2026-04-04T02:39:57Zhttps://recercat.cat/oai/request
oai:recercat.cat:2072/4886312025-11-07T14:02:30Zcom_2072_98col_2072_378192
RECERCAT author Davtian, Nina author Penalva Arias, Nuria author Teruel, Oriol author Comes, Pau author Rosell Melé, Antoni author Villanueva, Joan 2025-11-07T14:02:30Z 2025-11-07T14:02:30Z 2025 http://hdl.handle.net/2072/488631 Unidad de excelencia María de Maeztu CEX2019-000940-MOceanic dissolved black carbon (DBC) is the subject of a conundrum between the dominant riverine inputs in terms of mass flux and its stable and radiogenic carbon isotope composition inconsistent with a predominant riverine origin. Here, we analyzed seawater samples within specific and contrasting water masses along several latitudinal and longitudinal transects across the Atlantic Ocean to quantify DBC and map its latitudinal and water depth changes in this ocean. After comparing latitudinal changes in surface water DBC properties with those in atmospheric pyrogenic carbon inputs from seasonal, massive grass burning events in the African Savanna, we could not demonstrate the significance of atmospheric deposition as a non-riverine source of DBC in the Atlantic Ocean, likely due to the balance by DBC photo-bleaching. We found constant DBC concentrations and increasing trends in the condensation degree of DBC (i.e., B6CA:B5CA molar ratio) from surface to deep Atlantic waters and from the South Atlantic to the North Atlantic within individual shallow to deep water masses. Overall, our mapping of DBC in the Atlantic Ocean highlights the need to explore the following alternative hypotheses in the future to better understand the cycling of oceanic DBC: 1) enhanced regional atmospheric BC deposition from African savanna grassland fires impact particulate rather than dissolved BC in the Atlantic Ocean, 2) oceanic DBC has a predominantly non-pyrogenic origin, and 3) exports of terrigenous DBC across the Atlantic Ocean accompany those of terrigenous humic-like compounds from the North Atlantic via meridional circulation. open access Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original. https://creativecommons.org/licenses/by/4.0/ Atlantic Ocean Benzene polycarboxylic acids Dissolved black carbon Surface water Water column Mapping of dissolved black carbon in the Atlantic Ocean Article