English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Observational constraints on geomagnetic field changes from interannual tomillenial periods are reviewed, and the current resolution of field models(covering archeological to satellite eras) is discussed. With the perspectiveof data assimilation, emphasis is put on uncertainties entaching Gausscoefficients, and on the statistical properties of ground-based records. Theselatter potentially call for leaving behind the notion of geomagnetic jerks. Theaccuracy at which we recover interannual changes also requires considering withcaution the apparent periodicity seen in the secular acceleration fromsatellite data. I then address the interpretation of recorded magneticfluctuations in terms of core dynamics, highlighting the need for models thatallow (or pre-suppose) a magnetic energy orders of magnitudes larger than thekinetic energy at large length-scales, a target for future numericalsimulations of the geodynamo. I finally recall the first attempts atimplementing geomagnetic data assimilation algorithms.

Spatial And Temporal Changes Of The Geomagnetic Field: Insights From Forward And Inverse Core Field Models