57 research outputs found
The Coronal Analysis of SHocks and Waves (CASHeW) Framework
Coronal Bright Fronts (CBF) are large-scale wavelike disturbances in the
solar corona, related to solar eruptions. They are observed in extreme
ultraviolet (EUV) light as transient bright fronts of finite width, propagating
away from the eruption source. Recent studies of individual solar eruptive
events have used EUV observations of CBFs and metric radio type II burst
observations to show the intimate connection between low coronal waves and
coronal mass ejection (CME)-driven shocks. EUV imaging with the Atmospheric
Imaging Assembly(AIA) instrument on the Solar Dynamics Observatory (SDO) has
proven particularly useful for detecting CBFs, which, combined with radio and
in situ observations, holds great promise for early CME-driven shock
characterization capability. This characterization can further be automated,
and related to models of particle acceleration to produce estimates of particle
fluxes in the corona and in the near Earth environment early in events. We
present a framework for the Coronal Analysis of SHocks and Waves (CASHeW). It
combines analysis of NASA Heliophysics System Observatory data products and
relevant data-driven models, into an automated system for the characterization
of off-limb coronal waves and shocks and the evaluation of their capability to
accelerate solar energetic particles (SEPs). The system utilizes EUV
observations and models written in the Interactive Data Language (IDL). In
addition, it leverages analysis tools from the SolarSoft package of libraries,
as well as third party libraries. We have tested the CASHeW framework on a
representative list of coronal bright front events. Here we present its
features, as well as initial results. With this framework, we hope to
contribute to the overall understanding of coronal shock waves, their
importance for energetic particle acceleration, as well as to the better
ability to forecast SEP events fluxes.Comment: Accepted for publication in the Journal of Space Weather and Space
Climate (SWSC
PLATELET AGGREGATION AFTER EXPERIMENTAL BURN INJURY AND THERAPY
Based on data concerning the coagulation changes after thermal injury the authors studied platelet aggregation after burn and its treatment. Severe thermal injury of Ha and lib degree was inflicted in white male rats (200 ±20 g b. m.) under aether anaesthesia. It ranged over 17,5 ± 2,5 % of the body surface. The animals were divided into the following groups: 1) burned non-treated; 2) burned and treated with Sol. Hartmanni (Hr), 3) burned and treated with Hemodex (Hx), and 4) controls. The treatment was intraperitoneally carried out immediately after the injury as well as on 6th and 24th hour after it. An elevation of the platelet aggregation for all the groups on the 24th hour after the injury was established
Earth‐Moon‐Mars Radiation Environment Module framework
[1] We are preparing to return humans to the Moon and setting the stage for exploration to Mars and beyond. However, it is unclear if long missions outside of low-Earth orbit can be accomplished with acceptable risk. The central objective of a new modeling project, the Earth-Moon-Mars Radiation Exposure Module (EMMREM), is to develop and validate a numerical module for characterizing time-dependent radiation exposure in the Earth-Moon-Mars and interplanetary space environments. EMMREM is being designed for broad use by researchers to predict radiation exposure by integrating over almost any incident particle distribution from interplanetary space. We detail here the overall structure of the EMMREM module and study the dose histories of the 2003 Halloween storm event and a June 2004 event. We show both the event histories measured at 1 AU and the evolution of these events at observer locations beyond 1 AU. The results are compared to observations at Ulysses. The model allows us to predict how the radiation environment evolves with radial distance from the Sun. The model comparison also suggests areas in which our understanding of the physics of particle propagation and energization needs to be improved to better forecast the radiation environment. Thus, we introduce the suite of EMMREM tools, which will be used to improve risk assessment models so that future human exploration missions can be adequately planned for
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Galactic cosmic ray hazard in the unusual extended solar minimum between solar cycle 23 and 24
Galactic cosmic rays (GCRs) are extremely difficult to shield against and pose one of the most severe long-term hazards for human exploration of space. The recent solar minimum between solar cycles 23 and 24 shows a prolonged period of reduced solar activity and low interplanetary magnetic field strengths. As a result, the modulation of GCRs is very weak, and the fluxes of GCRs are near their highest levels in the last 25 years in the fall of 2009. Here we explore the dose rates of GCRs in the current prolonged solar minimum and make predictions for the Lunar Reconnaissance Orbiter (LRO) Cosmic Ray Telescope for the Effects of Radiation (CRaTER), which is now measuring GCRs in the lunar environment. Our results confirm the weak modulation of GCRs leading to the largest dose rates seen in the last 25 years over a prolonged period of little solar activity
Lunar radiation environment and space weathering from the Cosmic Ray Telescope for the Effects of Radiation (CRaTER)
[1] The Cosmic Ray Telescope for the Effects of Radiation (CRaTER) measures linear energy transfer by Galactic Cosmic Rays (GCRs) and Solar Energetic Particles (SEPs) on the Lunar Reconnaissance Orbiter (LRO) Mission in a circular, polar lunar orbit. GCR fluxes remain at the highest levels ever observed during the space age. One of the largest SEP events observed by CRaTER during the LRO mission occurred on June 7, 2011. We compare model predictions by the Earth-Moon-Mars Radiation Environment Module (EMMREM) for both dose rates from GCRs and SEPs during this event with results from CRaTER. We find agreement between these models and the CRaTER dose rates, which together demonstrate the accuracy of EMMREM, and its suitability for a real-time space weather system. We utilize CRaTER to test forecasts made by the Relativistic Electron Alert System for Exploration (REleASE), which successfully predicts the June 7th event. At the maximum CRaTER-observed GCR dose rate (∼11.7 cGy/yr where Gy is a unit indicating energy deposition per unit mass, 1 Gy = 1 J/kg), GCRs deposit ∼88 eV/molecule in water over 4 billion years, causing significant change in molecular composition and physical structure (e.g., density, color, crystallinity) of water ice, loss of molecular hydrogen, and production of more complex molecules linking carbon and other elements in the irradiated ice. This shows that space weathering by GCRs may be extremely important for chemical evolution of ice on the Moon. Thus, we show comprehensive observations from the CRaTER instrument on the Lunar Reconnaissance Orbiter that characterizes the radiation environment and space weathering on the Moon
Magnetic Field Strength in the Upper Solar Corona Using White-light Shock Structures Surrounding Coronal Mass Ejections
To measure the magnetic field strength in the solar corona, we examined 10
fast (> 1000 km/s) limb CMEs which show clear shock structures in SOHO/LASCO
images. By applying piston-shock relationship to the observed CME's standoff
distance and electron density compression ratio, we estimated the Mach number,
Alfven speed, and magnetic field strength in the height range 3 to 15 solar
radii (Rs). Main results from this study are: (1) the standoff distance
observed in solar corona is consistent with those from a magnetohydrodynamic
(MHD) model and near-Earth observations; (2) the Mach number as a shock
strength is in the range 1.49 to 3.43 from the standoff distance ratio, but
when we use the density compression ratio, the Mach number is in the range 1.47
to 1.90, implying that the measured density compression ratio is likely to be
underestimated due to observational limits; (3) the Alfven speed ranges from
259 to 982 km/s and the magnetic field strength is in the range 6 to 105 mG
when the standoff distance is used; (4) if we multiply the density compression
ratio by a factor of 2, the Alfven speeds and the magnetic field strengths are
consistent in both methods; (5) the magnetic field strengths derived from the
shock parameters are similar to those of empirical models and previous
estimates.Comment: Accepted for publication in ApJ, 11 Figures, 1 Tabl
Presentation of the International Treaties in the Framework of Glossaries and Frequency Dictionaries
В статье представлено исследование, связанное с изучением универсального международного договора - Венской конвенции о праве международных договоров на русском и английском языке, и обоснована актуальность составления сравнительного русско-английского частотного словаря и глоссария специальных научных терминов, используемых в рамках международных договоров. В рамках исследования были поставлены задачи: рассмотреть понятие «частотный словарь», особенности применения и составления. Используя частотный словарь найти самые частые термины в Венской конвенции о праве международных договоров. И рассмотреть саму конвенцию и объяснить в чём её важность.The article presents a study related to the study of universal international treaty - Vienna Convention on Law of international treaties in Russian and English, and justifies the relevance of compiling a comparative Russian-English frequency dictionary and a glossary of special scientific terms used in the framework of international treaties. Within the framework of the study, tasks were set: to consider the concept of "frequency dictionary," features of application and composition. Using the frequency dictionary, find the most common terms in the Vienna Convention on the Law of Treaties. And consider the convention itself and explain its importance
Synthesis of 3-D coronal-solar wind energetic particle acceleration modules
1. Introduction Acute space radiation hazards pose one of the most serious risks to future human and robotic exploration. Large solar energetic particle (SEP) events are dangerous to astronauts and equipment. The ability to predict when and where large SEPs will occur is necessary in order to mitigate their hazards. The Coronal-Solar Wind Energetic Particle Acceleration (C-SWEPA) modeling effort in the NASA/NSF Space Weather Modeling Collaborative [Schunk, 2014] combines two successful Living With a Star (LWS) (http://lws. gsfc.nasa.gov/) strategic capabilities: the Earth-Moon-Mars Radiation Environment Modules (EMMREM) [Schwadron et al., 2010] that describe energetic particles and their effects, with the Next Generation Model for the Corona and Solar Wind developed by the Predictive Science, Inc. (PSI) group. The goal of the C-SWEPA effort is to develop a coupled model that describes the conditions of the corona, solar wind, coronal mass ejections (CMEs) and associated shocks, particle acceleration, and propagation via physics-based modules. Assessing the threat of SEPs is a difficult problem. The largest SEPs typically arise in conjunction with X class flares and very fast (\u3e1000 km/s) CMEs. These events are usually associated with complex sunspot groups (also known as active regions) that harbor strong, stressed magnetic fields. Highly energetic protons generated in these events travel near the speed of light and can arrive at Earth minutes after the eruptive event. The generation of these particles is, in turn, believed to be primarily associated with the shock wave formed very low in the corona by the passage of the CME (injection of particles from the flare site may also play a role). Whether these particles actually reach Earth (or any other point) depends on their transport in the interplanetary magnetic field and their magnetic connection to the shock
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