Auroral activity observed from unusual latitudes in China and its underlying significance

Auroras have been observed at unusual latitudes of China over the past couple of years, which may be a direct result of the north magnetic pole’s drift and intense solar activity. However, the specific impact on the Asian space environment remains unknown. Here, we present auroral activities recorded in southern Inner Mongolia (~37.2° N in magnetic latitude) and the resulting ionospheric environmental changes detected by the Chinese Dual Auroral Radar Network (CN-DARN) during a recent severe geomagnetic storm. Leveraging the wide spatial coverage and continuous high time resolution monitoring capabilities of the CN-DARN, comprehensive analysis of ground-based and space-based multi-source data reveals that CN-DARN has captured the spatiotemporal evolution characteristics of dawnside subauroral polarization streams (SAPS). The study identifies a direct link between auroral intensification and dawnside SAPS acceleration for the first time, establishing a mechanistic connection between auroral activity and ionospheric convection dynamics in subauroral region. Moreover, the observations show that the ionospheric irregularities with high velocity of 1,000 m/s induced by the dawnside SAPS have propagated to Mohe (~ 48.6° N in magnetic latitude), the northernmost region of China. The research also reveals that intense auroral particle precipitation caused severe degradation of high-frequency (HF) communications in the Asian region. This study represents the first comprehensive investigation of auroral activity observed at unusual latitudes of China, unraveling the impact of auroral activities on the ionospheric environment of Asian mid-to-high latitudes. It also showcases the critical capabilities of the Chinese Meridian Project in addressing space environmental challenges of Asia.