Work

Quantifying the Mesoscale Contribution to FACs During a Magnetospheric Substorm

Year: 2024

Type: article

Abstract: Mesoscales, which couple small to large scales, and vice‐versa, are critical to the magnetosphere‐ionosphere coupling. Optical and radar measurements indicate that dynamical mesoscale features are present in the ionosphere, however quantifying their contribution to the overall dynamics remains a challenge. We use a new ionospheric data assimilation technique, Lompe (Local mapping of the polar ionospheric electrodynamics), to specify ionospheric electrodynamics using a wide variety of input data and a priori assumptions about the physical nature of the ionospheric electric field. We isolate the terms of the ionospheric Ohm's law and find that mesoscale structures in the FACs are driven by Hall gradients, while the larger scale patterns are associated with the divergence of the electric field. We calculate the relative contribution of mesoscales to the overall FAC patterns during a magnetospheric substorm, and find that in the nightside, mesoscale FACs contribute up to 60% of the total.

Source: Geophysical Research Letters

DOI: 10.1029/2024gl111045

Authors: S. Gasparini, L. Kepko, K. M. Laundal

Institutions: Goddard Space Flight Center, University of Bergen, Catholic University of America

Language: English

Topic: Ionosphere and magnetosphere dynamics

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,900

Funder: Trond Mohn stiftelse