Progress and challenges in remotely sensed terrestrial carbon fluxes

Geo-spatial Information Science, Journal Year: 2024, Volume and Issue: unknown, P. 1 - 21

Published: May 1, 2024

Accurate evaluation of terrestrial carbon balance is essential for designing climate change mitigation policies, and capabilities remote sensing techniques in monitoring fluxes are widely recognized their great contributions to regional global budget accounting. In this review, we synthesized satellite-based data methodologies estimate the main flux components uncertainties over past two decades. The gross primary production (GPP) during period 2001–2022 134 ± 14 PgC yr−1, nearly half them occurs tropical forest regions such as South America Africa. Less than 2% GPP converted into a net sink 2.28 1.12 yr−1 using atmospheric inversion 2015–2020, comparable stock change-based (2.49 yr−1) but twice large model-based (1.08 0.78 yr−1). By decomposing satellite-derived different terms including emissions from land-use wildfires (3.55 yr−1), inferred that ~ 43% would be respired through soil microbes (57.1 which higher previous bottom-up (39–46 We then propose an accurate requires enhance representations photosynthetic responses rising CO2 disturbances, develop satellite-constrained belowground dynamics separate natural anthropogenic emissions, by integrating multi-source satellite sensors orbit, revolutionized with focused field campaigns data-scarce regions.

Language: Английский

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Antecedent Conditions Mitigate Carbon Loss During Flash Drought Events

Geophysical Research Letters, Journal Year: 2024, Volume and Issue: 51(8)

Published: April 24, 2024

Abstract Flash droughts– the rapid drying of land and intensification drought conditions—have devasting impacts to natural resources, food supplies, economy. Less is currently known about drivers flash droughts their impact on landscape carbon losses. We leverage water cycle data from NASA OCO‐2 Soil Moisture Active Passive missions quantify U.S. exchange. On average, pre‐onset uptake fully offsets post‐onset losses, creating a neutral biosphere over ±3 month period surrounding onset. This contrasts with ecosystem models, which underestimate overestimate loss. Furthermore, spaceborne observations solar induced fluorescence (SIF) provide reliable indicator at lead times 2–3 months, due feedbacks between vegetation growth soil study expected improve understanding exchange, facilitate early warning.

Language: Английский

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Using OCO-2 Observations to Constrain Regional CO2 Fluxes Estimated with the Vegetation, Photosynthesis and Respiration Model

Remote Sensing, Journal Year: 2025, Volume and Issue: 17(2), P. 177 - 177

Published: Jan. 7, 2025

A good quantitative knowledge of regional sources and sinks atmospheric carbon dioxide (CO2) is essential for understanding the global cycle. It also a key prerequisite elaborating cost-effective national strategies to achieve goals Paris Agreement. However, available estimates CO2 fluxes many regions world remain uncertain, despite significant recent progress in remote sensing terrestrial vegetation CO2. In this study, we investigate feasibility inferring reliable net ecosystem exchange (NEE) using column-averaged dry-air mole fractions (XCO2) retrieved from Orbiting Carbon Observatory-2 (OCO-2) observations as constraints on parameters widely used Vegetation Photosynthesis Respiration model (VPRM), which predicts based indices derived multispectral satellite imagery. We developed regional-scale inverse modeling system that applies Bayesian variational optimization algorithm optimize VPRM coupled CHIMERE chemistry transport involves preliminary transformation input XCO2 data reduces impact boundary conditions inversion results. investigated potential our by applying it European region (that includes, particular, EU countries UK) warm season (May–September) 2021. The OCO-2 resulted major (more than threefold) reduction prior uncertainty NEE estimate. posterior estimate agrees with independent provided CarbonTracker Europe High-Resolution (CTE-HR) ensemble v10 intercomparison (MIP) inversions. found improves agreement simulations retrievals Total Column Observing Network (TCCON). Our sensitivity test experiments synthetic indicate would even if actual drastically differed their values. Furthermore, be robust strong biases random uncertainties conditions. Overall, study suggests approach offers relatively simple way derive while enhancing applicability where eddy covariance measurements are scarce.

Language: Английский

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Global greenhouse gas reconciliation 2022

Earth system science data, Journal Year: 2025, Volume and Issue: 17(3), P. 1121 - 1152

Published: March 18, 2025

Abstract. In this study, we provide an update on the methodology and data used by Deng et al. (2022) to compare national greenhouse gas inventories (NGHGIs) atmospheric inversion model ensembles contributed international research teams coordinated Global Carbon Project. The comparison framework uses transparent processing of net ecosystem exchange fluxes carbon dioxide (CO2) from inversions estimates terrestrial stock changes over managed land that can be evaluate NGHGIs. For methane (CH4), nitrous oxide (N2O), separate anthropogenic emissions natural sources based directly results make them compatible with Our global harmonized NGHGI database was updated inventory until February 2023 compiling periodical United Nations Framework Convention Climate Change (UNFCCC) Annex I countries sporadic less detailed reports non-Annex given communications biennial reports. data, ensemble 22 produced for most recent assessments budgets CO2, CH4, N2O Project ancillary data. CO2 in study goes through 2021, building our previous report 1990 2019, includes three new satellite compared improved managed-land mask. As a result, although significant differences exist between estimates, both situ lands indicate Russia Canada had larger sink years than reported their NGHGIs, while NGHGIs upward trend but downward Canada. CH4 N2O, are extended 2020. Rapid increases were observed developing countries, varying levels agreement results, developed showed slowly declining or stable emissions. Much denser sampling concentrations different satellites, into constellation, is expected coming years. proposed here applied regularly monitoring effectiveness mitigation policy progress meet objectives pledges. dataset constructed publicly available at https://doi.org/10.5281/zenodo.13887128 (Deng al., 2024).

Language: Английский

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X-BASE: the first terrestrial carbon and water flux products from an extended data-driven scaling framework, FLUXCOM-X

Biogeosciences, Journal Year: 2024, Volume and Issue: 21(22), P. 5079 - 5115

Published: Nov. 18, 2024

Abstract. Mapping in situ eddy covariance measurements of terrestrial land–atmosphere fluxes to the globe is a key method for diagnosing Earth system from data-driven perspective. We describe first global products (called X-BASE) newly implemented upscaling framework, FLUXCOM-X, representing an advancement previous generation FLUXCOM terms flexibility and technical capabilities. The X-BASE are comprised estimates CO2 net ecosystem exchange (NEE), gross primary productivity (GPP), evapotranspiration (ET), time novel, fully transpiration product (ETT), at high spatial (0.05°) temporal (hourly) resolution. NEE −5.75 ± 0.33 Pg C yr−1 period 2001–2020, showing much higher consistency with independent atmospheric carbon cycle constraints compared versions FLUXCOM. improvement was likely only possible thanks international effort increase precision collection processing pipelines, as well extension more site years resulting wider coverage bioclimatic conditions. However, shows very low interannual variability, which common state-of-the-art flux remains scientific challenge. With 125 2.1 same period, GPP slightly than estimates, mostly temperate boreal areas. amounts 74.7×103 0.9×103 km3 globally 2001–2020 but exceeds precipitation many dry areas, indicating overestimation these regions. On average 57 % estimated be transpiration, good agreement isotope-based approaches, land surface models. Despite considerable improvements products, further opportunities development exist. Pathways exploration include methodological choices selection satellite observations, their ingestion into configuration machine learning methods. For this, new FLUXCOM-X framework specifically designed have necessary experiment, diagnose, converge accurate estimates.

Language: Английский

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A global surface CO₂ flux dataset (2015–2022) inferred from OCO-2 retrievals using the GONGGA inversion system

Earth system science data, Journal Year: 2024, Volume and Issue: 16(6), P. 2857 - 2876

Published: June 19, 2024

Abstract. Accurate assessment of the size and distribution carbon dioxide (CO2) sources sinks is important for efforts to understand cycle support policy decisions regarding climate mitigation actions. Satellite retrievals column-averaged dry-air mole fractions CO2 (XCO2) have been widely used infer spatial temporal variations in fluxes through atmospheric inversion techniques. In this study, we present a global spatially resolved terrestrial ocean flux dataset 2015–2022. The was generated by Global ObservatioN-based system monitoring Greenhouse GAses (GONGGA) assimilation Orbiting Carbon Observatory-2 (OCO-2) XCO2 retrievals. We describe budget, interannual variability, seasonal scale set TransCom regions. 8-year mean net biosphere exchange were −2.22 ± 0.75 −2.32 0.18 Pg C yr−1, absorbing approximately 23 % 24 contemporary fossil fuel emissions, respectively. annual growth rate 5.17 0.68 which consistent with National Oceanic Atmospheric Administration (NOAA) measurement (5.24 0.59 yr−1). Europe has largest sink among 11 land regions, followed Boreal Asia Temperate Asia. evaluated comparing posterior simulations Total Column Observing Network (TCCON) as well Observation Package (ObsPack) surface flask observations aircraft observations. Compared using unoptimized fluxes, bias root square error (RMSE) largely reduced across full range locations, confirming that GONGGA improves estimates assimilating OCO-2 data. This will improve broader understanding dynamics their response change. can be accessed at https://doi.org/10.5281/zenodo.8368846 (Jin et al., 2023a).

Language: Английский

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Do State‐Of‐The‐Art Atmospheric CO₂ Inverse Models Capture Drought Impacts on the European Land Carbon Uptake?

Journal of Advances in Modeling Earth Systems, Journal Year: 2023, Volume and Issue: 15(6)

Published: June 1, 2023

Abstract The European land carbon uptake has been heavily impacted by several recent severe droughts, yet quantitative estimates of anomalies are uncertain. Atmospheric CO 2 inverse models (AIMs) provide observation‐based the large‐scale flux dynamics, but how well they capture drought impacts on terrestrial is poorly known. Here we assessed capacity state‐of‐the‐art AIMs in monitoring over 2001–2015 using observations environmental variability and vegetation function made comparisons with bottom‐up anomalies. We found that global inversions only limited surface give divergent impacts. Regional assimilating denser Europe demonstrated some improved consistency, all capturing a reduction during 2012 drought. However, failed to caused 2015 Finally, set assimilated satellite XCO or variables plus better captured induced both droughts. In addition, Orbiting Carbon Observatory—2 showed good potential impacts, performances for larger‐scale droughts like 2018 These results suggest may still be too sparse fully impact cycle at subcontinental scales Europe, ancillary data can used improve observational constraints atmospheric inversion systems.

Language: Английский

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Improved Constraints on the Recent Terrestrial Carbon Sink Over China by Assimilating OCO‐2 XCO₂ Retrievals

Journal of Geophysical Research Atmospheres, Journal Year: 2023, Volume and Issue: 128(14)

Published: July 10, 2023

Abstract The magnitude and distribution of China's terrestrial carbon sink remain uncertain due to insufficient observational constraints; satellite column‐average dry‐air mole fraction dioxide (XCO 2 ) retrievals may fill some this gap. Here, we estimate using atmospheric inversions the Orbiting Carbon Observatory (OCO‐2) XCO within different platforms, including Global Assimilation System (GCAS) v2, Copernicus Atmosphere Monitoring Service, OCO‐2 Model Inter‐comparison Project (MIP). We find that they consistently place largest net biome production (NBP) in south on an annual basis compared northeast other main agricultural areas during peak growing season, coinciding well with forests crops, respectively. Moreover, mean seasonal cycle amplitude NBP is obviously larger than biosphere model simulations slightly greater surface CO inversions. More importantly, constrained temperate, tropical, subtropical monsoon climate zones, better inter‐model consistency at a sub‐regional scale situ simulations. In addition, China for 2015–2019 be between 0.34 (GCASv2) 0.47 ± 0.16 PgC/yr (median std; v10 MIP), indicate impacts extremes (e.g., 2019 drought) interannual variations NBP. Our results suggest assimilating crucial improving our understanding regime.

Language: Английский

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Multi-sensor integrated mapping of global XCO2 from 2015 to 2021 with a local random forest model

ISPRS Journal of Photogrammetry and Remote Sensing, Journal Year: 2024, Volume and Issue: 208, P. 107 - 120

Published: Jan. 18, 2024

Language: Английский

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Spatio-temporal variation of atmospheric CO2 and its association with anthropogenic, vegetation, and climate indices over the state of Bihar, India

Environmental Advances, Journal Year: 2024, Volume and Issue: 16, P. 100513 - 100513

Published: Feb. 29, 2024

Carbon dioxide (CO2) in the Earth's atmosphere is a significant greenhouse gas and plays pivotal role shaping carbon dynamics of specific regions. Here, we have examined spatio-temporal variations atmospheric CO2 Bihar region India provided critical information regarding climate change mitigation. NASA's Orbiting Observatory-2 (OCO-2) satellite retrieved dry air column average concentrations (XCO2) datasets (2015-2021) are used to analyse hot/cold spots, anomalies, moments, their relationships with Bihar's vegetation index. The highest concentration (416 ± 1.5 ppm, hot moments) found April May (summer season) lowest (406 1.6 cold seen monsoon season. results reveal that seasonal XCO2 instrumental comprehending annual dynamics, impacting factors such as plant growth crop yields. Anomalies hotspots analyses identify Kaimur, Munger, Paschim Champaran hotspots, which house major industries, power stations, cement factories mining sites. Moreover, study shows negative correlations (p < 0.001) between various parameters, including Sun Induced Chlorophyll Fluorescence (SIF) at wavelengths 740 757, Normalized Difference Vegetation Index (NDVI), Enhanced (EVI), relative humidity. Particularly, NDVI EVI changes explain variability by 26% 24% 0.001), respectively. Additionally, humidity accounted for 37% variance XCO2. Our indicate socio-economic condition area has not been changed significantly during period. Further, increase afforestation activities counterbalanced small due developmental process over limited locations. These findings contribute our understanding regional implications mitigation efforts.

Language: Английский

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