The impacts of fossil fuel emission uncertainties and accounting for 3-D chemical CO2 production on inverse natural carbon flux estimates from satellite and in situ data
Atmospheric carbon dioxide (CO _2 ) inversions for estimating natural carbon fluxes typically do not allow for adjustment of fossil fuel CO _2 emissions, despite significant uncertainties in emission inventories and inadequacies in the specification of international bunker emissions in inversions. A...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2020-01-01
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| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/ab9795 |
| _version_ | 1797747450336772096 |
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| author | James S Wang Tomohiro Oda S Randolph Kawa Sarah A Strode David F Baker Lesley E Ott Steven Pawson |
| author_facet | James S Wang Tomohiro Oda S Randolph Kawa Sarah A Strode David F Baker Lesley E Ott Steven Pawson |
| author_sort | James S Wang |
| collection | DOAJ |
| description | Atmospheric carbon dioxide (CO _2 ) inversions for estimating natural carbon fluxes typically do not allow for adjustment of fossil fuel CO _2 emissions, despite significant uncertainties in emission inventories and inadequacies in the specification of international bunker emissions in inversions. Also, most inversions place CO _2 release from fossil fuel combustion and biospheric sources entirely at the surface. However, a non-negligible portion of the emissions actually occurs in the form of reduced carbon species, which are eventually oxidized to CO _2 downwind. Omission of this ‘chemical pump’ can result in a significant redistribution of the inferred total carbon fluxes among regions. We assess the impacts of different prescriptions of fossil fuel emissions and accounting for the chemical pump on flux estimation, with a novel aspect of conducting both satellite CO _2 observation-based and surface in situ -based inversions. We apply 3-D carbon monoxide (CO) loss rates archived from a state-of-the-art GEOS chemistry and climate model simulation in a forward transport model run to simulate the distribution of CO _2 originating from oxidation of carbon species. We also subtract amounts from the prior surface CO _2 fluxes that are actually emitted in the form of fossil and biospheric CO, methane, and non-methane volatile organic compounds (VOCs). We find that the posterior large-scale fluxes are generally insensitive to the finer-scale spatial differences between the ODIAC and CDIAC fossil fuel CO _2 gridded datasets and assumptions about international bunker emissions. However, accounting for 3-D chemical CO _2 production and the surface correction shifts the global carbon sink, e.g. from land to ocean and from the tropics to the north, with a magnitude and even direction that depend on assumptions about the surface correction. A GOSAT satellite-based inversion is more sensitive to the chemical pump than one using in situ observations, exhibiting substantial flux impacts of 0.28, 0.53, and −0.47 Pg C yr ^−1 over tropical land, global land, and oceans, due to differences in the horizontal and vertical sampling of the two observation types. Overall, the biases from neglecting the chemical pump appear to be minor relative to the flux estimate uncertainties and the differences between the in situ and GOSAT inversions, but their relative importance will grow in the future as observational coverage further increases and satellite retrieval biases decrease. |
| first_indexed | 2024-03-12T15:50:47Z |
| format | Article |
| id | doaj.art-49be2f16c19a4421acc9fe645e7334eb |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T15:50:47Z |
| publishDate | 2020-01-01 |
| publisher | IOP Publishing |
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| series | Environmental Research Letters |
| spelling | doaj.art-49be2f16c19a4421acc9fe645e7334eb2023-08-09T15:08:30ZengIOP PublishingEnvironmental Research Letters1748-93262020-01-0115808500210.1088/1748-9326/ab9795The impacts of fossil fuel emission uncertainties and accounting for 3-D chemical CO2 production on inverse natural carbon flux estimates from satellite and in situ dataJames S Wang0https://orcid.org/0000-0003-1713-8420Tomohiro Oda1https://orcid.org/0000-0002-8328-3020S Randolph Kawa2Sarah A Strode3https://orcid.org/0000-0002-8103-1663David F Baker4https://orcid.org/0000-0003-4144-4946Lesley E Ott5Steven Pawson6https://orcid.org/0000-0003-0200-717XGoddard Earth Science Technology and Research, Universities Space Research Association , Columbia, MD, United States of America; NASA Goddard Space Flight Center , Greenbelt, MD, United States of America; Now at the Institute for Advanced Sustainability Studies , Potsdam, GermanyGoddard Earth Science Technology and Research, Universities Space Research Association , Columbia, MD, United States of America; NASA Goddard Space Flight Center , Greenbelt, MD, United States of AmericaNASA Goddard Space Flight Center , Greenbelt, MD, United States of AmericaGoddard Earth Science Technology and Research, Universities Space Research Association , Columbia, MD, United States of America; NASA Goddard Space Flight Center , Greenbelt, MD, United States of AmericaCooperative Institute for Research in the Atmosphere, Colorado State University , Fort Collins, CO, United States of AmericaNASA Goddard Space Flight Center , Greenbelt, MD, United States of AmericaNASA Goddard Space Flight Center , Greenbelt, MD, United States of AmericaAtmospheric carbon dioxide (CO _2 ) inversions for estimating natural carbon fluxes typically do not allow for adjustment of fossil fuel CO _2 emissions, despite significant uncertainties in emission inventories and inadequacies in the specification of international bunker emissions in inversions. Also, most inversions place CO _2 release from fossil fuel combustion and biospheric sources entirely at the surface. However, a non-negligible portion of the emissions actually occurs in the form of reduced carbon species, which are eventually oxidized to CO _2 downwind. Omission of this ‘chemical pump’ can result in a significant redistribution of the inferred total carbon fluxes among regions. We assess the impacts of different prescriptions of fossil fuel emissions and accounting for the chemical pump on flux estimation, with a novel aspect of conducting both satellite CO _2 observation-based and surface in situ -based inversions. We apply 3-D carbon monoxide (CO) loss rates archived from a state-of-the-art GEOS chemistry and climate model simulation in a forward transport model run to simulate the distribution of CO _2 originating from oxidation of carbon species. We also subtract amounts from the prior surface CO _2 fluxes that are actually emitted in the form of fossil and biospheric CO, methane, and non-methane volatile organic compounds (VOCs). We find that the posterior large-scale fluxes are generally insensitive to the finer-scale spatial differences between the ODIAC and CDIAC fossil fuel CO _2 gridded datasets and assumptions about international bunker emissions. However, accounting for 3-D chemical CO _2 production and the surface correction shifts the global carbon sink, e.g. from land to ocean and from the tropics to the north, with a magnitude and even direction that depend on assumptions about the surface correction. A GOSAT satellite-based inversion is more sensitive to the chemical pump than one using in situ observations, exhibiting substantial flux impacts of 0.28, 0.53, and −0.47 Pg C yr ^−1 over tropical land, global land, and oceans, due to differences in the horizontal and vertical sampling of the two observation types. Overall, the biases from neglecting the chemical pump appear to be minor relative to the flux estimate uncertainties and the differences between the in situ and GOSAT inversions, but their relative importance will grow in the future as observational coverage further increases and satellite retrieval biases decrease.https://doi.org/10.1088/1748-9326/ab9795carbon cyclecarbon dioxideinverse modelingfossil fuel emissionsatmospheric chemistryremote sensing |
| spellingShingle | James S Wang Tomohiro Oda S Randolph Kawa Sarah A Strode David F Baker Lesley E Ott Steven Pawson The impacts of fossil fuel emission uncertainties and accounting for 3-D chemical CO2 production on inverse natural carbon flux estimates from satellite and in situ data Environmental Research Letters carbon cycle carbon dioxide inverse modeling fossil fuel emissions atmospheric chemistry remote sensing |
| title | The impacts of fossil fuel emission uncertainties and accounting for 3-D chemical CO2 production on inverse natural carbon flux estimates from satellite and in situ data |
| title_full | The impacts of fossil fuel emission uncertainties and accounting for 3-D chemical CO2 production on inverse natural carbon flux estimates from satellite and in situ data |
| title_fullStr | The impacts of fossil fuel emission uncertainties and accounting for 3-D chemical CO2 production on inverse natural carbon flux estimates from satellite and in situ data |
| title_full_unstemmed | The impacts of fossil fuel emission uncertainties and accounting for 3-D chemical CO2 production on inverse natural carbon flux estimates from satellite and in situ data |
| title_short | The impacts of fossil fuel emission uncertainties and accounting for 3-D chemical CO2 production on inverse natural carbon flux estimates from satellite and in situ data |
| title_sort | impacts of fossil fuel emission uncertainties and accounting for 3 d chemical co2 production on inverse natural carbon flux estimates from satellite and in situ data |
| topic | carbon cycle carbon dioxide inverse modeling fossil fuel emissions atmospheric chemistry remote sensing |
| url | https://doi.org/10.1088/1748-9326/ab9795 |
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