Rapid Variations of Earth’s Core Magnetic Field
Vincent Lesur, Nicolas Gillet, Magnus Hammer, Mioara Mandéa
Abstract
Abstract Evidence of fast variations in the Earth’s core field are seen both in magnetic observatory and satellite records. We present here how they have been identified at the Earth’s surface from ground-based observatory records and how their spatio-temporal structure is now characterised by satellite data. It is shown how their properties at the core mantle boundary are extracted through localised and global modelling processes, paying particular attention to their time scales. Finally are listed possible types of waves in the liquid outer core, together with their main properties, that may give rise to these observed fast variations.
Topics & Concepts
Earth's magnetic fieldGeophysicsCore (optical fiber)Earth (classical element)GeologyMagnetic fieldField (mathematics)Mercury's magnetic fieldL-shellGeodesyEnvironmental sciencePhysicsAstronomyOpticsMathematicsQuantum mechanicsPure mathematicsGeomagnetism and Paleomagnetism StudiesGeology and Paleoclimatology ResearchGeophysics and Gravity Measurements