Carbon fluxes across the land-ocean interface: the role of Submarine Groundwater Discharge

The land-ocean interface plays a key role in the global carbon cycle, chiefly influencing Earth climate. There are however large unknowns on sinks and sources of carbon in marine coastal areas. Among the sources, the supply of dissolved carbon via submarine groundwater discharge (SGD) remains poorly understood, mainly because SGD is an invisible process that is difficult to detect and quantify. SGD occurs along all coastlines worldwide and it is now recognized as a major source of solutes from the land to the coastal ocean. However, most of the studies worldwide have focused on the transfer of nutrients and metals via SGD and little is known on the relevance of SGD as a source of carbon to coastal oceans.

In this PhD project, we will focus on understanding the fluxes of key dissolved carbon compounds supplied by SGD to the coastal ocean. The main studied compounds include: i) Dissolved Organic Carbon (DOC), which influences coastal metabolism and ecosystem functioning; ii) CO₂ and CH₄, chiefly influencing coastal gas emissions and altering coastal carbonate chemistry; and iii) Black or Pyrogenic Carbon, produced by the incomplete combustion of biomass and fossil fuels. Understanding the role of SGD as a source of black carbon to the ocean is particularly relevant because there is little knowledge on this component. The study of black carbon has gained attention in recent years because it is environmentally persistent and can contribute significantly to the long-term burial of carbon to the lithosphere. This an interdisciplinary project that will combine field samplings in different Mediterranean coastal areas (e.g. Ebro Delta, Balearic Islands, France), the implementation of models to quantify SGD-driven carbon fluxes (based on radionuclides and other tracers) and the implementation of analytical techniques to quantify different carbon components.didate will contribute to advancing both our understanding of tumor dynamics and the development of sustainable, energy-aware technologies in modern radiotherapy.

We are looking for a highly motivated candidate with a BSc and/or MSc degree in Environmental Sciences, Oceanography or a related field relevant to the position. The ideal candidate will have a solid academic background in marine biogeochemistry, oceanography, hidrogeology or environmental chemistry.

The position involves sampling processes, laboratory and analytical work, as well as data analysis and interpretation. Previous experience in fieldwork, laboratory techniques (chemical analyses), and advanced data analysis will be highly valued. Programming skills in R or Python are particularly desirable.

The successful candidate should be able to work independently while also collaborating effectively within interdisciplinary research teams. Strong written and oral English skills are essential.

The MERS research group (ICTA & Department of Physics) investigates biogeochemical processes in marine and freshwater systems, which are highly sensitive to climate change. The MERS strategic research areas include: land-ocean and wetland-atmosphere interaction processes, application of radionuclides as tracers of environmental processes, anthropogenic impacts on coastal and oceanic ecosystems, dynamics of oceanic biogeochemical cycles, the interaction of marine organisms with global change, paleoceanography, and marine social sciences.

The Impactant research group operates the laboratory facilities at ICTA (Institut de Ciència i Tecnologia Ambientals), specializing in the characterization of organic components relevant to environmental, geochemical, and archaeological research. Recent research activities of Impactant research group focus on describing the global distribution and accumulation of pyrogenic carbon in the global oceans.