气候变化领域集成服务门户(CCPortal): The potential of Orbiting Carbon Observatory-2 data to reduce the uncertainties in CO2 surface fluxes over Australia using a variational assimilation scheme

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DOI	10.5194/acp-20-8473-2020
	The potential of Orbiting Carbon Observatory-2 data to reduce the uncertainties in CO2 surface fluxes over Australia using a variational assimilation scheme
	Villalobos Y.; Rayner P.; Thomas S.; Silver J.
发表日期	2020
ISSN	1680-7316
起始页码	8473
结束页码	8500
卷号	20 期号:14
英文摘要	This paper addresses the question of how much uncertainties in CO2 fluxes over Australia can be reduced by assimilation of total-column carbon dioxide retrievals from the Orbiting Carbon Observatory-2 (OCO-2) satellite instrument. We apply a four-dimensional variational data assimilation system, based around the Community Multiscale Air Quality (CMAQ) transport-dispersion model. We ran a series of observing system simulation experiments to estimate posterior error statistics of optimized monthly-mean CO2 fluxes in Australia. Our assimilations were run with a horizontal grid resolution of 81 km using OCO-2 data for 2015. Based on four representative months, we find that the integrated flux uncertainty for Australia is reduced from 0.52 to 0.13 PgC yr?1. Uncertainty reductions of up to 90% were found at grid-point resolution over productive ecosystems. Our sensitivity experiments show that the choice of the correlation structure in the prior error covariance plays a large role in distributing information from the observations. We also found that biases in the observations would significantly impact the inverted fluxes and could contaminate the final results of the inversion. Biases in prior fluxes are generally removed by the inversion system. Biases in the boundary conditions have a significant impact on retrieved fluxes, but this can be mitigated by including boundary conditions in our retrieved parameters. In general, results from our idealized experiments suggest that flux inversions at this unusually fine scale will yield useful information on the carbon cycle at continental and finer scales. © 2020 EDP Sciences. All rights reserved.
语种	英语
scopus关键词	air quality; carbon dioxide; carbon flux; computer simulation; data assimilation; satellite imagery; surface flux; uncertainty analysis; Australia
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/141210
作者单位	School of Earth Sciences, University of Melbourne, Melbourne, Australia; ARC Centre of Excellence for Climate Extremes, Sydney, Australia
推荐引用方式 GB/T 7714	Villalobos Y.,Rayner P.,Thomas S.,et al. The potential of Orbiting Carbon Observatory-2 data to reduce the uncertainties in CO2 surface fluxes over Australia using a variational assimilation scheme[J],2020,20(14).
APA	Villalobos Y.,Rayner P.,Thomas S.,&Silver J..(2020).The potential of Orbiting Carbon Observatory-2 data to reduce the uncertainties in CO2 surface fluxes over Australia using a variational assimilation scheme.Atmospheric Chemistry and Physics,20(14).
MLA	Villalobos Y.,et al."The potential of Orbiting Carbon Observatory-2 data to reduce the uncertainties in CO2 surface fluxes over Australia using a variational assimilation scheme".Atmospheric Chemistry and Physics 20.14(2020).