Subjects -> AERONAUTICS AND SPACE FLIGHT (Total: 123 journals)
 Showing 1 - 30 of 30 Journals sorted alphabetically Acta Astronautica       (Followers: 496) Advances in Aerospace Engineering       (Followers: 70) Advances in Aerospace Science and Technology       (Followers: 8) Advances in Astronautics Science and Technology       (Followers: 1) Advances in Space Research       (Followers: 458) Aeronautical Journal, The       (Followers: 13) Aerospace       (Followers: 60) Aerospace Medicine and Human Performance       (Followers: 19) Aerospace Science and Technology       (Followers: 430) Aerospace Scientific Journal       (Followers: 18) Aerospace Systems       (Followers: 6) Aerospace technic and technology       (Followers: 3) Aerotecnica Missili & Spazio : Journal of Aerospace Science, Technologies & Systems       (Followers: 4) AIAA Journal       (Followers: 1196) Air Force Magazine       (Followers: 10) Air Medical Journal       (Followers: 8) Aircraft Engineering and Aerospace Technology       (Followers: 264) Annual of Navigation       (Followers: 22) Artificial Satellites       (Followers: 23) ASTRA Proceedings       (Followers: 3) Astrodynamics       (Followers: 4) Aviation       (Followers: 17) Aviation Advances & Maintenance       (Followers: 5) Aviation in Focus - Journal of Aeronautical Sciences       (Followers: 10) Aviation Psychology and Applied Human Factors       (Followers: 27) Aviation Week       (Followers: 438) Canadian Aeronautics and Space Journal       (Followers: 34) CEAS Aeronautical Journal       (Followers: 30) Chinese Journal of Aeronautics       (Followers: 21) Ciencia y Poder Aéreo       (Followers: 2) Civil Aviation High Technologies       (Followers: 5) Control Systems       (Followers: 315) Cosmic Research       (Followers: 5) COSPAR Colloquia Series       (Followers: 11) Egyptian Journal of Remote Sensing and Space Science       (Followers: 24) Elsevier Astrodynamics Series       (Followers: 12) Fatigue of Aircraft Structures       (Followers: 15) Frontiers in Astronomy and Space Sciences       (Followers: 12) Gravitational and Space Research Gyroscopy and Navigation       (Followers: 260) IEEE Aerospace and Electronic Systems Magazine       (Followers: 279) IEEE Journal on Miniaturization for Air and Space Systems       (Followers: 2) IEEE Transactions on Aerospace and Electronic Systems       (Followers: 385) IEEE Transactions on Circuits and Systems I: Regular Papers       (Followers: 39) International Journal of Aeroacoustics       (Followers: 41) International Journal of Aerodynamics       (Followers: 37) International Journal of Aeronautical and Space Sciences       (Followers: 2) International Journal of Aerospace Engineering       (Followers: 82) International Journal of Aerospace Psychology       (Followers: 23) International Journal of Aerospace Sciences       (Followers: 32) International Journal of Applied Geospatial Research       (Followers: 7) International Journal of Aviation Management       (Followers: 9) International Journal of Aviation Technology, Engineering and Management       (Followers: 7) International Journal of Aviation, Aeronautics, and Aerospace       (Followers: 5) International Journal of Crashworthiness       (Followers: 12) International Journal of Micro Air Vehicles       (Followers: 11) International Journal of Satellite Communications Policy and Management       (Followers: 13) International Journal of Space Science and Engineering       (Followers: 11) International Journal of Space Structures       (Followers: 17) International Journal of Space Technology Management and Innovation       (Followers: 10) International Journal of Sustainable Aviation       (Followers: 5) International Journal of Turbo and Jet-Engines       (Followers: 6) Investigación Pecuaria       (Followers: 3) Journal of Aerodynamics       (Followers: 18) Journal of Aeronautical Materials       (Followers: 9) Journal of Aeronautics & Aerospace Engineering       (Followers: 31) Journal of Aerospace Engineering       (Followers: 69) Journal of Aerospace Engineering & Technology       (Followers: 18) Journal of Aerospace Information Systems       (Followers: 22) Journal of Aerospace Information Systems       (Followers: 34) Journal of Aerospace Technology and Management       (Followers: 7) Journal of Aircraft       (Followers: 337) Journal of Aircraft and Spacecraft Technology       (Followers: 9) Journal of Airline and Airport Management       (Followers: 12) Journal of Astrobiology & Outreach       (Followers: 3) Journal of Aviation Technology and Engineering       (Followers: 11) Journal of Aviation/Aerospace Education & Research       (Followers: 2) Journal of Engineering and Technological Sciences       (Followers: 1) Journal of Guidance, Control, and Dynamics       (Followers: 205) Journal of KONBiN       (Followers: 3) Journal of Navigation       (Followers: 280) Journal of Propulsion and Power       (Followers: 615) Journal of Space Safety Engineering       (Followers: 8) Journal of Space Weather and Space Climate       (Followers: 27) Journal of Spacecraft and Rockets       (Followers: 773) Journal of Spatial Science       (Followers: 3) Journal of the American Helicopter Society       (Followers: 8) Journal of the Astronautical Sciences       (Followers: 9) Journal of the Australasian Society of Aerospace Medicine       (Followers: 1) Journal of Wind Engineering and Industrial Aerodynamics       (Followers: 17) Life Sciences in Space Research       (Followers: 4) MAD - Magazine of Aviation Development       (Followers: 2) Mekanika : Jurnal Teknik Mesin i       (Followers: 1) Microgravity Science and Technology       (Followers: 2) New Space       (Followers: 6) Nonlinear Dynamics       (Followers: 20) npj Microgravity       (Followers: 3) Open Aerospace Engineering Journal       (Followers: 1) Perspectives of Earth and Space Scientists i Population Space and Place       (Followers: 9) Problemy Mechatroniki. Uzbrojenie, lotnictwo, inżynieria bezpieczeństwa / Problems of Mechatronics. Armament, Aviation, Safety Engineering       (Followers: 3) Proceedings of the Human Factors and Ergonomics Society Annual Meeting       (Followers: 16) Proceedings of the Institution of Mechanical Engineers Part G: Journal of Aerospace Engineering       (Followers: 46) Progress in Aerospace Sciences       (Followers: 81) Propulsion and Power Research       (Followers: 68) REACH - Reviews in Human Space Exploration       (Followers: 5) Research & Reviews : Journal of Space Science & Technology       (Followers: 17) RocketSTEM       (Followers: 6) Russian Aeronautics (Iz VUZ)       (Followers: 24) Science and Education : Scientific Publication of BMSTU       (Followers: 1) Space and Polity       (Followers: 4) Space Policy       (Followers: 29) Space Research Today       (Followers: 48) Space Safety Magazine       (Followers: 51) Space Science International       (Followers: 202) Space Science Reviews       (Followers: 97) SpaceNews       (Followers: 825) Spatial Information Research       (Followers: 1) Technical Soaring       (Followers: 1) Transport and Aerospace Engineering       (Followers: 1) Transportmetrica A : Transport Science       (Followers: 9) Unmanned Systems       (Followers: 5) Вісник Національного Авіаційного Університету       (Followers: 2)
Similar Journals
 Space Science ReviewsJournal Prestige (SJR): 3.262 Citation Impact (citeScore): 7Number of Followers: 97      Hybrid journal (It can contain Open Access articles) ISSN (Print) 1572-9672 - ISSN (Online) 0038-6308 Published by Springer-Verlag  [2656 journals]
• Distinguishing Tidal Disruption Events from Impostors
• Abstract: Recent claimed detections of tidal disruption events (TDEs) in multi-wavelength data have opened potential new windows into the evolution and properties of otherwise dormant supermassive black holes (SMBHs) in the centres of galaxies. At present, there are several dozen TDE candidates, which share some properties and differ in others. The range in properties is broad enough to overlap other transient types, such as active galactic nuclei (AGN) and supernovae (SNe), which can make TDE classification ambiguous. A further complication is that “TDE signatures” have not been uniformly observed to similar sensitivities or even targeted across all candidates. This chapter both reviews those events that are unusual relative to other TDEs, including the possibility of TDEs in pre-existing AGN, and summarises those characteristics thought to best distinguish TDEs from continuously accreting AGN, strongly flaring AGN, SNe, and Gamma-Ray Bursts (GRBs), as well as other potential impostors like stellar collisions, “micro-TDEs,” and circumbinary accretion flows. We conclude that multiple observables should be used to classify any one event as a TDE. We also consider the TDE candidate population as a whole, which, for certain host galaxy or SMBH characteristics, is distinguishable statistically from non-TDEs, suggesting that at least some TDE candidates do in fact arise from SMBH-disrupted stars.
PubDate: 2021-05-05

• Correction to: Small-Scale Dynamic Aurora
• Abstract: A Correction to this paper has been published: https://doi.org/10.1007/s11214-021-00821-y
PubDate: 2021-04-26

• The BepiColombo Planetary Magnetometer MPO-MAG: What Can We Learn from the
Hermean Magnetic Field'
• Abstract: The magnetometer instrument MPO-MAG on-board the Mercury Planetary Orbiter (MPO) of the BepiColombo mission en-route to Mercury is introduced, with its instrument design, its calibration and scientific targets. The instrument is comprised of two tri-axial fluxgate magnetometers mounted on a 2.9 m boom and are 0.8 m apart. They monitor the magnetic field with up to 128 Hz in a $$\pm 2048$$  nT range. The MPO will be injected into an initial $$480 \times 1500$$  km polar orbit (2.3 h orbital period). At Mercury, we will map the planetary magnetic field and determine the dynamo generated field and constrain the secular variation. In this paper, we also discuss the effect of the instrument calibration on the ability to improve the knowledge on the internal field. Furthermore, the study of induced magnetic fields and field-aligned currents will help to constrain the interior structure in concert with other geophysical instruments. The orbit is also well-suited to study dynamical phenomena at the Hermean magnetopause and magnetospheric cusps. Together with its sister instrument Mio-MGF on-board the second satellite of the BepiColombo mission, the magnetometers at Mercury will study the reaction of the highly dynamic magnetosphere to changes in the solar wind. In the extreme case, the solar wind might even collapse the entire dayside magnetosphere. During cruise, MPO-MAG will contribute to studies of solar wind turbulence and transient phenomena.
PubDate: 2021-04-21

• Editorial: Topical Collection on Understanding the Diversity of Planetary
Atmospheres
• PubDate: 2021-04-19

• Meteoroids as One of the Sources for Exosphere Formation on Airless Bodies
in the Inner Solar System
• Abstract: This manuscript represents a review on progress made over the past decade concerning our understanding of meteoroid bombardment on airless solar system bodies as one of the sources of the formation of their exospheres. Specifically, observations at Mercury by MESSENGER and at the Moon by LADEE, together with progress made in dynamical models of the meteoroid environment in the inner solar system, offer new tools to explore in detail the physical phenomena involved in this complex relationship. This progress is timely given the expected results during the next decade that will be provided by new missions such as DESTINY+, BepiColombo, the Artemis program or the Lunar Gateway.
PubDate: 2021-04-19

• In Dedication to Adam P. Showman
• PubDate: 2021-04-14

• The Mars Environmental Dynamics Analyzer, MEDA. A Suite of Environmental
Sensors for the Mars 2020 Mission
• Abstract: NASA’s Mars 2020 (M2020) rover mission includes a suite of sensors to monitor current environmental conditions near the surface of Mars and to constrain bulk aerosol properties from changes in atmospheric radiation at the surface. The Mars Environmental Dynamics Analyzer (MEDA) consists of a set of meteorological sensors including wind sensor, a barometer, a relative humidity sensor, a set of 5 thermocouples to measure atmospheric temperature at ∼1.5 m and ∼0.5 m above the surface, a set of thermopiles to characterize the thermal IR brightness temperatures of the surface and the lower atmosphere. MEDA adds a radiation and dust sensor to monitor the optical atmospheric properties that can be used to infer bulk aerosol physical properties such as particle size distribution, non-sphericity, and concentration. The MEDA package and its scientific purpose are described in this document as well as how it responded to the calibration tests and how it helps prepare for the human exploration of Mars. A comparison is also presented to previous environmental monitoring payloads landed on Mars on the Viking, Pathfinder, Phoenix, MSL, and InSight spacecraft.
PubDate: 2021-04-13

• The SuperCam Instrument Suite on the Mars 2020 Rover: Science Objectives
and Mast-Unit Description
• Abstract: On the NASA 2020 rover mission to Jezero crater, the remote determination of the texture, mineralogy and chemistry of rocks is essential to quickly and thoroughly characterize an area and to optimize the selection of samples for return to Earth. As part of the Perseverance payload, SuperCam is a suite of five techniques that provide critical and complementary observations via Laser-Induced Breakdown Spectroscopy (LIBS), Time-Resolved Raman and Luminescence (TRR/L), visible and near-infrared spectroscopy (VISIR), high-resolution color imaging (RMI), and acoustic recording (MIC). SuperCam operates at remote distances, primarily 2–7 m, while providing data at sub-mm to mm scales. We report on SuperCam’s science objectives in the context of the Mars 2020 mission goals and ways the different techniques can address these questions. The instrument is made up of three separate subsystems: the Mast Unit is designed and built in France; the Body Unit is provided by the United States; the calibration target holder is contributed by Spain, and the targets themselves by the entire science team. This publication focuses on the design, development, and tests of the Mast Unit; companion papers describe the other units. The goal of this work is to provide an understanding of the technical choices made, the constraints that were imposed, and ultimately the validated performance of the flight model as it leaves Earth, and it will serve as the foundation for Mars operations and future processing of the data.
PubDate: 2021-04-12

• Correction to: Radiometric Calibration Targets for the Mastcam-Z Camera on
the Mars 2020 Rover Mission
• Abstract: A Correction to this paper has been published: https://doi.org/10.1007/s11214-021-00828-5
PubDate: 2021-04-07

• Earth’s Nitrogen and Carbon Cycles
• Abstract: Understanding the Earth’s geological nitrogen (N) and carbon (C) cycles is fundamental for assessing the distribution of these volatiles between solid Earth (core, mantle and crust), oceans and atmosphere. This Special Communication about the Earth’s N and C cycles contains material that is relevant for researchers who are interested in the Topical Collection on planetary evolution “Reading Terrestrial Planet Evolution in Isotopes and Element Measurements”. Variations in the fluxes of N and C between these major reservoirs through geological time influenced the evolution and determined the unique composition of the Earth’s atmosphere. Here we review several key geological aspects of the N and C cycles of which our understanding has significantly advanced during the last decade through field-based, experimental and theoretical studies. Subduction zones are the most important pathway of both N and C from the Earth’s surface into the deep Earth. A key question in the flux quantification is how much of the volatile elements is stored in the downgoing slab and introduced into the mantle and how much is returned back to the surface and the atmosphere through arc magmatism. For N, the retention of N as $$\text{NH}_{4}^{+}$$ in minerals has a major influence on fluxes between reservoirs. The temperature-dependent stability of $$\text{NH}_{4}^{+}$$ -bearing minerals determines whether N is predominantly retained in the slab to mantle depths (in subduction zones with a low geothermal gradient) or devolatilized (in subduction zones with a high geothermal gradient). Several lines of evidence suggest that the mantle is regassing with respect to N due to a net influx of subducted N over time, but this issue is highly debated and evidence to the contrary also exists. Nevertheless, there is consensus that the majority of the planetary N budget is stored in the Earth’s mantle, with the continental crust also constituting a significant N reservoir. For C, release from the subducting slab occurs through decarbonation reactions, dissolution and formation of carbonatitic liquids, but reprecipitation of C in the slab or the forearc mantle wedge may limit the effectiveness of direct return of C into the atmosphere. Carbon release through regional metamorphism in collision zone orogens also has potentially profound effects on C release into the atmosphere and consensus has emerged that such orogens are sources rather than sinks of atmospheric CO2. On shorter timescales, contact metamorphism through interaction of mantle-derived magmas with C-bearing country rocks, and the resulting release of large quantities of CH4 and/or CO2, has been linked to global warming events.
PubDate: 2021-04-02

• Relative Atomic Solar System Abundances, Mass Fractions, and Atomic Masses
of the Elements and Their Isotopes, Composition of the Solar Photosphere,
and Compositions of the Major Chondritic Meteorite Groups
• Abstract: This brief special communications article gives data for atomic abundances and mass fractions for the elemental and isotopic solar system composition, the atomic masses of the elements and their isotopes, the composition of the solar photosphere, and the compositions of the major chondritic meteorite groups. This additional material is relevant for researchers who are interested in this Topical Collection on planetary evolution.
PubDate: 2021-04-01

• The Diversity of Planetary Atmospheric Chemistry
• Abstract: Atmospheres in our solar system range from oxidizing to reducing, transient to dense, veiled by clouds and hazes to transparent. Observations already suggest that exoplanets exhibit an even more diverse range of atmospheric chemistry and composition. Nevertheless, there are commonalities across the atmospheres of our solar system that provide valuable guidance and lessons for observing and interpreting exoplanetary atmospheres. Lessons gleaned from decades of study of planetary atmospheric chemistry are synthesized and explored to understand their implications for exoplanets.
PubDate: 2021-03-30

• High Resolution Imaging Camera (HiRIC) on China’s First Mars
Exploration Tianwen-1 Mission
• Abstract: The High-Resolution Imaging Camera (HiRIC) is one major payload of China’s first Mars exploration mission, and its main objective is to obtain the detailed observation images of the key areas on the Martian surface. In this paper, the leading group of HiRIC shows a full blueprint of the HiRIC. The HiRIC can achieve a high resolution (0.5 m at an altitude of 265 km) with a wide swath width of 9 km. The HiRIC adopts an Off-Axis Three-Mirror Astigmatic (TMA) optical system with a focal length of 4640 mm, an F-number of 12 and a Field of View (FOV) of 2° × 0.693°. In order to reduce the instrument weight, carbon-based material is widely used in the opto-mechanical structure which is in ultra-lightweight design, thus, a light-weight camera with a total mass of 42 kg is obtained. The Time Delay and Integration (TDI) Charge Coupled Devices (CCDs) and Complementary Metal-Oxide-Semiconductor Transistor (CMOS) detectors are all set on the imaging plane to achieve the push-broom imaging and frame imaging, respectively. And the high Signal-to-Noise Ratio (SNR) >100:1 can achieve in multi observation types for various scientific imaging tasks. After 4-year design and fabricate, the HiRIC has been assembly. The testing results show that the instrument is in good condition, and the Modulation Transfer Function (MTF) can achieve 0.18 at Nyquist frequency. The HiRIC can achieve a well image on China first Mars exploration mission.
PubDate: 2021-03-29

• The Location of Magnetic Reconnection at Earth’s Magnetopause
• Abstract: One of the major questions about magnetic reconnection is how specific solar wind and interplanetary magnetic field conditions influence where reconnection occurs at the Earth’s magnetopause. There are two reconnection scenarios discussed in the literature: a) anti-parallel reconnection and b) component reconnection. Early spacecraft observations were limited to the detection of accelerated ion beams in the magnetopause boundary layer to determine the general direction of the reconnection X-line location with respect to the spacecraft. An improved view of the reconnection location at the magnetopause evolved from ionospheric emissions observed by polar-orbiting imagers. These observations and the observations of accelerated ion beams revealed that both scenarios occur at the magnetopause. Improved methodology using the time-of-flight effect of precipitating ions in the cusp regions and the cutoff velocity of the precipitating and mirroring ion populations was used to pinpoint magnetopause reconnection locations for a wide range of solar wind conditions. The results from these methodologies have been used to construct an empirical reconnection X-line model known as the Maximum Magnetic Shear model. Since this model’s inception, several tests have confirmed its validity and have resulted in modifications to the model for certain solar wind conditions. This review article summarizes the observational evidence for the location of magnetic reconnection at the Earth’s magnetopause, emphasizing the properties and efficacy of the Maximum Magnetic Shear Model.
PubDate: 2021-03-29

• The Process of Stellar Tidal Disruption by Supermassive Black Holes
• Abstract: Tidal disruption events (TDEs) are among the brightest transients in the optical, ultraviolet, and X-ray sky. These flares are set into motion when a star is torn apart by the tidal field of a massive black hole, triggering a chain of events which is – so far – incompletely understood. However, the disruption process has been studied extensively for almost half a century, and unlike the later stages of a TDE, our understanding of the disruption itself is reasonably well converged. In this Chapter, we review both analytical and numerical models for stellar tidal disruption. Starting with relatively simple, order-of-magnitude physics, we review models of increasing sophistication, the semi-analytic “affine formalism,” hydrodynamic simulations of the disruption of polytropic stars, and the most recent hydrodynamic results concerning the disruption of realistic stellar models. Our review surveys the immediate aftermath of disruption in both typical and more unusual TDEs, exploring how the fate of the tidal debris changes if one considers non-main sequence stars, deeply penetrating tidal encounters, binary star systems, and sub-parabolic orbits. The stellar tidal disruption process provides the initial conditions needed to model the formation of accretion flows around quiescent massive black holes, and in some cases may also lead to directly observable emission, for example via shock breakout, gravitational waves or runaway nuclear fusion in deeply plunging TDEs.
PubDate: 2021-03-25

• Current Sheets, Plasmoids and Flux Ropes in the Heliosphere
• Abstract: Our understanding of processes occurring in the heliosphere historically began with reduced dimensionality - one-dimensional (1D) and two-dimensional (2D) sketches and models, which aimed to illustrate views on large-scale structures in the solar wind. However, any reduced dimensionality vision of the heliosphere limits the possible interpretations of in-situ observations. Accounting for non-planar structures, e.g. current sheets, magnetic islands, flux ropes as well as plasma bubbles, is decisive to shed the light on a variety of phenomena, such as particle acceleration and energy dissipation. In part I of this review, we have described in detail the ubiquitous and multi-scale observations of these magnetic structures in the solar wind and their significance for the acceleration of charged particles. Here, in part II, we elucidate existing theoretical paradigms of the structure of the solar wind and the interplanetary magnetic field, with particular attention to the fine structure and stability of current sheets. Differences in 2D and 3D views of processes associated with current sheets, magnetic islands and flux ropes are discussed. We finally review the results of numerical simulations and in-situ observations, pointing out the complex nature of magnetic reconnection and particle acceleration in a strongly turbulent environment.
PubDate: 2021-03-23

• Current Sheets, Plasmoids and Flux Ropes in the Heliosphere
• Abstract: Recent accumulation of a critical mass of observational material from different spacecraft complete with the enhanced abilities of numerical methods have led to a boom of studies revealing the high complexity of processes occurring in the heliosphere. Views on the solar wind filling the interplanetary medium have dramatically developed from the beginning of the space era. A 2-D picture of the freely expanding solar corona and non-interacting solar wind structures described as planar or spherically-symmetric objects has dominated for decades. Meanwhile, the scientific community gradually moved to a modern understanding of the importance of the 3-D nature of heliospheric processes and their studies via MHD/kinetic simulations, as well as observations of large-scale flows and streams both in situ and remotely, in white light and/or via interplanetary scintillations. The new 3-D approach has provided an opportunity to understand the dynamics of heliospheric structures and processes that could not even be imagined before within the 2-D paradigm. In this review, we highlight a piece of the puzzle, showing the evolution of views on processes related to current sheets, plasmoids, blobs and flux ropes of various scales and origins in the heliosphere. The first part of the review focuses on introducing these plasma structures, discussing their key properties, and paying special attention to their observations in different space plasmas.
PubDate: 2021-03-23

• The Navigation and Terrain Cameras on the Tianwen-1 Mars Rover
• Abstract: The Navigation and Terrain Cameras (NaTeCams) are binocular stereo cameras mounted on the Tianwen-1 Mars Rover. The NaTeCams are primarily designed to provide support for the guidance, navigation, and control of the rover, and they can also be used for scientific observations. NaTeCam is a color imaging system using a complementary metal oxide semiconductor (CMOS) active pixel sensor (APS). An overview of the camera design is provided. Preflight calibration and performance are also discussed. Specific details about the camera operation and ground test are presented.
PubDate: 2021-03-17

• Do Intrinsic Magnetic Fields Protect Planetary Atmospheres from Stellar
Winds'
• Abstract: The accumulation of detailed ion flux measurements from long-lived spacecraft orbiting the solar system’s terrestrial planets have enabled recent studies to estimate the rate of solar wind driven atmospheric ion escape from Venus, Earth, and Mars, as well as the influence of solar wind and solar extreme ultraviolet (EUV) ionizing radiation on the atmospheric ion escape rates. Here, we introduce the basic forces and processes of ion escape, review the recent studies of ion escape rates, and provide a general framework for understanding ion escape as a process that can be limited by potential bottlenecks, such as ion supply, solar wind energy transfer, and transport efficiency, effectively determining the state of the ion escape process at each planet. We find that ion escape from Venus and Earth is energy-limited, though exhibit different dependencies on solar wind and EUV, revealing the influence of Earth’s intrinsic magnetic field. In contrast, ion escape from Mars is in a supply-limited state, mainly due to its low gravity, and has likely contributed relatively little to the total loss of the early Martian atmosphere, in comparison to neutral escape processes. Contrary to the current paradigm, the comparisons between the solar system planets show that an intrinsic magnetic dipole field is not required to prevent stellar wind-driven escape of planetary atmospheres, and the presence of one may instead increase the rate of ion escape. Anticipating the atmospheres of the exoplanets that will begin to be characterized over the coming decade, and the need to explain their evolution, we argue that a modern, nuanced, and evidence-based view of the magnetic field’s role in atmospheric escape is required.
PubDate: 2021-03-09
DOI: 10.1007/s11214-021-00791-1

• Slow-Mode Magnetoacoustic Waves in Coronal Loops
• Abstract: Rapidly decaying long-period oscillations often occur in hot coronal loops of active regions associated with small (or micro-) flares. This kind of wave activity was first discovered with the SOHO/SUMER spectrometer from Doppler velocity measurements of hot emission lines, thus also often called “SUMER” oscillations. They were mainly interpreted as global (or fundamental mode) standing slow magnetoacoustic waves. In addition, increasing evidence has suggested that the decaying harmonic type of pulsations detected in light curves of solar and stellar flares are likely caused by standing slow-mode waves. The study of slow magnetoacoustic waves in coronal loops has become a topic of particular interest in connection with coronal seismology. We review recent results from SDO/AIA and Hinode/XRT observations that have detected both standing and reflected intensity oscillations in hot flaring loops showing the physical properties (e.g., oscillation periods, decay times, and triggers) in accord with the SUMER oscillations. We also review recent advances in theory and numerical modeling of slow-mode waves focusing on the wave excitation and damping mechanisms. MHD simulations in 1D, 2D and 3D have been dedicated to understanding the physical conditions for the generation of a reflected propagating or a standing wave by impulsive heating. Various damping mechanisms and their analysis methods are summarized. Calculations based on linear theory suggest that the non-ideal MHD effects such as thermal conduction, compressive viscosity, and optically thin radiation may dominate in damping of slow-mode waves in coronal loops of different physical conditions. Finally, an overview is given of several important seismological applications such as determination of transport coefficients and heating function.
PubDate: 2021-03-08
DOI: 10.1007/s11214-021-00811-0

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