Influence of Atmospheric Processes on the Solubility and Composition of Iron in Saharan Dust.
Aerosol iron was examined in Saharan dust plumes using a combination of iron near-edge X-ray absorption spectroscopy and wet-chemical techniques. Aerosol samples were collected at three sites located in the Mediterranean, the Atlantic, and Bermuda to characterize iron at different atmospheric transport lengths and time scales. Iron(III) oxides were a component of aerosols at all sampling sites and dominated the aerosol iron in Mediterranean samples. In Atlantic samples, iron(II and III) sulfate, iron(III) phosphate, and iron(II) silicates were also contributors to aerosol composition. With increased atmospheric transport time, iron(II) sulfates are found to become more abundant, aerosol iron oxidation state became more reduced, and aerosol acidity increased. Atmospheric processing including acidic reactions and photoreduction likely influence the form of iron minerals and oxidation state in Saharan dust aerosols and contribute to increases in aerosol-iron solubility.
Amelia F
AF
Longo
Yan
Y
Feng
Barry
B
Lai
Department of Earth, Ocean and Atmospheric Science, Florida State University , Tallahassee, Florida 32306, United States.
William M
WM
Landing
Department of Earth, Ocean and Atmospheric Science, Florida State University , Tallahassee, Florida 32306, United States.
Rachel U
RU
Shelley
Foundation for Research and Technology, Hellas , Patras 70013, Greece.|National Observatory of Athens , Penteli GR-15236, Greece.
Athanasios
A
Nenes
National Observatory of Athens , Penteli GR-15236, Greece.|Department of Chemistry, University of Crete , Iraklion 71003, Greece.
Nikolaos
N
Mihalopoulos
Department of Chemistry, University of Crete , Iraklion 71003, Greece.
Kalliopi
K
Violaki
Ellery D
ED
Ingall
D000336:Aerosols; D004391:Dust; D007501:Iron / Q000737:chemistry*; D012995:Solubility; D056928:X-Ray Absorption Spectroscopy
D000336:Aerosols; D004391:Dust; D007501:Iron