My research interests and achievements since moving to America have mainly involved numerical models and theory. My goal is to develop tools and methods that can be used also to facilitate observational oceanography. My collaborative efforts have led to my work in biologivcal oceanography, and projected ocean acidification. Below are descriptions of selected current projects and achievements.

Open Source Software and its adoption by the oceanographic comunity is something I am very invested in. I highlight some of the efforts I have been involved in.

Unlocking the impact of mesoscale turbulence on the subpolar North Atlantic

Important for the global heat transport, the subpolar North Atlantic is a place where important dynamics are difficult to observe and to model. Building on the SAGE method, using also methods from topology and unsupervised machine learning, I am uncovering regions of coherent dynamics that can be used to infer mechanisms important for understanding the circulation. Interactions of currents with canyons and regions associated with export of water from the shelf into the deep are topics I am investigating. Implications include:

  • Unique regimes are identified
  • SAGE is scaled to larger data volumes
  • The shelf and deep currents stand out
  • Canyons are of particular importance

Collaborators: V. Balaji, Alistair Adcroft and Mathieu Le Corre

Decoding ecological complexity using the SAGE method

Global ecology effects our climate and the ocean food chain. Defining glogal regions or provinces help monitor its health, but is difficult due to the overwhelmingly complex ecosystem data. I developed the SAGE (Systematic AGgregated Eco-province) method combining statistical tools, unsupervised machine learning and graphs to determine global provinces in the Darwin ecosystem model. SAGE delivers AEPs (Aggregated Eco-Provinces) for global or regional use, and you can set the 'aggregation' level to fit your needs using the tool here. Implications include:

  • Unique ecological provinces are identified
  • Similar species assemblages are found with very different biomass
  • Regions with similar biomass can have radically different ecology
  • Our framework is both global and nested, making it appropriate for regional and global studies

Collaborators: Steph Dutkiewitz, Chris Hill, Gael Forget

Using machine learning to discover global dynamical regions

Applying an unsupervised learning algorithm the the depth integrated ECCO data, the ocean partitioned itself neatly into globally coherent dynamical regimes in terms of the barotropic vorticity. This means that the way the terms of the barotropic vorticity equation are balanced fall into a subset of configurations. For the decedal ocean, this is remarkably robust. Implications include:

  • Global coherency fitting with the state of the art interpretation
  • Tracing regions that can act as barriers for biology
  • Assessing parameterizations fro the Gulf Stream path or the Antarctic Circumpolar Circulation
  • Ideas of the coupling between the overturning and gyre circulation

Collaborators: Carl Wunsch, Patrick Heimbach

Presenting a benchmark for Sea Surface Height predictability

Sea Surface Height is a critical quantity for vast numbers of people. Living by the coast means that small changes can accumulate, and understanding how the Sea Surface Height varies is cruicial. To check if predictions are skillful, a benchmark is nessesairy to compare against. Developed using linear methods, this suggests that using more complicated methods is merited. Key points include:

  • Sea Surface Height predictability is reasonable using linear statistical models
  • Predictability is related to planetary waves close to the equator, and more to do with advective signals further polewards
  • Complicated models can likely make progress!

Collaborators: Carl Wunsch, Patrick Heimbach<

Barotropic Vorticity dynamics

Vorticity is a tool that is very useful for understanding ocean dynamics. To assess what term does what and where and how things are dissipated a closer look at exactly what is going on is key! Using the closure in the MITgcm/ECCO, we can:

  • Determine relative contribution magnitudes
  • Assess impact of small-scale terms
  • Determine the impact of frameworks e.g. depth integrated or depth averaged

Collaborators: Yvonne Firing, Joel J.-M. Hirschi A. George Nurser

Open Source software initiatives

Adopting Open Source means that oceanography can lean on innovations across a wide range of fields and industry. Open development processes lead to better software in terms of readability, ability to modify and fix bugs as well as for teaching purposes.

  • White paper to NASA on Open Code, BAMS paper to follow
  • Involvement in the URSSI planning phase
  • Developing tools for ECCO in python
  • Introducing Open Source tools to the NOCS compute systems
  • Organising, funding and hosting Software Carpentry workshops