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The characteristics of phase scintillation (represented by the phase scintillation indices, σφ) from GPS and Beidou are statistically analyzed using a ground‐based receiver at Zhongshan Station, Antarctica, from 2020 to 2022 for the first time. The phase scintillation of the GPS and Beidou signals present a similar pattern of occurrence. The statistical results on the occurrence morphology of phase scintillation show that the phase scintillation predominately occurs in the magnetic pre‐noon and pre‐midnight sectors. Moreover, phase scintillation performs a dependence on solar and geomagnetic activities. Furthermore, the phase scintillation also gives a seasonal variation with the maximum occurrence happened at the autumn and the minimum occurrence during the summer. Consequently, these results improve understanding of the morphological characteristics of the phase fluctuations in the less studied Antarctic region. The study also demonstrates the use of the combined data set to improve the coverage in the Antarctic region. Key Points: Morphological characteristics of phase scintillation of GPS and Beidou signals at Zhongshan station, Antarctica, for the first timeThe occurrences of phase scintillation mainly concentrated in the prenoon and pre‐midnight sectors for both signalsThe similar behaviors of phase scintillation convey the usefulness of the combined data for irregularity studies in the polar region [ABSTRACT FROM AUTHOR]

Dayside magnetosphere interactions are essential for energy and momentum transport between the solar wind and the magnetosphere. In this study, we investigate a new phenomenon within this regime. Sudden enhancements of ion fluxes followed by repeating dropouts and recoveries were observed by Magnetospheric Multiscale on 5 November 2016, which is the very end of the recovery phase from a moderate geomagnetic storm. These repetitive flux variations display energy‐dispersive characteristics with periods relevant to ion bounce motion, suggesting they are corresponding echoes. Alongside the flux variations, bipolar electric field impulses originating from external sources were detected. We traced the source region of the initial injection and found it is located near the spacecraft's position. To elucidate the underlying physics, a test‐particle simulation is conducted. The results reveal that radial transport resulting from impulse‐induced acceleration can give rise to these echoes. Observations demonstrate dayside magnetosphere interactions are more common than we previously considered, which warrants further research. Plain Language Summary: In spacecraft observations, the quasi‐periodical motion of particles in the geomagnetic field can generate repeating signals known as "echoes". Examining the relationship between the periods of echoes and the particle's energy is necessary for determining their types. The present study reports a novel mechanism responsible for generating echoes that arise from the ion bounce motion along magnetic field lines. Observations from both ground‐based stations and spacecraft, as well as numerical simulations, suggest these echoes can result from the acceleration and radial diffusion of ions responding to external field variations. These findings extend the current understanding of interactions in the dayside outer magnetosphere. Key Points: Ion acceleration and corresponding bounce echoes were observed by MMS in the dayside outer magnetosphereObservations and simulations suggest these echoes are driven by the accompanied electric field impulsesImpulse‐induced ion radial transport with positive phase space density radial gradient leads to the observed pattern [ABSTRACT FROM AUTHOR]

Solar wind dynamic pressure pulse is one of the sources of ultra‐low frequency (ULF) waves. Based on 1‐second resolution magnetic field observations from SuperMAG from 2012 to 2019, we conducted a statistical study on temporal and spatial variations of global ULF power after the arrival of positive dynamic pressure pulses. The magnetosphere responds quickly to the dynamic pressure pulse within 1 min. At low L‐shells, it takes 4–6 min for the ULF waves to reach a power maximum, then ULF waves decay on a timescale of about 10 min. The spatial distribution of ULF wave power is closely related to the direction of the interplanetary magnetic field (IMF) when the dynamic pressure pulse arrives. The southward IMF leads to the reconnection on the dayside and more intense substorm activities on the nightside, accompanied by stronger ULF wave power globally. The power enhancement in the Pc2 band exhibits a notable fluctuation concentrated primarily in the range of L = 7 to 9, compared with the quiet period. In contrast, the amplification of Pc3 wave power occurs predominantly at higher L‐shells. However, the fluctuation of Pc5 power exhibits an opposite pattern, indicating disparate excitation and propagation mechanisms. In addition, seasonal effects affect the ULF power in different bands, which can be explained by the Russell‐McPherron (R‐M) effect. Our statistical results on long‐term, global‐scale geomagnetic observations illustrate that pressure pulses are important sources of ULF waves, and the spatial distribution of wave power varies greatly under different solar wind conditions. Key Points: SuperMAG ultra‐low frequency (ULF) parameters are used to study the spatial and temporal responses of ULF waves to pressure impulsesThe ULF power has great differences in the distribution as a function of magnetic local time and L‐shellSeasonal effects have significant influences on the magnetic field power in different bands [ABSTRACT FROM AUTHOR]

An auroral substorm is an important physical process of energy accumulation and explosive release in the Earth's magnetosphere, and is an important research object of space environment monitoring and space weather warnings. A westward traveling surge (WTS) is a typical auroral physical process of an auroral substorm. Its static characteristic is auroral folding at the polar boundary of an auroral oval and its dynamic characteristic is the westward motion of auroral folding. According to the static characteristic of a WTS, we defined a set of feature parameters based on the morphology and designed a set of automatic detection and discrimination methods; that is, the WTS was identified by using the extracted features and pattern recognition approaches. This approach was tested by using the aurora data of the ultraviolet auroral spectral imager of the Defense Meteorological Satellite Program (DMSP) satellite. The results showed that the accuracy rate of automatic recognition was 61.39%~63.61% and the precision rate was 55.52%~57.92%. The experimental results showed that the approach was effective at detecting the typical characteristics of an auroral substorm (WTS). [ABSTRACT FROM AUTHOR]

Two important phenomena of the solar wind–magnetosphere–ionosphere coupling are auroral particle precipitation and the formation of ions flowing upward from the ionosphere. They have opposite transport directions of energy and substance. Based on the observations of particle precipitation and ion drift from the DMSP F13 satellite in January and July 2005, the ionospheric ion upflows in dayside auroral oval (0600–1800 MLT) can be divided into five types according to the velocity of ion upflows and the spectrum characteristics of auroral particle precipitation, and the distribution for different types of ion upflows is studied. The results show that the ion upflows mainly occur in the geomagnetic latitude (MLAT) range of 70–80°.The main magnetospheric source region of ion upflows (type A and D) caused by the accelerated electron (mainly the soft electron) corresponds to Low Latitude Boundary Layer (LLBL) and Cusp, and ion upflows of type B and C (related to the process of ambipolar diffusion caused by electron acceleration) mainly occur in LLBL and Boundary Plasma Sheet (BPS), while ion upflows of type E without electron acceleration mainly occur in the central plasma sheet (CPS).The dawn–dusk asymmetry is obvious in the winter season, with the ion upflows mainly occurring on the dawn/dusk side ionosphere. However, the ion upflows in summer mainly occur at the magnetic noon, with a symmetric distribution centered at the magnetic noon. The occurrence of ion upflow in winter is significantly higher than that in summer, and it is significantly enhanced during the period of moderate geomagnetic activity. The upward region expands to the lower latitude when the geomagnetic activity is enhanced. The effect of interplanetary magnetic field (IMF) components has also been studied in this paper. When IMF Bx is negative, the upflow occurrence increases in the region of 1500–1800 MLT and 0600–0900 MLT, with the MLAT range below 70°. The direction of IMF By may lead to the high-incidence area reverse at the prenoon or postnoon region. The occurrence of ion upflows with the MLAT range below 75° increases significantly when IMF is southward. Type A ion upflow has the highest velocity of ion upflows, followed by type E, and type D has the lowest. The average velocity of ion upflows in winter is significantly higher than that in summer. [ABSTRACT FROM AUTHOR]