Atmospheric fluxes of ²¹⁰Pb to the western Mediterranean Sea and the Saharan dust influence

Pb 210 is a well known tracer of particle dynamics in the marine environment. Geochemical models partially rely on the knowledge of its atmospheric input. Unfortunately, this is poorly known in the western Mediterranean Sea, especially regarding long-term records. In this work we have evaluated the ²¹⁰Pb annual atmospheric flux to this region from the analysis of 12 soil cores collected from coastal and island sites and total atmospheric deposition collected in Corsica during 1 year. The ²¹⁰Pb fluxes ranged from 34 ± 3 to 121 ± 12 Bq m¯² yr¯¹ , with an average of 75 Bq m¯² yr¯¹, and were strongly correlated (R²= 0.95) with mean annual rainfall. This provides the possibility to determine ²¹⁰Pb fluxes in a given location if the mean annual rainfall is well known, a useful outcome for both marine biogeochemical and soil erosion studies in this region. We have also estimated the mean annual atmospheric flux of ²¹⁰Pb due to Saharan dust events registered in total deposition north of Barcelona during the last 17 years, yielding a value of 20 Bq m¯² yr¯¹ . This flux represents a fraction of about 16% of the total atmospheric deposition of ²¹⁰Pb in this area, but it could be up to 50% in sites with lower rainfall

Spatial variability of atmospheric fluxes of metals (Al, Fe, Cd, Zn and Pb) and phosphorus over the whole Mediterranean from a one-year monitoring experiment: Biogeochemical implications

International audienc

Atmospheric fluxes of ²¹⁰Pb to the western Mediterranean Sea and the Saharan dust influence

Pb 210 is a well known tracer of particle dynamics in the marine environment. Geochemical models partially rely on the knowledge of its atmospheric input. Unfortunately, this is poorly known in the western Mediterranean Sea, especially regarding long-term records. In this work we have evaluated the ²¹⁰Pb annual atmospheric flux to this region from the analysis of 12 soil cores collected from coastal and island sites and total atmospheric deposition collected in Corsica during 1 year. The ²¹⁰Pb fluxes ranged from 34 ± 3 to 121 ± 12 Bq m¯² yr¯¹ , with an average of 75 Bq m¯² yr¯¹, and were strongly correlated (R²= 0.95) with mean annual rainfall. This provides the possibility to determine ²¹⁰Pb fluxes in a given location if the mean annual rainfall is well known, a useful outcome for both marine biogeochemical and soil erosion studies in this region. We have also estimated the mean annual atmospheric flux of ²¹⁰Pb due to Saharan dust events registered in total deposition north of Barcelona during the last 17 years, yielding a value of 20 Bq m¯² yr¯¹ . This flux represents a fraction of about 16% of the total atmospheric deposition of ²¹⁰Pb in this area, but it could be up to 50% in sites with lower rainfall

Dust in the Ocean

International audienc

Marine ecosystems'responses to climatic and anthropogenic forcings in the Mediterranean

International audienceNot Availabl

Marine ecosystems’ responses to climatic and anthropogenic forcings in the Mediterranean

Corrigendum : https://doi.org/10.1016/j.pocean.2011.08.003International audienceThe semi-enclosed nature of the Mediterranean Sea, together with its smaller inertia due to the relative short residence time of its water masses, make it highly reactive to external forcings, in particular variations of water, energy and matter fluxes at the interfaces. This region, which has been identified as a “hotspot” for climate change, is therefore expected to experience environmental impacts that are considerably greater than those in many other places around the world. These natural pressures interact with the increasing demographic and economic developments occurring heterogeneously in the coastal zone, making the Mediterranean even more sensitive. This review paper aims to provide a review of the state of current functioning and responses of Mediterranean marine biogeochemical cycles and ecosystems with respect to key natural and anthropogenic drivers and to consider the ecosystems’ responses to likely changes in physical, chemical and socio-economical forcings induced by global change and by growing anthropogenic pressure at the regional scale. The current knowledge on and expected changes due to single forcing (hydrodynamics, solar radiation, temperature and acidification, chemical contaminants) and combined forcing (nutrient sources and stoichiometry, extreme events) affecting the biogeochemical fluxes and ecosystem functioning are explored. Expected changes in biodiversity resulting from the combined action of the different forcings are proposed. Finally, modeling capabilities and necessity for modeling are presented. A synthesis of our current knowledge of expected changes is proposed, highlighting relevant questions for the future of the Mediterranean ecosystems that are current research priorities for the scientific community. Finally, we discuss how these priorities can be approached by national and international multi-disciplinary research, which should be implemented on several levels, including observational studies and modeling at different temporal and spatial scales