TY - JOUR
T1 - Tracking the changes of iron solubility and air pollutants traces as African dust transits the Atlantic in the Saharan dust outbreaks
AU - Rodríguez, Sergio
AU - Prospero, Joseph M.
AU - López-Darias, Jessica
AU - García-Alvarez, María Isabel
AU - Zuidema, Paquita
AU - Nava, Silvia
AU - Lucarelli, Franco
AU - Gaston, Cassandra J.
AU - Galindo, Luis
AU - Sosa, Elisa
N1 - Funding Information:
The project AEROATLAN (CGL 2015-66299-P) is funded by the Ministry of Economy and Competitiveness of Spain and the European Regional Development Fund. M.I.G. was awarded with a grant provided by the Canarian Agency for Research, Innovation and Information Society , co-funded by the European Social Funds. J.L.D. is awarded with a posdoc contract Agustín de Bethencourt, funded by the program Fomento de la Transferencia of the Cabildo de Tenerife. We acknowledge the complementary data provided by AERONET and NASA Giovanni online data system (developed and maintained by the NASA GES DISC). The authors gratefully acknowledge the NOAA Air Resources Laboratory for the provision of the HYSPLIT transport and dispersion model used in this publication (SM). We also thank the brotherhood of fishermen of La Punta del Hidalgo (Cofradía de Pescadores de La Punta del Hidalgo) of Tenerife for collecting offshore seawater and the Research Support General Service (SEGAI) of the University of La Laguna for the laboratory facilities.
PY - 2021/2/1
Y1 - 2021/2/1
N2 - We studied the solubility, in real sea water, of iron present in the African dust outbreaks that traverse the Atlantic. Based on measurements of soluble iron (sFe) and aerosol chemistry, we found iron solubilities within the range of 0.4–1.8% in Tenerife, 0.4–3.1% in Barbados and 1.6–12% in Miami. We apportioned the concentrations of sFe between the three sources and processes that we identified: (1) dust, (2) heavy fuel oil combustion emissions, associated with an excess of vanadium and nickel, and (3) atmospheric processing, which is influenced by acidic pollutants. We tracked the propagation of the dust-front of the African dust outbreaks across the Atlantic, which are associated with dust peak events at the impacting sites. During the westward transport across the Atlantic, the contribution to sFe from dust decreased (63%, 43% and 9% in Tenerife, Barbados and Miami, respectively), whereas the contribution due to atmospheric processing increased (26%, 45% and 74% in Tenerife, Barbados and Miami, respectively). In these Saharan-dust outbreaks, the concentrations of sFe due to heavy fuel oil combustion were significantly lower (mostly < 5 ng/m3) than those in the polluted marine atmosphere (10–200 ng/m3). The overall results are consistent with the idea that the mixing of dust with acid pollutants increases the solubility of iron during the African-dust outbreaks that traverse the Atlantic.
AB - We studied the solubility, in real sea water, of iron present in the African dust outbreaks that traverse the Atlantic. Based on measurements of soluble iron (sFe) and aerosol chemistry, we found iron solubilities within the range of 0.4–1.8% in Tenerife, 0.4–3.1% in Barbados and 1.6–12% in Miami. We apportioned the concentrations of sFe between the three sources and processes that we identified: (1) dust, (2) heavy fuel oil combustion emissions, associated with an excess of vanadium and nickel, and (3) atmospheric processing, which is influenced by acidic pollutants. We tracked the propagation of the dust-front of the African dust outbreaks across the Atlantic, which are associated with dust peak events at the impacting sites. During the westward transport across the Atlantic, the contribution to sFe from dust decreased (63%, 43% and 9% in Tenerife, Barbados and Miami, respectively), whereas the contribution due to atmospheric processing increased (26%, 45% and 74% in Tenerife, Barbados and Miami, respectively). In these Saharan-dust outbreaks, the concentrations of sFe due to heavy fuel oil combustion were significantly lower (mostly < 5 ng/m3) than those in the polluted marine atmosphere (10–200 ng/m3). The overall results are consistent with the idea that the mixing of dust with acid pollutants increases the solubility of iron during the African-dust outbreaks that traverse the Atlantic.
KW - Acid processing
KW - Anthropogenic soluble iron
KW - Dust aging
KW - Iron solubility
KW - Soluble iron
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U2 - 10.1016/j.atmosenv.2020.118092
DO - 10.1016/j.atmosenv.2020.118092
M3 - Article
AN - SCOPUS:85097778970
VL - 246
JO - Atmospheric Environment
JF - Atmospheric Environment
SN - 1352-2310
M1 - 118092
ER -