干旱区生态环境知识资源中心(Arid): Sensitivity of isoprene emissions to drought over south-eastern Australia: Integrating models and satellite observations of soil moisture

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DOI	10.1016/j.atmosenv.2019.04.038
	Sensitivity of isoprene emissions to drought over south-eastern Australia: Integrating models and satellite observations of soil moisture
	Emmerson, Kathryn M.1; Palmer, Paul, I 2; Thatcher, Marcus 1; Haverd, Vanessa 3; Guenther, Alex B.4
通讯作者	Emmerson, Kathryn M.
来源期刊	ATMOSPHERIC ENVIRONMENT
ISSN	1352-2310
EISSN	1873-2844
出版年	2019
卷号	209 页码:112-124
英文摘要	South-east Australia, characterized by arid and semi-arid climate, has experienced large-scale rainfall reductions in recent decades. Larger temporal and spatial drought conditions are predicted in future. The temperate south east coastal zone is characterized by dense forests of Eucalyptus. Drought conditions have implications for the functioning of these indigenous ecosystems, and for emissions of reactive gases that are upwind of major metropolitan regions along the eastern coast. Here, we focus on the impact of drought on the emission of isoprene, a volatile organic compound emitted by a range of trees and shrubs. Previous model calculations grossly overestimate observations of the isoprene mixing ratio, potentially due to overestimated emission factors for native vegetation, but could also be due to drought-induced isoprene emission reductions. We develop the implementation of the Model of Emissions of Gases and Aerosols from Nature (MEGAN) within the CSIRO Chemical Transport Model to include a parameterization of drought using soil moisture. We test this parameterization using two approaches. First, we drive MEGAN using soil moisture fields from two Australian land surface models achieving reductions in isoprene emissions of 24-52% during summer. Second, we use a simple statistical approach to nudge model soil moisture towards satellite observations from the Soil Moisture and Ocean Salinity (SMOS) instrument. This work is the first application of SMOS towards isoprene emission modelling, providing a constraint on surface soil moisture which extends to global scales. Applying these soil moisture approaches, domain average isoprene emissions reduce by 38-58% in summer. Using these results, errors in basal emissions are likely in the region of 40%. Comparison of modelled soil moisture to observations using root density weighted averages across depths of 4 m showed minor differences of up to 0.04 m(3)m(-3). We find that the choice of land surface model used in the SMOS assimilations has a greater impact on isoprene emissions than adjusting either the nudging strength or the number of soil levels these satellite data may influence. However there are only small differences of 3% when using hourly or 24-hourly soil moisture input data to drive the emission calculations, suggesting that the lower temporal availability of satellite data does not reduce model quality. As the spatial resolution of satellite observations of atmospheric composition and land surface properties begin to approach the resolution of regulatory air quality models, we anticipate that these data will improve model predictive skills further.
英文关键词	Isoprene emissions Drought Soil moisture SMOS
类型	Article
语种	英语
国家	Australia ; Scotland ; USA
开放获取类型	hybrid, Green Published
收录类别	SCI-E
WOS记录号	WOS:000470945900011
WOS关键词	MONOTERPENE EMISSIONS ; MEGAN MODEL ; DATA SET ; PHOTOSYNTHESIS ; WATER ; IMPACT ; PREDICTIONS ; MECHANISM ; AEROSOLS ; STRESS
WOS类目	Environmental Sciences ; Meteorology & Atmospheric Sciences
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
来源机构	Commonwealth Scientific and Industrial Research Organisation
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/214502
作者单位	1.CSIRO Oceans & Atmosphere, PMB1, Aspendale, Vic 3195, Australia; 2.Univ Edinburgh, Sch GeoSci, Edinburgh EH9 3JW, Midlothian, Scotland; 3.CSIRO Oceans & Atmosphere, Canberra, ACT 2601, Australia; 4.Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA 92697 USA
推荐引用方式 GB/T 7714	Emmerson, Kathryn M.,Palmer, Paul, I,Thatcher, Marcus,et al. Sensitivity of isoprene emissions to drought over south-eastern Australia: Integrating models and satellite observations of soil moisture[J]. Commonwealth Scientific and Industrial Research Organisation,2019,209:112-124.
APA	Emmerson, Kathryn M.,Palmer, Paul, I,Thatcher, Marcus,Haverd, Vanessa,&Guenther, Alex B..(2019).Sensitivity of isoprene emissions to drought over south-eastern Australia: Integrating models and satellite observations of soil moisture.ATMOSPHERIC ENVIRONMENT,209,112-124.
MLA	Emmerson, Kathryn M.,et al."Sensitivity of isoprene emissions to drought over south-eastern Australia: Integrating models and satellite observations of soil moisture".ATMOSPHERIC ENVIRONMENT 209(2019):112-124.