Work

Influence of the IMF Elevation Angle on Midday Auroral Intensity During Northward IMF

Year: 2025

Type: article

Abstract: Using global ultraviolet imager auroral observations, we have investigated the possible role of the IMF elevation angle (), which is determined by IMF B x and B z , on the midday auroral intensity for northward B z conditions. The results show that in summer and equinoxes, the peak midday auroral intensity enhances by 11%–19% from non‐favorable conditions, when favors tail lobe reconnection in each hemisphere. Larger absolute and relative difference also occurred in the polar cap, especially in summer. We propose that these effects contribute to stronger midday auroral intensity due to lobe reconnection, which are associated with special B x polarities (i.e., B x < 0 and B x > 0 in the northern and southern hemispheres, respectively). In addition, when favorable (or B x ) condition occurs in one hemisphere, we find no evident midday aurora enhancement in the conjugate hemisphere in statistics. This suggests the lobe reconnection generally dominates in one hemisphere for both solstice and equinoctial periods.

Source: Geophysical Research Letters

DOI: 10.1029/2025gl117831

Authors: Shengting Zhu, Xiaoli Luan, Jiuhou Lei, Su Zhou

Institutions: University of Science and Technology of China, Deep Space Exploration Laboratory, Guiyang 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

Funder: National Natural Science Foundation of China