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Posters
Title: Predicting Solar Energetic Particle Events
Authors: John Davis, Ron Moore, Edward West, Allen Gary
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Submitted by: John Davis
Title: Predicting the Radiation Environments for Future Space Exploration Missions
Authors: Myung-Hee Y. Kim, Francis A. Cucinotta, and John W. Wilson
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Abstract: Accurate projections of radiation fluence and doses to astronauts are necessary for planning exploratory space missions. Characterization of the ionizing radiation environment is challenging because the interplanetary plasma and radiation fields are modulated by solar disturbances and the radiation doses received by astronauts in interplanetary space are likewise influenced. A solar modulation model has been developed for near future cycles, and a model of the GCR environment represented by GCR deceleration potential,
ф, has been derived from GCR flux and Climax neutron monitor rate measurements over the last four decades, where the magnitude of modulation changes as the sign of the interplanetary magnetic field changes. With these projected GCR environments, elemental fluences and point dose equivalents inside a typical spacecraft are calculated in free space for the next two solar cycles. This data will guide radiation protection in future space exploration.
Submitted by: Myung-Hee
Y. Kim
Title: Forecasting Interplanetary Shocks Using Energetic Particle Data
Authors: George C. Ho
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Abstract: The locally accelerated component of an Interplanetary (IP) shock is referred to as Energetic Storm Particle (ESP) event due to its strong association with geomagnetic storms. The ESP event can encompass ion activity for several hours upstream and downstream of the IP shock. In this work, we use historical low energy ion data on NASA's Advanced Composition Explorer (ACE) spacecraft, which situated ~240 Re upstream at L1 Lagrangian point, to train an ESP event forecasting model. Our approach centers on the observation that large ESP events are often preceded by identifiable signatures in the low energy ion particle intensity. Using these identifiable signatures as input, we train an artificial neural network to predict the time remaining until the maximum intensity of an ESP event. We have designed the model such that the shock prediction is only activated once it has detected a dispersive onset signature in the particle intensity which signals an onset of a solar energetic particle event. Our dispersive onset classifier scores 0.77 in the true skill score, and our shock countdown model has an average error of 10.1 and 4.9 hours when the shock is 24 to 12 hours and 6 to 0 hours away, respectively. We have implemented the model in a Real-Time Interplanetary Shock Prediction (RISP) system. The system automatically ingests the NOAA's ACE real-time solar wind data, and presents the shock prediction online in a real time fashion (http://sd-www.jhuapl.edu/ACE/EPAM/RUMS/). RISP has been designed from the beginning to be a real time operational system; hence the system also provides users with uncertainty of each forecast. This allows users to evaluate our forecast in an objective manner. The RISP system are believed to the first operational shock prediction system that make use of ACE real-time low energy ion measurements.
Submitted by: George C. Ho
Title: Acceleration Regions of the Solar Wind
Authors: Leon Ofman
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Abstract: The radiation environment that can affect future manned exploration goals is formed in part by charged particles that are produced by solar disturbances, such as CME driven shocks. The solar wind magnetized plasma provides the background medium in which the shocks and energetic particles propagate. The acceleration of the solar wind close the sun in streamers and coronal holes, and the physical properties of the multi-component solar wind plasma modulate the properties of the heliospheric plasma. The acceleration of the solar wind varies on short time scale (<days) due to solar activity, and the global solar wind outflow structure varies on long time scale (years) due to the solar cycle. The results of multifluid models of the solar wind acceleration in coronal streamers, and in coronal hole are shown. The implication of the solar wind acceleration to the formation of the heliospheric plasma is discussed.
Submitted by: Leon Ofman
Title: Solar Weather Buoys (SWBs) and the Vision for Space Exploration
Authors: E. C. Roelof and R. Muller
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Abstract: Solar Weather Buoys (SWBs) will provide unambiguous in situ observations of the spatial longitudinal extent and evolution of the major Solar Energetic Particle (SEP) and Coronal Mass Ejection (CME) events, bringing our understanding of their acceleration and propagation from the Sun to 1 AU up to the level of prediction.
SWBs will give
prompt and reliable warning of the injection of biologically damaging doses of high-energy particle radiation for astronauts exposed on the surface of the Moon or in transit to the surface of Mars, safeguarding our outward journey to the surfaces of the Moon and Mars.
By launching in 2022, the 5-year deployment phase will be completed in time to catch the rise-to-maximum phase of the solar cycle (2027-2030). During the remainder of the solar cycle (2031-2036), SWBs will paint a definitive scientific picture of how large SEPs and CMEs propagate from the inner heliosphere (being simultaneously observed by IHSentinels, Solar Orbiter, and solar imagers) to 1 AU and beyond towards Mars orbit at 1.4 AU. During this time SWBs prompt warning capability will be honed and perfected so that they will function with high reliability at the anticipated launch time for the manned mission to Mars (2035).
Submitted by: E. C. Roelof
Title: Innovative Interstellar Explorer
Authors: R. L. McNutt, Jr., R. E. Gold, S. M. Krimigis, E. C. Roelof, M. Gruntman, G. Gloeckler, P. L. Koehn , W. S. Kurth, S. R. Oleson, J. C. Leary, D. I. Fiehler, B. J. Anderson, M. Horanyi, and R. A. Mewaldt
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Abstract: An interstellar precursor mission has been under discussion in the scientific community for at least 30 years. Fundamental scientific questions about the interaction of the Sun with the interstellar medium can only be answered with in situ measurements that such a mission can provide. The Innovative Interstellar Explorer (IIE) and its use of Radioisotope Electric Propulsion (REP) is being studied under a NASA Vision Mission grant. Speed is provided by a combination of a high-energy launch, using current launch vehicle technology, a Jupiter gravity assist, and long-term, low-thrust, continuous acceleration provided by an ion thruster running off electricity provided by advanced radioisotope electric generators. A payload of nine instruments with an aggregate mass of ~35 kg and requiring ~30 W has been carefully chosen to address the compelling science questions. The nominal 20-day launch window opens on 22 October 2014 followed by a Jupiter gravity assist on 5 February 2016. The REP system accelerates the spacecraft to a burnout speed of 7.8 AU per year at 104 AU on 13 October 2032 (Voyager 1's current speed is ~3.6 AU/yr). The spacecraft will return at least 500 bits per second format least 200 AU ~30 years after launch. Additional (backup) launch opportunities occur every 13 months to early 2018. In addition to addressing basic heliospheric science, the mission will ensure continued information on the far-heliospheric galactic cosmic ray population after the Voyagers have fallen silent and as the era of human Mars exploration begins.
Submitted by: R. L. McNutt, Jr.
Title: The frequency distribution of solar proton events: 5 solar cycles and 45 solar cycles
Authors: D.F. Smart, M.A. Shea, G.A.M. Dreschhoff, H.E. Spence, and L. Kepko
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Abstract: Very large solar proton events, those having an omni-directional solar proton fluence greater than 109 cm-2 at ener-gies >30 MeV, impose operational constraints on manned space missions and equipment. Solar particle data from earth-orbiting spacecraft for the last 5 solar cycles are often used to generate a proton event frequency distribution. The analysis of impulsive NOy events in polar ice results in an ~450-year record of very large solar proton events. The
frequency distribution of these large events is consistent with the frequency distribution derived from the analysis of
radionuclides found in moon rocks. This long-term record indicates that solar proton events with a >30 MeV omni-directional fluence exceeding 6 x 109 cm-2 are very rare. However, the number of very large fluence solar proton events per solar cycle is extremely variable, ranging from 0 to 8 per solar cycle.
Submitted by: Don F. Smart
Title: Capabilities of UV Coronagraphic Spectroscopy for Studying the Source Regions of the Solar Energetic Particles and the Solar Wind
Authors: Leonard Strachan, John Raymond, John Kohl, Steven Cranmer, Larry Gardner and Jun Lin
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Harvard-Smithsonian Center for Astrophysics
Cambridge, MA 02138
We summarize the unique capabilities of UV coronagraphic spectroscopy for determining the detailed plasma properties of the source regions of both transient phenomena such as CMEs, flares, and solar energetic particles (SEPs) and more time-steady solar wind streams. Examples from past observations with UVCS/SOHO are presented to show how these measurements can constrain important parameters for CME shocks, reconnection current sheets, and solar wind. Finally, we describe future diagnostics and instrument capabilities (e.g. measurement of coronal electron velocity distributions and magnetic fields) which can be used to provide tighter constraints for SEP and solar wind models.
Submitted by: Merrick Berg
Title: Development of Empirical Tools for Forecasting Safe or Dangerous Space Weather from Magnetograms
Authors: D. A. Falconer (UAH/MSFC/NSSTC), R. L. Moore, G. A. Gary, (NASA/MSFC/NSSTC)
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Abstract: Just as with Earth weather forecasting, being able to forecast the chance of severe space weather is important. The drivers of the most severe space weather in Earth-Moon space are CMEs that originate on the Sun 0-4 days earlier. By identifying the likely source regions of CMEs and assessing their combined chance of producing a CME, we could forecast the chance of a CME occurring during the next 24 hours and if the chance was sufficiently low, say
≤ 5%;, we could then declare the coming day an All-Clear Day. There are two kinds of CME source regions, active regions with strong transverse fields (sunspot active regions) and former sunspot active regions with weaker transverse fields (spotless active regions); sunspot regions produce most of the powerful CMEs, but spotless active regions cannot be ignored. We are developing a tool to assess the chance that a source region of either type will produce a CME during a forecast period. We have found that the CME productivity of a sunspot active region is strongly correlated with a measure of its total nonpotentiality from a magnetogram (Falconer et al 2003, & 2005), where total nonpotentiality is the magnetic size times the magnetic twist of the active region. From this measure, the prediction that all strongly nonpotential sunspot active regions will produce at least one CME during a 3 day period and all weakly nonpotential sunspot active regions will not produce a CME during the same 3 day period is right 75% of the time. Using our present sample (48 magnetograms of 43 sunspot active regions), we have begun to empirically determine the chance of CME occurrence as a function of active region total nonpotentiality for several forecast windows. We find that the more nearly potential active regions have low to negligible chance of CME occurrence (for a 24 hour forecast window the two weakest nonpotentiality categories have a 0% and 7% rate), but the uncertainties in the actual chance of CME occurrence are large due to our present small sample size (1 σ range 0-6% and 2-16% respectively). We have submitted a proposal to NASA's LWS TR&T Program to increase our sample size several fold by evaluating the total nonpotentiality of active regions in our sample on the 4 days when the active region is near disk center (< 30
degrees). Due to weather, MSFC vector magnetograms often do not exist for each day when the active region is near disk center, but we can use the space-based SOHO/MDI magnetograph which has continuous coverage with good cadence (15 full-disk magnetograms a day). The disadvantage of MDI relative to MSFC is that MDI only measures the line-of-sight component of the magnetic field, but in Falconer et al (2003) we devised a measure of total nonpotentiality that can be evaluated from a line-of-sight magnetogram. We also propose to use MDI magnetograms to test this measure for spotless active regions. The results presented in this poster show that our measure of active-region total nonpotentiality from line-of-sight magnetograms is a useful tool for operational forecasting of dangerous CMEs, and warrants further testing and evaluation as a predictor of CMEs or the absence of CMEs.
Submitted by: David Falconer
Title: Compact Combined Ion and Neutron Spectrometer (CINS) for Space Application
Authors: Dennis K. Haggerty, Richard H. Maurer, Cary J. Zeitlin, David R. Roth and John O. Goldsten
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Abstract: Compact Combined Ion and Neutron Spectrometer (CINS) for Space Application
Dennis K. Haggerty, Richard H. Maurer, Cary J. Zeitlin, David R. Roth and John O. Goldsten
We have been funded by NSBRI (The National Space Biomedical Research Institute) to develop a concept and design for a Combined Ion and Neutron Spectrometer for use as a compact global radiation monitor on future interplanetary transport and landing vehicles. The intent of this instrument is to monitor the entire interior radiation environment in habitats that astronauts will experience on long interplanetary missions such as a round trip to MARS. The specific objectives are to:
a. design and fabricate a prototype Combined Ion and Neutron Spectrometer (CINS) for space applications;
b. calibrate and evaluate the response functions of the CINS detector systems using ground-based accelerator beams of appropriate type and energy;
c. use CINS in a ground based accelerator comparison with traditionally used space instrumentation such as the Tissue Equivalent Proportional Counter (TEPC);
d. evaluate the effects of baseline and new radiation shielding materials as countermeasures by measuring charged and neutral secondary particle generation from a simulated space environment.
The prototype instrument is being developed using heritage from the Neutron Energy Spectrometer developed under previous NSBRI grants, instrument electronics from unmanned spacecraft missions such as MESSENGER, and the design and operation experience with the Mars Odyssey Orbiter MARIE instrument.
Submitted by: Dennis Haggerty
Title: SEP events with >40 MeV proton intensities above the "streaming limit" intensity
Authors: D. Lario
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Abstract: Large solar energetic particle (SEP) events constitute a serious radiation hazard to astronauts on deep space missions such as those to the Moon or Mars. It is essential to
determine the highest intensities reached during large SEP events, especially at energies that pose serious risks to human health and spacecraft performance (e.g., protons above ~40 MeV). It has been argued that the highest particle intensities measured during large
SEP events occur in association with the passage of shocks driven by coronal mass ejections (CMEs); whereas the intensities measured early in the SEP events (i.e., the
prompt components) are bounded by a maximum-intensity plateau that results from wave-particle interactions that restrict the free streaming of particles (also called the "streaming limit"). We analyze the highest intensities measured by the GOES spacecraft during the last 20 years to examine whether the highest intensities are measured during the prompt component of the SEP events or during the energetic storm particle (ESP) events. We find three [two] events in which the highest 39-82 MeV [110-500 MeV] proton intensities measured during the prompt component of the SEP events exceed the previously determined "streaming limit" intensity. Arguments to explain the exceeding of this limit during these SEP events invoke either interplanetary conditions that inhibit the amplification of waves resonating with the streaming particles, or the presence of
interplanetary structures able to confine and/or mirror energetic particles.
Submitted by: D. Lario
Title: Advanced Interplanetary Particle Hazard Estimates For 21st
Century Manned And Robotic Missions
Authors: Insoo Jun, joan Feynman, Alexander Ruzmaikin, and Randall Swimm
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Abstract: Our objective is to reduce the costs, weights and physical sizes of space systems while maintaining adequate system survivability. To do this we improved the reliability of estimates of an extremely important quantity: namely the high-energy particles expected to impact space systems. At present our ability to reliably predict space environments for missions not shielded by planetary magnetic fields is surprisingly poor. System survivability is now ensured by setting grossly over-conservative mission requirements, resulting in high mission costs and weight and physically large systems. Our goal is to improve the reliability of predictions for interplanetary space and Moon and Mars particle environments so that mission requirements can be better determined for both robotic and manned missions. In this study, we present a modular approach that estimates the mission-integrated fluences for high energy protons and heavier ions for arbitrary trajectory, launch on an arbitrary future day, and improved radial dependence law.
Submitted by: Insoo Jun
Title: The Sun-Earth Connection of Major Geomagnetic Storms
Authors: Jie Zhang
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Abstract: We address the issues in observing and understanding the chain Sun-Earth connection activities that result in major geomagnetic storms, one of severe space weather phenomena. From 1996 to 2004, there are 77 major geomagnetic storms (defined as Dst <= -100). A systematic multi-step process is carried out to identify the event chain for each of the major events. It is found that a major geomagnetic storm event could be driven by three types of solar sources (1) S type, a single halo CME, (2) M-type, multiple halo CMEs, or (3) C-type, CIR (corotating interaction region) originated from coronal hole. Throughout the solar cycle 23rd, there are more major events originated from western solar hemisphere than from eastern hemisphere, probably due to the spiral interplanetary magnetic field connecting the western hemisphere and the geo-space. Before solar polar field reversal in 2001, a significant number of events originate from the northern hemisphere. However, after the polar field reversal, events predominantly originate from the southern hemisphere. This effect indicates that the global solar field plays an important role in determining the geo-effective southward magnetic field in the solar wind disturbances. It is recognized that the lack of observations in the inner heliosphere makes it difficult to unambiguously determine the solar sources of geo-effective space weather events.
Submitted by: Jie Zhang
Title: Overview of Solar Energetic Particle Event Hazards to Human Crews
Authors: Lawrence W. Townsend
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Abstract:
Department of Nuclear Engineering
The University of Tennessee
Knoxville, TN 37996-2300 USA
One of the most significant health risks for human missions to Earth's moon and Mars is exposure to the harsh space radiation environment. Crews on these exploration missions will be exposed to a complex mixture of very energetic particles. Chronic exposures to the ever-present background galactic cosmic ray (GCR) spectrum consisting of various fluxes of all naturally - occurring chemical elements are combined with infrequent, possibly acute exposures to large fluxes of solar energetic particles, consisting of protons and heavier particles. The GCR environment is primarily a concern for stochastic effects, such as the induction of cancer, with subsequent mortality in many cases, and late deterministic effects, such as cataracts and possible damage to the central nervous system. An acute radiation syndrome response ( radiation sickness ) is not possible from the GCR environment since the maximum organ doses are well below levels of concern. The sporadic occurrence of extremely large solar energetic particle events, usually associated with intense solar activity, is a major concern for Lunar and Mars missions because of the possible manifestation of acute effects from the accompanying high doses of such radiations, especially acute radiation syndrome effects such as nausea, emesis, hemorrhaging or possibly even death. Large solar energetic particle events can also contribute significantly to crew risks from cancer mortality. In this presentation an overview of current estimates of critical organ doses and equivalent doses for crews of Lunar and Mars bases and on those on transits between Earth and Mars is presented. Particular emphasis is placed upon potential doses from large solar energetic particle events. The current status of space radiation transport code development for use in shielding analyses for human missions in deep space is also described.
Submitted by: Merrick Berg
Title: Space Weather Through Radio Imaging Spectroscopy
Authors: Dale E. Gary, Timothy S. Bastian, Stephen M. White, Thomas H. Zurbuchen
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Abstract: The Frequency Agile Solar Radiotelescope (FASR) is a solar-dedicated radio facility now under development that will do radio imaging spectroscopy of the solar atmosphere from the chromosphere to heights of several solar radii. The poster describes the current state of the art of radio imaging of space weather phenomena, such as CMEs, shock waves, eruptions, and high-enery particles, then examines the transformative new results expected from FASR.
Submitted by: Dale E. Gary
Title: The Radiation Assessment Detector (RAD) on the Mars Science Laboratory: Linking SSP Scientific Interest with Exploration Goals and Objectives
Authors: D.M. Hassler, A. Posner, M. Bullock, S. Rafkin, D. Grinspoon, R.F. Wimmer-Schweingruber, R. Beaujean, S. Burmeister, R. Muller-Mellin, S. Bottcher, G. Reitz, F. Cucinotta, T. Cleghorn
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Abstract: The Radiation Assessment Detector (RAD) is a simple, lightweight energetic particle spectrometer to fly as part of the NASA 2009 Mars Science Laboratory (MSL) Mission. RAD will detect and analyze all relevant energetic particle species (p, n, He, Fe, etc.) incident on the Martian surface, including direct and indirect radiation created both in the atmosphere and the regolith. Fully characterizing and understanding the radiation environment is fundamental to quantitatively assessing the habitability of Mars, and an essential precursor measurement for future manned Mars missions.
The RAD instrument consists of a solid-state detector stack and CsI calorimeter with active coincidence logic to identify charged energetic particles using the dE/dx vs E method. RAD also uses a separate plastic scintillator and anti-coincidence shield to detect neutrons and gamma rays. Each of these techniques and components have been used for radiation detection in space since the 1960s, but combined in this way, for the first time with RAD. The RAD project exemplifies the strong collaboration and cooperation between SMD and ESMD, and their common scientific and Exploration goals and objectives. RAD is funded by NASA Exploration Systems Mission Directorate.
Submitted by: Don Hassler (Southwest Research Institute)
Title: Solar Probe: Report of the Science and Technology Definition Team
Authors: Solar Probe Science and Technology Definition Team: D. J. McComas, Chair; L. W. Acton; M. Balat-Pichelin; V. Bothmer; R. B. Dirling, Jr.; W. C. Feldman; G. Gloeckler; S. R. Habbal; D. M. Hassler; I. Mann; W. H. Matthaeus; R. L. McNutt, Jr.; R. A. Mewaldt; N. Murphy; L. Ofman; E. C. Sittler, Jr., C. W. Smith; M. Velli; and T. H. Zurbuchen
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Abstract: Solar Probe will be a historic mission, flying into one of the last unexplored regions of the solar system, the Sun's atmosphere or corona, for the first time. Approaching as close as 3 RS above the Sun's surface, Solar Probe will employ a combination of in-situ measurements and imaging to achieve the mission's primary scientific goal: to understand how the Sun's corona is heated and how the solar wind is accelerated. Solar Probe will revolutionize our knowledge of the physics of the origin and evolution of the solar wind. Moreover, by making the only direct, in-situ measurements of the region where some of the deadliest solar energetic particles are energized, Solar Probe will make unique and fundamental contributions to our ability to characterize and forecast the radiation environment in which future space explorers will work and live.
Submitted by: R. L. McNutt, Jr.
Title: RADSAFE
Authors: Robert Reed, Robert Weller, Ronald Schrimpf, Kenneth LaBel
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Abstract: RADSAFE is a revolutionary, modular computational system for predicting the radiation response of electronic devices, circuits, and systems from detailed device structure, circuit topology, and characteristics of the radiation environment. Its goals to be informed by the best available physics, implemented by robust algorithms, enabled by supercomputer technology, and calibrated by data.
Submitted by: Robert Reed, email: robert.reed@vanderbilt.edu
Title: Solar Particle Events and Self-Organized Criticality: Are Deterministic Predictions of Events Possible?
Authors: M.A. Xapsos, C. Stauffer, J.L. Barth and E.A. Burke
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Abstract: Evidence is presented that solar particle events are a self-organized critical phenomenon. Using daily and monthly fluences of solar protons measured by the IMP-8 and GOES satellite instrumentation over a 28-year period, long-term correlation of events, fractal characteristics and power function behavior for the density functions of fluence magnitudes and waiting times are demonstrated. The implications are that it is not possible to predict the time of occurrence and magnitude of solar particle events within narrow limits. This is discussed in the context of the Vision for Space Exploration.
Submitted by: Michael A. Xapsos, NASA/GSFC
Title: Early Diagnostics of Coronal Mass Ejections as a Potential Cause of Geomagnetic Activity
Geomagnetic Activity
Authors: Vasyl Yurchyshyn
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Submitted by: Vasyl Yurchyshyn
Title: Planning for SECCHI Observations of the Solar Corona and Heliosphere
Authors: S.P. Plunkett, R.A. Howard, N.B. Rich, D. Wang, A.E. Esfandiari, R.A. Harrison, W.T. Thompson, and J.-P. Wuelser
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Abstract: The Sun-Earth Connections Coronal and Heliospheric Investigation (SECCHI) instrument suite consists of five almost identical telescopes on each of the STEREO spacecraft. Each instrument suite includes an extreme ultraviolet disk imager (EUVI), two coronagraphs (COR1 and COR2) and two heliospheric imagers (HI1 and HI2) that will image the corona and heliosphere to distances beyond the Earth's orbit. SECCHI observations will consist of a synoptic program optimized to provide simultaneous identical images for stereoscopic viewing of coronal and heliospheric structures from both STEREO spacecraft, and special observations that can be tailored to meet specific science objectives. This paper will describe the observational capabilities of the SECCHI instruments, and will discuss the operational resources available and constraints on observations at various stages of the mission.
Submitted by: Simon P. Plunkett
Title: Flare prediction with active region tracking using the Solar Feature Catalogues
Authors: V.V.Zharkova, A.Benkhalil, S.Zharkov and S.S.Ipson
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Abstract: We present an expansion of our active region tracking technique on a short cadence H-alpha images combined with magnetograms in the Solar Feature Catalogues and their correlation with solar flare
occurrences to a possible tool for prediction of solar flares.
Submitted by: V.V.Zharkova
Title: Use of Solar Feature Catalogues for medium and short term solar activity forecast
Authors: Zharkova V.V., Zharkov S. and Schetinin V.
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Abstract: We discuss the automated tools used for extraction of active solar features and their implementation into the future space missions for the solar activity prediction. Based on the statistical properties of Solar Feature Catalogues (SFCs) we explore options for prediction of the medium and short term solar activity with SFCs.
Submitted by: V.V.Zharkova
Title: Early Diagnostics of Dangerous Active Regions
Authors: Valentyna Abramenko
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Abstract: We calculated power spectra of the line-of-sight magnetograms for 16 active regions of different flare activity. Data obtained by the Michelson Doppler Imager instrument onboard the Solar and Heliospheric Observatory in high resolution mode were used in this study. For each active region, the daily soft X-ray flare index, A, was calculated. This index characterizes the flare productivity of an active region per day, being equal to 1 when the specific flare productivity is one C1.0 flare per day. The power index, \alpha, of the magnetic power spectrum, averaged over all analyzed magnetograms for a given active region, was compared with the flare index.
It was found that active regions, which produced X-class flares, possessed a steep power spectrum with \alpha > 2.0,
while flare-quiet active regions with low magnitude of A displayed a Kolmogorov-type spectrum of \alpha \approx 5/3. Observational data suggest that the flare index A may be determined from the power index \alpha by A(\alpha)= 409.5 (\alpha-5/3)^{2.49}. The magnitude of the power index at the stage of emergence of an active region seems not to be related to the current
flaring level of this active region, but rather reflects its future flare
productivity, when the the magnetic configuration becomes well-evolved. This finding shows the way to distinguish at the very early stage dangerous active regions that have a potential to produce strong flares.
Submitted by: Valentyna Abramenko
Title: Charged Particle Spectrometer for Crewed Missions
Authors: David H. Kaplan and James H. Adams, Jr.
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Abstract: It is necessary to measure the radiation environment within crewed space systems to check the accuracy of computer models used to determine the radiation exposure of the crew. All radiologically significant components of the radiation field need to be measured. These include neutrons, protons and the nuclei of the nuclei of all the abundant elements from H to Fe over the energy range where their fluxes are high enough to be radiologically significant.
The instrumentation to make these measurements includes various types of dosimeters, a Tissue Equivalent Proportional Counter (TEPC), a directional charged particle spectrometer for both internal and external use and an external electron detector.
This poster will present a concept for a directional charged particle spectrometer to monitor the nuclei of the elements H though Fe from 20 MeV to 10 GeV within the crew quarters and externally.
Submitted by: James H. Adams, Jr
Title: A First-Principles Approach to Forecasting Solar Eruptive Events
Authors: C. R. DeVore & S. K. Antiochos, Naval Research
Laboratory
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Abstract: Solar eruptive events – coronal mass ejections and their
associated flares – are a principal source of the transient disturbances that
drive space weather and pose both prompt and delayed hazards to spacecraft and
astronauts. It is generally accepted that the energy powering the eruptions is
stored in the magnetic fields of the corona, and that its release is triggered
suddenly when some critical threshold is attained. Methods currently used to
forecast such events are based on empirical measures of the magnetic stresses in
coronal structures known to be prone to eruption, and are qualitative or
semiquantitative at best, due to our limited understanding of the underlying
physical mechanisms.
We have initiated development of a quantitative, first-principles approach to
forecasting solar eruptions. The method is based upon our observationally
supported “breakout” model for coronal mass ejections, combined with a widely
accepted maximum-energy principle for closed magnetostatic equilibria in the
corona. The energy principle states that for every coronal structure there is a
well-defined energy at which its magnetic field must expand outward until it
opens, i.e., until the field lines stretch arbitrarily far from the Sun into
interplanetary space. This expansion will be gradual rather than explosive,
however, if all of the overlying field is forced to open along with the stressed
field low in the atmosphere. In a sufficiently magnetically complex corona, on
the other hand, a null point with an associated directional discontinuity can
exist in the overlying field. Field lines will break and reconnect across the
null in this configuration, thereby removing part of the overlying field and
reducing the amount of energy required for the remainder to open. The pent-up
excess energy is liberated in a violent expulsion of the stressed field and its
entrained plasma, which “break out” through the formerly restraining field
above.
Applying these concepts to forecasting requires a method to calculate the
energies needed to open the coronal field (1) in the absence of reconnection,
which maximizes the open energy, and (2) in the presence of optimal
reconnection, which minimizes this energy. These two energies, together with
that of the relaxed post-eruption field configuration, determine the threshold
energy for eruption onset and characterize the energy available to power both
the coronal mass ejection and its associated flare. We calculate the event
energies for the idealized case of an axisymmetric Sun, and compare those
results with our detailed, time-dependent simulations of solar eruptions. We
will discuss additional numerical experiments needed to verify the physical
model, the mathematical advances required to extend the technique to general
three-dimensional configurations, and the observational data needed to initiate
and validate solar forecasts.
Submitted by: C. R. DeVore
Title: Improved Estimation of Magnetic Footpoint Velocities in Active Regions
Authors: P. Schuck and J. Krall
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Abstract: The accurate estimation of magnetic footpoint velocities from a sequence of photospheric magnetograms is critical for predicting activity associated with that active region. In particular, accurate footpoint velocities can be used to directly compute accurate values for magnetic energy and helicity fluxes through the photosphere. We have developed a new technique for determining the magnetic footpoint velocities in which we apply the magnetic induction equation and an affine velocity profile to a windowed subregion of the magnetogram sequence. This produces an overdetermined system that can be solved directly by standard least squares methods. Using synthetic data, in which the actual optical flow velocities are known, we show that the new technique is superior to the usual local correlation tracking (LCT) approach.
Submitted by: J. Krall
Title: Three-Dimensional Geometry of the Flux-Rope Drivers of SEP Events
Authors: J. Krall[1], V. Yurchyshyn[2], O. C. St Cyr[3,4] and J. Chen[1]
Hyperlink:
Abstract: The dynamics of shock-driven solar-energetic particle (SEP) events depend on the three-dimensional (3D) geometry of the erupting magnetic structures that drive these events. Based on observations, we have determined the geometry of a typical flux-rope CME, which is parameterized in terms of overall size, axial aspect ratio, and the eccentricity of the ellipse formed by the curved axis of the flux rope. Further, we have found that the near-Sun magnetic configuration, as obtained from a match of the model geometry to observed halo-CME morphologies for specific events, is closely related to the interplanetary CME (ICME) magnetic configuration, as determined by matching the model ICME to the corresponding in situ magnetic field and plasma measurements; this association gives us confidence in our 3D CME model. Our present tools are a) an erupting flux-rope code that models a CME/ICME from Sun to Earth and b) a 3D CME generator that produces 3D CME fields and densities, synthetic coronagraphs, etc., for specified geometrical parameters. We will discuss how these tools might be applied to SEP event modeling.
Submitted by: J. Krall
Title: Statistical Study of Low Energy Heliosphere Particle Fluxes from 1.4 to 5 AU Over a Solar Cycle
Authors: C. Denker, L. J. Lanzerotti, T. P. Armstrong; J. D. Patterson
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Abstract: We present statistical studies of high resolution ion and electron energy spectra (~ 50keV to ~ 5 MeV) as measured by the HI-SCALE instrument on the Ulysses spacecraft over a time interval longer than a solar cycle (from launch in 1990 to nearly the present). Ulysses was the only spacecraft that continually measured the inner (~1.4 to ~ 5 AU) heliosphere particle population during these years. The data thus provide measures of the lower energy population of particles that a spacecraft traveling outward from Earth would have encountered, and that also impacted the atmosphere and surface of Mars and the surfaces of the Martian satellites, Phobos and Deimos, during this interval. Comparisons of Ulysses particle fluxes with those from the EPAM instrument on the ACE spacecraft (the HI-SCALE back-up instrument) have shown that it is common for the particle fluxes in the inner heliosphere following solar events to be distributed quite uniformly in heliolatitude. Thus, the Ulysses measurements, while taken over a range of heliolatitudes, can provide important statistical information that can be used to estimate the low energy radiation dosages and potential sputtering fluxes to planetary surfaces and to heliosphere spacecraft surfaces and solar arrays over a solar cycle.
Submitted by: Louis J. Lanzerotti, ljl-at-njit.edu
Title: Initiation of Coronal Mass Ejections: Implications for Forecasting Solar Energetic Particle Storms
Authors: R. L. Moore, A. C. Sterling, D. A. Falconer, and J. M. Davis
Hyperlink:Abstract:
PDF file
Submitted by: Ron Moore
Title: The Wind Spacecraft at L1 - L1 onwards
Authors: K.W.OGILVIE and M.D.DESCH
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Abstract: Wind will be in orbit about L1 until
further notice, accompanied by ACE.
Together, they form a powerful
component of the Heliospheric
Observatory. ACE has excellent
particle composition capabilities,
and real time data reporting, while
Wind has the ability to radio-track
shocks from ICMEs. Both spacecraft
have magnetometers and plasma and
energetic particle instruments.
For many purposes they form the
equivalent of a third STEREO.
The poster describes these
attributes in more detail.
Submitted by: OGILVIE 301-286-5904
Title: Current and Future Observations of Solar Flares for Space Exploration
Author(s): Tom Woods (LASP / Univ. of Colorado)
Hyperlink:
Abstract: PDF file
Submitted by: Tom Woods
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