气候变化领域集成服务门户(CCPortal): Prior biosphere model impact on global terrestrial CO2 fluxes estimated from OCO-2 retrievals

CCPortal

DOI	10.5194/acp-19-13267-2019
	Prior biosphere model impact on global terrestrial CO2 fluxes estimated from OCO-2 retrievals
	Philip S.; Johnson M.S.; Potter C.; Genovesse V.; Baker D.F.; Haynes K.D.; Henze D.K.; Liu J.; Poulter B.
发表日期	2019
ISSN	16807316
起始页码	13267
结束页码	13287
卷号	19 期号:20
英文摘要	This study assesses the impact of different state of the art global biospheric CO2 flux models, when applied as prior information, on inverse model "top-down" estimates of terrestrial CO2 fluxes obtained when assimilating Orbiting Carbon Observatory 2 (OCO-2) observations. This is done with a series of observing system simulation experiments (OSSEs) using synthetic CO2 column-average dry air mole fraction (XCO2) retrievals sampled at the OCO-2 satellite spatiotemporal frequency. The OSSEs utilized a 4- D variational (4D-Var) assimilation system with the GEOSChem global chemical transport model (CTM) to estimate CO2 net ecosystem exchange (NEE) fluxes using synthetic OCO-2 observations. The impact of biosphere models in inverse model estimates of NEE is quantified by conducting OSSEs using the NASA-CASA, CASA-GFED, SiB-4, and LPJ models as prior estimates and using NEE from the multi-model ensemble mean of the Multiscale Synthesis and Terrestrial Model Intercomparison Project as the "truth". Results show that the assimilation of simulated XCO2 retrievals at OCO-2 observing modes over land results in posterior NEE estimates which generally reproduce "true" NEE globally and over terrestrial TransCom-3 regions that are well-sampled. However, we find larger spread among posterior NEE estimates, when using different prior NEE fluxes, in regions and seasons that have limited OCO-2 observational coverage and a large range in "bottom-up" NEE fluxes. Seasonally averaged posterior NEE estimates had standard deviations (SD) of - 10% to - 50% of the multi-modelmean NEE for different TransCom-3 land regions with significant NEE fluxes (regions/seasons with a NEE flux - 0:5 PgC yr1). On a global average, the seasonally averaged residual impact of the prior model NEE assumption on the posterior NEE spread is - 10 %-20% of the posterior NEE mean. Additional OCO-2 OSSE simulations demonstrate that posterior NEE estimates are also sensitive to the assumed prior NEE flux uncertainty statistics, with spread in posterior NEE estimates similar to those when using variable prior model NEE fluxes. In fact, the sensitivity of posterior NEE estimates to prior error statistics was larger than prior flux values in some regions/times in the tropics and Southern Hemisphere where sufficient OCO-2 data were available and large differences between the prior and truth were evident. Overall, even with the availability of spatiotemporally dense OCO-2 data, noticeable residual differences (up to - 20 %- 30% globally and 50% regionally) in posterior NEE flux es- timates remain that were caused by the choice of prior model flux values and the specification of prior flux uncertainties. © Author(s) 2019.
语种	英语
scopus关键词	atmospheric chemistry; biosphere; carbon cycle; carbon dioxide; carbon flux; ecosystem approach; global perspective; satellite data; terrestrial ecosystem; terrestrial environment
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/144069
作者单位	NASA Ames Research Center, Moffett Field, CA 94035, United States; NASA Postdoctoral Program Administered by Universities Space Research Association, Columbia, MD 21046, United States; School of Natural Sciences, California State University, Monterey Bay, CA 93955, United States; NOAA Earth System Research Laboratory, Global Monitoring Division, Boulder, CO 80305-3337, United States; Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, CO 80521, United States; Department of Atmospheric Science, Colorado State University, Fort Collins, CO 80523, United States; Department of Mechanical Engineering, University of Colorado at Boulder, Boulder, CO 80309, United States; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, United States; NASA Goddard Space Flight Center, Greenbelt, MD 20771, United States; NASA Academic Mission Services by Universities Space Research Association, Mountain View, CA 94043, United States
推荐引用方式 GB/T 7714	Philip S.,Johnson M.S.,Potter C.,et al. Prior biosphere model impact on global terrestrial CO2 fluxes estimated from OCO-2 retrievals[J],2019,19(20).
APA	Philip S..,Johnson M.S..,Potter C..,Genovesse V..,Baker D.F..,...&Poulter B..(2019).Prior biosphere model impact on global terrestrial CO2 fluxes estimated from OCO-2 retrievals.Atmospheric Chemistry and Physics,19(20).
MLA	Philip S.,et al."Prior biosphere model impact on global terrestrial CO2 fluxes estimated from OCO-2 retrievals".Atmospheric Chemistry and Physics 19.20(2019).