Globally, antimicrobial resistance (AMR) is a serious problem causing 700,000 deaths annually. By 2050, AMR is expected to cause approximately 10 million deaths globally each year if allowed to ...increase at the present rate. Many individuals have limited knowledge regarding appropriate antibiotic use and AMR. Most antibiotic use occurs in the outpatient setting, with approximately 30% of antibiotics prescribed deemed unnecessary. Antimicrobial stewardship (AMS) is a means to reduce inappropriate antibiotic use and AMR. While existing AMS efforts generally focus on the inpatient setting, a significant gap is present in the outpatient setting. A common theme across various national action plans to reduce AMR is the need for education and awareness. The importance of communicating information in a manner easily comprehended by the patient in addition to productive clinician–patient dialogue cannot be overestimated. Enhancing the public’s and patients’ AMS health literacy is an underrecognized approach to help address AMR. We describe Four Core Elements of Enhancing AMS Health Literacy in the Outpatient Setting, utilizing the Centers for Disease Control and Prevention’s framework: (1) leadership commitment, (2) intervention/action, (3) tracking/reporting, and (4) education/expertise. We call upon leaders in outpatient settings to embrace this approach to curb inappropriate antimicrobial use.
Discovery of diffuse aurora on Mars Schneider, N. M.; Deighan, J. I.; Jain, S. K. ...
Science (American Association for the Advancement of Science),
11/2015, Volume:
350, Issue:
6261
Journal Article
Peer reviewed
Open access
Planetary auroras reveal the complex interplay between an atmosphere and the surrounding plasma environment. We report the discovery of low-altitude, diffuse auroras spanning much of Mars' northern ...hemisphere, coincident with a solar energetic particle outburst. The Imaging Ultraviolet Spectrograph, a remote sensing instrument on the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft, detected auroral emission in virtually all nightside observations for ~5 days, spanning nearly all geographic longitudes. Emission extended down to ~60 kilometer (km) altitude (1 microbar), deeper than confirmed at any other planet. Solar energetic particles were observed up to 200 kilo--electron volts; these particles are capable of penetrating down to the 60 km altitude. Given minimal magnetic fields over most of the planet, Mars is likely to exhibit auroras more globally than Earth.
Abstract
Mars’s magnetosphere is hybrid, having contributions from both an induced magnetosphere like Venus and the localized crustal magnetic fields. However, the planetary fields also include ...large-scale, more global components. In this study, we investigate their role in Mars’s magnetospheric topological responses to the interplanetary magnetic field (IMF) clock angle using observations from the Mars Atmospheric Volatile and EvolutioN mission. We show that the large-scale planetary field has a “dipole-like” influence on the Mars global magnetosphere by examining the open field topology. We find that the “dipole-like” planetary field, as at Earth, results in a more open magnetosphere during southward IMF. The clock angle effects on the twisted magnetotail current sheet are similarly consistent with this analogy. It reinforces the idea that Mars’s magnetosphere and solar wind interaction are more Earth-like than previously thought.
One possible ion escape channel at Mars is a polar wind‐like outflow driven by parallel electric fields and/or other acceleration mechanisms. With independent potential estimates from ionospheric ...photoelectron measurements by the Solar Wind Electron Analyzer (SWEA) and ion measurements by the SupraThermal And Thermal Ion Composition (STATIC) onboard the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft, magnetic field‐aligned potentials are calculated as the difference of the two. The calculated field‐aligned potentials have average values that range from 0 to −1.5 V, relative to the ionospheric source region. These field‐aligned potentials likely result from ambipolar electric fields and are found on both closed and open field lines. On the dayside, these potentials range from 0 to −0.7 V, corresponding to an electric field magnitude <3 mV/km, which peaks near the ion exobase and can effectively accelerate ions and enhance ion outflow.
Plain Language Summary
The Mars Atmosphere and Volatile EvolutioN (MAVEN) mission is dedicated to studying atmospheric loss from Mars at the current epoch and estimating the total loss to space over Martian history. Atmospheric escape can be in the form of neutral particles and charged particles (i.e., ions and electrons). Charged particles subject to electromagnetic forces at Mars. Ions, more gravitationally bounded than electrons, can be accelerated to escape velocities by these forces. One of the accelerating forces for ions at Mars is in the form of ambipolar electric field, produced by electron‐ion separation. This study provides the first statistical analysis of amiboplar electric field at Mars with MAVEN data. Integrating this force over a spatial distance, the resulting potential, determined from MAVEN's measurements, ranges from 0 to −1.5 eV. These potentials can accelerate more ions to escape velocity and enhance ion escape. This study is cruel to characterize low‐energy ion escape, an important atmospheric loss channel.
Key Points
This study provides a statistical analysis of field‐aligned potentials at Mars, which we attribute to the ambipolar electric field
The potential difference between the ionospheric source region and the spacecraft ranges from 0 to 1.5 V with E directing away from Mars
Derived dayside electric fields are <3 mV/km and located near the ion exobase, where they are most effective at enhancing ion outflow
Discrete aurorae have been observed at magnetized planets such as Earth and Jupiter, triggered by accelerated electrons. Similar aurorae have also been observed at Mars with only localized strong ...crustal magnetisms. However, our understanding of this phenomenon at Mars is still limited. In particular, direct and quantitative comparisons of the auroral and its source electron events are lacking as these two types of observations are usually made at different times and/or locations. In this study, we establish empirical criteria to select electron events (“auroral electrons”) that could trigger detectable auroral emissions with Mars Atmosphere and Volatile EvolutioN measurements, thereby enabling a direct statistical comparison. We find auroral electrons share similar statistical characteristics to those previously reported for discrete auroral events. This study bridges the gap between electron observations and auroral detections and enables collaborations across different Mars missions, as well as comparative planetary studies of discrete aurora.
Plain Language Summary
Aurorae have been observed in the polar regions at magnetized planets such as Earth and Jupiter, triggered by accelerated electrons. Similarly, localized auroral emissions have also been reported at Mars with no global dipole field but localized strong crustal magnetisms. However, our understanding of aurorae at Mars is still very limited in terms of their characteristics and the source electrons. In particular, direct and quantitative comparisons of the auroral and electron events are lacking as these two types of observations are usually made at different times and/or locations because of the limitation of single‐spacecraft observations. This study establishes empirical criteria to select auroral electrons and statistically compare these two types of observations. This study bridges the gap between the electron observations and auroral detections and enables collaborations across different Mars missions, as well as studies of auroral phenomena at different planets.
Key Points
We establish empirical criteria to select electron events that could trigger detectable auroral observations
We find similar statistical behaviors in selected electron events as discrete auroral events and explore the cause of statistical trends
This study bridges the gap of these two types of observations and motivates collaborations across different Mars missions
Discrete aurorae have been observed at Mars by multiple spacecraft, including Mars Express, Mars Atmosphere and Volatile EvolutioN (MAVEN), and most recently the United Arab Emirates Hope spacecraft. ...Meanwhile, there have been studies on the source particles responsible for producing these detectable aurorae (termed “auroral electrons”). By utilizing empirical criteria to select auroral electrons established by Xu et al. (2022, https://doi.org/10.1029/2022GL097757), we conduct statistical analyses of the impact of upstream drivers on the occurrence rate and fluxes of auroral electrons. We find the occurrence rate increases with upstream dynamic pressure and weakly depends on the interplanetary magnetic field strength. Meanwhile, the integrated auroral electron flux somewhat decreases with increasing upstream drivers. Auroral electron precipitation also occurs more frequently and is more intense over regions of strong crustal fields compared to weak crustal fields. Aside from emissions, auroral electrons are expected to cause significant impact ionization and enhance the plasma density locally. In this study, we also quantify the nightside ionospheric impact of auroral electron precipitation, specifically the thermal ion (O+, O2+ ${O}_{2}^{+}$, and CO2+ $C{O}_{2}^{+}$) density enhancement, with MAVEN observations. Our results show that the ion density is increased by up to an order of magnitude at low altitudes. The crustal effects on ion density profiles for nominal electron and auroral electron precipitation are also discussed.
Plain Language Summary
Localized auroral emissions have been observed at Mars by multiple spacecraft, including Mars Express, Mars Atmosphere and Volatile EvolutioN (MAVEN), and most recently the United Arab Emirates Hope spacecraft. Meanwhile, there have been studies on the source particles responsible for producing these detectable aurorae, termed “auroral electrons.” By utilizing previously established criteria to select auroral electrons, we conduct statistical analyses of the impact of upstream drivers on the occurrence rate and also the intensity of auroral electrons. In the meantime, auroral emission is not the sole effect of electrons impacting the collisional atmosphere, but also an enhanced local ionization. Using both MAVEN observations, we show that the ion density is increased by up to an order of magnitude at low altitudes comparing auroral electron and nonauroral electron events.
Key Points
The occurrence rates of auroral electrons increase but their integrated energy fluxes somewhat decrease with increasing upstream drivers
We quantify the planetary ion density enhancement resulting from auroral electron precipitation to be up to an order of magnitude
Auroral electron precipitation occurs more frequently and is more intense over strong crustal fields than weak crustal fields
We report for the first time, simultaneous ion, electron, magnetic field vector and electric field wave measurements made possible by Mars Atmosphere and Volatile EvolutioN, during ion energy flux ...spikes in low‐altitude radial crustal magnetic fields on the Mars dayside. Observations show energetic electrons and ions (E > 25 eV) precipitating on magnetic field lines assumed as closed. Ions (E < 1.4 keV) display broad velocity distributions toward Mars, showing ions flowing from higher altitude possibly after magnetic reconnection or loss cone filling from pitch angle scattering effects. Precipitating ions (E < 1.4 keV) show nonadiabatic features depending on ion mass and energy and returning ions (E < 1.4 keV) show evidence of conserving the first adiabatic invariant in a mirror field. We observe magnetic field perturbations up to 60 nT, electric field wave amplitudes up to 38 mV/m, and brief periods of peaked electron spectra. At ∼175 km and at times Mars Atmosphere and Volatile EvolutioN is below the mirroring altitude of electrons, we observe mirroring and transverse heating of H+ ions alongside increased electric field wave amplitude fluctuations. It suggests field aligned potential drops result from different mirror altitudes of ions and electrons. Ions E > 1.4 keV (O+) occur as injected accelerated ion beams and ions heated after energization or deceleration. Energy dispersed kilo‐electron‐volt ions suggest a selection effect in radial magnetic fields for lower‐energy Marsward ions, compared to reflection of higher‐energy anti‐Sunward ions. Precipitating kilo‐electron‐volt ions show energy deposition rates of 3.6 ×10−6 W/m2 and sputtering escape rates from precipitating O+ ions of 1.5 ×105/(cm2.s) and 2.1 ×106/(cm2.s) are calculated.
Plain Language Summary
Mars Atmosphere and Volatile EvolutioN arrived at Mars on 21 September 2014 to study the effects of the solar wind interaction on the upper atmosphere. This study reports the raining of both energetic electrons and multiple populations of ions at low altitudes and over regions of ancient magnetic field from the Martian crust. These observations are associated with large magnetic field deflections and large electric field fluctuations. The results are important for understanding plasma transport and associated electrodynamics where the crustal magnetic fields point vertically toward or away from the planet. Such analysis was not possible with previous missions, which did not include the complete set of space plasma instruments carried by Mars Atmosphere and Volatile EvolutioN. Some ions display behaviors not expected for the small curvature of the crustal magnetic fields; ions that are locally tied that would require much larger magnetic field structures or ions injected along the direction of the magnetic field. Oxygen ions that originate from Mars that have been picked up by the solar wind and moving at very high speeds are selected over regions of vertical magnetic field to travel directly toward the planet. These ions will have head on impacts with Mars to heat and blast atmosphere out into space.
Key Points
Investigated plasma transport and associated electrodynamics during ion energy flux spikes in radial crustal fields on the Mars dayside
Precipitating ion and electron energy flux spikes on closed field consisting of ion beams E > 1.4 keV and broad ion distributions E < 1.4 keV
Considered impact of low‐altitude precipitating O+ ions E > 25 eV on localized heating and atmospheric escape
The objective of this White Paper, submitted to ESA’s Voyage 2050 call, is to get a more holistic knowledge of the dynamics of the Martian plasma system, from its surface up to the undisturbed solar ...wind outside of the induced magnetosphere. This can only be achieved with coordinated multi-point observations with high temporal resolution as they have the scientific potential to track the whole dynamics of the system (from small to large scales), and they constitute the next generation of the exploration of Mars analogous to what happened at Earth a few decades ago. This White Paper discusses the key science questions that are still open at Mars and how they could be addressed with coordinated multipoint missions. The main science questions are: (i) How does solar wind driving impact the dynamics of the magnetosphere and ionosphere? (ii) What is the structure and nature of the tail of Mars’ magnetosphere at all scales? (iii) How does the lower atmosphere couple to the upper atmosphere? (iv) Why should we have a permanent in-situ Space Weather monitor at Mars? Each science question is devoted to a specific plasma region, and includes several specific scientific objectives to study in the coming decades. In addition, two mission concepts are also proposed based on coordinated multi-point science from a constellation of orbiting and ground-based platforms, which focus on understanding and solving the current science gaps.
We report for the first time, simultaneous ion, electron, magnetic field vector and electric field wave measurements made possible by Mars Atmosphere and Volatile EvolutioN, during ion energy flux ...spikes in low‐altitude radial crustal magnetic fields on the Mars dayside. Observations show energetic electrons and ions (E > 25 eV) precipitating on magnetic field lines assumed as closed. Ions (E < 1.4 keV) display broad velocity distributions toward Mars, showing ions flowing from higher altitude possibly after magnetic reconnection or loss cone filling from pitch angle scattering effects. Precipitating ions (E < 1.4 keV) show nonadiabatic features depending on ion mass and energy and returning ions (E < 1.4 keV) show evidence of conserving the first adiabatic invariant in a mirror field. We observe magnetic field perturbations up to 60 nT, electric field wave amplitudes up to 38 mV/m, and brief periods of peaked electron spectra. At ∼175 km and at times Mars Atmosphere and Volatile EvolutioN is below the mirroring altitude of electrons, we observe mirroring and transverse heating of H+ ions alongside increased electric field wave amplitude fluctuations. It suggests field aligned potential drops result from different mirror altitudes of ions and electrons. Ions E > 1.4 keV (O+) occur as injected accelerated ion beams and ions heated after energization or deceleration. Energy dispersed kilo‐electron‐volt ions suggest a selection effect in radial magnetic fields for lower‐energy Marsward ions, compared to reflection of higher‐energy anti‐Sunward ions. Precipitating kilo‐electron‐volt ions show energy deposition rates of 3.6 ×10(exp -6) W/sq m and sputtering escape rates from precipitating O+ ions of 1.5 ×10(exp 5)/(sq cm.s) and 2.1 ×10(exp 6)/(sq cm.s) are calculated.
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