Work

Observations of High‐Resolution Two‐Dimensional Ionospheric Flow Dynamics Associated With Poleward Boundary Intensifications

Year: 2026

Type: article

Abstract: Poleward boundary intensifications (PBIs) are one of the most common auroral disturbances and have been shown to play a key role in substorm dynamics. PBIs are commonly interpreted as the ionospheric signature of magnetotail reconnection, providing insight into X‐line evolution. While PBIs have been linked to ionospheric flow channels using line‐of‐sight observations, their two‐dimensional flow dynamics remain poorly understood. Using coordinated THEMIS All‐Sky Imager and SuperDARN observations, we present high‐resolution two‐dimension flows derived by the spherical elementary current systems (SECS) method in association with PBI morphology. AMPERE magnetic perturbation data are presented for one event to analyze the current system associated with a dawn‐cell PBI. Ionospheric flow channel observations are used to infer plasma inflow in the magnetotail, and our results show they play a determining role in PBI morphology, including spatial extent, number, and propagation. These results suggest that inflow properties strongly influence X‐line dynamics.

Source: Geophysical Research Letters

DOI: 10.1029/2025gl120760

Authors: Katherine Davidson, Yukitoshi Nishimura, Larry Lyons, Eric Donovan, Vassilis Angelopoulos, Nozomu Nishitani

Institutions: Boston University, University of California, Los Angeles, University of Calgary, Nagoya University

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: $3,190

Funders: National Science Foundation, National Aeronautics and Space Administration, Air Force Office of Scientific Research