Correlation-based Bayesian modelling of the Holocene geomagnetic field: GFZ

Correlation-based Bayesian modelling of the Holocene geomagnetic field

The geomagnetic main field, generated by geodynamo processes in the Earth's fluid outer core, plays an important role in shielding our habitat against solar wind and cosmic rays. Global reconstructions of geomagnetic field evolution on millennial timescales have broad applications e.g.

for studying characteristics of the geodynamo process and Earth's core dynamics;
as reference for numerical dynamo simulations;
as dating tool for sediment cores, volcanic material and archeological artefacts;
or to study cosmogenic isotope production rates.

Both spatial and temporal resolution of millennial scale models are limited, due to a strongly heterogeneous distribution of available data and large data and dating uncertainties. However, neither model uncertainties, nor the sensitivity of the resulting model to prior assumptions, are well quantified so far. Another question is, wether the dipole contribution is rather independent from the smaller-scale field evolution. The aim of this project is to develop a new, correlation-based Bayesian modeling method for paleo- and archeomagnetic data.

The algorithm will be implemented as a readily adaptable and documented Python library. Furthermore, we will use this method to produce an improved Holocene field model which will, for the first time, include robust and realistic uncertainty estimates depending on data coverage in space and time.

A set of parameters for this model will be provided, as well as software for modeling various field quantities - including Gauss coefficients - together with estimates of uncertainities. The latter are particularly important when the model is used in data assimilation with the aim of predicting the future evolution of Earth's magnetic field.

Time Frame

2018 - 2021

Funding

Deutsche Forschungsgemeinschaft

Principal Investigators