Evaluating the consistency between OCO-2 and OCO-3 XCO₂ estimates derived from the NASA ACOS version 10 retrieval algorithm

Atmospheric measurement techniques, Journal Year: 2023, Volume and Issue: 16(12), P. 3173 - 3209

Published: June 27, 2023

Abstract. The version 10 (v10) Atmospheric Carbon Observations from Space (ACOS) Level 2 full-physics (L2FP) retrieval algorithm has been applied to multiyear records of observations NASA's Orbiting Observatory and 3 sensors (OCO-2 OCO-3, respectively) provide estimates the carbon dioxide (CO2) column-averaged dry-air mole fraction (XCO2). In this study, a number improvements ACOS v10 L2FP are described. post-processing quality filtering bias correction XCO2 against multiple truth proxies also discussed. OCO data volumes two for time period August 2019 through February 2022 compared, highlighting differences in spatiotemporal sampling but demonstrating broad agreement between where they overlap space. A evaluation sources both suggest broadly similar error characteristics. Mean OCO-3 relative collocated OCO-2 approximately 0.2 −0.3 ppm land ocean observations, respectively. Comparison Total Column Observing Network (TCCON) measurements shows root mean squared errors (RMSEs) 0.8 0.9 An fields derived atmospheric inversion systems that assimilated only near-surface CO2 i.e., did not assimilate satellite measurements, yielded RMSEs 1.0 1.1 Evaluation uncertainties over small areas, as well biases across land–ocean crossings, indicates behavior characteristics sensors. Taken together, these results demonstrate consistency suggesting may be used together scientific analyses.

Language: Английский

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Carbon emissions from the 2023 Canadian wildfires

Nature, Journal Year: 2024, Volume and Issue: 633(8031), P. 835 - 839

Published: Aug. 28, 2024

Abstract The 2023 Canadian forest fires have been extreme in scale and intensity with more than seven times the average annual area burned compared to previous four decades 1 . Here, we quantify carbon emissions from these May September on basis of inverse modelling satellite monoxide observations. We find that magnitude is 647 TgC (570–727 TgC), comparable fossil fuel large nations, only India, China USA releasing per year 2 widespread hot–dry weather was a principal driver fire spread, being warmest driest since at least 1980 3 Although temperatures were relative historical record, climate projections indicate are likely be typical during 2050s, even under moderate mitigation scenario (shared socioeconomic pathway, SSP 2–4.5) 4 Such conditions drive increased activity suppress uptake by forests, adding concerns about long-term durability forests as sink 5–8

Language: Английский

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The Total Carbon Column Observing Network's GGG2020 data version

Earth system science data, Journal Year: 2024, Volume and Issue: 16(5), P. 2197 - 2260

Published: May 6, 2024

Abstract. The Total Carbon Column Observing Network (TCCON) measures column-average mole fractions of several greenhouse gases (GHGs), beginning in 2004, from over 30 current or past measurement sites around the world using solar absorption spectroscopy near-infrared (near-IR) region. TCCON GHG data have been used extensively for multiple purposes, including studies carbon cycle and anthropogenic emissions, as well to validate improve observations space-based sensors. Here, we describe an update retrieval algorithm process near-IR spectra generate associated products. This version, called GGG2020, was initially released April 2022. It includes updates improvements all steps retrieval, but not limited conversion original interferograms into spectra, spectroscopic information column post hoc air mass dependence correction, scaling align with calibration scales situ measurements. All are available through https://tccondata.org/ (last access: 22 2024) hosted on CaltechDATA (https://data.caltech.edu/, last 2024). Each site has a unique DOI its record. An archive sites' is also https://doi.org/10.14291/TCCON.GGG2020 (Total Team, 2022). files updated approximately monthly, required deliver no later than 1 year after acquisition. Full details locations provided “Code availability” section.

Language: Английский

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Permafrost Carbon: Progress on Understanding Stocks and Fluxes Across Northern Terrestrial Ecosystems

Journal of Geophysical Research Biogeosciences, Journal Year: 2024, Volume and Issue: 129(3)

Published: Feb. 26, 2024

Abstract Significant progress in permafrost carbon science made over the past decades include identification of vast stocks, development new pan‐Arctic maps, an increase terrestrial measurement sites for CO 2 and methane fluxes, important factors affecting cycling, including vegetation changes, periods soil freezing thawing, wildfire, other disturbance events. Process‐based modeling studies now key elements cycling advances statistical inverse enhance understanding region C budgets. By combining existing data syntheses model outputs, is likely a wetland source small ecosystem sink with lower net uptake toward higher latitudes, excluding wildfire emissions. For 2002–2014, strongest was located western Canada (median: −52 g m −2 y −1 ) smallest sinks Alaska, Canadian tundra, Siberian tundra (medians: −5 to −9 ). Eurasian regions had largest median fluxes (16–18 CH 4 Quantifying regional scale balance remains challenging because high spatial temporal variability relatively low density observations. More accurate require: (a) better maps characterizing wetlands dynamics disturbances, abrupt thaw; (b) establishment year‐round flux underrepresented areas; (c) improved models that represent cycle dynamics, non‐growing season emissions effects.

Language: Английский

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Recent gains in global terrestrial carbon stocks are mostly stored in nonliving pools

Science, Journal Year: 2025, Volume and Issue: 387(6740), P. 1291 - 1295

Published: March 20, 2025

Terrestrial sequestration of carbon has mitigated ≈30% anthropogenic emissions. However, its distribution across different pools, live or dead biomass and soil sedimentary organic carbon, remains uncertain. Analyzing global observational datasets changes in terrestrial we found that ≈35 ± 14 gigatons (GtC) have been sequestered on land between 1992 2019, whereas changed by ≈1 7 GtC. Global vegetation models instead imply mostly biomass. We identify key processes not included most can explain this discrepancy. Most gains are as nonliving matter thus more persistent than previously appreciated, with a substantial fraction linked to human activities such river damming, wood harvest, garbage disposal landfills.

Language: Английский

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Chapter 2 : Climate Trends. Fifth National Climate Assessment

Published: Jan. 1, 2023

Language: Английский

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Increased Terrestrial Carbon Export and CO₂ Evasion From Global Inland Waters Since the Preindustrial Era

Global Biogeochemical Cycles, Journal Year: 2023, Volume and Issue: 37(10)

Published: Oct. 1, 2023

Abstract Global carbon dioxide (CO 2 ) evasion from inland waters (rivers, lakes, and reservoirs) (C) export land to oceans constitute critical terms in the global C budget. However, magnitudes, spatiotemporal patterns, underlying mechanisms of these fluxes are poorly constrained. Here, we used a coupled terrestrial–aquatic model assess how multiple changes climate, use, atmospheric CO concentration, nitrogen (N) deposition, N fertilizer manure applications have affected riverine along terrestrial‐aquatic continuum. We estimate that terrestrial loadings, export, preindustrial period (1800s) were 1,820 ± 507 (mean standard deviation), 765 132, 841 190 Tg yr −1 , respectively. During 1800–2019, multifactorial caused an increase 25% (461 reaching 2,281 2010s, with 23% (104 this exported ocean 59% (273 being emitted atmosphere. Our results showed water recycles exports nearly half net sink into atmosphere oceans, highlighting important role balance, amount should be taken account future budgets. analysis supports view major feature cycle–the transfer ocean–has undergone dramatic change over last two centuries as result human activities.

Language: Английский

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Soil respiration–driven CO ₂ pulses dominate Australia’s flux variability

Science, Journal Year: 2023, Volume and Issue: 379(6639), P. 1332 - 1335

Published: March 31, 2023

The Australian continent contributes substantially to the year-to-year variability of global terrestrial carbon dioxide (CO 2 ) sink. However, scarcity in situ observations remote areas prevents deciphering processes that force CO flux variability. In this study, by examining atmospheric measurements from satellites period 2009–2018, we find recurrent end-of-dry-season pulses over continent. These largely control Australia’s balance. They cause two three times larger seasonal variations compared with previous top-down inversions and bottom-up estimates. occur shortly after onset rainfall are driven enhanced soil respiration preceding photosynthetic uptake semiarid regions. suggested continental-scale relevance soil-rewetting has substantial implications for our understanding modeling climate–carbon cycle feedbacks.

Language: Английский

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A novel geospatial machine learning approach to quantify non-linear effects of land use/land cover change (LULCC) on carbon dynamics

International Journal of Applied Earth Observation and Geoinformation, Journal Year: 2024, Volume and Issue: 128, P. 103712 - 103712

Published: Feb. 20, 2024

Land Use and Cover Change (LULCC) introduces considerable uncertainties in its relationship with carbon emissions, posing challenges to nature-based climate mitigation. The effective establishment protection of sinks through land use management lack clarity. To address this challenge, study utilized top-down interannual grided CO2 data from satellite observations, revealing a 7 % decline mainland China 2016 2019. Faced anomaly, we proposed novel approach that combined machine learning traditional regression analysis, investigate the nonlinear between annual spatiotemporal variations net exchange LULCC. Sentinel-2 imagery was employed for high-resolution (10 m) LULC classification based on uniform rules. Particularly, time-series class probabilities were considered estimated using deep framework via Google Earth Engine (GEE) cloud platform, which allows us access effects dynamic GIS methods applied enhance interpretability, integrating multi-source remote sensing datasets, particularly capturing features aspects LULCC emissions. Threshold revealed how transformed areas associated or sources. results mapped sink shrinkage locations, highlighting correlations significant reductions snow cover (−6.25 %), changing water patterns (−1.3 urban expansion (1 mixed forest changes (regrowth 4 deforestation −1%). This research aims advance understanding emissions sensing, bridging different observation within geostatistical context, expects provide new validation method bottom-up approach.

Language: Английский

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The importance of digital elevation model accuracy in X_CO2 retrievals: improving the Orbiting Carbon Observatory 2 Atmospheric Carbon Observations from Space version 11 retrieval product

Atmospheric measurement techniques, Journal Year: 2024, Volume and Issue: 17(5), P. 1375 - 1401

Published: March 6, 2024

Abstract. Knowledge of surface pressure is essential for calculating column-averaged dry-air mole fractions trace gases, such as CO2 (XCO2). In the NASA Orbiting Carbon Observatory 2 (OCO-2) Atmospheric Observations from Space (ACOS) retrieval algorithm, retrieved pressures have been found to unacceptable errors, warranting a parametric bias correction. This correction depends on difference between and priori pressures, which are derived meteorological model that hypsometrically adjusted elevation using digital (DEM). As result, effectiveness OCO-2 contingent upon accuracy referenced DEM. Here, we investigate several different DEM datasets use in ACOS algorithm: OCODEM used v10 previous versions, NASADEM+ (a composite SRTMv4, ASTER GDEMv3, GIMP, RAMPv2 DEMs) v11, Copernicus GLO-90 (GLO-90 DEM), two polar regional DEMs (ArcticDEM REMA). We find (ASTER GDEMv3) has persistent negative order 10 20 m across most regions north 60° N latitude, relative all other considered (OCODEM, ArcticDEM, DEM). Variations elevations lead variations XCO2 approximately 0.4 ppm, meaning v11 retrievals tends be 0.8 ppm lower than v10. Our analysis also suggests superior global continuity compared DEMs, motivating post-processing update Lite files (which NASADEM+) v11.1 by substituting globally. improves spatial bias-corrected product both high-latitude while resulting marginal or no change within ± latitude. addition, provides increased data throughput after quality control filtering regions, partly due but mostly corrections parameters. Given large-scale differences NASADEM+, replacing with yields ∼ 100 TgC shift inferred carbon uptake zones spanning 30 60 90° N, 5 % 7 estimated pan-Arctic land sink. Changes fluxes smaller, given evidence improved accuracies this DEM, large changes likely erroneous.

Language: Английский

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