Atmospheric Black Carbon Loadings and Sources over Eastern Sub-Saharan Africa Are Governed by the Regional Savanna Fires
Vast black carbon (BC) emissions from sub-Saharan Africa are perceived to warm the regional climate, impact rainfall patterns, and impair human respiratory health. However, the magnitudes of these perturbations are ill-constrained, largely due to limited ground-based observations and uncertainties i...
| Main Authors: | , , , , , , , , , , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | English |
| Published: |
American Chemical Society (ACS)
2023
|
| Online Access: | https://hdl.handle.net/1721.1/148194 |
| _version_ | 1811094895351300096 |
|---|---|
| author | Kirago, Leonard Gustafsson, Örjan Gaita, Samuel M Haslett, Sophie L deWitt, H Langley Gasore, Jimmy Potter, Katherine E Prinn, Ronald G Rupakheti, Maheswar Ndikubwimana, Jean de Dieu Safari, Bonfils Andersson, August |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Kirago, Leonard Gustafsson, Örjan Gaita, Samuel M Haslett, Sophie L deWitt, H Langley Gasore, Jimmy Potter, Katherine E Prinn, Ronald G Rupakheti, Maheswar Ndikubwimana, Jean de Dieu Safari, Bonfils Andersson, August |
| author_sort | Kirago, Leonard |
| collection | MIT |
| description | Vast black carbon (BC) emissions from sub-Saharan Africa are perceived to warm the regional climate, impact rainfall patterns, and impair human respiratory health. However, the magnitudes of these perturbations are ill-constrained, largely due to limited ground-based observations and uncertainties in emissions from different sources. This paper reports multiyear concentrations of BC and other key PM2.5 aerosol constituents from the Rwanda Climate Observatory, serving as a regional receptor site. We find a strong seasonal cycle for all investigated chemical species, where the maxima coincide with large-scale upwind savanna fires. BC concentrations show notable interannual variability, with no clear long-term trend. The Δ14C and δ13C signatures of BC unambiguously show highly elevated biomass burning contributions, up to 93 ± 3%, with a clear and strong savanna burning imprint. We further observe a near-equal contribution from C3 and C4 plants, irrespective of air mass source region or season. In addition, the study provides improved relative emission factors of key aerosol components, organic carbon (OC), K+, and NO3-, in savanna-fires-influenced background atmosphere. Altogether, we report quantitative source constraints on Eastern Africa BC emissions, with implications for parameterization of satellite fire and bottom-up emission inventories as well as regional climate and chemical transport modeling. |
| first_indexed | 2024-09-23T16:07:11Z |
| format | Article |
| id | mit-1721.1/148194 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T16:07:11Z |
| publishDate | 2023 |
| publisher | American Chemical Society (ACS) |
| record_format | dspace |
| spelling | mit-1721.1/1481942023-02-24T03:03:19Z Atmospheric Black Carbon Loadings and Sources over Eastern Sub-Saharan Africa Are Governed by the Regional Savanna Fires Kirago, Leonard Gustafsson, Örjan Gaita, Samuel M Haslett, Sophie L deWitt, H Langley Gasore, Jimmy Potter, Katherine E Prinn, Ronald G Rupakheti, Maheswar Ndikubwimana, Jean de Dieu Safari, Bonfils Andersson, August Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Vast black carbon (BC) emissions from sub-Saharan Africa are perceived to warm the regional climate, impact rainfall patterns, and impair human respiratory health. However, the magnitudes of these perturbations are ill-constrained, largely due to limited ground-based observations and uncertainties in emissions from different sources. This paper reports multiyear concentrations of BC and other key PM2.5 aerosol constituents from the Rwanda Climate Observatory, serving as a regional receptor site. We find a strong seasonal cycle for all investigated chemical species, where the maxima coincide with large-scale upwind savanna fires. BC concentrations show notable interannual variability, with no clear long-term trend. The Δ14C and δ13C signatures of BC unambiguously show highly elevated biomass burning contributions, up to 93 ± 3%, with a clear and strong savanna burning imprint. We further observe a near-equal contribution from C3 and C4 plants, irrespective of air mass source region or season. In addition, the study provides improved relative emission factors of key aerosol components, organic carbon (OC), K+, and NO3-, in savanna-fires-influenced background atmosphere. Altogether, we report quantitative source constraints on Eastern Africa BC emissions, with implications for parameterization of satellite fire and bottom-up emission inventories as well as regional climate and chemical transport modeling. 2023-02-23T16:47:24Z 2023-02-23T16:47:24Z 2022 2023-02-23T16:13:57Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/148194 Kirago, Leonard, Gustafsson, Örjan, Gaita, Samuel M, Haslett, Sophie L, deWitt, H Langley et al. 2022. "Atmospheric Black Carbon Loadings and Sources over Eastern Sub-Saharan Africa Are Governed by the Regional Savanna Fires." Environmental Science and Technology, 56 (22). en 10.1021/ACS.EST.2C05837 Environmental Science and Technology Creative Commons Attribution 4.0 International license https://creativecommons.org/licenses/by/4.0/ application/pdf American Chemical Society (ACS) ACS |
| spellingShingle | Kirago, Leonard Gustafsson, Örjan Gaita, Samuel M Haslett, Sophie L deWitt, H Langley Gasore, Jimmy Potter, Katherine E Prinn, Ronald G Rupakheti, Maheswar Ndikubwimana, Jean de Dieu Safari, Bonfils Andersson, August Atmospheric Black Carbon Loadings and Sources over Eastern Sub-Saharan Africa Are Governed by the Regional Savanna Fires |
| title | Atmospheric Black Carbon Loadings and Sources over Eastern Sub-Saharan Africa Are Governed by the Regional Savanna Fires |
| title_full | Atmospheric Black Carbon Loadings and Sources over Eastern Sub-Saharan Africa Are Governed by the Regional Savanna Fires |
| title_fullStr | Atmospheric Black Carbon Loadings and Sources over Eastern Sub-Saharan Africa Are Governed by the Regional Savanna Fires |
| title_full_unstemmed | Atmospheric Black Carbon Loadings and Sources over Eastern Sub-Saharan Africa Are Governed by the Regional Savanna Fires |
| title_short | Atmospheric Black Carbon Loadings and Sources over Eastern Sub-Saharan Africa Are Governed by the Regional Savanna Fires |
| title_sort | atmospheric black carbon loadings and sources over eastern sub saharan africa are governed by the regional savanna fires |
| url | https://hdl.handle.net/1721.1/148194 |
| work_keys_str_mv | AT kiragoleonard atmosphericblackcarbonloadingsandsourcesovereasternsubsaharanafricaaregovernedbytheregionalsavannafires AT gustafssonorjan atmosphericblackcarbonloadingsandsourcesovereasternsubsaharanafricaaregovernedbytheregionalsavannafires AT gaitasamuelm atmosphericblackcarbonloadingsandsourcesovereasternsubsaharanafricaaregovernedbytheregionalsavannafires AT haslettsophiel atmosphericblackcarbonloadingsandsourcesovereasternsubsaharanafricaaregovernedbytheregionalsavannafires AT dewitthlangley atmosphericblackcarbonloadingsandsourcesovereasternsubsaharanafricaaregovernedbytheregionalsavannafires AT gasorejimmy atmosphericblackcarbonloadingsandsourcesovereasternsubsaharanafricaaregovernedbytheregionalsavannafires AT potterkatherinee atmosphericblackcarbonloadingsandsourcesovereasternsubsaharanafricaaregovernedbytheregionalsavannafires AT prinnronaldg atmosphericblackcarbonloadingsandsourcesovereasternsubsaharanafricaaregovernedbytheregionalsavannafires AT rupakhetimaheswar atmosphericblackcarbonloadingsandsourcesovereasternsubsaharanafricaaregovernedbytheregionalsavannafires AT ndikubwimanajeandedieu atmosphericblackcarbonloadingsandsourcesovereasternsubsaharanafricaaregovernedbytheregionalsavannafires AT safaribonfils atmosphericblackcarbonloadingsandsourcesovereasternsubsaharanafricaaregovernedbytheregionalsavannafires AT anderssonaugust atmosphericblackcarbonloadingsandsourcesovereasternsubsaharanafricaaregovernedbytheregionalsavannafires |