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Core Surface Flow Changes Associated With the 2017 Pacific Geomagnetic Jerk.

ABSTRACT: 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 year^-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.

SUBMITTER: Whaler KA

PROVIDER: S-EPMC9539959 | biostudies-literature | 2022 Aug

REPOSITORIES: biostudies-literature

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Core Surface Flow Changes Associated With the 2017 Pacific Geomagnetic Jerk.

Whaler K A KA Hammer M D MD Finlay C C CC Olsen N N

Geophysical research letters 20220805 15

A geomagnetic jerk was seen in <i>Swarm</i> 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 ac ...[more]

PMID: 36247515

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