Work

Statistical Evaluation of a Foreshock Transient Model Using Ground‐Based ULF Wave Observations

Year: 2026

Type: article

Abstract: Hot flow anomalies and foreshock bubbles are discontinuity–driven foreshock transients that generate significant geospace disturbances. A recently developed analytical model can predict their upstream perturbations. In this study, we further evaluate this model by comparing its predictions with geomagnetic disturbances measured by ground‐based magnetometers. We find that the model‐predicted foreshock ion‐driven current density, a measure of the foreshock transient's strength, correlates well with ground‐based magnetic wave power in the Pc3 band, with correlation coefficients reaching ∼0.55–0.6. This degree of correlation outperforms that derived by using locally measured upstream wave power or simple combinations of foreshock ion parameters in place of current density, indicating the model's effectiveness. The correlation coefficient's dependence on magnetic local time and ground station latitude may suggest the azimuthal and radial propagation of transient‐driven disturbances. Additionally, the model limitations are discussed. These results demonstrate the model's capability to forecast geospace disturbances driven by foreshock transients.

Source: Geophysical Research Letters

DOI: 10.1029/2026gl124981

Authors: Terry Zixu Liu, Vassilis Angelopoulos, Hui Zhang, Ying‐Dong Jia, Siqi Zhao

Institutions: Shandong University, University of California, Los Angeles, University of Potsdam

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 Aeronautics and Space Administration, National Natural Science Foundation of China