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High-angular-resolution measurements allow the direct observation of the scattering of energetic electrons by chorus waves in the magnetosphere, which causes quasiperiodic electron precipitation that gives rise to pulsating aurorae. Pulsating aurorae A pulsating aurora is a type of aurora that occurs in patches that blink on and off in an almost periodic fashion. They usually arise in the closing phase of an auroral display, at dawn, and cover up to several hundred kilometres of the sky, at an altitude of about 100 kilometres. Many such patches sometimes cover the entire sky. The pulsations arise from intermittent injections of energetic electrons into the upper atmosphere, but just how the injections happen has been unclear because of instrumental limitations on the observations. Satoshi Kasahara and colleagues report observations that show that the energetic electrons are quasiperiodically scattered by 'chorus waves'—intense electromagnetic plasma waves that arise at the magnetic equator and move towards the poles—at the same time as pulsating aurorae are seen from the ground. Auroral substorms, dynamic phenomena that occur in the upper atmosphere at night, are caused by global reconfiguration of the magnetosphere, which releases stored solar wind energy 1 , 2 . These storms are characterized by auroral brightening from dusk to midnight, followed by violent motions of distinct auroral arcs that suddenly break up, and the subsequent emergence of diffuse, pulsating auroral patches at dawn 1 , 3 . Pulsating aurorae, which are quasiperiodic, blinking patches of light tens to hundreds of kilometres across, appear at altitudes of about 100 kilometres in the high-latitude regions of both hemispheres, and multiple patches often cover the entire sky. This auroral pulsation, with periods of several to tens of seconds, is generated by the intermittent precipitation of energetic electrons (several to tens of kiloelectronvolts) arriving from the magnetosphere and colliding with the atoms and molecules of the upper atmosphere 4 , 5 , 6 , 7 . A possible cause of this precipitation is the interaction between magnetospheric electrons and electromagnetic waves called whistler-mode chorus waves 8 , 9 , 10 , 11 . However, no direct observational evidence of this interaction has been obtained so far 12 . Here we report that energetic electrons are scattered by chorus waves, resulting in their precipitation. Our observations were made in March 2017 with a magnetospheric spacecraft equipped with a high-angular-resolution electron sensor and electromagnetic field instruments. The measured 13 , 14 quasiperiodic precipitating electron flux was sufficiently intense to generate a pulsating aurora, which was indeed simultaneously observed by a ground auroral imager.

Background:Many patients with RA consider improvement in pain the priority in treatment. However, pain has multiple causes, not just inflammatory. Central sensitivity syndromes (CSS) is one of the causes of pain in RA; therefore, we hypothesised that CSS may also influence satisfaction with treatment in patients with RA. To our knowledge, the effect of CSS-related pain on satisfaction with treatment has not been reported for patients with RA. We believe that improving patients’ satisfaction is important because higher satisfaction with treatment is associated with improved compliance and persistence with treatment, as well as with reduced regimen complexity and treatment burden[1].Objectives:In this cross-sectional study, we evaluated the effects of central sensitivity syndrome (CSS) in patients with rheumatoid arthritis (RA) on the assessment of clinical disease activity and satisfaction with treatment.Methods:Participants were 240 consecutive patients with RA (61 men and 179 women; mean age, 70.1 ± 11.9 years; mean disease duration, 13.3 ± 10.6 years) who were receiving long-term follow-up. All patients were evaluated for clinical disease activity and satisfaction with treatment. CSS was evaluated with the Central Sensitization Inventory (CSI) [2]. An overall score ≥40 indicates the presence of CSS and an overall score from 30 to 39 indicates the presence of mild CSS. And we asked, ‘How satisfied are you with your treatment?’; answers were (a) very satisfied, (b) satisfied, (c) not satisfied or (d) very dissatisfied. For univariable analysis, we condensed the four answers into two: ‘dissatisfied’ or ‘satisfied’ [3]. We also evaluated satisfaction with treatment by using the VAS, for which scores could range from 0 mm (very dissatisfied) to 100 mm (very satisfied).Results:Of the 240 patients, 20 (8.3%) were classified as having CSS, 22 patients (9.1%) as having mild CSS. CSI score was significantly correlated with clinical disease activity index scores (CDAI) (r=0.305, p<0.01), patient satisfaction with treatment(r=-0.278, p<0.01). With regard to patients’ satisfaction with treatment, univariable analysis showed that PtGA, pain VAS, HAQ-DI, DAS28 CRP, CDAI and CSI score of patients who were satisfied with treatment significantly differed from those of dissatisfied patients. Multivariable analysis revealed that CSI score, PtGA and HAQ-DI scores were associated with patient satisfaction (Table 1). Cut-off points determined by receiver operating characteristic analysis indicated that CSI scores of ≥30 were also associated with patient dissatisfaction, with 70.0% sensitivity and 88.2% specificity.Table 1. Independent factor of patient satisfaction determined using univariable and multivariable logistic regression analysis.Conclusion:In patients with RA, CSS may affect the disease activity index and reduce patients’ satisfaction with treatment.REFERENCES:[1] Barbosa CD, et al. A literature review to explore the link between treatment satisfaction and adherence, compliance, and persistence. Patient Prefer Adherence. 2012; 6: 39–48.[2] Mahlich J, et al. Shared Decision-Making and Patient Satisfaction in Japanese Rheumatoid Arthritis Patients: A New “Preference Fit” Framework for Treatment Assessment. Rheumatol Ther. 2019; 6(2): 269-283.[3] Mayer TG, et al. The development and psychometric validation of the central sensitization inventory. Pain Pract. 2012; 12(4): 276-285.Acknowledgements:We thank the staffs (Ms. Mayumi Tanabe and Yukari Jo) at Orthopedic Surgery, Yamaguchi University Graduate School of Medicine, for their assistance with this study.Disclosure of Interests:None declared.

Relativistic electron microbursts, which are bursty enhancements of the precipitation of relativistic electrons, are often observed by low‐altitude satellite measurements. These microbursts are likely to play an important role in high‐energy electron flux loss in the outer radiation belt. Some observations suggest that whistler chorus waves are a cause of relativistic electron microbursts. First, we derived the relativistic time of flight model considering the propagation of whistler mode waves, and then investigated characteristics of the precipitations. We found that relativistic electron precipitation has a positive energy dispersion at low altitude. The duration of electron precipitation by one whistler chorus element decreases when the energy of the precipitated electrons is increased. We then performed three‐dimensional test particle simulation with a newly developed wave‐particle interaction model using realistic plasma parameters in the inner magnetosphere. The test particle simulation showed for the first time that the resonant interactions with whistler chorus elements at high‐latitudes produce bursty enhancements of relativistic electron precipitation, thus confirming the results of the TOF analysis. A few Hz modulations are embedded in the precipitating electron flux variations, which is associated with the repetition period of the whistler chorus elements. The simulation results indicate that microbursts of relativistic electrons of the outer belt are caused by chorus wave‐particle interactions at high latitudes and a series of rising tone elements of chorus waves produce a few Hz modulation of microbursts observed by the SAMPEX satellite. Key Points Newly developed GEMSIS‐RBW code that can solve wave‐particle interactions Energy dispersion of relativistic electron precipitations derived from TOF model A few Hz modulation of microbursts associated with whistler chorus emissions

We analyzed time‐of‐flight (TOF) data from the Arase satellite to investigate temporal variations of the molecular ion group (O2+, NO+, and N2+) at 19.2 keV/q in the inner magnetosphere for 6 years from the solar declining to rising phase. The molecular ions counts were estimated by subtracting the background contamination of oxygen counts. While the number of clear molecular ion events was small, the estimated counts exhibited good correlation with the solar wind dynamic pressure and SYM‐H index. Long‐term variations of the molecular ions differed from those of counts of the O+ and N+ group. Additionally, we discuss the importance of the solar wind dynamic pressure in causing variations of molecular ions in the inner magnetosphere. Plain Language Summary Molecular ions (O2+, NO+, and N2+) have been observed in the magnetosphere. Molecular ions in the ionosphere are required to obtain energy through short‐lived reactions with electrons to escape from low altitudes to the magnetosphere. The escaping mechanisms of molecular ions are not fully understood. This study analyzed 6 years of data from the Arase satellite to investigate long‐term variations of molecular ion group in the inner magnetosphere. We discuss the importance of the solar wind dynamic pressure in causing variations of molecular ions in the inner magnetosphere. Key Points Continuous molecular ion group observations in the inner magnetosphere for 6 years Counts of molecular ion group increase following enhancements in the solar wind dynamic pressure The ratio of molecular ion group to O+ and N+ was lower in the rising phase of the solar cycle than that during the solar minimum

A technique for estimating a plasma drift velocity distribution in the ionosphere is presented. This technique is based on a framework for representing a global vector field on a sphere by using a set of localized basis functions which is newly derived as a variant of the spherical elementary current system (SECS). A vector field on a sphere can be divided into its divergence-free (DF) component and curl-free (CF) component. The DF and CF components can then be represented by weighted sums of the DF and CF vector-valued basis functions, respectively. While the SECS basis functions have a singular point, the new basis functions do not diverge over a sphere. This property of the new basis function allows us to achieve robust prediction of the drift velocity at any point in the ionosphere. Assuming that the ionospheric plasma drift velocity has no divergence, its distribution can be represented by a weighted sum of the DF basis functions. The proposed technique estimates the ionospheric plasma drift velocity distribution from the SuperDARN data by using the DF basis functions. Since there are some wide gaps in the spatial coverage of the SuperDARN, an empirical convection model is combined with the framework based on the new basis functions. It is demonstrated that the proposed technique is useful for the estimation and modeling of the ionospheric plasma velocity distribution.

This paper presents the highlights of joint observations of the inner magnetosphere by the Arase spacecraft, the Van Allen Probes spacecraft, and ground-based experiments integrated into spacecraft programs. The concurrent operation of the two missions in 2017–2019 facilitated the separation of the spatial and temporal structures of dynamic phenomena occurring in the inner magnetosphere. Because the orbital inclination angle of Arase is larger than that of Van Allen Probes, Arase collected observations at higher L -shells up to L ∼ 10 . After March 2017, similar variations in plasma and waves were detected by Van Allen Probes and Arase. We describe plasma wave observations at longitudinally separated locations in space and geomagnetically-conjugate locations in space and on the ground. The results of instrument intercalibrations between the two missions are also presented. Arase continued its normal operation after the scientific operation of Van Allen Probes completed in October 2019. The combined Van Allen Probes (2012-2019) and Arase (2017-present) observations will cover a full solar cycle. This will be the first comprehensive long-term observation of the inner magnetosphere and radiation belts.

We developed a three‐dimensional relativistic test particle code and used it to calculate the trajectories of relativistic electrons in the outer radiation belt. By applying time‐varying magnetic field data calculated from the Tsyganenko model and using observed solar wind data and the Dst index, we examined the drift loss of relativistic electrons by magnetopause shadowing (MPS). Since other loss processes such as wave‐particle interactions are not included in this simulation, the pure MPS effect can be discussed. A split was found in the outer radiation belt after the enhancement of the solar wind dynamic pressure. Isolated electrons outside of the split have a narrow pitch angle distribution around 90° and are confined to a narrow range of the L shell. We found that the existence of the isolated electrons depends on the large geomagnetic tilt angle. These findings indicate that the split can be seen during summer and winter after MPS occurs. We suggest that this split in the outer radiation belt during summer and winter is evidence that MPS actually causes the loss of the outer radiation belt.

Relativistic electron fluxes of the outer radiation belt often decrease rapidly in response to solar wind disturbances. The importance of the magnetopause shadowing (MPS) effect on such electron losses has yet to be quantified. If the MPS is essential for outer radiation belt electron losses, a close relationship between the outer edge of the outer belt and the magnetopause standoff distance is expected. Using GOES and THEMIS data, we examined earthward movement of the outer edge of the outer belt during electron loss events at geosynchronous orbit and its correlation with the magnetopause standoff distance. In events with significant earthward movement, we found a good correlation. There were no clear correlations in events without significant earthward movement, however. Comparing the observational results with a test particle simulation, the observed dependence between the outer edge and the magnetopause standoff distance is consistent with the MPS effect. Key Points We investigated the outer edge of the outer belt using the THEMIS data The outer edge position is correlated with the solar wind dynamic pressure The results indicate that magnetopause shadowing is effective for the loss

We studied on the crystallinity of as-sputtered and annealed MoS2 thin films by Raman scattering. The samples were prepared by RF magnetron sputtering, and the thermal annealing was carried out under sulfurous atmosphere. Although as-sputtered MoS2 thin films clearly showed the deterioration of the lattice ordering, it was drastically improved by the thermal annealing due to the sulfurization of the sample. And since the sulfurization occurred remarkably on the top surface of MoS2 sputtered thin films, it was expected to be an effective method to realize a few-layer MoS2 sputtered thin films with high crystallinity.

We simulate the 3‐D evolution of a thin current sheet as it impinges on the ionosphere from a magnetospheric source in a manner analogous to that which may occur during the onset of an auroral substorm. We consider two scenarios: one in which electron inertia alone acts to allow motion between the plasma and the geomagnetic field, and a second where a resistive layer at the interface between the ionosphere and magnetosphere is included. These two scenarios in our fluid model are intended to represent what have become known as “Alfvénic” and “Quasi‐static” or “Inverted‐V” aurora, respectively. In the absence of resistivity the evolution is shown to be driven by a combination of Kelvin‐Helmholtz and tearing instabilities leading to vortices similar to folds and the eventual break‐up of the planar arc into distorted fine‐scale sheets and filamentary currents. The later stage of this evolution is driven by an instability on the steep transverse current gradients created by the former instabilities. With a resistive layer present the K‐H instability dominates leading to the formation of auroral curls. We show how these evolutionary processes can be ordered based on the ratio of the transverse electric and magnetic fields (ΔEX/ΔBY) across the current sheet relative to the Alfvén speed, and demonstrate how the evolution is dependent on wave reflection from the topside ionosphere.