EarthRef.org Digital Archive (ERDA) -- Global geomagnetic Laschamp excursion characteristics

Description
These animations illustrate global geomagnetic field characteristics from 50 to 30~ka BP from several different spherical harmonic field models as compared to LSMOD.2 in the related publication. LSMOD.2 is our preferred model, giving the currently best representation of the geomagnetic field evolution over the Laschamp (~41 ka) and Mono Lake (~36 to 31 ka) excursions. Models A, B, D and X have been derived to investigate the robustness of model features. Model IMOLEe is from R. Leonhard, K. Fabian, M. Winklhofer, A. Ferk, C. Laj and C. Kissel (2009), Geomagnetic field evolution during the Laschamp excursion, Earth Planet. Sci. Lett., 278, 87-95.

The panels from left to right are, in row 1: Maps of field intensity at Earth's surface (F surf.), paleo-secular variation index Pi, radial field component (Br at the core-mantle boundary (CMB, with continents for reference purpose); row 2: maps of virtual dipole moment (VDM) at Earth's surface and virtual geomagnetic pole (VGP) latitude, the geomagnetic power spectrum at the CMB (red dots) compared to the present-day (IGRF 12th generation) spectrum (grey dots), and two polar views of Br at the CMB with the inner core tangent cylinder outlined in black; row 3: time series of dipole latitude (Dip. Lat., blue, right ordinate) and dipole moment (DM, black, left ordinate) in top and of the three dipole spherical harmonic coefficients (g10, g11, h11) in the bottom panel, time series of globally averaged Pi with value given below, and time series of dipole (D) and non-dipole (ND) power at the CMB in the top and quadrupole (Q) and octupole (O) power in the bottom panel. The age is given in the top right and indicated by red vertical bars on the time series in row 3.

Related contribution "Global geomagnetic Laschamp excursion characteristics - LSMOD and GGF100k" contains results from our preferred model LSMOD.2 and the 100 ka field reconstruction GGF100k.