Biogeochemical cycles and ecosystem dynamics: models, computational methods, and applications
Biogeochemistry integrates research questions and methodologies from geoscience, biology, and chemistry, with the final goal to understand how life and the biosphere modulate the fluxes and space-time distributions of energy and matters in the Earth System at the global, regional, and sub-regional scale. Free energy fluxes keep the Earth System in a far from equilibrium state and fuel the global biogeochemical cycles of water and chemical elements through biotic (biosphere) and abiotic (lithosphere, atmosphere, hydrosphere) compartments of Earth. Biogeochemical cycles exist for Carbon, Nitrogen, Phosphorus, Oxygen, Sulphur and any other chemical element, including pollutants such as Mercury. Human activities can and do affect those cycling, by increasing some of the fluxes, with potential cascading consequences on the whole system. Ecology further expands the focus on the biosphere, by exploring the relationships among living organisms and between living organisms and the environment.
Ocean biogeochemistry and marine ecosystems science investigate multi-scale processes spanning from biogeochemical dynamics at low trophic levels within a specific marine ecosystem (e.g. exchange and transport of inorganic nutrients among different phytoplankton groups) to the global Carbon, Nitrogen, Phosphorus cycles, and their response to anthropic pressures effects in marine environments, including climate changes, pollution, ocean acidification, eutrophication.
The research activity of the ECHO group of OGS focuses on quantitative approaches to biogeochemistry and ecosystem dynamics, such as numerical analysis, synthesis, integration and modeling of the state and dynamics of estuarine, coastal and marine systems. ECHO research activities include the development, analysis and use of methods of numerical analysis and models of varying complexity (physical models, biogeochemical models, ecological models) also covering the development and application of methods based on high-performance supercomputers.
Applications address impacts of natural and anthropogenic pressures on marine systems, climate change projections, biodiversity and ecosystem functioning, food webs and networks, ecosystem approach to fisheries and aquaculture, operational oceanography and data assimilation, analysis of integrated eco-socio-economic systems, sustainable development, integrated coastal zone management, governance.
A non-exhaustive list of topics proposed within the PhD programme is:
- Development of schemes for real time integration of observations from remote platforms (e.g. satellites or surface current radars) in numerical models.
- Ocean optics: analysis of the multi-spectral bio-optical interactions in marine systems and integration of multi- and hyper-spectral observations from last generation sensors on board of satellites.
- Analysis of mutual feedbacks among living and non-living compartments in marine environments with coupled physical-biogeochemical models, such as turbulence effects on inorganic nutrients distribution and transport, or dynamics of interactions between ocean currents and connectivity.
- Development and implementation of ecosystem-based approach methods to provide information for the integrated environmental management of the coastal zones, ecosystem services, marine spatial planning.
- Development and application of size spectra models to describe marine ecosystem dynamics, from virus to whales.
- Trait or individual (agent) based models for plankton network dynamics and analysis of relationships between biodiversity, stability, resilience.
- Finite element models for high-resolution description of hydrodynamics and biogeochemistry in coastal area and open seas.