气候变化领域集成服务门户(CCPortal): BVOC-aerosol-climate feedbacks investigated using NorESM

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DOI	10.5194/acp-19-4763-2019
	BVOC-aerosol-climate feedbacks investigated using NorESM
	Sporre M.K.; Blichner S.M.; Karset I.H.H.; Makkonen R.; Berntsen T.K.
发表日期	2019
ISSN	16807316
起始页码	4763
结束页码	4782
卷号	19 期号:7
英文摘要	Both higher temperatures and increased CO2 concentrations are (separately) expected to increase the emissions of biogenic volatile organic compounds (BVOCs). This has been proposed to initiate negative climate feedback mechanisms through increased formation of secondary organic aerosol (SOA). More SOA can make the clouds more reflective, which can provide a cooling. Furthermore, the increase in SOA formation has also been proposed to lead to increased aerosol scattering, resulting in an increase in diffuse radiation. This could boost gross primary production (GPP) and further increase BVOC emissions. In this study, we have used the Norwegian Earth System Model (NorESM) to investigate both these feedback mechanisms. Three sets of experiments were set up to quantify the feedback with respect to (1) doubling the CO2, (2) increasing temperatures corresponding to a doubling of CO2 and (3) the combined effect of both doubling CO2 and a warmer climate. For each of these experiments, we ran two simulations, with identical setups, except for the BVOC emissions. One simulation was run with interactive BVOC emissions, allowing the BVOC emissions to respond to changes in CO2 and/or climate. In the other simulation, the BVOC emissions were fixed at present-day conditions, essentially turning the feedback off. The comparison of these two simulations enables us to investigate each step along the feedback as well as estimate their overall relevance for the future climate. We find that the BVOC feedback can have a significant impact on the climate. The annual global BVOC emissions are up to 63% higher when the feedback is turned on compared to when the feedback is turned off, with the largest response when both CO2 and climate are changed. The higher BVOC levels lead to the formation of more SOA mass (max 53 %) and result in more particles through increased new particle formation as well as larger particles through increased condensation. The corresponding changes in the cloud properties lead to a 0:43Wm2 stronger net cloud forcing. This effect becomes about 50% stronger when the model is run with reduced anthropogenic aerosol emissions, indicating that the feedback will become even more important as we decrease aerosol and precursor emissions. We do not find a boost in GPP due to increased aerosol scattering on a global scale. Instead, the fate of the GPP seems to be controlled by the BVOC effects on the clouds. However, the higher aerosol scattering associated with the higher BVOC emissions is found to also contribute with a potentially important enhanced negative direct forcing (0:06Wm2). The global total aerosol forcing associated with the feedback is 0:49Wm2, indicating that it has the potential to offset about 13% of the forcing associated with a doubling of CO2. © 2019. This work is distributed under the Creative Commons Attribution 4.0 License.
语种	英语
scopus关键词	aerosol; atmospheric chemistry; carbon dioxide; climate feedback; concentration (composition); feedback mechanism; high temperature; volatile organic compound
来源期刊	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/144500
作者单位	Department of Geosciences, University of Oslo, Oslo, Norway; Climate System Research, Finnish Meteorological Institute, P.O. Box 503, Helsinki, Finland; Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, P.O. Box 64, 00014, Helsinki, Finland; CICERO Center for International Climate ResearchOslo, Norway
推荐引用方式 GB/T 7714	Sporre M.K.,Blichner S.M.,Karset I.H.H.,et al. BVOC-aerosol-climate feedbacks investigated using NorESM[J],2019,19(7).
APA	Sporre M.K.,Blichner S.M.,Karset I.H.H.,Makkonen R.,&Berntsen T.K..(2019).BVOC-aerosol-climate feedbacks investigated using NorESM.Atmospheric Chemistry and Physics,19(7).
MLA	Sporre M.K.,et al."BVOC-aerosol-climate feedbacks investigated using NorESM".Atmospheric Chemistry and Physics 19.7(2019).