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It is well known that the interaction between interplanetary (IP) shocks and the Earth’s magnetosphere would generate/excite various types of geomagnetic phenomena. Progresses have been made on the Earth’s magnetospheric response to solar wind forcing in recent years in the aspects associated with magnetospheric substorms. Strong substorms and super substorms could be triggered externally by sudden changes of solar wind dynamic pressures. When a strong substorms (AE > 1000 nT) or super substorms (AE > 2000 nT) occurs, singly charged oxygen ions escaped from the Earth’s ionosphere are found to be a dominated ion population in the magnetotail and in the inner magnetosphere—ring current region. The products of a strong substorms or super substorms- plasmoid, burst bulk flows are also found to contain significant oxygen ions, even substorm injections can be dominated by oxygen ions. Thus, the magnetospheric dynamic must consider the contributions from the heavy oxygen ions. Also, the IP shock induced super substorms associated electromagnetic pulses (dB/dt) would shift the energetic particle (injections) inward and accelerate existing population significantly. Extensive attempts have also been made to understand how the solar wind energy couples with the magnetosphere to excite magnetospheric substorms. The statistical analysis shows that strong substorms (AE > 1000 nT) and super substorms (AE > 2000 nT) triggered by interplanetary shocks are most likely to occur under the southward interplanetary magnetic field (IMF) and fast solar wind pre-conditions. In addition, strong substorms after the IP shock arrival are more likely to occur when IMF points toward (away from) the Sun around spring (autumn) equinox, which can be ascribed to the Russell-McPherron effect. Thus, the southward IMF precondition of an interplanetary shock and the Russell-McPherron effect can be considered as precursors of a strong substorm and/or super substorm triggered by IP shocks. Moreover, the average duration of CME sheath region which is just behind the interplanetary shock are found to be about 7 hours. This indicates that southward IMF compressed by shock could last at least 7 hours long in the downstream of the interplanetary shock (sheath region) if a southward IMF pre-condition is present, which explains why the largest substorm often occur in the CME sheath.

Kinetic Alfvén waves (KAWs) are ubiquitous throughout the plasma universe. Although they are broadly believed to provide a potential approach for energy exchange between electromagnetic fields and plasma particles, neither the detail nor the efficiency of the interactions has been well-determined yet. The primary difficulty has been the paucity of knowledge of KAWs’ spatial structure in observation. Here, we apply a particle-sounding technique to Magnetospheric Multiscale mission data to quantitatively determine the perpendicular wavelength of KAWs from ion gyrophase-distribution observations. Our results show that KAWs’ perpendicular wavelength is statistically 2.4 ± 0.7 times proton thermal gyro-radius. This observation yields an upper bound of the energy the majority proton population can reach in coherent interactions with KAWs, that is, roughly 5.76 times proton perpendicular thermal energy. Therefore, the method and results shown here provide a basis for unraveling the effects of KAWs in dissipating energy and accelerating particles in a number of astrophysical systems, e.g., planetary magnetosphere, astrophysical shocks, stellar corona and wind, and the interstellar medium. Kinetic Alfven Waves (KAWs) are ubiquitous in space plasmas. Here, the authors show that application of particle sounding technique to Magnetospheric Multiscale Mission data enables measuring perpendicular wavelength of KAWs.

Anthropogenic activities are resulting in an increase of the use and extraction of heavy metals. Heavy metals cannot be degraded and hence accumulate in the environment, having the potential to contaminate the food chain. This pollution threatens soil quality, plant survival and human health. The remediation of heavy metals deserves attention, but it is impaired by the cost of these processes. Phytoremediation and biochar are two sound environmental technologies which could be at the forefront to mitigate soil pollution. This review provides an overview of the state of the art of the scientific research on phytoremediation and biochar application to remediate heavy-metal-contaminated soils. Research to date has attempted only in a limited number of occasions to combine both techniques, however we discuss the potential advantages of combining both, and the potential mechanisms involved in the interaction between phytoremediators and biochar. We identified specific research needs to ensure a sustainable use of phytoremediation and biochar as remediation tools.

To compare the effect of ultrasound (US)-guided dry needling (DN) with traditional DN in the treatment of pain and dysfunction for patients with knee osteoarthritis (KOA). A double-blind, randomized controlled trial. Eighty-four participants (61.26±5.57 years) completed the study. G1 achieved significant improvement in VAS at 8 weeks compared to G2 and G3 (G1 vs. G2: MD = -15.61, 95% CI [-25.49, -5.51], p = 0.001; G1 vs. G3: MD = -19.90, 95% CI [-29.71, -10.08], p< 0.001). G1 achieved significant improvement in KOOS-pain at 8 weeks compared to G2 and G3 (G1 vs. G2: MD = 9.76, 95% CI [2.38, 17.14], p = 0.006; G1 vs. G3: MD = 9.48, 95% CI [2.31, 16.66], p = 0.010). KOOS-symptoms and KOOS-QoL were not statistically significant between groups. G2 had no significant difference of the perceptions as G1 with p = 0.128. G2 were successfully blinded to placebo US-guided DN. US-guided DN with exercise therapy may be more effective than traditional DN with exercise therapy or exercise therapy alone in reduce pain of KOA.

Identifying how energy transfer proceeds from macroscales down to microscales in collisionless plasmas is at the forefront of astrophysics and space physics. It provides information on the evolution of involved plasma systems and the generation of high-energy particles in the universe. Here we report two cross-scale energy-transfer events observed by NASA’s Magnetospheric Multiscale spacecraft in Earth’s magnetosphere. In these events, hot ions simultaneously undergo interactions with macroscale (~ 10 5 km) ultra-low-frequency waves and microscale ( ~ 10 3 km) electromagnetic-ion-cyclotron (EMIC) waves. The cross-scale interactions cause energy to directly transfer from macroscales to microscales, and finally dissipate at microscales via EMIC-wave-induced ion energization. The direct measurements of the energy transfer rate in the second event confirm the efficiency of this cross-scale transfer process, whose timescale is estimated to be roughly ten EMIC-wave periods about (1 min). Therefore, these observations experimentally demonstrate that simultaneous macroscale and microscale wave-ion interactions provide an efficient mechanism for cross-scale energy transfer and plasma energization in astrophysical and space plasmas. Cross-scale energy transfers in collisionless plasmas help understanding involved mechanisms. Here, the authors show simultaneous macro- and micro-scale wave-ion interactions provide an efficient mechanism for cross-scale energy transfer and plasma energization in astrophysical and space plasmas.

Two dipolarization front (DF) structures observed by Cluster in the Earth midtail region (XGSM ≈ −15 RE), showing respectively the feature of Fermi and betatron acceleration of suprathermal electrons, are studied in detail in this paper. Our results show that Fermi acceleration dominates inside a decaying flux pileup region (FPR), while betatron acceleration dominates inside a growing FPR. Both decaying and growing FPRs are associated with the DF and can be distinguished by examining whether the peak of the bursty bulk flow (BBF) is co‐located with the DF (decaying) or is behind the DF (growing). Fermi acceleration is routinely caused by the shrinking length of flux tubes, while betatron acceleration is caused by a local compression of the magnetic field. With a simple model, we reproduce the processes of Fermi and betatron acceleration for the higher‐energy (>40 keV) electrons. For the lower‐energy (<20 keV) electrons, Fermi and betatron acceleration are not the dominant processes. Our observations reveal that betatron acceleration can be prominent in the midtail region even though the magnetic field lines are significantly stretched there. Key Points Fermi acceleration dominates inside a decaying flux pileup region Betatron acceleration dominates inside a growing flux pileup region Betatron acceleration is caused by a local compression of magnetic field

On 10 May 2024, a super space storm—characterized by the Dst index plummeting to −412 nT and induced by a strong coronal mass ejection on the Sun—attacked the Earth's magnetosphere. This geomagnetic storm, according to the human record of Dst index, is the third‐strongest one throughout history (only slightly lower than those in 1989 and 2003). In such an extreme condition, how the magnetopause evolves and reforms remains unclear, because only a few spacecraft measurements were available in the dayside magnetosphere during previous events. Here, by utilizing in‐situ measurements of multiple spacecraft together with ground magnetometers, we for the first time determine the extreme compression of the magnetopause from higher than 10 RE down to 5 RE. This observation of such severe deformation is also consistent with the prediction of the theoretical model. This study provides crucial insights into the extreme behavior of the magnetopause during the influence of a superstorm. Plain Language Summary On 10 May 2024, a series of powerful solar eruptions hit Earth, causing an extreme geomagnetic storm. The Dst index during this storm, a measure of storm intensity, dropped to −412 nT, marking it as the third‐strongest event ever recorded. This caused significant degradations in GPS and radio communications. Here, using measurements from several spacecraft and ground‐based magnetometers, we observed the boundary of the Earth's magnetic field, known as the magnetopause, being compressed from over 10 RE down to just 5 RE. This standoff distance is also consistent with the prediction of theoretical model. These findings enhance our understanding of planetary magnetopauses under extreme conditions. Key Points We present joint observations from multiple satellites and ground magnetometers of the third‐strongest magnetic storm on record Space‐based observations confirm that the magnetopause was compressed below the geostationary orbit For the first time, we use ground‐based magnetometers to determine that the standoff distance of the magnetopause is approximately 5 RE

Airborne dust is one of the most important natural aerosols; it has various environmental impacts on air quality, ocean fertilization, and the global climate change. Asian dust, representing one of the major dust sources in the world, has been widely studied due to its long-range transport capability. However, its transport to the Arctic has been less investigated. In this study, two typical transport routes were identified based on the recorded dust events in China during 2011–2015. Accordingly, two specific Asian dust long-range transport events were selected and compared, i.e., one observed at Barrow, Alaska (traveled mostly over lands within 6–7 d), and the other one observed at Alert, Canada (traveled mostly over oceans within 7–8 d). The transport routes of the two dust events had been cross-validated by using air mass trajectory modeling, meteorology reanalysis data, ground-based aerosol columnar and profiling observations, and spaceborne remote sensing. It was found that different transport routes to the Arctic had divergent effects on the evolution of aerosol properties, revealing different mixing extents between dust, anthropogenic particles, smoke, and sea salts. Based on the Snow, Ice, and Aerosol Radiative (SNICAR) model, the albedo simulation indicated that dust and elemental carbon together reduced the surface albedo by 0.35 % to 2.63 % compared to the pure snow condition. This study implied that the dust long-range transport from China to the Arctic was ubiquitous and may be a potential contributor to the Arctic regional climate.

Besides the cusp, polar cap, and auroral oval, the nightside subauroral zone has also recently been reported as a source region of the ionospheric oxygen outflows. However, the detailed mass and energy sources of these ions remain open questions. Here, we address this issue from the perspective of the response of conjugate hemispheres. Investigation of Van Allen Probes data demonstrates a notable preference of oxygen outflows from the nightside subauroral zone from the sunlit hemisphere. This characteristic eliminates the possibility of nightside auroral precipitation playing a significant role, as it is more prominent in darkness. Instead, it highlights sunlight‐induced ionization as the mass source and enhanced plasma waves from the magnetotail as the energy source. The results presented here further support the nightside subauroral zone as an independent source of magnetospheric oxygen ions. Plain Language Summary Single‐charged oxygen ions, believed to ultimately originate from the ionosphere, are the main carriers of the ring current during severe space weather, including super geomagnetic storms and substorms. Therefore, comprehending where and how they come from is crucial for understanding the magnetosphere and space weather. Recent studies have reported the nightside subauroral zone as a source region, besides the usually cited cusp, polar cap, and auroral oval. However, the detailed mechanisms for the subauroral oxygen outflows remain open questions. In this study, we address this issue by studying how opposite hemispheres react simultaneously in subauroral oxygen outflow events observed by the Van Allen Probes. Data analysis reveals that these outflows tend to occur in the local summer hemisphere, where the nightside subauroral ionosphere receives more sunlight compared to the opposite hemisphere. This feature rules out nightside auroral precipitation playing a significant role, as it is more noticeable in the dark. Instead, it points to sunlight‐induced ionization as the source of mass and enhanced plasma waves from the magnetotail as the source of energy. Our findings reinforce the idea that the nightside subauroral zone is an important source of ionospheric oxygen outflows. Key Points The Van Allen Probes have observed oxygen outflows from the nightside subauroral ionosphere in a single hemisphere Statistics reveal a preference for the outflows in sunlit hemisphere, distinguishing them from auroral outflows more prominent in darkness This preference highlights sunlight‐induced ionization and waves from the magnetotail as the source of mass and energy

It is generally believed that long-duration gamma-ray bursts (GRBs) originate from the core collapse of rapidly spinning massive stars, and at least some of them are powered by hyperaccreting black holes (BHs). However, definite proofs about the progenitor and central engine of these GRBs have not been directly observed in the past. Here, we report the existence of a quasiperiodic oscillation (QPO) signature with periodic frequency ∼0.02 Hz in the early X-ray afterglow phase of GRB 220711B. Such a low-frequency QPO likely signals the precession of a relativistic jet launched from a GRB hyperaccreting BH central engine. The energy injection signature from the late X-ray observations (from 5 × 102 s ∼ 1 × 104 s) is consistent with the precession hypothesis. The prompt gamma-ray light curve does not show any QPO signature, suggesting that the X-ray flaring emission in the early afterglow phase and prompt emission likely originate from different accretion processess, indicating that the progenitor stars of GRBs have a core-envelope structure with a stratified angular momentum distribution and the late-time accretion disk likely has a misalignment with respect to the rotation axis of the BH. Such a misalignment is not expected in a canonical collapsar model. As a result, the QPO signature in GRB 220711B may reveal a new formation channel of long GRBs, possibly a stellar-merger-induced core collapse, with the orbital angular momentum of the binary misaligned with the spin axis of the collapsing star.