Biogeochemical Cycles

The atmosphere is considered as an important pathway for delivering nutrients to sensitive marine environments such as the remote ocean waters or the oligotrophic Mediterranean Sea. Atmospheric deposition of nitrogen (N), phosphorus (P), iron (Fe), copper (Cu) and other elements is thought to be an important driver for the marine biological activity particular during sea-water stratification. Airborne dust, mostly emitted from soils in arid and semi-arid regions, represents the most important source of airborne trace metal nutrients and phosphorous.  

Emissions from anthropogenic activity has considerably modulated the deposition patterns of these nutrients, with profound impacts on biogeochemical cycles. Apart from direct emissions of reactive nitrogen (oxidized from combustion and reduced forms from agriculture), changes in atmospheric acidity modulate gas-particle partitioning of semi volatiles and the bioavailability by increasing their solubility. The latter is especially important in the case of airborne dust acidification, as it can mobilize Fe, P, Cu, trace nutrients that may promote or inhibit primary productivity throughout the oceans. Airborne particles of biological origin (e.g. bacteria, viruses, fungi, fungal spores, pollen) have been found to make a significant contribution to atmospheric sources of N and P, indicating potentially significant interactions between terrestrial and marine ecosystems.

At LAPI, we use advanced analytical approaches (e.g. chromatography and high resolution mass spectrometry) as powerful tools in chemical analysis. The high-resolution analysis achieved with these analytical approaches identify and quantify the inorganic and organic species associated with the nutrients in atmospheric particles, as well as the impact of atmospheric processing thereon. The development of high resolution online analytical techniques for field deployment, combined with atmospheric modeling address questions of high ecological importance for nutrient deposition and marine ecosystems.

Research themes

Useful links

Violaki, K., Bourrin, F., Aubert, D., Kouvarakis, G., Delsaut N., and N. Mihalopoulos. Organic Phosphorus in atmospheric deposition over Mediterranean Sea: An important missing piece of the P cycle. Progress in Oceanography, Elsevier, 2018, 163, pp.50-58.

Ellery D. Ingall, Yan Feng, Amelia F. Longo, Barry Lai, Rachel U. Shelley, William M. Landing, Peter L. Morton, Athanasios Nenes, Nikolaos Mihalopoulos, Kalliopi Violaki, Yuan Gao, Shivraj Sahai, and Erin Castorina. The effect of pH on the solubility of aerosol iron. Atmosphere 2018, 9(5), 201; 

Ito, T., Nenes, A., Johnson, M. S., Meskhidze, N., Valett, J., and Deutsch, C. (2016) Late 20th century deoxygenation of the tropical Pacific enhanced by aerosol pollutants, Nature Geosci., doi:10.1038/ngeo2717;

Myriokefalitakis, S., Nenes, A., Baker, A.R., Mihalopoulos, A. and Kanakidou, M. (2016) Bioavailable atmospheric phosphorous supply to the global ocean: a 3-D global modelling study, Biogeosciences, 13, 6519-6543.

Stockdale, A., Krom, M.D., Mortimer, R.J.G., Benning, L.G., Carslaw, K., Herbert, R., Shi, Z., Myriokefalitakis, S., Kanakidou, M., and Nenes, A. (2016) Supply of bioavailable phosphorus to the oceans: understanding the nature of atmospheric acid processing of mineral dusts, Proc.Nat.Acad.Sci,, doi:10.1073/pnas.1608136113

Kalliopi Violaki, Ting Fang, Nikos Mihalopoulos, Rodney. Weber, Athanasios Nenes, A real-time, online automated system for measurement of water soluble reactive Phosphate (SRP) ions in atmospheric particles, Anal. , 88 (14), pp 7163–7170, 2016. DOI: 10.1021/acs.analchem.6b01264

Amelia F. Longo, Yan Feng , Barry Lai, William M. Landing, Rachel U. Shelley, Athanasios Nenes, Nikolaos Mihalopoulos, Kalliopi Violaki, and Ellery D. Ingall, Influence of atmospheric processes on the solubility and composition of iron in Saharan dust. Environ. Sci. Technol., 50 (13), pp 6912–6920, 2016. DOI: 10.1021/acs.est.6b02605.

Violaki, K., Sciare, J., Williams, J., Baker, A.R., Martino, M., and N. Mihalopoulos. Organic nitrogen in marine aerosols: A global perspective. Biogeosciences 12, 3131-3140, 2015. doi:10.5194/bg-12-3131-2015.

Longo, A.F., Ingall, E.D., Diaz, J.M., Oakes, M., King, L.E., Mihalopoulos, N., Violaki, K., Avila, A., Nenes, A., Benitez-Nelson, C.R., Brandes, J., McNulty, I., and D.J. Vine. P-NEXFS Characterization of Phosphorus Composition in Mediterranean Aerosols. Geophysical Research Letters, Volume 41(11), 4043-4049, 2014. DOI:10.1002/2014GL060555.

Nenes, A., Krom, M.D., Mihalopoulos, N., Van Cappellen, P., Shi, Z., Bougiatioti, A., Zarmpas, P., and Herut, B. (2011) Atmospheric acidification of mineral aerosols: A source of bioavailable phosphorus for the oceans, Atmos.Chem.Phys., 11, 6265-6272