Deserts: Can they be the potential suppliers of bioavailable iron?

Saydam, A.C.

doi:10.1029/2001gl013562

Cited by 39 publications

(43 citation statements)

References 10 publications

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“…For our data the low EF (< 10) for all studied elements and depths indicates significant contribution from a crustal source, as previously documented in sediment trap samples in the northwestern Mediterranean by Roussiez et al (2012). It is well documented that the EMS is occasionally influenced by Sahara dust events from northern Africa, containing natural crustal material (Guerzoni et al, 1999;Herut et al, 2005;Jickells, 1995;Ridame and Guieu, 2002;Saydam and Senyuva, 2002).…”

Section: Sources Of Natural and Anthropogenic Compounds In The Deep Isupporting

confidence: 82%

Downward fluxes of elemental carbon, metals and polycyclic aromatic hydrocarbons in settling particles from the deep Ionian Sea (NESTOR site), Eastern Mediterranean

et al. 2013

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To assess sources and major processes controlling the vertical transport of both anthropogenic and natural chemical species in a deep basin of the Eastern Mediterranean Sea (SE Ionian Sea, Nestor site), we performed chemical characterization (elemental carbon, major and trace metals and polycyclic aromatic hydrocarbons) of marine sinking particles. Sediment traps were deployed at five successive depths, 700, 1200, 2000, 3200 and 4300 m from the sea surface from May 2007 to October 2008. Fluxes of all measured chemical species, attributed to both natural and anthropogenic sources, exhibited minimum values from January to March 2008 and maximum from April to September 2008. Crustal matter flux from atmospheric inputs – either "freshly" deposited or stored in the surface layers – plays an important role in the temporal variability of particulate marine matter fluxes along with particulate organic carbon export, imposing ballast effects. Tracers (elemental carbon, retene) of the devastating forest fires that occurred in August 2007 in southern Greece were detected in sediment trap material from all depths with a delay of 15 days at 4300 m, indicating a rapid and well-coupled transport of sinking particulate material between the sea-surface and deep layers of the Eastern Mediterranean Sea. This is in accordance with an evident covariance between certain compounds, suggesting common sources and/or transport mechanisms to depth. Lateral inputs of pollutants at the deepest trap (4300 m) are probably of importance, related to the periodic influence of deep Adriatic water at the study site

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Section: Sources Of Natural and Anthropogenic Compounds In The Deep Isupporting

confidence: 82%

Downward fluxes of elemental carbon, metals and polycyclic aromatic hydrocarbons in settling particles from the deep Ionian Sea (NESTOR site), Eastern Mediterranean

et al. 2013

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“…The atmospheric chemical processing of iron occurs in clouds because they provide a relatively high acidic environment. Observations confirm the relatively high solubility of the iron found in precipitation (e.g., Saydam and Senyuva, 2002). Concerning the solar radiation influence, Zhu et al (1997) observed higher values of soluble iron during the daytime.…”

Section: Iron Solubility and Atmospheric Processingsupporting

confidence: 68%

Atmospheric processing of iron carried by mineral dust

2013

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Nutrification of the open ocean originates mainly from deposited aerosol in which the bio-avaliable iron is likely to be an important factor. The relatively insoluble iron in dust from arid soils becomes more soluble after atmospheric processing and, through its deposition in the ocean, could contribute to marine primary production. To numerically simulate the atmospheric route of iron from desert sources to sinks in the ocean, we developed a regional atmospheric dust-iron model that included parameterization of the transformation of iron to a soluble form caused by dust mineralogy, cloud processes and solar radiation. When compared with field data on the aerosol iron, which were collected during several Atlantic cruises, the results from the higher-resolution simulation experiments showed that the model was capable of reproducing the major observed patterns

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“…It has been suggested that during atmospheric transport, photoreduction of Fe (III), which is stable and relatively insoluble, produces Fe (II), a biologically available and soluble species (e.g., Graedel et al 1986, Duce andTindale 1991). Saydam and Senyuva (2002) propose that oxalate released by fungi in desert dust facilitates photoreduction of Fe (III). Complexation of Fe (II and III) with organic ligands (Butler 1998) with clay minerals in the aerosol acts to stabilize the iron in a bioavailable form.…”

Section: Nutrient Influx and Biogeochemical Effectsmentioning

confidence: 99%