Core surface flow changes associated with the 2017 Pacific geomagnetic jerk

Kathy Whaler, M. D. Hammer, C. C. Finlay, N. Olsen

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

A geomagnetic jerk was seen in Swarm satellite data in 2017 over the Pacific region. We invert time series of spatial gradient secular variation data between 2014 and 2020, reduced to a grid of points at satellite altitude, for spatially- and temporally-regularized core surface flow. Pacific region flow acceleration was almost constant before and after the jerk, with a sharp change, especially in the azimuthal component, at the jerk epoch, despite the temporal regularization. Azimuthal acceleration is oppositely signed either side of 160°W, where it effectively vanishes, and also reverses sign at the jerk epoch. Acceleration features drift westward at about 900 km yr−1. Unlike previous studies, the evidence presented here for low latitude waves does not depend on imposing flow equatorial symmetry, quasi- or tangential geostrophy, or band-pass filtering, and has no reliance on stochastic models or numerical simulations.
Original languageEnglish
Article number e2022GL098616
JournalGeophysical Research Letters
Issue number15
Early online date18 Jul 2022
Publication statusPublished - 16 Aug 2022


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