Using Information Theory in Earth Sciences
Second Workshop on Information Theory and the Earth Sciences; Santander, Spain, 16–19 May 2018
Information flow in Earth sciences can encompass many realms. In this schematic, soils are influenced by and influence the biosphere and hydrosphere. Governing these interactions is entropy, represented by the equation at the bottom. A recent workshop sought to tease out how information theory can be used to understand interactions and couplings between different parts of complex environmental systems and models of those systems Credit: Modifed from Goodwell et al., 2018, https://doi.org/10.1073/pnas.1800236115
By Cristina Prieto, Uwe Ehret, and Grey Nearing
Information theory provides a powerful conceptual framework for learning, model building, and prediction in the Earth sciences. It extends probability theory in certain important ways that make it particularly applicable to questions related to value and uncertainty associated with models, data, and forecasts:
How much information does a model or hypothesis contain about the environmental systems we are interested in?
How much information does a data set contain, and how much is redundant with respect to a specific science or forecasting question?
What is the best way to combine information contained in local data with information encoded in general hypotheses, laws, or theories?
How do information theory approaches complement and go beyond existing methods (e.g., Bayesian) for uncertainty analysis?
Last May, a workshop held at the Environmental Hydraulic Institute of Cantabria (IHCantabria) aimed to stimulate new developments in the implementation of information theory to solve practical problems in the Earth sciences. This meeting followed from a workshop held in Germany in 2016 and is linked to a series of upcoming AGU and European Geosciences Union meeting sessions (e.g., “Better Informed Than Uncertain: Applications of Information Theory in the Earth Sciences” to be held at AGU’s Fall Meeting 2018).
Interested participants attended a preworkshop tutorial day, which covered the basics of information theory and gave a broad overview of applications in the Earth sciences. After this tutorial day, participants engaged in moderated discussions, presented posters, and attended lectures on the following topics:
the main concepts and methods of information theory and its relationship with other fields
information flow in process networks of complex system dynamics
the information physics of outlier events sometimes referred to as black swans
the impact of deforestation on rainfall recycling
Discussion topics included information theory and uncertainty as basic concepts of science, approaches to assimilate information and knowledge of many types and sources into models, the potential of formulating generalized null models based on information theory, the use of information theory for diagnostic model evaluation, and approaches to overcome barriers to practical application of information theory to the Earth sciences.
In addition to the inspiring exchange of concepts and ideas, the workshop produced a joint debate paper and a journal research paper (both under preparation), the decision to organize a 2019 summer school on information theory at IHCantabria, and plans for a 2020 workshop in Canada.