcing
	Tomás Sherwen, Mat J. Evans, Lucy J. Carpenter, Johan A. Schmidt, and Loretta J. Mickley
	2017-01-31
发表期刊	Atmospheric Chemistry and Physics
出版年	2017
英文摘要	Tropospheric ozone (O₃) is a global warming gas, but the lack of a firm observational record since the preindustrial period means that estimates of its radiative forcing (RF_TO₃) rely on model calculations. Recent observational evidence shows that halogens are pervasive in the troposphere and need to be represented in chemistry-transport models for an accurate simulation of present-day O₃. Using the GEOS-Chem model we show that tropospheric halogen chemistry is likely more active in the present day than in the preindustrial. This is due to increased oceanic iodine emissions driven by increased surface O₃, higher anthropogenic emissions of bromo-carbons, and an increased flux of bromine from the stratosphere. We calculate preindustrial to present-day increases in the tropospheric O₃ burden of 113 Tg without halogens but only 90 Tg with, leading to a reduction in RF_TO₃ from 0.43 to 0.35 Wm⁻². We attribute ∼ 50 % of this reduction to increased bromine flux from the stratosphere, ∼ 35 % to the ocean–atmosphere iodine feedback, and ∼ 15 % to increased tropospheric sources of anthropogenic halogens. This reduction of tropospheric O₃ radiative forcing due to halogens (0.087 Wm⁻²) is greater than that from the radiative forcing of stratospheric O₃ (∼ 0.05 Wm⁻²). Estimates of RF_TO₃ that fail to consider halogen chemistry are likely overestimates (∼ 25 %).
领域	地球科学
URL	查看原文
引用统计
文献类型	期刊论文
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/287904
专题	地球科学
推荐引用方式 GB/T 7714	Tomás Sherwen, Mat J. Evans, Lucy J. Carpenter, Johan A. Schmidt, and Loretta J. Mickley. Halogen chemistry reduces tropospheric O₃ radiative forcing[J]. Atmospheric Chemistry and Physics,2017.
APA	Tomás Sherwen, Mat J. Evans, Lucy J. Carpenter, Johan A. Schmidt, and Loretta J. Mickley.(2017).Halogen chemistry reduces tropospheric O₃ radiative forcing.Atmospheric Chemistry and Physics.
MLA	Tomás Sherwen, Mat J. Evans, Lucy J. Carpenter, Johan A. Schmidt, and Loretta J. Mickley."Halogen chemistry reduces tropospheric O₃ radiative forcing".Atmospheric Chemistry and Physics (2017).