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Using data from the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission, we explore the plasma properties of Martian magnetotail current sheets (CS), to further understand the solar wind interaction with Mars and ion escape. There are some CS exhibit energetic oxygen ions that show narrow beam structures in the energy spectrum, which primarily occurs in the hemisphere where the solar wind electric field (Esw) is directed away from the planet. On average, these CS have a higher escaping flux than that of the CS without energetic oxygen ion beams, suggesting different roles in ion escape. The CS with energetic oxygen ion beams exhibits different proton and electron properties to the CS without energetic oxygen ion beams, indicating their different origins. Our analysis suggests that the CS with energetic oxygen ion beams may result from the interaction between the penetrated solar wind and localized oxygen ion plumes. Plain Language Summary: Ion escape into space, driven by solar wind interactions with Mars, plays a pivotal role in the evolution of the Martian atmosphere. An important escape channel of planetary oxygen ions is the current sheet in the nightside magnetotail. Yet, our existing understanding of plasma characteristics within this magnetic structure remains quite limited. Based on the MAVEN observations, we find the current sheets can be categorized into two distinct types according to the energy distribution patterns of oxygen ions: one is with the appearance of energetic oxygen ions with narrow beam structure, the other one is not. On average, the current sheets with energetic oxygen ion beams have a higher escaping flux than those without, suggesting different roles in ion escape. Furthermore, the two types of current sheets exhibit markedly distinct plasma properties, indicating that they have different origins. Here we suggest that the current sheet with energetic oxygen ion beams arise from the interaction between the penetrated solar wind and localized oxygen ion plumes. Key Points: Martian magnetotail current sheets occasionally exhibit energetic oxygen ions that show beam structures in the energy spectrumThe current sheets with energetic oxygen ion beam usually have a higher escaping flux than those withoutPlasma properties in current sheets differ significantly differences between those with and without energetic oxygen ion beams [ABSTRACT FROM AUTHOR]

A sudden and significant intensification of the auroral arc with expanding motion (we call it "local-arc breaking" hereafter) is an important event in many aspects but easy to miss for real-time watching due to its short rise time. To ease this problem, a real-time alert system for local-arc breaking was developed for the Kiruna all-sky camera (ASC) using ASC images in the JPEG format. The identification of the local-arc breaking is made in two steps using the "expert system" in both steps: (1) explicit criteria for classification of each pixel and simple calculations afterward are applied to each ASC image to obtain a simple set of numbers, or the "ASC auroral index", representing the occupancy of aurora pixels and characteristic intensity of the brightest aurora in the image; (2) using this ASC auroral index, the level of auroral activity is estimated, aiming for Level 6 as clear local-arc breaking and Level 4 as a precursor for it (reserving Levels 1–3 for less active aurora and Level 5 for less intense sudden intensification). The first step is further divided into two stages. Stage (1a) uses simple criteria for R (red), G (green), and B (blue) values in the RGB color code and the H (hue) value calculated from these RGB values, each pixel of a JPEG image is classified into three aurora categories (from brightest to faintest, "strong aurora", "green arc", and "visible diffuse (aurora)") and three non-aurora light source categories ("cloud", "artificial light", and "Moon"). Here, strong aurora means that the ordinary green color by atomic oxygen's 558 nm emission is either nearly saturated or mixed with red color at around 670 nm emitted, by molecular nitrogen. In stage (1b), the percentage of the occupying area (pixel coverage) for each category and the characteristic intensity of the strong aurora pixels are calculated. The obtained ASC auroral index is posted in both an ASCII format and plots in real time (https://www.irf.se/alis/allsky/nowcast/ , last access: 11 April 2023). When Level 6 (local-arc breaking) is detected, an automatic alert email is sent out to the registered addresses immediately. The alert system started on 5 November 2021, and the results (both Level 6 detection and Level 4 detection) were compared to the manual (eye) identification of the auroral activity in the ASC during the rest of the aurora season of the Kiruna ASC (i.e., all images during a total of 5 months until April 2022 were examined and occasionally double-checked in the sky). Unless the Moon or the cloud blocks the brightened region, a nearly one-to-one correspondence between Level 6 and eye-identified local-arc breaking in the ASC images is achieved with an uncertainty of under 10 min. [ABSTRACT FROM AUTHOR]

A real-time alert system of sudden and significant intensification of auroral arc with expanding motion (we call it "Local-Arc-Breaking" hereafter) was developed for Kiruna all-sky camera (ASC) using ASC jpeg images. The identification is made in two steps: (1) Using an "expert system" in which a combinations of simple criteria is applied to each pixels with calculations afterward (expert system), each jpeg image of the ASC is converted into a simple set of numbers, or "ASC auroral index", representing the occupancy of auroral pixels and characteristic intensity of the brightest aurora in the image. (2) Using this ASC auroral index, the level of auroral activity is estimated, aiming Level 6 as clear Local-Arc-Breaking and Level 4 as precursor for it (reserving Levels 1-3 for less active aurorae). The first step is further divided into two stages: (1a) Using simple criteria for R (red), G (green), B (blue), and H (hue) values in the RGB and HLS colour codes, each pixel of a jpeg image is classified into several categories according to its colour as "visible diffuse", "green arc", "strong aurora" (which means saturated or mixed with N2 red line at 670 nm), "cloud", "artificial light", and "moon". (1b) The percentage of the occupying area (pixel coverage) for each category and the characteristic intensity of "strong aurora" are calculated. The obtained ASC aurora index is posted in both a ascii format and plots on a real-time bases at https://www.irf.se/alis/allsky/nowcast/. When Level 6 is detected, automatic alert E-mail is sent out to the registered addresses immediately. The alert system started 5 November, 2021, and the results (both Level 6 detection and Level 4 detection) were compared to the manual eye-)identification of the auroral activity during the rest of the auroral season of Kiruna ASC (i.e., total five months until April 2022). Unless the Moon or cloud blocks the brightened region, nearly one-to-one correspondence between Level 6 and Local-Arc-Breaking judged by original ASC images is achieved within ten minutes uncertainty. [ABSTRACT FROM AUTHOR]

In this chapter, we review the contribution of space missions to the determination of the elemental and isotopic composition of Earth, Moon and the terrestrial planets, with special emphasis on currently planned and future missions. We show how these missions are going to significantly contribute to, or sometimes revolutionise, our understanding of planetary evolution, from formation to the possible emergence of life. We start with the Earth, which is a unique habitable body with actual life, and that is strongly related to its atmosphere. The new wave of missions to the Moon is then reviewed, which are going to study its formation history, the structure and dynamics of its tenuous exosphere and the interaction of the Moon’s surface and exosphere with the different sources of plasma and radiation of its environment, including the solar wind and the escaping Earth’s upper atmosphere. Missions to study the noble gas atmospheres of the terrestrial planets, Venus and Mars, are then examined. These missions are expected to trace the evolutionary paths of these two noble gas atmospheres, with a special emphasis on understanding the effect of atmospheric escape on the fate of water. Future missions to these planets will be key to help us establishing a comparative view of the evolution of climates and habitability at Earth, Venus and Mars, one of the most important and challenging open questions of planetary science. Finally, as the detection and characterisation of exoplanets is currently revolutionising the scope of planetary science, we review the missions aiming to characterise the internal structure and the atmospheres of these exoplanets. [ABSTRACT FROM AUTHOR]

A solar-flare-induced, high-latitude (peak at 70–75 ∘ geographic latitude – GGlat) ionospheric current system was studied. Right after the X9.3 flare on 6 September 2017, magnetic stations at 68–77 ∘ GGlat near local noon detected northward geomagnetic deviations (ΔB) for more than 3 h, with peak amplitudes of >200 nT without any accompanying substorm activities. From its location, this solar flare effect, or crochet, is different from previously studied ones, namely, the subsolar crochet (seen at lower latitudes), auroral crochet (pre-requires auroral electrojet in sunlight), or cusp crochet (seen only in the cusp). The new crochet is much more intense and longer in duration than the subsolar crochet. The long duration matches with the period of high solar X-ray flux (more than M3-class flare level). Unlike the cusp crochet, the interplanetary magnetic field (IMF) BY is not the driver, with the BY values of only 0–1 nT out of a 3 nT total field. The equivalent ionospheric current flows eastward in a limited latitude range but extended at least 8 h in local time (LT), forming a zonal current region equatorward of the polar cap on the geomagnetic closed region. EISCAT radar measurements, which were conducted over the same region as the most intense ΔB , show enhancements of electron density (and hence of ion-neutral density ratio) at these altitudes (∼100 km) at which strong background ion convection (>100 m s -1) pre-existed in the direction of tidal-driven diurnal solar quiet (Sq0) flow. Therefore, this new zonal current can be related to this Sq0-like convection and the electron density enhancement, for example, by descending the E-region height. However, we have not found why the new crochet is found in a limited latitudinal range, and therefore, the mechanism is still unclear compared to the subsolar crochet that is maintained by a transient redistribution of the electron density. The signature is sometimes seen in the auroral electrojet (AE = AU - AL) index. A quick survey for X-class flares during solar cycle 23 and 24 shows clear increases in AU for about half the > X2 flares during non-substorm time, despite the unfavourable latitudinal coverage of the AE stations for detecting this new crochet. Although some of these AU increases could be the auroral crochet signature, the high-latitude crochet can be a rather common feature for X flares. We found a new type of the solar flare effect on the dayside ionospheric current at high latitudes but equatorward of the cusp during quiet periods. The effect is also seen in the AU index for nearly half of the > X2-class solar flares. A case study suggests that the new crochet is related to the Sq0 (tidal-driven part) current. [ABSTRACT FROM AUTHOR]

Ion escape is of particular interest for studying the evolution of the atmosphere on geological timescales. Previously, using Cluster-CODIF data, we investigated the oxygen ion outflow from the plasma mantle for different solar wind conditions and geomagnetic activity. We found significant correlations between solar wind parameters, geomagnetic activity (Kp index), and the O+ outflow. From these studies, we suggested that O+ ions observed in the plasma mantle and cusp have enough energy and velocity to escape the magnetosphere and be lost into the solar wind or in the distant magnetotail. Thus, this study aims to investigate where the ions observed in the plasma mantle end up. In order to answer this question, we numerically calculate the trajectories of O+ ions using a tracing code to further test this assumption and determine the fate of the observed ions. Our code consists of a magnetic field model (Tsyganenko T96) and an ionospheric potential model (Weimer 2001) in which particles initiated in the plasma mantle region are launched and traced forward in time. We analysed 131 observations of plasma mantle events in Cluster data between 2001 and 2007, and for each event 200 O+ particles were launched with an initial thermal and parallel bulk velocity corresponding to the velocities observed by Cluster. After the tracing, we found that 98 % of the particles are lost into the solar wind or in the distant tail. Out of these 98 %, 20 % escape via the dayside magnetosphere. [ABSTRACT FROM AUTHOR]

Observations of the terrestrial ion escape to space and the transport of escaping ions in the magnetosphere are reviewed, with the main stress on subjects that were not covered in reviews over past 2 decades, during which Cluster has significantly improved our knowledge of them. Here, outflowing ions from the ionosphere are classified in terms of energy rather than location: (1) as cold ions refilling the plasmasphere faster than Jeans escape, (2) as cold supersonic ions such as the polar wind, and (3) as suprathermal ions energized by wave–particle interaction or parallel potential acceleration, mainly starting from cold supersonic ions. The majority of the suprathermal ions above the ionosphere become "hot" at high altitudes, with much higher velocity than the escape velocity even for heavy ions. This makes heavy hot ions more abundant in the magnetosphere than heavy ions transported by cold refilling ions or cold supersonic flow. The immediate destination of these terrestrial ions varies from the plasmasphere, the inner magnetosphere including those entering the ionosphere in the other hemisphere and the tailward outer boundaries, the magnetotail, and the solar wind (magnetosheath, cusp, and plasma mantle). Due to time-variable return from the magnetotail, ions with different routes and energy meet in the inner magnetosphere, making it a zoo of different types of ions in both energy and energy distribution. While the mass-independent drift theory has successfully disentangled this zoo of ions, there are many poorly understood phenomena, e.g., mass-dependent energization. Half of the heavy ions in this zoo also finally escape to space, mainly due to magnetopause shadowing (overshooting of ion drift beyond the magnetopause) and charge exchange near the mirror altitude where the exospheric neutral density is at its highest. The amount of heavy ions mixing directly with the solar wind is already the same as or larger than that entering into the magnetotail and is large enough to extract the solar wind kinetic energy in the cusp–plasma mantle through the mass-loading effect and drive the current system near the cusp independently of the global current system. Considering the past solar and solar wind conditions, ion escape might even have influenced the evolution of the terrestrial biosphere. [ABSTRACT FROM AUTHOR]

We have investigated the consequences of extreme space weather on ion outflow from the polar ionosphere by analyzing the solar storm that occurred early September 2017, causing a severe geomagnetic storm. Several X‐flares and coronal mass ejections were observed between 4 and 10 September. The first shock—likely associated with a coronal mass ejection—hit the Earth late on 6 September, produced a storm sudden commencement, and began the initial phase of the storm. It was followed by a second shock, approximately 24 hr later, that initiated the main phase and simultaneously the Dst index dropped to Dst = −142 nT and Kp index reached Kp = 8. Using COmposition DIstribution Function data on board Cluster satellite 4, we estimated the ionospheric O+ outflow before and after the second shock. We found an enhancement in the polar cap by a factor of 3 for an unusually high ionospheric O+ outflow (mapped to an ionospheric reference altitude) of 1013 m−2 s−1. We suggest that this high ionospheric O+ outflow is due to a preheating of the ionosphere by the multiple X‐flares. Finally, we briefly discuss the space weather consequences on the magnetosphere as a whole and the enhanced O+ outflow in connection with enhanced satellite drag. Key Points: Multiple X‐flares and three CMEs occurred in 4‐10 September 2017, CMEs are the driver of the storm, whereas the X‐flares might have preheated the ionosphereThe O+ outflow in the polar cap and cusp is estimated to be 1013 m‐2s‐1 during the main phase of the geomagnetic stormThe entire magnetosphere is affected by space weather event, and the O+ enhancement in the cusp might be a good indicator for satellite drag fluctuations [ABSTRACT FROM AUTHOR]

By conserving momentum during the mixing of fast solar wind flow and slow planetary ion flow in an inelastic way, mass loading converts kinetic energy to other forms – e.g. first to electrical energy through charge separation and then to thermal energy (randomness) through gyromotion of the newly born cold ions for the comet and Mars cases. Here, we consider the Earth's exterior cusp and plasma mantle, where the ionospheric origin escaping ions with finite temperatures are loaded into the decelerated solar wind flow. Due to direct connectivity to the ionosphere through the geomagnetic field, a large part of this electrical energy is consumed to maintain field-aligned currents (FACs) toward the ionosphere, in a similar manner as the solar wind-driven ionospheric convection in the open geomagnetic field region. We show that the energy extraction rate by the mass loading of escaping ions (ΔK) is sufficient to explain the cusp FACs, and that ΔK depends only on the solar wind velocity accessing the mass-loading region (usw) and the total mass flux of the escaping ions into this region (mloadFload), as ΔK ∼ −mloadFloadu2sw∕4. The expected distribution of the separated charges by this process also predicts the observed flowing directions of the cusp FACs for different interplanetary magnetic field (IMF) orientations if we include the deflection of the solar wind flow directions in the exterior cusp. Using empirical relations of u0 ∝ Kp + 1.2 and Fload ∝ exp(0.45Kp) for Kp = 1–7, where u0 is the solar wind velocity upstream of the bow shock, ΔK becomes a simple function of Kp as log10(ΔK) = 0.2 ⋅ Kp + 2 ⋅ log10(Kp + 1.2) + constant. The major contribution of this nearly linear increase is the Fload term, i.e. positive feedback between the increase of ion escaping rate Fload through the increased energy consumption in the ionosphere for high Kp, and subsequent extraction of more kinetic energy ΔK from the solar wind to the current system by the increased Fload. Since Fload significantly increases for increased flux of extreme ultraviolet (EUV) radiation, high EUV flux may significantly enhance this positive feedback. Therefore, the ion escape rate and the energy extraction by mass loading during ancient Earth, when the Sun is believed to have emitted much higher EUV flux than at present, could have been even higher than the currently available highest values based on Kp = 9. This raises a possibility that the ion escape has substantially contributed to the evolution of the Earth's atmosphere. [ABSTRACT FROM AUTHOR]

Recent studies strongly suggest that a majority of the observed O+ cusp outflows will eventually escape into the solar wind, rather than be transported to the plasma sheet. Therefore, an investigation of plasma sheet flows will add to these studies and give a more complete picture of magnetospheric ion dynamics. Specifically, it will provide a greater understanding of atmospheric loss. We have used Cluster spacecraft 4 to quantify the H+ and O+ total transports in the near-Earth plasma sheet, using data covering 2001-2005. The results show that both H+ and O+ have earthward net fluxes of the orders of 1026 and 1024 s-1, respectively. The OC plasma sheet return flux is 1 order of magnitude smaller than the O+ outflows observed in the cusps, strengthening the view that most ionospheric O+ outflows do escape. The H+ return flux is approximately the same as the ionospheric outflow, suggesting a stable budget of H+ in the magnetosphere. However, low-energy H+, not detectable by the ion spectrometer, is not considered in our study, leaving the complete magnetospheric H+ circulation an open question. Studying tailward flows separately reveals a total tailward O+ flux of about 0:5×1025 s-1, which can be considered as a lower limit of the nightside auroral region O+ outflow. Lower velocity flows (< 100 km s-1) contribute most to the total transports, whereas the high-velocity flows contribute very little, suggesting that bursty bulk flows are not dominant in plasma sheet mass transport. [ABSTRACT FROM AUTHOR]

Atmospheric loss and ion outflow play an important role in the magnetospheric dynamics and in the evolution of the atmosphere on geological timescales—an evolution which is also dependent on the solar activity. In this paper, we investigate the total O + outflow [ s - 1 ] through the plasma mantle and its dependency on several solar wind parameters. The oxygen ion data come from the CODIF instrument on board the spacecraft Cluster 4 and solar wind data from the OMNIWeb database for a period of 5 years (2001–2005). We study the distribution of the dynamic pressure and the interplanetary magnetic field for time periods with available O + observations in the plasma mantle. We then divided the data into suitably sized intervals. Additionally, we analyse the extreme ultraviolet radiation (EUV) data from the TIMED mission. We estimate the O + escape rate [ions/s] as a function of the solar wind dynamic pressure, the interplanetary magnetic field (IMF) and EUV. Our analysis shows that the O + escape rate in the plasma mantle increases with increased solar wind dynamic pressure. Consistently, it was found that the southward IMF also plays an important role in the O + escape rate in contrast to the EUV flux which does not have a significant influence for the plasma mantle region. Finally, the relation between the O + escape rate and the solar wind energy transferred into the magnetosphere shows a nonlinear response. The O + escape rate starts increasing with an energy input of approximately 10 11 W . [ABSTRACT FROM AUTHOR]

The behaviour of ions in space and an atmosphere is determined by a balance of many different factors: ionisation, interaction with neutrals, and the integrated effect of electric and magnetic fields over a much larger size and time scale than that of electrons. This causes the ion behaviour to be quite different from the electron behaviour in the solar wind-magnetosphere-ionosphere interactions and magnetospheric dynamics. The less coherence with local fields for ion behaviour than electron behaviour, together with the complication of different masses of different ions, make ion phenomena difficult to analyze, and hence many ion phenomena are remained poorly understood. This lecture overviews some of these ion phenomena with particular stress on relatively less investigated areas.* Ion injection phenomena in the dayside magnetosphere: cusp, transient injections, returning ionospheric ions, as constrainer but not carrier of large-scale electric current. * Ion escape to space: destination, amount, oxidation effect, consequence of atmospheric evolution, active role in energy extraction from the solar wind.* Inner magnetospheric ions: multiple sources of structured sub-keV ions, relation to substorm electric field, modulation by Pc5 waves, unexpected mass-dependency, relation to aurora.* Exospheric origin cold ions: variable production in both space and time, influence on bow shock and foreshock, resultant Mars-Venus-Earth difference.* Space weather and substorm: shortest propagation path, effect on the ionosphere, long term trend, and few-min local forecast.* Ions by ionising radiation from nuclear accidents: new monitoring method. [ABSTRACT FROM AUTHOR]

Recent in-situ studies suggest that ion and neutral escapes have substantially affected the evolution of the atmosphere and life. To examine this problem, we need a dedicated mission. One example is ESCAPE (\url{http://cluster.irap.omp.eu/public/ESCAPE/ESCAPE\%5fM5\%5fProposal\%5fV1.1.pdf}) targeting comprehensive understanding of both ion escape and neutral escape, with as much cost as 400 Meur. \newline\newline Size and cost of the mission can be reduced significantly by limiting our target, e.g., to the total ion escape rate, during very active solar/geomagnetic conditions, which are the most relevant from the atmospheric evolution viewpoint for the present Earth. By limiting measurements to ions, the Sun-Earth Lagrange L2 point becomes an ideal place because a semi-stable Lissajous/Halo orbit around L2 rather than orbiting the Earth allows to quickly explore the 2D cross-section of the tail magnetosphere, through which all escaping ions will flow after picked up by the solar wind. \newline\newline One advantage of the Sun-Earth L2 is that we expect good piggyback opportunities, because L2 is a favorite place for large space observatories (e.g., ESA's Herschel, Gaia, and Euclid) that require relatively large launchers. The resulting large piggyback capabilities at L2 are not useful for Earth observation or commercial purposes, allowing extra science missions as piggyback. In fact, ESA recently announced a science mission opportunity of nearly one ton starting from L2 as piggyback of PLATO or ARIEL missions. \newline\newline The size of a piggyback L2 mission for ion escape measurements can range from a formation of one mother plus two daughter spacecraft (Far Tail Explore: FATE) down to a single cubesat mission. The cubesat/daughter is equipped with two ion instruments (MCP-type for 0.1-20 keV and SSD-type for 15-85 keV that can cover picked-up O$^+$ up to 1000 km/s) and minimum additional supportive payload (magnetometer and/or Langmuir probe), costing less than 10 Meur including instrument and launch. In the FATE mission (\url{http://www..irf.se/\%7Eyamau/future/f1/Fate\%5fphase1\%5ffinal.pdf}) that we proposed for ESA's A/O, the mother spacecraft has more complete particle and supportive packages. \newline\newline With FATE instrumentation, it is possible (1) to obtain the total ion escape (flux, active cross-section, and composition) from the Earth and its variability at the ultimate downstream, (2) to identify the relative importance of the different ion escape routes and mixing of different plasmas far downstream, (3) to monitor interplanetary shocks / solar energetic particles (SEP) at the Earth and L2 for more accurate space weather warning, (4) to study fine-scale magnetospheric boundary far downstream where all boundary-related instabilities are well developed including folding including transient interactions with SEP. [ABSTRACT FROM AUTHOR]

The evolution of the Earth's atmosphere cannot be understood without an assessment of the amount of atmospheric escape to space. While the current neutral escape from the Earth's atmosphere is considered negligible (at least for the heavier species), the ion escape is more difficult to evaluate because of the diversity of escape mechanisms and the complexity of ion escape routes, and the possible recirculation of the plasma. Tracking the heavy ions is therefore of paramount importance. It is difficult to assess the total ion escape rate based on measurements in near-Earth space, in particular because the net escape rate is the difference between the upward ion flux and the downward flux of recirculated plasma. Both the upward and downward contributions are characterized by a strong spatial and time variability and a dependence on solar and geomagnetic conditions.It was recently proposed to measure the net outflow rate from a vantage point in the deep tail (ESA F1 FATE mission proposal). It is reasonable to assume that the return flow from beyond ~200 RE is negligible, so that an evaluation of the net escape rate becomes more straightforward. A contribution that would be missed are ions that are transformed into escaping energetic neutral atoms through charge exchange. Ions that are lost through magnetopause shadowing will be dragged along with the magnetosheath flow and can still be detected in the magnetosheath adjacent to the tail magnetopause, except if they are too energetic. Using simulations based on a simplified model, we examine whether it is possible to disentangle the contributions from the different atmospheric escape processes from their combined signatures in the deep tail. [ABSTRACT FROM AUTHOR]

An extremely strong Coronal Mass Ejection (CME) impacted Mars on 12 July 2011, while the Mars Express spacecraft was present inside the nightside ionosphere. Estimated solar wind density and speed during the event are 39 particles cm−3 and 730 km/s, corresponding to nominal solar wind flux at Mars when the solar system was ∼1.1 Ga old. Comparing with expected average atmospheric heavy ion fluxes under similar XUV conditions, the CME impact is found to have no significant effect on the escape rate 3.3 × 1024s−1, with an upper limit at 1025s−1 if the observed tail contraction is not taken into account. On the subsequent orbit, 7 h later after magnetosphere response, fluxes were only 2.4% of average. As such, even under primordial solar wind conditions we are unable to find support for a strong solar wind-driven ion escape, rather the main effect appears to be acceleration of the escaping ions by ×10-×20 typical characteristic energy. [ABSTRACT FROM AUTHOR]

For the past 50 years, Moore's law has been well followed by the semiconductor industry. The scaling of transistors and interconnects has been enabled not only by various technological advancements but also by novel patterning approaches. However, in order to keep up with Moore's law, further shrinking at all levels of the integrated circuit is needed. Among them is the back end of line (BEOL), where increasingly smaller metal pitches require tight specifications for vias connecting metal lines. In this paper, BEOL via shrink options is investigated, targeting the bottom critical dimension (CD) 10.5 nm in order to land on metal pitch 21 nm lines below, while maintaining low defectivity, as well as low global and local CD uniformity (CDU and LCDU, respectively). Approaches to this shrink consist of modifications to the etch chemistry at different levels of the mask etch and liner-assisted shrink, either organic or inorganic. Numerical analysis of CD-scanning electron microscopy (CDSEM) images quantitatively shows the efficiency of different approaches via shrink, together with associated CDU, LCDU, and defectivity values. CDSEM results are supplemented by large-area voltage contrast defectivity and transmission electron microscopy data sets. [ABSTRACT FROM AUTHOR]

Key Point: The editors thank the 2021 peer reviewers [ABSTRACT FROM AUTHOR]

The article presents a list of 2020 reviewers of the periodical and offer gratitude for their supports and for of the periodical, which include Andrew Akala Hassanali Akbari,and Jay Albert.

Hyperglycemia in extremely low-birth weight infants (ELBWIs) is frequently observed during the acute perinatal phase, (i.e., first 1–2 weeks postnatal period); however it can occasionally persists for >2 weeks, extending to the post-acute phase. Since such prolonged hyperglycemia (PH) is not typical for ELBWIs, the aim of the present study was to further understand the clinical details of PH. Twenty-five hyperglycemic ELBWIs born before 28 weeks of gestation from 2015 to 2018 were included in the study. Based on the duration of hyperglycemia, we separated the subjects into two groups: non-prolonged hyperglycemia (NPH) who achieved remission within ≤2 weeks [n = 18, median 3.0 (range, 2.0–4.0) days], and PH, whose hyperglycemia persisted for >2 weeks [n = 7, median 50.0 (range, 33.5–66.0) days]. Compared to the NPH group, glucose metabolism of the PH group was more deteriorate. The peak blood glucose level was significantly higher in the PH group [PH: median 472 mg/dL, NPH: median 275 mg/dL, p < 0.001], and a higher proportion of subjects in the PH group required insulin therapy [PH: 100% (7/7) vs. NPH: 22% (4/22)]. Multivariate analysis revealed that among perinatal factors, prematurity was the only independent risk factor for PH (glucocorticoid therapy: p = 0.884, gestational age: p = 0.006), with a cutoff of 23W4D determined by receiver operating characteristic analysis. Our data revealed distinctive clinical features of PH, suggesting a type different from the previously reported hyperglycemia in ELBWIs. Specifically, extreme prematurity, less than 24 weeks of gestation, is a risk for PH, and aggressive interventions, such as insulin would be required. [ABSTRACT FROM AUTHOR]

Key Points: The editors thank the 2019 peer reviewers [ABSTRACT FROM AUTHOR]

On behalf of the journal, AGU, and the scientific community, the Editors would like to sincerely thank those who reviewed manuscripts for Geophysical Research Letters in 2018. The hours reading and commenting on manuscripts not only improves the manuscripts but also increases the scientific rigor of future research in the field. We particularly appreciate the timely reviews, in light of the demands imposed by the rapid review process at Geophysical Research Letters. With the revival of the "major revisions" decisions, we appreciate the reviewers' efforts on multiple versions of some manuscripts. Many of those listed below went beyond and reviewed three or more manuscripts for our journal, and those are indicated in italics. In total, 4,484 referees contributed to 7,557 individual reviews in journal. Thank you again. We look forward to the coming year of exciting advances in the field and communicating those advances to our community and to the broader public. Key Point: In total, 4,484 referees contributed to 7,557 individual reviews in journal [ABSTRACT FROM AUTHOR]

We present the status of the low-temperature devices shared by several neutron instruments of the Materials and Life Science Experimental Facility (MLF), J-PARC. In recent years, the Cryogenics and Magnets group of the Sample Environment (SE) team has introduced three cryostats at the MLF: a top-loading 4He cryostat, a bottom-loading 3He cryostat, and a 3He–4He dilution refrigerator insert. The group also manages a superconducting magnet which entered into service in 2012. Progress has been made with these SE, including the development of a new system for controlling the 3He cryostat and an oscillating radial collimator for using efficiently the superconducting magnet. These innovations have significantly increased the frequency with which these cryostats and magnet are used. During the last Japanese fiscal year, some of them were used approximately half of the total number of days of beam operation. [ABSTRACT FROM AUTHOR]

The Editors of the Journal of Geophysical Research Space Physics extend a sincere and heartfelt thank you to the 1,448 scientists that conducted 3,511 manuscript reviews for the journal in calendar year 2017. We deeply appreciate the time and effort that you have devoted to the research community. Key Points: The Editors of JGR Space Physics thank everyone that served as a manuscript reviewer in 2017; we greatly appreciate your serviceThe 1,448 scientists submitted 3,511 reviews on 1,146 unique manuscripts in 2017, numbers that are slightly down from the previous yearThe average time for a reviewer to submit a report is 20.5 days, with 64% of reports submitted within the requested 3‐week window [ABSTRACT FROM AUTHOR]

Abstract: Space Weather Editors recognize contribution from peer reviewers. [ABSTRACT FROM AUTHOR]

The Rosetta mission shall accompany comet 67P/Churyumov-Gerasimenko from a heliocentric distance of >3.6 astronomical units through perihelion passage at 1.25 astronomical units, spanning low and maximum activity levels. Initially, the solar wind permeates the thin comet atmosphere formed from sublimation, until the size and plasma pressure of the ionized atmosphere define its boundaries: A magnetosphere is born. Using the Rosetta Plasma Consortium ion composition analyzer, we trace the evolution from the first detection of water ions to when the atmosphere begins repelling the solar wind (~3.3 astronomical units), and we report the spatial structure of this early interaction. The near-comet water population comprises accelerated ions (<800 electron volts), produced upstream of Rosetta, and lower energy locally produced ions; we estimate the fluxes of both ion species and energetic neutral atoms. [ABSTRACT FROM AUTHOR]

Objective: There have been very few population-based prospective studies that have investigated the risks of deaths by suicide and other externally caused injuries (ECIs) among cancer patients in an Asian population. This study investigated whether the risk of death by both suicide and ECIs increases during the first year following the initial diagnosis of cancer. Methods: Data were analyzed from a population-based cohort of Japanese residents between 1990 and 2010, collected during the Japan Public Health Center-based Prospective Study. Poisson regression models were used to calculate adjusted risk ratios (RRs) for both suicide and ECI deaths. To adjust for unmeasured confounding factors, case-crossover analyses were conducted for all patients with cancer who died by suicide and ECIs. Results: A population-based cohort of 102,843 Japanese residents was established. During the follow-up period, there were 34 suicides and 48 ECI deaths among patients with cancer, as compared with 527 suicides and 707 ECI deaths among those who did not have cancer. Analyses revealed that those who were newly diagnosed with cancer were at a greatly increased risk of death by suicide and ECIs within the first year after their diagnosis (suicide RR= 23.9, 95% CI: 13.8-41.6; ECI RR= 18.8, 95% CI: 11.4-31.0). Furthermore, the case-crossover analyses generally confirmed the results of the Poisson regressions. Conclusions: The risks of suicide and ECI deaths within the first year after a cancer diagnosis were higher than those among cancer-free populations. A diagnosis of cancer is a critical experience that may increase the risk of fatal outcomes. [ABSTRACT FROM AUTHOR]

Background: DNA double strand breaks induced by DNA damaging agents, such ionizing radiation, are repaired by multiple DNA repair pathways including non-homologous end-joining (NHEJ) repair and homologous recombination (HR) repair. ATM-dependent DNA damage checkpoint regulates a part of DNA repair pathways, however, the exact role of ATM activity remains to be elucidated. In order to define the molecular structure of DNA double strand breaks requiring ATM activity we examined repair of DNA double strand breaks induced by different restriction endonucleases in normal human diploid cells treated with or without ATM-specific inhibitor. Results: Synchronized G1 cells were treated with various restriction endonucleases. DNA double strand breaks were detected by the foci of phosphorylated ATM at serine 1981 and 53BP1. DNA damage was detectable 2 hours after the treatment, and the number of foci decreased thereafter. Repair of the 3'-protruding ends created by Pst I and Sph I was efficient irrespective of ATM function, whereas the repair of a part of the blunt ends caused by Pvu II and Rsa I, and 5'- protruding ends created by Eco RI and Bam HI, respectively, were compromised by ATM inhibition. Conclusions: Our results indicate that ATM-dependent pathway plays a pivotal role in the repair of a subset of DNA double strand breaks with specific end structures. [ABSTRACT FROM AUTHOR]

Background: Calprotectin, a major cytosol protein of leukocytes, exists in plasma and other body fluids of healthy human subjects. Since the calprotectin concentration rises markedly in some inflammatory diseases including rheumatoid arthritis, this protein has been thought to be a marker of inflammatory disease. Recently, we identified calprotectin in human dental calculus and gingival crevicular fluid (GCF), and found that the calprotectin concentration in GCF from patients with periodontitis was significantly higher than that in GCF from healthy subjects. In the present study, the association of GCF calprotectin level with GCF volume, gingival index (GI), and levels of biochemical markers including collagenase and aspartate aminotransferase (AST) in GCF was investigated to clarify the relationship between GCF calprotectin level and periodontal inflammation. Methods: Ninety GCF samples collected from periodontal pockets with a probing depth of more than 4 mm in 54 patients with adult periodontitis were used for these assays. The GCF volume was measured, and GI in each site was recorded. The calprotectin content in GCF samples was determined by ELISA using a specific antibody. The activity of collagenase or AST was measured by a respective assay kit. Results: The total amount of calprotectin and GCF volume showed a highly significant correlation (r = 0,64, P<0.0001), whereas the calprotectin concentration had no correlation with the QCF volume (r = 0 01, P = 0.924). The mean calprotectin concentration in GCF increased with the degree of GI, and the concentration in individual samples was significantly correlated with the GI score (r = 0.56. P<;0.0001). Significant positive correlations were observed in GCF calprotectin versus collagenase (r = 0.57, P<0.0001) and GCF calprotectin versus AST levels (r = 0.40, P<0.005). Conclusions: From the present results and our previous findings, it is shown that the GCF calprotectin level significantly correlates not only with clinical indicators but also with current biochemical marker levels and that calprotectin may be a useful marker for periodontal inflammation. [ABSTRACT FROM AUTHOR]