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Sample records for genesis solar wind

  1. Solar Wind Elemental Abundances from GENESIS Collectors

    NASA Astrophysics Data System (ADS)

    Burnett, D. S.; Woolum, D. S.; Jurewicz, A. J. G.; McKeegan, K. D.; Guan, Y.

    2007-03-01

    GENESIS bulk solar wind analyses were made by SIMS on Si, Sandia diamond-like-C, and epitaxial Si on sapphire (SoS). Preliminary Fe, Mg, Ca, Cr and Na fluences are calculated. The eventual goal is to test for fractionation (or lack thereof) of solar-wind

  2. Genesis Capsule Yields Solar Wind Samples

    NASA Astrophysics Data System (ADS)

    Wiens, Roger C.; Burnett, Donald S.; Stansbery, Eileen K.; McNamara, Karen M.

    2004-11-01

    NASA's Genesis capsule, carrying the first samples ever returned from beyond the Moon, took a hard landing in the western Utah desert on 8 September after its parachutes failed to deploy. Despite the impact, estimated at 310 km per hour, some valuable solar wind collector materials have been recovered. With these samples, the Genesis team members are hopeful that nearly all of the primary science goals may be met. The Genesis spacecraft was launched in August 2001 to collect and return samples of solar wind for precise isotopic and elemental analysis. The spacecraft orbited the Earth-Sun Lagrangian point (L1), ~1.5 million km sunward of the Earth, for 2.3 years. It exposed ultrapure materials-including wafers of silicon, silicon carbide, germanium, chemically deposited diamond, gold, aluminum, and metallic glass-to solar wind ions, which become embedded within the substrates' top 100 nm of these materials.

  3. The Genesis Solar Wind Sample Return Mission

    NASA Technical Reports Server (NTRS)

    Wiens, Roger C.; Burnett, Donald S.; Neugebauer, Marcia; Sasaki, Chester; Sevilla, Donald; Stansbery, Eileen; Clark, Ben; Smith, Nick; Oldham, Lloyd

    1990-01-01

    The Genesis spacecraft was launched on August 8 from Cape Canaveral on a journey to become the first spacecraft to return from interplanetary space. The fifth in NASA's line of low-cost Discovery-class missions, its goal is to collect samples of solar wind and return them to Earth for detailed isotopic and elemental analysis. The spacecraft is to collect solar wind for over two years, while circling the L1 point 1.5 million km sunward of the earth, before heading back for a capsule-style re-entry in September, 2004. After parachute deployment, a mid-air helicopter recovery will be used to avoid a hard landing. The mission has been in the planning stages for over ten years. Its cost, including development, mission operations, and sample analysis, is approximately $209M. The Genesis science team, headed by principal investigator Donald Burnett of Caltech, consists of approximately 20 co-investigators from universities and science centers around the country and internationally. The spacecraft consists of a relatively flat spacecraft bus containing most of the subsystem components, situated below a sample return capsule (SRC) which holds the solar-wind collection substrates and an electrostatic solar wind concentrator. Some of the collectors are exposed throughout the collection period, for a sample of bulk solar wind, while others are exposed only to certain solar wind regimes, or types of flow. Ion and electron spectrometers feed raw data to the spacecraft control and data-handling (C&DH) unit, which determines ion moments and electron flux geometries in real time. An algorithm is used to robotically decide between interstream (IS), coronal hole (CH), and coronal mass ejection (CME) regimes, and to control deployment of the proper arrays to sample these wind regimes independently. This is the first time such a solar-wind decision algorithm has been used on board a spacecraft.

  4. Genesis Solar Wind Samples: Update of Availability

    NASA Technical Reports Server (NTRS)

    Gonzalez, C. P.; Allums, K. K.; Allton, J. H.

    2015-01-01

    The Genesis mission collected solar wind atoms for 28 months with a variety of collectors. The array wafer collector availability is displayed in the online catalog. The purpose of this report is to update the community on availability of array wafer samples and to preview other collectors which are in the process of being added to the online catalog. A total of fifteen pure materials were selected based on engineering and science requirements. Most of the materials were semiconductor wafers which were mounted on the arrays.

  5. The GENESIS Mission Solar Wind Samples: Collection Times, Estimated Fluences, and Solar-Wind Conditions

    NASA Astrophysics Data System (ADS)

    Reisenfeld, D. B.; Wiens, R. C.; Barraclough, B. L.; Steinberg, J. E.; Dekoning, C.; Zurbuchen, T. H.; Burnett, D. S.

    2005-03-01

    We have correlated the GENESIS sample collection times for the different solar-wind regimes with compositional data from GENESIS/GIM and ACE/SWICS instruments. We discuss GENESIS regime selection and new results in solar-wind elemental fractionation.

  6. Genesis Solar Wind Array Collector Cataloging Status

    NASA Technical Reports Server (NTRS)

    Burkett, P.J.; Rodriguez, M.C.; Calaway, M.C.; Allton, J.H.

    2009-01-01

    Genesis solar wind array collectors were fractured upon landing hard in Utah in 2004. The fragments were retrieved from the damaged canister, imaged, repackaged and shipped to the Johnson Space Center curatorial facility [1]. As of January 2009, the collection consists of 3460 samples. Of these, 442 are comprised into "multiple" sample groupings, either affixed to adhesive paper (177) or collected in jars (17), culture trays (87), or sets of polystyrene vials (161). A focused characterization task was initiated in May 2008 to document the largest samples in the collection. The task consisted of two goals: to document sapphire based fragments greater than 2 cm in one dimension, and to document silicon based fragments greater than 1 cm in one direction.

  7. Genesis Solar-Wind Sample Return Mission: The Materials

    NASA Technical Reports Server (NTRS)

    Jurewicz, A. J. G.; Burnett, D. S.; Wiens, R. C.; Woolum, D.

    2003-01-01

    The Genesis spacecraft has two primary instruments which passively collect solar wind. The first is the collector arrays , a set of panels, each of which can deploy separately to sample the different kinds of solar wind (regimes). The second is the concentrator, an electrostatic mirror which will concentrate ions of mass 4 through mass 25 by about a factor of 20 by focusing them onto a 6 cm diameter target. When not deployed, these instruments fit into a compact canister. After a two year exposure time, the deployed instruments can be folded up, sealed into the canister, and returned to earth for laboratory analysis. Both the collector arrays and the concentrator will contain suites of ultra-high purity target materials, each of which is tailored to enable the analysis of a different family of elements. This abstract is meant to give a brief overview of the Genesis mission, insight into what materials were chosen for flight and why, as well as head s up information as to what will be available to planetary scientist for analysis when the solar-wind samples return to Earth in 2003. Earth. The elemental and isotopic abundances of the solar wind will be analyzed in state-of-the-art laboratories, and a portion of the sample will be archived for the use of future generations of planetary scientists. Technical information about the mission can be found at www.gps.caltech.edu/genesis.

  8. Genesis Solar-Wind Sample Return Mission: The Materials

    NASA Technical Reports Server (NTRS)

    Jurewicz, A. J. G.; Burnett, D. S.; Wiens, R. C.; Woolum, D.

    2003-01-01

    The Genesis spacecraft has two primary instruments which passively collect solar wind. The first is the collector arrays , a set of panels, each of which can deploy separately to sample the different kinds of solar wind (regimes). The second is the concentrator, an electrostatic mirror which will concentrate ions of mass 4 through mass 25 by about a factor of 20 by focusing them onto a 6 cm diameter target. When not deployed, these instruments fit into a compact canister. After a two year exposure time, the deployed instruments can be folded up, sealed into the canister, and returned to earth for laboratory analysis. Both the collector arrays and the concentrator will contain suites of ultra-high purity target materials, each of which is tailored to enable the analysis of a different family of elements. This abstract is meant to give a brief overview of the Genesis mission, insight into what materials were chosen for flight and why, as well as head s up information as to what will be available to planetary scientist for analysis when the solar-wind samples return to Earth in 2003. Earth. The elemental and isotopic abundances of the solar wind will be analyzed in state-of-the-art laboratories, and a portion of the sample will be archived for the use of future generations of planetary scientists. Technical information about the mission can be found at www.gps.caltech.edu/genesis.

  9. Genesis Solar Wind Sample Curation: A Progress Report

    NASA Technical Reports Server (NTRS)

    Allton, Judith H.; Calaway, M. J.; Rodriquez, M. C.; Hittle, J. D.; Wentworth, S. J.; Stansbery, E. K.; McNamara, K. M.

    2006-01-01

    In the year since the Genesis solar wind collector fragments were returned, early science samples, specimens for cleaning experiments, and science allocations have been distributed. Solar wind samples are stored under nitrogen and handled in an ISO Class 4 (Class 10) laboratory. For array collector fragments, a basic characterization process has been established. This characterization consists of identification of solar wind regime, whole fragment image for identification and surface quality, higher magnification images for contaminant particle density, and assessment of molecular film contaminant thickness via ellipsometry modeling. Compilations of this characterization data for AuOS (gold film on sapphire), and sapphire from the bulk solar wind for fragments greater than 2 cm are available. Removal of contaminant particles using flowing ultrapure water (UPW) energized megasonically is provided as requested.

  10. The Genesis Mission Solar Wind Collection: Solar-Wind Statistics over the Period of Collection

    NASA Technical Reports Server (NTRS)

    Barraclough, B. L.; Wiens, R. C.; Steinberg, J. E.; Reisenfeld, D. B.; Neugebauer, M.; Burnett, D. S.; Gosling, J.; Bremmer, R. R.

    2004-01-01

    The NASA Genesis spacecraft was launched August 8, 2001 on a mission to collect samples of solar wind for 2 years and return them to earth September 8, 2004. Detailed analyses of the solar wind ions implanted into high-purity collection substrates will be carried out using various mass spectrometry techniques. These analyses are expected to determine key isotopic ratios and elemental abundances in the solar wind, and by extension, in the solar photosphere. Further, the photospheric composition is thought to be representative of the solar nebula with a few exceptions, so that the Genesis mission will provide a baseline for the average solar nebula composition with which to compare present-day compositions of planets, meteorites, and asteroids. The collection of solar wind samples is almost complete. Collection began for most substrates in early December, 2001, and is scheduled to be complete on April 2 of this year. It is critical to understand the solar-wind conditions during the collection phase of the mission. For this reason, plasma ion and electron spectrometers are continuously monitoring the solar wind proton density, velocity, temperature, the alpha/proton ratio, and angular distribution of suprathermal electrons. Here we report on the solar-wind conditions as observed by these in-situ instruments during the first half of the collection phase of the mission, from December, 2001 to present.

  11. The Genesis Mission Solar Wind Collection: Solar-Wind Statistics over the Period of Collection

    NASA Technical Reports Server (NTRS)

    Barraclough, B. L.; Wiens, R. C.; Steinberg, J. E.; Reisenfeld, D. B.; Neugebauer, M.; Burnett, D. S.; Gosling, J.; Bremmer, R. R.

    2004-01-01

    The NASA Genesis spacecraft was launched August 8, 2001 on a mission to collect samples of solar wind for 2 years and return them to earth September 8, 2004. Detailed analyses of the solar wind ions implanted into high-purity collection substrates will be carried out using various mass spectrometry techniques. These analyses are expected to determine key isotopic ratios and elemental abundances in the solar wind, and by extension, in the solar photosphere. Further, the photospheric composition is thought to be representative of the solar nebula with a few exceptions, so that the Genesis mission will provide a baseline for the average solar nebula composition with which to compare present-day compositions of planets, meteorites, and asteroids. The collection of solar wind samples is almost complete. Collection began for most substrates in early December, 2001, and is scheduled to be complete on April 2 of this year. It is critical to understand the solar-wind conditions during the collection phase of the mission. For this reason, plasma ion and electron spectrometers are continuously monitoring the solar wind proton density, velocity, temperature, the alpha/proton ratio, and angular distribution of suprathermal electrons. Here we report on the solar-wind conditions as observed by these in-situ instruments during the first half of the collection phase of the mission, from December, 2001 to present.

  12. Investigation of Backside Textures for Genesis Solar Wind Silicon Collectors

    NASA Technical Reports Server (NTRS)

    Gonzalez, C. P.; Burkett, P. J.; Rodriguez, M. C.; Allton, J. H.

    2014-01-01

    Genesis solar wind collectors were comprised of a suite of 15 types of ultrapure materials. The single crystal, pure silicon collectors were fabricated by two methods: float zone (FZ) and Czochralski (CZ). Because of slight differences in bulk purity and surface cleanliness among the fabrication processes and the specific vendor, it is desirable to know which variety of silicon and identity of vendor, so that appropriate reference materials can be used. The Czochralski method results in a bulk composition with slightly higher oxygen, for example. The CZ silicon array wafers that were Genesis-flown were purchased from MEMC Electronics. Most of the Genesis-flown FZ silicon was purchased from Unisil and cleaned by MEMC, although a few FZ wafers were acquired from International Wafer Service (IWS).

  13. The Genesis Mission: Solar Wind Conditions, and Implications for the FIP Fractionation of the Solar Wind.

    SciTech Connect

    Reisenfeld, D. B.; Wiens, R. C.; Barraclough, B. L.; Steinberg, J. T; Dekoning, C. A.; Zurbuchen, T. H.; Burnett, D. S.

    2005-01-01

    The NASA Genesis mission collected solar wind on ultrapure materials between November 30, 2001 and April 1, 2004. The samples were returned to Earth September 8, 2004. Despite the hard landing that resulted from a failure of the avionics to deploy the parachute, many samples were returned in a condition that will permit analyses. Sample analyses of these samples should give a far better understanding of the solar elemental and isotopic composition (Burnett et al. 2003). Further, the photospheric composition is thought to be representative of the solar nebula, so that the Genesis mission will provide a new baseline for the average solar nebula composition with which to compare present-day compositions of planets, meteorites, and asteroids. Sample analysis is currently underway. The Genesis samples must be placed in the context of the solar and solar wind conditions under which they were collected. Solar wind is fractionated from the photosphere by the forces that accelerate the ions off of the Sun. This fractionation appears to be ordered by the first ionization potential (FIP) of the elements, with the tendency for low-FIP elements to be over-abundant in the solar wind relative to the photosphere, and high-FIP elements to be under-abundant (e.g. Geiss, 1982; von Steiger et al., 2000). In addition, the extent of elemental fractionation differs across different solarwind regimes. Therefore, Genesis collected solar wind samples sorted into three regimes: 'fast wind' or 'coronal hole' (CH), 'slow wind' or 'interstream' (IS), and 'coronal mass ejection' (CME). To carry this out, plasma ion and electron spectrometers (Barraclough et al., 2003) continuously monitored the solar wind proton density, velocity, temperature, the alpha/proton ratio, and angular distribution of suprathermal electrons, and those parameters were in turn used in a rule-based algorithm that assigned the most probable solar wind regime (Neugebauer et al., 2003). At any given time, only one of three

  14. The genesis solar-wind sample return mission

    SciTech Connect

    Wiens, Roger C

    2009-01-01

    , each theory predicting a different solar isotopic composition and each invoking a different early solar-system process to produce the heterogeneity. Other volatiles such as C, N, and H may also have experienced similar effects, but with only two isotopes it is often impossible to distinguish with these elements between mass-dependent fractionation and other effects such as mixing or mass-independent fractionation. Table 1 provides a summary of the major measurement objectives of the Genesis mission. Determining the solar oxygen isotopic composition is at the top of the list. Volatile element and isotope ratios constitute six of the top seven priorities. A number of disciplines stand to gain from information from the Genesis mission, as will be discussed later. Based on the Apollo solar-wind foil experiment, the Genesis mission was designed to capture solar wind over orders of magnitude longer duration and in a potentially much cleaner environment than the lunar surface.

  15. Solar Wind Fractionation — Isotopic and Elemental — and Implications for Solar Compositions and Future Genesis Analyses

    NASA Astrophysics Data System (ADS)

    Wiens, R. C.; Reisenfeld, D. B.; Heber, V. S.; Burnett, D. S.

    2010-03-01

    Fractionation between solar wind and the solar photosphere is substantial, both for elements and isotopes. GENESIS measurements are key to understanding these fractionations, which will in turn provide more accurate solar compositions.

  16. Genesis Solar Wind Science Canister Components Curated as Potential Solar Wind Collectors and Reference Contamination Sources

    NASA Technical Reports Server (NTRS)

    Allton, J. H.; Gonzalez, C. P.; Allums, K. K.

    2016-01-01

    The Genesis mission collected solar wind for 27 months at Earth-Sun L1 on both passive and active collectors carried inside of a Science Canister, which was cleaned and assembled in an ISO Class 4 cleanroom prior to launch. The primary passive collectors, 271 individual hexagons and 30 half-hexagons of semiconductor materials, are described in. Since the hard landing reduced the 301 passive collectors to many thousand smaller fragments, characterization and posting in the online catalog remains a work in progress, with about 19% of the total area characterized to date. Other passive collectors, surfaces of opportunity, have been added to the online catalog. For species needing to be concentrated for precise measurement (e.g. oxygen and nitrogen isotopes) an energy-independent parabolic ion mirror focused ions onto a 6.2 cm diameter target. The target materials, as recovered after landing, are described in. The online catalog of these solar wind collectors, a work in progress, can be found at: http://curator.jsc.nasa.gov/gencatalog/index.cfm This paper describes the next step, the cataloging of pieces of the Science Canister, which were surfaces exposed to the solar wind or component materials adjacent to solar wind collectors which may have contributed contamination.

  17. Argon, Krypton, and Xenon in Three Solar Wind Regimes as Collected by GENESIS

    NASA Astrophysics Data System (ADS)

    Vogel, N.; Baur, H.; Burnett, D. S.; Maden, C.; Wieler, R.

    2011-03-01

    We present new heavy noble gas fluxes and elemental compositions (36Ar/84Kr, 84Kr/132Xe) for the fast, slow, and CME-related Solar Wind as collected by Genesis in order to rule on element fractionation processes during Solar Wind formation.

  18. The GENESIS Mission: Solar Wind Isotopic and Elemental Compositions and Their Implications

    NASA Astrophysics Data System (ADS)

    Wiens, R. C.; Burnett, D. S.; McKeegan, K. D.; Kallio, A. P.; Mao, P. H.; Heber, V. S.; Wieler, R.; Meshik, A.; Hohenberg, C. M.; Mabry, J. C.; Gilmour, J.; Crowther, S. A.; Reisenfeld, D. B.; Jurewicz, A.; Marty, B.; Pepin, R. O.; Barraclough, B. L.; Nordholt, J. E.; Olinger, C. T.; Steinberg, J. T.

    2008-12-01

    The GENESIS mission was a novel NASA experiment to collect solar wind at the Earth's L1 point for two years and return it for analysis. The capsule crashed upon re-entry in 2004, but many of the solar-wind collectors were recovered, including separate samples of coronal hole, interstream, and CME material. Laboratory analyses of these materials have allowed higher isotopic precision than possible with current in-situ detectors. To date GENESIS results have been obtained on isotopes of O, He, Ne, Ar, Kr, and Xe on the order of 1% accuracy and precision, with poorer uncertainty on Xe isotopes and significantly better uncertainties on the lighter noble gases. Elemental abundances are available for the above elements as well as Mg, Si, and Fe. When elemental abundances are compared with other in situ solar wind measurements, agreement is generally quite good. One exception is the Ne elemental abundance, which agrees with Ulysses and Apollo SWC results, but not with ACE. Neon is of particular interest because of the uncertainty in the solar Ne abundance, which has significant implications for the standard solar model. Helium isotopic results of material from the different solar wind regimes collected by GENESIS is consistent with isotopic fractionation predictions of the Coulomb drag model, suggesting that isotopic fractionation corrections need to be applied to heavier elements as well when extrapolating solar wind to solar compositions. Noble gas isotopic compositions from GENESIS are consistent with those obtained for solar wind trapped in lunar grains, but have for the first time yielded a very precise Ar isotopic result. Most interesting for cosmochemistry is a preliminary oxygen isotopic result from GENESIS which indicates a solar enrichment of ~4% in 16O relative to the planets, consistent with a photolytic self-shielding phenomenon during solar system formation. Analyses of solar wind N and C isotopes may further elucidate this phenomenon. Preliminary results

  19. Decontaminating Solar Wind Samples with the Genesis Ultra-Pure Water Megasonic Wafer Spin Cleaner

    NASA Technical Reports Server (NTRS)

    Calaway, Michael J.; Rodriquez, M. C.; Allton, J. H.; Stansbery, E. K.

    2009-01-01

    The Genesis sample return capsule, though broken during the landing impact, contained most of the shattered ultra-pure solar wind collectors comprised of silicon and other semiconductor wafers materials. Post-flight analysis revealed that all wafer fragments were littered with surface particle contamination from spacecraft debris as well as soil from the impact site. This particulate contamination interferes with some analyses of solar wind. In early 2005, the Genesis science team decided to investigate methods for removing the surface particle contamination prior to solar wind analysis.

  20. Genesis Solar Wind Interstream, Coronal Hole and Coronal Mass Ejection Samples: Update on Availability and Condition

    NASA Technical Reports Server (NTRS)

    Allton, J. H.; Gonzalez, C. P.; Allums, K. K.

    2017-01-01

    Recent refinement of analysis of ACE/SWICS data (Advanced Composition Explorer/Solar Wind Ion Composition Spectrometer) and of onboard data for Genesis Discovery Mission of 3 regimes of solar wind at Earth-Sun L1 make it an appropriate time to update the availability and condition of Genesis samples specifically collected in these three regimes and currently curated at Johnson Space Center. ACE/SWICS spacecraft data indicate that solar wind flow types emanating from the interstream regions, from coronal holes and from coronal mass ejections are elementally and isotopically fractionated in different ways from the solar photosphere, and that correction of solar wind values to photosphere values is non-trivial. Returned Genesis solar wind samples captured very different kinds of information about these three regimes than spacecraft data. Samples were collected from 11/30/2001 to 4/1/2004 on the declining phase of solar cycle 23. Meshik, et al is an example of precision attainable. Earlier high precision laboratory analyses of noble gases collected in the interstream, coronal hole and coronal mass ejection regimes speak to degree of fractionation in solar wind formation and models that laboratory data support. The current availability and condition of samples captured on collector plates during interstream slow solar wind, coronal hole high speed solar wind and coronal mass ejections are de-scribed here for potential users of these samples.

  1. Solar and Solar-Wind Composition Results from the Genesis Mission

    NASA Astrophysics Data System (ADS)

    Wiens, R. C.; Burnett, D. S.; Hohenberg, C. M.; Meshik, A.; Heber, V.; Grimberg, A.; Wieler, R.; Reisenfeld, D. B.

    The Genesis mission returned samples of solar wind to Earth in September 2004 for ground-based analyses of solar-wind composition, particularly for isotope ratios. Substrates, consisting mostly of high-purity semiconductor materials, were exposed to the solar wind at L1 from December 2001 to April 2004. In addition to a bulk sample of the solar wind, separate samples of coronal hole (CH), interstream (IS), and coronal mass ejection material were obtained. Although many substrates were broken upon landing due to the failure to deploy the parachute, a number of results have been obtained, and most of the primary science objectives will likely be met. These objectives include He, Ne, Ar, Kr, and Xe isotope ratios in the bulk solar wind and in different solar-wind regimes, and 15N/14N and 18O/17O/16O to high precision. The greatest successes to date have been with the noble gases. Light noble gases from bulk solar wind and separate solar-wind regime samples have now been analyzed. Helium results show clear evidence of isotopic fractionation between CH and IS samples, consistent with simplistic Coulomb drag theory predictions of fractionation between the photosphere and different solar-wind regimes, though fractionation by wave heating is also a possible explanation. Neon results from closed system stepped etching of bulk metallic glass have revealed the nature of isotopic fractionation as a function of depth, which in lunar samples have for years deceptively suggested the presence of an additional, energetic component in solar wind trapped in lunar grains and meteorites. Isotope ratios of the heavy noble gases, nitrogen, and oxygen are in the process of being measured.

  2. Solar and Solar-Wind Composition Results from the Genesis Mission

    NASA Astrophysics Data System (ADS)

    Wiens, R. C.; Burnett, D. S.; Hohenberg, C. M.; Meshik, A.; Heber, V.; Grimberg, A.; Wieler, R.; Reisenfeld, D. B.

    2007-06-01

    The Genesis mission returned samples of solar wind to Earth in September 2004 for ground-based analyses of solar-wind composition, particularly for isotope ratios. Substrates, consisting mostly of high-purity semiconductor materials, were exposed to the solar wind at L1 from December 2001 to April 2004. In addition to a bulk sample of the solar wind, separate samples of coronal hole (CH), interstream (IS), and coronal mass ejection material were obtained. Although many substrates were broken upon landing due to the failure to deploy the parachute, a number of results have been obtained, and most of the primary science objectives will likely be met. These objectives include He, Ne, Ar, Kr, and Xe isotope ratios in the bulk solar wind and in different solar-wind regimes, and 15N/14N and 18O/17O/16O to high precision. The greatest successes to date have been with the noble gases. Light noble gases from bulk solar wind and separate solar-wind regime samples have now been analyzed. Helium results show clear evidence of isotopic fractionation between CH and IS samples, consistent with simplistic Coulomb drag theory predictions of fractionation between the photosphere and different solar-wind regimes, though fractionation by wave heating is also a possible explanation. Neon results from closed system stepped etching of bulk metallic glass have revealed the nature of isotopic fractionation as a function of depth, which in lunar samples have for years deceptively suggested the presence of an additional, energetic component in solar wind trapped in lunar grains and meteorites. Isotope ratios of the heavy noble gases, nitrogen, and oxygen are in the process of being measured.

  3. Isotopic and Elemental Compositions of Ar, Kr, and Xe in Bulk, Slow, and Fast Solar Wind Targets from Genesis

    NASA Astrophysics Data System (ADS)

    Vogel, N.; Baur, H.; Burnett, D. S.; Heber, V. S.; Wieler, R.

    2010-03-01

    We present new heavy noble gas isotopic and elemental data from GENESIS targets exposed to the bulk, the fast, and the slow solar wind. Implications on fractionation effects between the Sun and the Solar Wind will be discussed.

  4. Depth profiling analysis of solar wind helium collected in diamond-like carbon film from Genesis

    DOE PAGES

    Bajo, Ken-ichi; Olinger, Chad T.; Jurewicz, Amy J.G.; ...

    2015-01-01

    The distribution of solar-wind ions in Genesis mission collectors, as determined by depth profiling analysis, constrains the physics of ion solid interactions involving the solar wind. Thus, they provide an experimental basis for revealing ancient solar activities represented by solar-wind implants in natural samples. We measured the first depth profile of ⁴He in a collector; the shallow implantation (peaking at <20 nm) required us to use sputtered neutral mass spectrometry with post-photoionization by a strong field. The solar wind He fluence calculated using depth profiling is ~8.5 x 10¹⁴ cm⁻². The shape of the solar wind ⁴He depth profile ismore » consistent with TRIM simulations using the observed ⁴He velocity distribution during the Genesis mission. It is therefore likely that all solar-wind elements heavier than H are completely intact in this Genesis collector and, consequently, the solar particle energy distributions for each element can be calculated from their depth profiles. Ancient solar activities and space weathering of solar system objects could be quantitatively reproduced by solar particle implantation profiles.« less

  5. ISOTOPIC MASS FRACTIONATION OF SOLAR WIND: EVIDENCE FROM FAST AND SLOW SOLAR WIND COLLECTED BY THE GENESIS MISSION

    SciTech Connect

    Heber, Veronika S.; Baur, Heinrich; Wieler, Rainer; Bochsler, Peter; McKeegan, Kevin D.; Neugebauer, Marcia; Reisenfeld, Daniel B.; Wiens, Roger C.

    2012-11-10

    NASA's Genesis space mission returned samples of solar wind collected over {approx}2.3 years. We present elemental and isotopic compositions of He, Ne, and Ar analyzed in diamond-like carbon targets from the slow and fast solar wind collectors to investigate isotopic fractionation processes during solar wind formation. The solar wind provides information on the isotopic composition for most volatile elements for the solar atmosphere, the bulk Sun and hence, on the solar nebula from which it formed 4.6 Ga ago. Our data reveal a heavy isotope depletion in the slow solar wind compared to the fast wind composition by 63.1 {+-} 2.1 per mille for He, 4.2 {+-} 0.5 per mille amu{sup -1} for Ne and 2.6 {+-} 0.5 per mille amu{sup -1} for Ar. The three Ne isotopes suggest that isotopic fractionation processes between fast and slow solar wind are mass dependent. The He/H ratios of the collected slow and fast solar wind samples are 0.0344 and 0.0406, respectively. The inefficient Coulomb drag model reproduces the measured isotopic fractionation between fast and slow wind. Therefore, we apply this model to infer the photospheric isotopic composition of He, Ne, and Ar from our solar wind data. We also compare the isotopic composition of oxygen and nitrogen measured in the solar wind with values of early solar system condensates, probably representing solar nebula composition. We interpret the differences between these samples as being due to isotopic fractionation during solar wind formation. For both elements, the magnitude and sign of the observed differences are in good agreement with the values predicted by the inefficient Coulomb drag model.

  6. Molecular Substrate Alteration by Solar Wind Radiation Documented on Flown Genesis Mission Array Materials

    NASA Technical Reports Server (NTRS)

    Calaway, Michael J.; Stansbery, Eileen K.

    2006-01-01

    The Genesis spacecraft sampling arrays were exposed to various regimes of solar wind during flight that included: 313.01 days of high-speed wind from coronal holes, 335.19 days of low-speed inter-stream wind, 191.79 days of coronal mass ejections, and 852.83 days of bulk solar wind at Lagrange 1 orbit. Ellipsometry measurements taken at NASA s Johnson Space Center show that all nine flown array materials from the four Genesis regimes have been altered by solar wind exposure during flight. These measurements show significant changes in the optical constant for all nine ultra-pure materials that flew on Genesis when compared with their non-flight material standard. This change in the optical constant (n and k) of the material suggests that the molecular structure of the all nine ultra-pure materials have been altered by solar radiation. In addition, 50 samples of float-zone and czochralski silicon bulk array ellipsometry results were modeled with an effective medium approximation layer (EMA substrate layer) revealing a solar radiation molecular damage zone depth below the SiO2 native oxide layer ranging from 392 to 613 . This bulk solar wind radiation penetration depth is comparable to the depth of solar wind implantation depth of Mg measured by SIMS and SARISA.

  7. Oxygen Isotope Analysis of a Genesis Solar Wind Concentrator Sample With MegaSIMS

    NASA Astrophysics Data System (ADS)

    Kallio, A. P.; McKeegan, K. D.; Mao, P. H.; Jarzebinski, G.; Coath, C. D.; Kunihiro, T.; Wiens, R. C.; Allton, J.; Callaway, M.; Rodriguez, M.; Burnett, D.

    2008-05-01

    The determination of the oxygen isotopic composition of the sun is the highest priority science objective of the GENESIS mission. We have performed the first oxygen isotopic analyses of the GENESIS solar wind concentrator sample #60001 using the UCLA MegaSIMS instrument. The MegaSIMS is a hybrid secondary ionisation and accelerator multicollector mass spectrometer. The problems of instrumental background, sample surface contamination (both adsorbed and particulate) and detector cross-talk can now be dealt with and we can measure consistently solar wind oxygen depth profiles. Our preliminary oxygen isotope data indicate that the solar wind sample is 16O enriched compared to terrestrial but the details of isotopic fractionation in the concentrator and in the solar wind itself have to be worked out before a value for the sun can be calculated.

  8. Solar and solar-wind composition results from the genesis mission

    SciTech Connect

    Wiens, Roger C.; Burnett, D. S.; Hohenberg, C. M.; Meshik, A.; Heber, V.; Grimberg, A.; Wieler, R.; Reisenfeld, D. B.

    2007-02-20

    The Genesis mission returned samples of solar wind to Earth in September, 2004 for ground-based analyses of solar-wind composition, particularly for isotope ratios. Substrates, consisting mostly of high-purity semiconductor materials, were exposed to the solar wind at L1 from December 2001 to April 2004. In addition to a bulk sample of the solar wind, separate samples of coronal hole, interstream, and coronal mass ejection material were obtained. While many of the substrates were broken upon landing due to the failure to deploy the parachute, a number of results have been obtained, and most of the primary science objectives will likely be met. These include noble gas (He, Ne, Ar, Kr, and Xe) isotope ratios in the bulk solar wind and in different solarwind regimes, and the nitrogen and oxygen isotope ( 18O/17O/16O) ratios to high precision. The greatest successes to date have been with the noble gases. Light noble gases from bulk solar wind and separate solar-wind regime samples have been analyzed to date. The regime compositions are so far ambiguous on the occurrence of the type of isotopic fractionation expected from Coulomb drag acceleration. Neon results from closed system stepped etching of bulk metallic glass have revealed the nature of isotopic fractionation as a function of depth, which in lunar samples have for years deceptively suggested the presence of a separate solar component. Isotope ratios of the heavy noble gases, nitrogen, and oxygen are still in the process of being measured.

  9. RIMS analysis of Ca and Cr in genesis solar wind collectors.

    SciTech Connect

    Veryovkin, I. V.; Tripa, C. E.; Zinovev, A. V.; King, B. V.; Pellin, M. J.; Burnett, D. S.; Materials Science Division; Univ. of Newcastle; California Inst. of Tech.

    2011-01-01

    RIMS depth profiles have been measured for Cr and Ca in Genesis solar wind collector made from Si and compared to such measurements for ion-implanted Si reference material. The presence of surface contamination has been shown to be a significant factor influencing the total Ca and Cr fluence measured in the Genesis collectors. A procedure to remove the contaminant signal from these depth profiles using the reference material implanted with a minor isotope demonstrated that 36% of the measured Ca fluence in our Genesis sample comes from terrestrial contamination.

  10. Exodus: redirecting Genesis for solar wind observations 4-8 million km from Earth

    NASA Astrophysics Data System (ADS)

    Steinberg, J.; Barraclough, B.; Gosling, J.; Reisenfeld, D.; Wiens, R.; Liewer, P.; Murphy, N.

    2003-04-01

    Genesis is an ongoing NASA Discovery mission designed to collect samples of the solar wind at L1 and return them to Earth for analysis. After the return capsule is dropped off in September, 2004, the spacecraft, with its in situ solar wind ion and electron spectrometers, is available to perform a new solar wind mission. Spacecraft capabilities, including ample remaining Dv, allow it to achieve and maintain a distant retrograde orbit, a heliocentric orbit in which the spacecraft spends a significant amount of time ˜0.025 AU upstream and downstream of Earth (˜2.5x the Earth-L1 distance). From this orbit Genesis observations may be used, together with those from available L1 spacecraft, to compare solar wind parameters across important spatial scales. The multi-point collaborative studies will uniquely allow us to understand the propagation and evolution of solar wind plasma, as well as the internal spatial structure of large solar wind transients, for spacecraft separation distances of 0.025 to 0.05 AU. Such separation distances are significantly greater than can be attained between any pair of current and proposed satellites in Earth or in L1 halo orbits. At the same time the separations will be small enough to allow confident tracking of particular solar wind structures between spacecraft. In addition to groundbreaking science, the Genesis spacecraft would be a pathfinder for potential future space weather sentinels. We present a proposal to redirect the Genesis spacecraft after its prime mission is complete, and create a new, inexpensive mission: EXODUS.

  11. A 15N-poor isotopic composition for the solar system as shown by Genesis solar wind samples.

    PubMed

    Marty, B; Chaussidon, M; Wiens, R C; Jurewicz, A J G; Burnett, D S

    2011-06-24

    The Genesis mission sampled solar wind ions to document the elemental and isotopic compositions of the Sun and, by inference, of the protosolar nebula. Nitrogen was a key target element because the extent and origin of its isotopic variations in solar system materials remain unknown. Isotopic analysis of a Genesis Solar Wind Concentrator target material shows that implanted solar wind nitrogen has a (15)N/(14)N ratio of 2.18 ± 0.02 × 10(-3) (that is, ≈40% poorer in (15)N relative to terrestrial atmosphere). The (15)N/(14)N ratio of the protosolar nebula was 2.27 ± 0.03 × 10(-3), which is the lowest (15)N/(14)N ratio known for solar system objects. This result demonstrates the extreme nitrogen isotopic heterogeneity of the nascent solar system and accounts for the (15)N-depleted components observed in solar system reservoirs.

  12. Solar wind neon from Genesis: implications for the lunar noble gas record.

    PubMed

    Grimberg, Ansgar; Baur, Heinrich; Bochsler, Peter; Bühler, Fritz; Burnett, Donald S; Hays, Charles C; Heber, Veronika S; Jurewicz, Amy J G; Wieler, Rainer

    2006-11-17

    Lunar soils have been thought to contain two solar noble gas components with distinct isotopic composition. One has been identified as implanted solar wind, the other as higher-energy solar particles. The latter was puzzling because its relative amounts were much too large compared with present-day fluxes, suggesting periodic, very high solar activity in the past. Here we show that the depth-dependent isotopic composition of neon in a metallic glass exposed on NASA's Genesis mission agrees with the expected depth profile for solar wind neon with uniform isotopic composition. Our results strongly indicate that no extra high-energy component is required and that the solar neon isotope composition of lunar samples can be explained as implantation-fractionated solar wind.

  13. Recent Optical and SEM Characterization of Genesis Solar Wind Concentrator Diamond on Silicon Collector

    NASA Technical Reports Server (NTRS)

    Allton, Judith H.; Rodriquez, M. C.; Burkett, P. J.; Ross, D. K.; Gonzalez, C. P.; McNamara, K. M.

    2013-01-01

    One of the 4 Genesis solar wind concentrator collectors was a silicon substrate coated with diamond-like carbon (DLC) in which to capture solar wind. This material was designed for analysis of solar nitrogen and noble gases [1, 2]. This particular collector fractured during landing, but about 80% of the surface was recovered, including a large piece which was subdivided in 2012 [3, 4, 5]. The optical and SEM imaging and analysis described below supports the subdivision and allocation of the diamond-on-silicon (DOS) concentrator collector.

  14. Genesis Solar Wind Collector Cleaning Assessment: 60366 Sample Case Study

    NASA Technical Reports Server (NTRS)

    Goreva, Y. S.; Gonzalez, C. P.; Kuhlman, K. R.; Burnett, D. S.; Woolum, D.; Jurewicz, A. J.; Allton, J. H.; Rodriguez, M. C.; Burkett, P. J.

    2014-01-01

    In order to recognize, localize, characterize and remove particle and thin film surface contamination, a small subset of Genesis mission collector fragments are being subjected to extensive study via various techniques [1-5]. Here we present preliminary results for sample 60336, a Czochralski silicon (Si-CZ) based wafer from the bulk array (B/C).

  15. Using Image Pro Plus Software to Develop Particle Mapping on Genesis Solar Wind Collector Surfaces

    NASA Technical Reports Server (NTRS)

    Rodriquez, Melissa C.; Allton, J. H.; Burkett, P. J.

    2012-01-01

    The continued success of the Genesis mission science team in analyzing solar wind collector array samples is partially based on close collaboration of the JSC curation team with science team members who develop cleaning techniques and those who assess elemental cleanliness at the levels of detection. The goal of this collaboration is to develop a reservoir of solar wind collectors of known cleanliness to be available to investigators. The heart and driving force behind this effort is Genesis mission PI Don Burnett. While JSC contributes characterization, safe clean storage, and benign collector cleaning with ultrapure water (UPW) and UV ozone, Burnett has coordinated more exotic and rigorous cleaning which is contributed by science team members. He also coordinates cleanliness assessment requiring expertise and instruments not available in curation, such as XPS, TRXRF [1,2] and synchrotron TRXRF. JSC participates by optically documenting the particle distributions as cleaning steps progress. Thus, optical document supplements SEM imaging and analysis, and elemental assessment by TRXRF.

  16. Size Distribution of Genesis Solar Wind Array Collector Fragments Recovered

    NASA Technical Reports Server (NTRS)

    Allton, J. H.; Stansbery, E. K.; McNamara, K. M.

    2005-01-01

    Genesis launched in 2001 with 271 whole and 30 half hexagonally-shaped collectors mounted on 5 arrays, comprised of 9 materials described in [1]. The array collectors were damaged during re-entry impact in Utah in 2004 [2], breaking into many smaller pieces and dust. A compilation of the number and approximate size of the fragments recovered was compiled from notes made during the field packaging performed in the Class 10,000 cleanroom at Utah Test and Training Range [3].

  17. The First Year of Solar-Wind Data From the GENESIS Mission

    NASA Astrophysics Data System (ADS)

    Wiens, R. C.; Barraclough, B. L.; Steinberg, J. T.; Reisenfeld, D. B.; Neugebauer, M.; Burnett, D. S.

    2002-12-01

    The GENESIS mission was launched in August, 2001, and has been in an L1 halo orbit for over a year. The primary purpose of the mission is to collect solar-wind samples that will be returned to Earth in 2004 for high-precision isotopic and elemental analyses. GENESIS uses conventional ion and electron spectrometers to record solar-wind conditions during collection, and to make real-time determinations of the solar-wind regimes to facilitate collection of separate samples of interstream (IS), coronal hole (CH), and coronal mass ejection (CME) flows. Of particular interest is the use of a bi-directional electron (BDE) index to determine the presence of CMEs. And although GENESIS lacks a magnetometer, the field vector, with sign ambiguity, is determined by the electron direction, and matches other spacecraft magnetometer data well. GENESIS in-situ data and on-board regime determinations are available on the web. The data from Fall, 2001 were characterized by numerous CME regimes (comprising 32% of the time in the 4th quarter, based on the on-board algorithm), with little CH flow (only 2%). A strong CH flow was observed every solar rotation from mid-January through late May. June was quiet, nearly all IS flow. The first and second quarters of 2002 were approximately 28% CME flow, with CH flow dropping from 18% to 6%. The discovery of unexpectedly noticeable BDE signals during CH flows at 1 AU (Steinberg et al., 2002) caused us early on to modify our regime selection algorithm to accommodate these. The on-board algorithm intentionally errs on the side of overestimating CME flows in order to keep the CH sample more pure. Comparisons have been made of various compositional parameters determined by Genesis (Barraclough et al., this meeting) and by ACE SWICS (Reisenfeld et al., this meeting) for times corresponding to the Genesis collection periods for each of the three regimes. The Genesis L1 halo orbit is ~0.8 x 0.25 million km radius, somewhat larger than the ~0.3 x 0

  18. Depth profiling analysis of solar wind helium collected in diamond-like carbon film from Genesis

    SciTech Connect

    Bajo, Ken-ichi; Olinger, Chad T.; Jurewicz, Amy J.G.; Burnett, Donald S.; Sakaguchi, Isao; Suzuki, Taku; Itose, Satoru; Ishihara, Morio; Uchino, Kiichiro; Wieler, Rainer; Yurimoto, Hisayoshi

    2015-01-01

    The distribution of solar-wind ions in Genesis mission collectors, as determined by depth profiling analysis, constrains the physics of ion solid interactions involving the solar wind. Thus, they provide an experimental basis for revealing ancient solar activities represented by solar-wind implants in natural samples. We measured the first depth profile of ⁴He in a <Genesis collector; the shallow implantation (peaking at <20 nm) required us to use sputtered neutral mass spectrometry with post-photoionization by a strong field. The solar wind He fluence calculated using depth profiling is ~8.5 x 10¹⁴ cm⁻². The shape of the solar wind ⁴He depth profile is consistent with TRIM simulations using the observed ⁴He velocity distribution during the Genesis mission. It is therefore likely that all solar-wind elements heavier than H are completely intact in this Genesis collector and, consequently, the solar particle energy distributions for each element can be calculated from their depth profiles. Ancient solar activities and space weathering of solar system objects could be quantitatively reproduced by solar particle implantation profiles.

  19. The Genesis Solar Wind Concentrator: Flight and Post-Flight Conditions and Modeling of Instrumental Fractionation

    NASA Astrophysics Data System (ADS)

    Wiens, Roger C.; Reisenfeld, Daniel B.; Olinger, Chad; Wurz, Peter; Heber, Veronika S.; Burnett, Donald S.

    2013-06-01

    The Genesis mission Solar Wind Concentrator was built to enhance fluences of solar wind by an average of 20x over the 2.3 years that the mission exposed substrates to the solar wind. The Concentrator targets survived the hard landing upon return to Earth and were used to determine the isotopic composition of solar-wind—and hence solar—oxygen and nitrogen. Here we report on the flight operation of the instrument and on simulations of its performance. Concentration and fractionation patterns obtained from simulations are given for He, Li, N, O, Ne, Mg, Si, S, and Ar in SiC targets, and are compared with measured concentrations and isotope ratios for the noble gases. Carbon is also modeled for a Si target. Predicted differences in instrumental fractionation between elements are discussed. Additionally, as the Concentrator was designed only for ions ≤22 AMU, implications of analyzing elements as heavy as argon are discussed. Post-flight simulations of instrumental fractionation as a function of radial position on the targets incorporate solar-wind velocity and angular distributions measured in flight, and predict fractionation patterns for various elements and isotopes of interest. A tighter angular distribution, mostly due to better spacecraft spin stability than assumed in pre-flight modeling, results in a steeper isotopic fractionation gradient between the center and the perimeter of the targets. Using the distribution of solar-wind velocities encountered during flight, which are higher than those used in pre-flight modeling, results in elemental abundance patterns slightly less peaked at the center. Mean fractionations trend with atomic mass, with differences relative to the measured isotopes of neon of +4.1±0.9 ‰/amu for Li, between -0.4 and +2.8 ‰/amu for C, +1.9±0.7‰/amu for N, +1.3±0.4 ‰/amu for O, -7.5±0.4 ‰/amu for Mg, -8.9±0.6 ‰/amu for Si, and -22.0±0.7 ‰/amu for S (uncertainties reflect Monte Carlo statistics). The slopes of the

  20. First Results of the Genesis Solar Wind Ion and Electron Spectrometers

    NASA Astrophysics Data System (ADS)

    Wiens, R. C.; Barraclough, B. L.; Steinberg, J. T.; Dors, E.; Gosling, J. T.; Neugebauer, M.; Burnett, D. S.

    2001-12-01

    The NASA Genesis mission to collect and return samples of solar wind to Earth was launched August 8, 2001 on a trajectory to orbit the L1 point for 2.5 years. The spacecraft is a sun-pointed spinner equipped with ion and electron spectrometers which were turned on in late August and have been working successfully. An on-board algorithm processes the raw spectrometer data to identify the solar wind regime, classifying it as either interstream, coronal hole, or coronal mass ejection, and deploys the appropriate regime-specific solar wind collector, all in real time without ground intervention. The performance of this on-board regime selection is the subject of a separate talk. Raw data, moments, and regime selections are telemetered to the ground three times a week, giving relatively rapid access to the data. The Genesis ion monitor (GIM) consists of an electrostatic sector and 8 CEM detectors. Each spectrum consists of 40 azimuthal angles, 8 polar angles (0-24 deg from the average solar wind direction, centered 4.5 degrees west of the sun), and 40 energy steps, ranging up to 15 keV/q. The electron monitor (GEM) sensor head is an exact copy of those on ACE and Ulysses. The sensor has 7 polar angles covering +/-75 degrees from the plane normal to the average solar wind direction, with 24 azimuthal bins. Energies currently covered are 20 to 960 eV, but can be configured for either higher or lower energies. Full energy/angle spectra from both instruments are produced every ~2.5 minutes. The Genesis spacecraft L1 orbit insertion is scheduled for early November. Its L1 halo orbit has a radius of ~1 million km, significantly larger than the ~0.3 and ~0.7 x 0.2 million km orbits of ACE and SOHO, respectively, presenting opportunities for time-resolved cluster observations of solar wind flow properties. We will present highlights of our observations since turn-on.

  1. Status of Reconstruction of Fragmented Diamond-on-Silicon Collector From Genesis Spacecraft Solar Wind Concentrator

    NASA Technical Reports Server (NTRS)

    Rodriquez, Melissa C.; Calaway, M. C.; McNamara, K. M.; Hittle, J. D.

    2009-01-01

    In addition to passive solar wind collector surfaces, the Genesis Discovery Mission science canister had on board an electrostatic concave mirror for concentrating the solar wind ions, known as the concentrator . The 30-mm-radius collector focal point (the target) was comprised of 4 quadrants: two of single crystal SiC, one of polycrystalline 13C diamond and one of diamond-like-carbon (DLC) on a silicon substrate. [DLC-on-silicon is also sometimes referenced as Diamond-on-silicon, DOS.] Three of target quadrants survived the hard landing intact, but the DLC-on-silicon quadrant fractured into numerous pieces (Fig. 1). This abstract reports the status of identifying the DLC target fragments and reconstructing their original orientation.

  2. Plan for Subdividing Genesis Mission Diamond-on-Silicon 60000 Solar Wind Collector

    NASA Technical Reports Server (NTRS)

    Burkett, Patti J.; Allton, J. A.; Clemett, S. J.; Gonzales, C. P.; Lauer, H. V., Jr.; Nakamura-Messenger, K.; Rodriquez, M. C.; See, T. H.; Sutter, B.

    2013-01-01

    NASA's Genesis solar wind sample return mission experienced an off nominal landing resulting in broken, albeit useful collectors. Sample 60000 from the collector is comprised of diamond-like-carbon film on a float zone (FZ) silicon wafer substrate Diamond-on-Silicon (DOS), and is highly prized for its higher concentration of solar wind (SW) atoms. A team of scientist at the Johnson Space Center was charged with determining the best, nondestructive and noncontaminating method to subdivide the specimen that would result in a 1 sq. cm subsample for allocation and analysis. Previous work included imaging of the SW side of 60000, identifying the crystallographic orientation of adjacent fragments, and devising an initial cutting plan.

  3. Impurity characterization of solar wind collectors for the genesis discovery mission by resonance ionization mass spectrometry.

    SciTech Connect

    Calaway, W. F.

    1999-02-01

    NASA's Genesis Discovery Mission is designed to collect solar matter and return it to earth for analysis. The mission consists of launching a spacecraft that carries high purity collector materials, inserting the spacecraft into a halo orbit about the L1 sun-earth libration point, exposing the collectors to the solar wind for two years, and then returning the collectors to earth. The collectors will then be made available for analysis by various methods to determine the elemental and isotopic abundance of the solar wind. In preparation for this mission, potential collector materials are being characterized to determine baseline impurity levels and to assess detection limits for various analysis techniques. As part of the effort, potential solar wind collector materials have been analyzed using resonance ionization mass spectrometry (RIMS). RIMS is a particularly sensitivity variation of secondary neutral mass spectrometry that employs resonantly enhanced multiphoton ionization (REMPI) to selectively postionize an element of interest, and thus discriminates between low levels of that element and the bulk material. The high sensitivity and selectivity of RIMS allow detection of very low concentrations while consuming only small amounts of sample. Thus, RIMS is well suited for detection of many heavy elements in the solar wind, since metals heavier than Fe are expected to range in concentrations from 1 ppm to 0.2 ppt. In addition, RIMS will be able to determine concentration profiles as a function of depth for these implanted solar wind elements effectively separating them from terrestrial contaminants. RIMS analyses to determine Ti concentrations in Si and Ge samples have been measured. Results indicate that the detection limit for RIMS analysis of Ti is below 100 ppt for 10{sup 6} averages. Background analyses of the mass spectra indicate that detection limits for heavier elements will be similar. Furthermore, detection limits near 1 ppt are possible with higher

  4. Extraction of Solar Wind Nitrogen and Noble Gases From the Genesis Gold Foil Collector

    NASA Astrophysics Data System (ADS)

    Schlutter, D. J.; Pepin, R. O.

    2005-12-01

    The Genesis gold foil is a bulk solar wind collector, integrating fluences from all three of the wind regimes. Pyrolytic extraction of small foil samples at Minnesota yielded He fluences, corrected for backscatter, in good agreement with measurements by on-board spacecraft instruments, and He/Ne elemental ratios close to those implanted in collector foils deployed on the lunar surface during the Apollo missions. Isotopic distributions of He, Ne and Ar are under study. Pyrolysis to temperatures above the gold melting point generates nitrogen blanks large enough to obscure the solar-wind nitrogen component. An alternative technique for nitrogen and noble gas extraction, by room-temperature amalgamation of the gold foil surface, will be discussed. Ne and Ar releases in preliminary tests of this technique on small foil samples were close to 100% of the amounts expected from the high-temperature pyrolysis yields, indicating that amalgamation quantitatively liberates gases from several hundred angstroms deep in the gold, beyond the implantation depth of most of the solar wind. Present work is focused on two problems currently interfering with accurate nitrogen measurements at the required picogram to sub-picogram levels: a higher than expected blank likely due to tiny air bubbles rolled into the gold sheet during fabrication, and the presence of a refractory hydrocarbon film on Genesis collector surfaces (the "brown stain") that, if left in place on the foil, shields the underlying gold from mercury attack. We have found, however, that the film is efficiently removed within tens of seconds by oxygen plasma ashing. Potential nitrogen contaminants introduced during the crash of the sample return canister are inert in amalgamation, and so are not hazards to the measurements.

  5. Analysis of Solar Wind Samples Returned by Genesis Using Laser Post Ionization Secondary Neutral Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Veryovkin, I. V.; Calaway, W. F.; Tripa, C. E.; Pellin, M. J.; Burnett, D. S.

    2005-12-01

    A new secondary neutral mass spectrometry (SNMS) instrument implementing laser post ionization (LPI) of ion sputtered and laser desorbed neutral species has been developed and constructed for the specific purpose of quantitative analysis of metallic elements at ultra trace levels in solar wind collector samples returned to Earth by the Genesis Discovery mission. The first LPI SNMS measurements are focusing on determining Al, Ca, Cr, and Mg in these samples. These measurements provide the first concentration and isotopic abundances determinations for several key metallic elements and also elucidate possible fractionation effects between the photosphere and the solar wind compositions. It is now documented that Genesis samples suffered surface contamination both during flight and during the breach of the Sample Return Capsule when it crashed. Since accurate quantitative analysis is compromised by sample contamination, several features have been built into the new LPI SNMS instrument to mitigate this difficulty. A normally-incident, low-energy (<500 eV) ion beam combined with a keV energy ion beam and a desorbing laser beam (both microfocused) enables dual beam analyses. The low-energy ion beam can be used to remove surface contaminant by sputtering with minimum ion beam mixing. This low-energy beam also will be used to perform ion beam milling, while either the microfocused ion or laser beam probes the solar wind elemental compositions as a function of sample depth. Because of the high depth resolution of dual beam analyses, such depth profiles clearly distinguish between surface contaminants and solar wind implanted atoms. In addition, in-situ optical and electron beam imaging for observing and avoiding particulates and scratches on solar wind sample surfaces is incorporated in the new LPI SNMS instrument to further reduce quantification problems. The current status of instrument tests and analyses will be presented. This work is supported by the U. S. Department of

  6. The GENESIS Solar-Wind Sample: Summary of In-Situ Spacecraft Measurements During the Sample Collection Period

    NASA Astrophysics Data System (ADS)

    Reisenfeld, D. B.; Steinberg, J. T.; Wiens, R. C.; Barraclough, B. L.; Zurbuchen, T. H.; Burnett, D. S.

    2004-12-01

    The GENESIS mission returned samples of solar wind to earth on September 8. These samples were collected between 30-Nov-2001 and 01-Apr-2004 at the L1 point on ultrapure substrates that are being analyzed using various laboratory techniques. The primary purpose of the GENESIS mission is to determine to unprecedented accuracy (e.g., ±1%-0.1%, 2σ ) the isotopic composition of the solar wind, and by extension, of the Sun, particularly for oxygen, nitrogen, carbon, and the noble gases. In addition to a continuously-collected sample, separate samples of the different regimes-coronal hole (CH), interstream (IS), and coronal mass ejection (CME)-were collected to help deconvolve any fine-scale isotopic fractionation associated with solar-wind ionization and acceleration. The four different samples (3 regimes plus one cumulative sample) are long-term averages over varying solar-wind conditions, and need to be understood within the context of other measurements besides those that can be made on the substrates themselves. These include charge state, v, T, density, and magnetic field data. Additionally, comparisons of in-situ elemental composition measurements with the measurements made on GENESIS samples will be useful in validating the different measurement techniques. For these reasons, we are compiling a database of conditions as measured by in-situ spacecraft instruments stationed at L1 over the time period of the GENESIS sample collection. Comparison with ACE/SWICS elemental and charge-state abundances confirmed early in the GENESIS mission that the GENESIS regime-selection algorithm was successfully isolating the CME material, protecting the CH and IS samples from CME contamination. The data also demonstrate the discrimination between IS and CH flow types based mostly on solar-wind speed, but allowing compensation for evolution effects due to the transit to 1 AU.

  7. Cleaning Genesis Solar Wind Collectors with Ultrapure Water: Residual Contaminant Particle Analysis

    NASA Technical Reports Server (NTRS)

    Allton, J. H.; Wentworth, S. J.; Rodriquez, M. C.; Calaway, M. J.

    2008-01-01

    Additional experience has been gained in removing contaminant particles from the surface of Genesis solar wind collectors fragments by using megasonically activated ultrapure water (UPW)[1]. The curatorial facility has cleaned six of the eight array collector material types to date: silicon (Si), sapphire (SAP), silicon-on-sapphire (SOS), diamond-like carbon-on-silicon (DOS), gold-on-sapphire (AuOS), and germanium (Ge). Here we make estimates of cleaning effectiveness using image analysis of particle size distributions and an SEM/EDS reconnaissance of particle chemistry on the surface of UPW-cleaned silicon fragments (Fig. 1). Other particle removal techniques are reported by [2] and initial assessment of molecular film removal is reported by [3].

  8. Genesis Solar Wind Collector Cleaning Assessment: Update on 60336 Sample Case Study

    NASA Technical Reports Server (NTRS)

    Goreva, Y. S.; Allums, K. K.; Gonzalez, C. P.; Jurewicz, A. J.; Burnett, D. S.; Allton, J. H.; Kuhlman, K. R.; Woolum, D.

    2015-01-01

    To maximize the scientific return of Genesis Solar Wind return mission it is necessary to characterize and remove a crash-derived particle and thin film surface contamination. A small subset of Genesis mission collector fragments are being subjected to extensive study via various techniques. Here we present an update on the sample 60336, a Czochralski silicon (Si-CZ) based wafer from the bulk array (B/C). This sample has undergone multiple cleaning steps (see the table below): UPW spin wash, aggressive chemical cleanings (including aqua regia, hot xylene and RCA1), as well as optical and chemical (EDS, ToF-SIMS) imaging. Contamination appeared on the surface of 60336 after the initial 2007 UPW cleaning. Aqua regia and hot xylene treatment (8/13/2013) did little to remove contaminants. The sample was UPW cleaned for the third time and imaged (9/16/13). The UPW removed the dark stains that were visible on the sample. However, some features, like "the Flounder" (a large, 100 micron feature in Fig. 1b) appeared largely intact, resisting all previous cleaning efforts. These features were likely from mobilized adhesive, derived from the Post-It notes used to stabilize samples for transport from Utah after the hard landing. To remove this contamination, an RCA step 1 organic cleaning (RCA1) was employed. Although we are still uncertain on the nature of the Flounder and why it is resistant to UPW and aqua regia/hot xylene treatment, we have found RCA1 to be suitable for its removal. It is likely that the glue from sticky pads used during collector recovery may have been a source for resistant organic contamination [9]; however [8] shows that UPW reaction with crash-derived organic contamination does not make particle removal more difficult.

  9. First Results on Kr and Xe Abundances in the Bulk Solar Wind Measured in Silicon Targets exposed on GENESIS

    NASA Astrophysics Data System (ADS)

    Heber, V. S.; Baur, H.; Wieler, R.; Vogel, N.; Wiens, R. C.; Burnett, D. S.

    2008-12-01

    The solar wind (SW) Kr and Xe elemental and isotopic composition is one of the primary objectives of the GENESIS mission. Solar Kr and Xe abundances cannot be analyzed insitu in the present-day SW due to their low abundances nor can they be measured in the solar photosphere due to the lack of suitable spectral lines. Thus, solar data have been exclusively derived from SW-irradiated regolith samples. Here we present first results on bulk SW Kr and Xe abundances, as well as selected isotope ratios, from captured SW returned by GENESIS. Five aliquot analyses were done by UV laser ablation from Si targets (rastered areas are between 10 and 50mm2). Measured SW fluences (atoms/cm2) are 2.97(4)E+10 36Ar, 1.22(6)E+7 84Kr and 1.4(2)E+6 132Xe. The measured 86Kr/84Kr of 0.3035(36) is in good agreement with SW- Kr obtained from lunar regoliths. The same is true for 129Xe/132Xe of 1.043(25). Our preliminary Kr and Xe elemental abundances are in fair agreement with earlier values derived from lunar soils, although the Genesis SW 36Ar/84Kr of 2390(150) is 30% larger than the lunar value, presumed to be representative for the solar wind in the last 100 Ma. The GENESIS 84Kr/132Xe of 8.2(1.5) is within 10% of the value derived from relatively recently irradiated lunar soils. The understanding of fractionation processes in the SW is important to finally deduce solar abundances for noble gases (and other elements) from SW data. Former investigations showed that Kr and Xe are enriched in the SW relative to Ar and solar abundances. This fractionation process operates upon ionization of SW particles and affects mainly the elemental composition of the SW. However, adopting the recently strongly reduced solar Ne and Ar abundances at constant Kr and Xe would now question this fractionation model for Kr and Xe. We reassess models of fractionation processes in the light of the modified solar abundances and also compare the GENESIS Ar, Kr and Xe data with current estimates of solar abundances.

  10. VARIATIONS IN SOLAR WIND FRACTIONATION AS SEEN BY ACE/SWICS AND THE IMPLICATIONS FOR GENESIS MISSION RESULTS

    SciTech Connect

    Pilleri, P.; Wiens, R. C.; Reisenfeld, D. B.; Zurbuchen, T. H.; Lepri, S. T.; Shearer, P.; Gilbert, J. A.; Steiger, R. von

    2015-10-10

    We use Advanced Composition Explorer (ACE)/Solar Wind Ion Composition Spectrometer (SWICS) elemental composition data to compare the variations in solar wind (SW) fractionation as measured by SWICS during the last solar maximum (1999–2001), the solar minimum (2006–2009), and the period in which the Genesis spacecraft was collecting SW (late 2001—early 2004). We differentiate our analysis in terms of SW regimes (i.e., originating from interstream or coronal hole flows, or coronal mass ejecta). Abundances are normalized to the low-first ionization potential (low-FIP) ion magnesium to uncover correlations that are not apparent when normalizing to high-FIP ions. We find that relative to magnesium, the other low-FIP elements are measurably fractionated, but the degree of fractionation does not vary significantly over the solar cycle. For the high-FIP ions, variation in fractionation over the solar cycle is significant: greatest for Ne/Mg and C/Mg, less so for O/Mg, and the least for He/Mg. When abundance ratios are examined as a function of SW speed, we find a strong correlation, with the remarkable observation that the degree of fractionation follows a mass-dependent trend. We discuss the implications for correcting the Genesis sample return results to photospheric abundances.

  11. Discrimination and quantification of contamination and implanted solar wind in Genesis collector shards using grazing incidence synchrotron x-ray techniqies: Initial results

    SciTech Connect

    Kitts, K.; Sutton, S.; Eng, P.; Ghose, S.; Burnett, D.

    2006-12-13

    Grazing incidence X-ray fluorescence is a non-destructive technique that can differentiate the embedded solar wind component from surface contamination and collector background in the Genesis shards. Initial solar Fe abundance in D30554 is 8 x 10{sup 12}/cm{sup 2}. Accurate knowledge of the composition of the Sun provides a baseline, which allows an understanding of how the solar system has evolved over time and how solar processes and solar wind mechanics behave. Unfortunately, the errors in photospheric abundances are too large for many planetary science problems and this hampers our understanding of these different processes. Analyses of solar wind implanted in meteorites or lunar soils have provided more precise data but alteration processes on these bodies may complicate such information. In response to this need for pristine solar wind samples, NASA developed and launched the Genesis Probe. Unfortunately, the probe smashed into the Utah desert shattering the 300 collector plates into 15,000+ pieces all of which are now coated in a both a fine terrestrial dust and Si and Ge powder from the disrupted collectors themselves. The solar wind penetration depth is 100-200 nm and the superposed contamination layers are typically 40-50 nm. Stringent cleaning regimes have the potential of removing the solar wind itself. The best solution is to have sufficient spatial resolution to separately analyze the surface contamination and penetrated solar wind. To that end, three Genesis collector array shards and their appropriate flight spares were characterized via grazing incidence x-ray fluorescence and x-ray reflectivity. The goals were (1) to evaluate the various cleaning methods used to eliminate contamination, (2) to identify the collector substrates most suited for this technique, (3) to determine whether the solar wind signature could be deconvolved from the collector background signature, and (4) to measure the relative abundances of Ca to Ge in the embedded solar

  12. Solar composition from the Genesis Discovery Mission

    PubMed Central

    Burnett, D. S.; Team, Genesis Science

    2011-01-01

    Science results from the Genesis Mission illustrate the major advantages of sample return missions. (i) Important results not otherwise obtainable except by analysis in terrestrial laboratories: the isotopic compositions of O, N, and noble gases differ in the Sun from other inner solar system objects. The N isotopic composition is the same as that of Jupiter. Genesis has resolved discrepancies in the noble gas data from solar wind implanted in lunar soils. (ii) The most advanced analytical instruments have been applied to Genesis samples, including some developed specifically for the mission. (iii) The N isotope result has been replicated with four different instruments. PMID:21555545

  13. Helium, neon, and argon composition of the solar wind as recorded in gold and other Genesis collector materials

    NASA Astrophysics Data System (ADS)

    Pepin, Robert O.; Schlutter, Dennis J.; Becker, Richard H.; Reisenfeld, Daniel B.

    2012-07-01

    We report compositions and fluxes of light noble gases in the solar wind (SW), extracted by stepped pyrolysis and amalgamation from gold collector materials carried on the Genesis Solar Wind Sample Return Mission. Results are compared with data from other laboratories on SW-He, Ne and Ar distributions implanted in Genesis aluminum, carbon, and silicon collectors and extracted by laser ablation. Corrections for mass-dependent losses (“backscatter”) of impinging SW ions due to scattering from the collector material are substantially larger for gold than for these lower atomic weight targets. We assess such losses by SRIM simulation calculations of SW backscatter from gold which are applied to the measurements to recover the composition of the incident SW. Averaged results of integrated stepped pyrolysis and single-step amalgamation measurements, with 1σ errors, are as follows: for SW-Ne and Ar isotope ratios (3He/4He was not measured), 20Ne/22Ne = 14.001 ± 0.042, 21Ne/22Ne = 0.03361 ± 0.00018, 36Ar/38Ar = 5.501 ± 0.014; for SW element ratios, 4He/20Ne = 641 ± 15, 20Ne/36Ar = 51.6 ± 0.5; and for SW fluxes in atoms cm-2 s-1 at the Genesis L1 station, 4He = 1.14 ± 0.04 × 107, 20Ne = 1.80 ± 0.06 × 104, 36Ar = 3.58 ± 0.11 × 102. Except for the 21Ne/22Ne and 20Ne/36Ar ratios, these values are in reasonable accord (within ∼1-3σ) with measurements on different collector materials reported by one or both of two other Genesis noble gas research groups. We further find, in three stepped pyrolysis experiments on gold foil, that He, Ne and Ar are released at increasing temperatures without elemental fractionation, in contrast to a pyrolytic extraction of a single non-gold collector (Al) where the release patterns point to mass-dependent thermal diffusion. The pyrolyzed gold foils exhibit enhancements, relative to sample totals, in 20Ne/22Ne and 21Ne/22Ne ratios evolved at low temperatures. The absence of elemental fractionation in pyrolytic release from gold

  14. Using Image Pro Plus Software to Develop Particle Mapping on Genesis Solar Wind Collector Surfaces

    NASA Astrophysics Data System (ADS)

    Rodriguez, M. C.; Allton, J. H.; Burkett, P. J.

    2012-03-01

    The Genesis curatorial facility at JSC provides optical analysis of collector array surfaces as cleaning steps progress in an updated master cleaning plan coordinated by the Genesis mission PI Don Burnett.

  15. Nitrogen isotopes in the recent solar wind from the analysis of genesis targets: evidence for large scale isotope heterogeneity in the nascent solar system

    SciTech Connect

    Wiens, Roger C; Marty, Bernard; Zimmermann, Laurent; Burnard, Peter G; Burnett, Donald L; Heber, Veronika S; Wieler, Rainer; Bochsler, Peter

    2009-01-01

    Nitrogen, the fifth most abundant element in the universe, displays the largest stable isotope variations in the solar system reservoirs after hydrogen. Yet the value of isotopic composition of solar nitrogen, presumably the best proxy of the protosolar nebula composition, is not known. Nitrogen isotopes trapped in Genesis spacecraft target material indicate a 40 % depletion of {sup 15}N in solar wind N relative to inner planets and meteorites, and define a composition for the present-day Sun undistinguishable from that of Jupiter's atmosphere. These results indicate that the isotopic composition of of nitrogen in the outer convective zone of the Sun (OCZ) has not changed through time, and is representative of the protosolar nebula. Large {sup 15}N enrichments during e.g., irradiation, or contributions from {sup 15}N-rich presolar components, are required to account for planetary values.

  16. Enhanced Cleaning of Genesis Solar Wind Sample 61348 for Film Residue Removal

    NASA Technical Reports Server (NTRS)

    Allums, K. K.; Gonzalez, C. P.; Kuhlman, K. R.; Allton, J. H.

    2015-01-01

    The Genesis mission returned to Earth on September 8, 2004, experiencing a nonnominal reentry. During the recovery of the collector materials from the capsule, many of the collector fragments were placed on the adhesive protion of post-it notes to prevent the fragments from moving during transport back to Johnson Space Center. This unknowingly provided an additional contaminate that would prove difficult to remove with the limited chemistries allowed in the Genesis Curation Laboratory. Generally when collector material samples are prepared for allocation to PIs, the samples are cleaned front side only with Ultra-Pure Water (UPW) via megasonic dispersion to the collector surface to remove crash debris and contamination. While this cleaning method works well on samples that were not placed on post-its during recovery, it has caused movement of the residue on the back of the sample to be deposited on the front in at least two examples. Therefore, samples placed on the adhesive portion on post-it note, require enhanced cleaning methods since post-it residue has proved resistant to UPW cleaning.

  17. Similarities and differences between the solar wind light noble gas compositions determined on Apollo 15 SWC foils and on NASA Genesis targets

    NASA Astrophysics Data System (ADS)

    Vogel, N.; Bochsler, P.; Bühler, F.; Heber, V. S.; Grimberg, A.; Baur, H.; Horstmann, M.; Bischoff, A.; Wieler, R.

    2015-10-01

    We compare the solar wind (SW) He, Ne, and Ar compositions collected during the Apollo Solar Wind Composition (SWC) experiments (1969-1972; Al- & Pt-foils) and the Genesis mission (2002-2004; so-called DOS targets considered here). While published SW 20Ne/22Ne and 36Ar/38Ar ratios of both data sets agree, differences exist in the 4He/3He, 4He/20Ne, and 20Ne/36Ar ratios. However, 20Ne/36Ar ratios from Apollo-16 Pt-foils, exclusively adopted as SW values by the SWC team, are consistent with the Genesis results. We investigate if the differences indicate a variability of the SW over the course of about 30 yr, or systematic biases of the two data sets, which were collected in different environments and measured several decades apart in different laboratories (University of Bern; ETH Zurich). New measurements of Apollo-15 SWC aluminum foils in Zurich generally agree with the original measurements performed in Bern. Zurich samples show slightly lower 4He concentrations suggesting a few percent of diffusive loss of 4He during storage of the foils. A 3% difference between the He isotopic ratios measured in Bern and in Zurich possibly represents an analytical bias between the laboratories. The low SW 4He/20Ne and 20Ne/36Ar ratios in Apollo-15 Al-foils compared to Genesis data are consistent with a mixture of Genesis-like SW and noble gases from small amounts of lunar dust. Our data suggest that the mean SW He, Ne, and Ar isotopic and elemental compositions have not significantly changed between the overall Apollo and Genesis mission collection periods.

  18. Solar Wind He and Ne - Implications of Surface Studies and Preliminary Data from Bulk Metallic Glass Flown on GENESIS

    NASA Astrophysics Data System (ADS)

    Grimberg, A.; Heber, V. S.; Homan, O. J.; Hays, C. C.; Jurewicz, A. J.; Burnett, D. S.; Baur, H.; Wieler, R.

    2005-12-01

    The Bulk Metallic Glass (BMG) flown on GENESIS is one of only a few target materials that survived the impact landing without major damage. Some scratches have led to localized noble gas loss but most particles do not harm He and Ne analyses due to their low gas content. To date, He and Ne isotopes from bulk solar wind in the BMG have been measured but precision will be improved. Preliminary data from pyrolysis extraction confirm previous values measured in SWC foils exposed on the lunar surface. However, the 4He/3He ratio of 2430 ±120 and the 20Ne/22Ne of 13.75 ±0.1 are slightly heavier than the SWC average. First measurements done with UV-laser ablation show higher 3He contents and an even heavier 20Ne/22Ne ratio of 14.04 ±0.1. Ne ratios are corrected for backscatter losses with a factor of 1.015 as calculated by TRIM whereas He correction factors are still not verified yet. The search for the He and Ne composition of Solar Energetic Particles (SEP) with stepwise etching has not been yet successful due to a molecular contamination (brown stain). This film was deposited on the BMG surface in space and is resistant to HNO3, the most suitable acid for homogeneous BMG etching. Extensive X-ray photoelectron spectroscopy (XPS) analyses have been carried out on 90 spots covering the entire surface to determine composition and distribution of this brown stain. These data show that the brown stain is an ubiquitous organic layer mainly consisting of Si, C, O and minor F. Since the BMG element Zr is always visible in the XPS spectra, contamination at the measured spots is very unlikely to be thicker than 10 nm. Ultrasonic cleaning of the surface with common solvents removed about 50 % of the particles but did not affect the brown stain. Moreover it led to an apparent gas loss of ~30 % for He. Cleaning with oxygen plasma lowered the carbon-signal in the XPS spectra, however it did not remove the brown stain either. A combination of oxygen plasma ashing followed by plasma

  19. Discrimination and quantification of Fe and Ni abundances in Genesis solar wind implanted collectors using X-ray standing wave fluorescence yield depth profiling with internal referencing

    DOE PAGES

    Choi, Y.; Eng, P.; Stubbs, J.; ...

    2016-08-21

    In this paper, X-ray standing wave fluorescence yield depth profiling was used to determine the solar wind implanted Fe and Ni fluences in a silicon-on-sapphire (SoS) Genesis collector (60326). An internal reference standardization method was developed based on fluorescence from Si and Al in the collector materials. Measured Fe fluence agreed well with that measured previously by us on a sapphire collector (50722) as well as SIMS results by Jurewicz et al. Measured Ni fluence was higher than expected by a factor of two; neither instrumental errors nor solar wind fractionation effects are considered significant perturbations to this value. Impuritymore » Ni within the epitaxial Si layer, if present, could explain the high Ni fluences and therefore needs further investigation. As they stand, these results are consistent with minor temporally-variable Fe and Ni fractionation on the timescale of a year.« less

  20. Discrimination and quantification of Fe and Ni abundances in Genesis solar wind implanted collectors using X-ray standing wave fluorescence yield depth profiling with internal referencing

    SciTech Connect

    Choi, Y.; Eng, P.; Stubbs, J.; Sutton, S. R.; Schmeling, M.; Veryovkin, I. V.; Burnett, D.

    2016-08-21

    In this paper, X-ray standing wave fluorescence yield depth profiling was used to determine the solar wind implanted Fe and Ni fluences in a silicon-on-sapphire (SoS) Genesis collector (60326). An internal reference standardization method was developed based on fluorescence from Si and Al in the collector materials. Measured Fe fluence agreed well with that measured previously by us on a sapphire collector (50722) as well as SIMS results by Jurewicz et al. Measured Ni fluence was higher than expected by a factor of two; neither instrumental errors nor solar wind fractionation effects are considered significant perturbations to this value. Impurity Ni within the epitaxial Si layer, if present, could explain the high Ni fluences and therefore needs further investigation. As they stand, these results are consistent with minor temporally-variable Fe and Ni fractionation on the timescale of a year.

  1. Discrimination and quantification of Fe and Ni abundances in Genesis solar wind implanted collectors using X-ray standing wave fluorescence yield depth profiling with internal referencing

    SciTech Connect

    Choi, Y.; Eng, P.; Stubbs, J.; Sutton, S. R.; Schmeling, M.; Veryovkin, I. V.; Burnett, D.

    2016-08-21

    In this paper, X-ray standing wave fluorescence yield depth profiling was used to determine the solar wind implanted Fe and Ni fluences in a silicon-on-sapphire (SoS) Genesis collector (60326). An internal reference standardization method was developed based on fluorescence from Si and Al in the collector materials. Measured Fe fluence agreed well with that measured previously by us on a sapphire collector (50722) as well as SIMS results by Jurewicz et al. Measured Ni fluence was higher than expected by a factor of two; neither instrumental errors nor solar wind fractionation effects are considered significant perturbations to this value. Impurity Ni within the epitaxial Si layer, if present, could explain the high Ni fluences and therefore needs further investigation. As they stand, these results are consistent with minor temporally-variable Fe and Ni fractionation on the timescale of a year.

  2. 78 FR 76609 - Genesis Solar, LLC; NRG Delta LLC; Mountain View Solar, LLC; Pheasant Run Wind, LLC; Pheasant Run...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-18

    ...; Mountain Wind Power II, LLC; Summerhaven Wind, LP; Notice of Effectiveness of Exempt Wholesale Generator or...-captioned entities as Exempt Wholesale Generators or Foreign Utility Companies became effective by operation...

  3. 76 FR 54454 - Issuance of Loan Guarantee to Genesis Solar, LLC, for the Genesis Solar Energy Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-01

    ... Issuance of Loan Guarantee to Genesis Solar, LLC, for the Genesis Solar Energy Project AGENCY: U.S... Genesis Solar, LLC, for construction and startup of the Genesis Solar Energy Project (GSEP), a 250... Statement for the Genesis Solar Energy Project, Riverside County, California (75 Federal Register 52736...

  4. Development of Genesis Solar Wind Sample Cleanliness Assessment: Initial Report on Sample 60341 Optical Imagery and Elemental Mapping

    NASA Technical Reports Server (NTRS)

    Gonzalez, C. P.; Goreva, Y. S.; Burnett, D. S.; Woolum, D.; Jurewicz, A. J.; Allton, J. H.; Rodriguez, P. J.; Burkett, P. J.

    2014-01-01

    Since 2005 the Genesis science team has experimented with techniques for removing the contaminant particles and films from the collection surface of the Genesis fragments. A subset of 40 samples have been designated as "cleaning matrix" samples. These are small samples to which various cleaning approaches are applied and then cleanliness is assessed optically, by TRXRF, SEM, ToF-SIMS, XPS, ellipsometry or other means [1-9]. Most of these sam-ples remain available for allocation, with cleanliness assessment data. This assessment allows evaluation of various cleaning techniques and handling or analytical effects. Cleaning techniques investigated by the Genesis community include acid/base etching, acetate replica peels, ion beam, and CO2 snow jet cleaning [10-16]. JSC provides surface cleaning using UV ozone exposure and ultra-pure water (UPW) [17-20]. The UPW rinse is commonly used to clean samples for handling debris between processing by different researchers. Optical microscopic images of the sample taken before and after UPW cleaning show what has been added or removed during the cleaning process.

  5. ToF-SIMS Investigation of the Effectiveness of Acid-Cleaning procedures for Genesis Solar Wind Collectors

    NASA Technical Reports Server (NTRS)

    Goreva, Y. S.; Humanyun, M.; Burnett, D. S.; Jurewicz, A. J.; Gonzalez, C. P.

    2014-01-01

    ToF-SIMS images of Genesis sample surfaces contain an incredible amount of important information, but they also show that the crash-derived surface contamination has many components, presenting a challenge to cleaning. Within the variability, we have shown that there are some samples which appear to be clean to begin with, e.g. 60471, and some are more contaminated. Samples 60493 and 60500 are a part of a focused study of the effectiveness of aqua regia and/or sulfuric acid cleaning of small flight Si implanted with Li-6 using ToF-SIMS.

  6. Genesis Solar Wind Sample 61422: Experiment in Variation of Sequence of Cleaning Solvent for Removing Carbon-Bearing Contamination

    NASA Technical Reports Server (NTRS)

    Allton, J. H.; Kuhlman, K. R.; Allums, K. K.; Gonzalez, C. P.; Jurewicz, A. J. G.; Burnett, D. S.; Woolum, D. S.

    2015-01-01

    The recovered Genesis collector fragments are heavily contaminated with crash-derived particulate debris. However, megasonic treatment with ultra-pure-water (UPW; resistivity (is) greater than18 meg-ohm-cm) removes essentially all particulate contamination greater than 5 microns in size [e.g.1] and is thus of considerable importance. Optical imaging of Si sample 60336 revealed the presence of a large C-rich particle after UPW treatment that was not present prior to UPW. Such handling contamination is occasionally observed, but such contaminants are normally easily removed by UPW cleaning. The 60336 particle was exceptional in that, surprisingly, it was not removed by additional UPW or by hot xylene or by aqua regia treatment. It was eventually removed by treatment with NH3-H2O2. Our best interpretation of the origin of the 60336 particle was that it was adhesive from the Post-It notes used to stabilize samples for transport from Utah after the hard landing. It is possible that the insoluble nature of the 60336 particle comes from interaction of the Post-It adhesive with UPW. An occasional bit of Post-It adhesive is not a major concern, but C particulate contamination also occurs from the heat shield of the Sample Return Capsule (SRC) and this is mixed with inorganic contamination from the SRC and the Utah landing site. If UPW exposure also produced an insoluble residue from SRC C, this would be a major problem in chemical treatments to produce clean surfaces for analysis. This paper reports experiments to test whether particulate contamination was removed more easily if UPW treatment was not used.

  7. LOCKYER (Large Optimized Coronagraph for KeY Emission line Research): A SMEX Mission to Provide Crucial Measurements of the Genesis of the Solar Wind and CMEs

    NASA Astrophysics Data System (ADS)

    Ko, Y. K.; Vourlidas, A.; Korendyke, C.; Laming, J. M.

    2016-12-01

    The LOCKYER mission is designed to uncover the physical processes of acceleration and heating of the quiescent and transient solar wind. It builds on the success of the Ultraviolet Coronagraph Spectrometer (UVCS) on SOHO with a massive increase in effective area at Lyman-alpha (200x larger than UVCS), thanks to a modern optical design and the use of a 4m boom. The larger effective area enables spectral line observations from many ions, including He II (at 1640 Å), allowing us to access the region where the coronal plasma transitions from fluid to kinetic behavior. In addition, a visible light channel provides simultaneous high-resolution coronagraphic images for the global coronal structure and dynamics creating a greatly-expanded UVCS-LASCO `hybrid' instrument within the tight constraints of a SMEX mission. The LOCKYER mission aims to answer the following questions: 1) What are the physical processes responsible for the heating and acceleration of the primary (proton, electron, helium) and secondary (minor ion) plasma components of the fast and slow solar wind? 2) How are CMEs heated and accelerated? LOCKYER would greatly advance our knowledge of how and where the solar wind is formed, and how the variations in coronal microphysics impact the solar wind and heliosphere. The LOCKYER measurements are highly complementary to the Solar Probe Plus and Solar Orbiter measurements and provide detailed empirical descriptions of the coronal plasma at heights where the primary energy and momentum addition occur.

  8. Solar Wind Five

    NASA Technical Reports Server (NTRS)

    Neugebauer, M. (Editor)

    1983-01-01

    Topics of discussion were: solar corona, MHD waves and turbulence, acceleration of the solar wind, stellar coronae and winds, long term variations, energetic particles, plasma distribution functions and waves, spatial dependences, and minor ions.

  9. Solar Wind Magnetic Fields

    NASA Technical Reports Server (NTRS)

    Smith, E. J.

    1995-01-01

    The magnetic fields originate as coronal fields that are converted into space by the supersonic, infinitely conducting, solar wind. On average, the sun's rotation causes the field to wind up and form an Archimedes Spiral. However, the field direction changes almost continuously on a variety of scales and the irregular nature of these changes is often interpreted as evidence that the solar wind flow is turbulent.

  10. Solar Wind Magnetic Fields

    NASA Technical Reports Server (NTRS)

    Smith, E. J.

    1995-01-01

    The magnetic fields originate as coronal fields that are converted into space by the supersonic, infinitely conducting, solar wind. On average, the sun's rotation causes the field to wind up and form an Archimedes Spiral. However, the field direction changes almost continuously on a variety of scales and the irregular nature of these changes is often interpreted as evidence that the solar wind flow is turbulent.

  11. 75 FR 52966 - Notice of Availability of the Final Environmental Impact Statement for the Genesis Solar, LLC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-30

    ... Genesis Solar, LLC Genesis Solar Energy Project and Proposed California Desert Conservation Area Plan... Genesis Solar LLC's Genesis Solar Energy Project (GSEP) and by this notice is announcing its availability... amendment the CDCA Plan to make the area suitable for solar energy development; a reduced acreage...

  12. Flank solar wind interaction

    NASA Technical Reports Server (NTRS)

    Moses, Stewart L.; Greenstadt, Eugene W.; Coroniti, Ferdinand V.

    1994-01-01

    In this report we will summarize the results of the work performed under the 'Flank Solar Wind Interaction' investigation in support of NASA's Space Physics Guest Investigator Program. While this investigation was focused on the interaction of the Earth's magnetosphere with the solar wind as observed by instruments on the International Sun-Earth Explorer (ISEE) 3 spacecraft, it also represents the culmination of decades of research performed by scientists at TRW on the rich phenomenology of collisionless shocks in space.

  13. Basics of the Solar Wind

    NASA Astrophysics Data System (ADS)

    Meyer-Vernet, Nicole

    2012-09-01

    Preface; 1. The wind from the sun: an introduction; 2. Toolkit for space plasma physics; 3. Anatomy of the sun; 4. The outer solar atmosphere; 5. How does the solar wind blow?; 6. Structure and perturbations; 7. Bodies in the wind: dust, asteroids, planets and comets; 8. The solar wind in the universe; Index.

  14. The Solar Wind

    NASA Technical Reports Server (NTRS)

    Herring, J. R.; Licht, A. L.

    1960-01-01

    Parker's model of a spherically expanding corona, the "solar wind," is compared with D. E. Blackwell's observations of the 1954 minimum equatorial corona. A significant discrepancy is found between the predicted and the observed electron densities at distances from the sun greater than 20 solar radii. Blackwell's data are found to be consistent with a model in which the corona expands mostly within a disk less than 25 solar radii thick, lying within the sun's equatorial plane. The thickness of the disk as a function of distance from the sun is qualitatively explained in terms of magnetic pressure. The solar wind is found to have a considerable effect on the lunar atmosphere. First, the calculated density of the lunar atmosphere is greatly reduced by collisions with protons in the solar wind. If the flux of particles in this wind has the conventional values ranging between 10(exp 10) to 10(exp 11) per sq cm-sec, the calculations yield a lunar pressure of 10(exp -13) atmosphere of argon, in agreement with the value predicted by Elsmore and Whitfield on the basis of observations on the occultation of radio stars. Second, following a suggestion by Gold, it was found that the collisions of solar-wind protons with the lunar surface produce an atmosphere of cold neutral hydrogen with a density of 10(exp 5) per cu cm at the lunar surface. The density falls off at greater distances in accordance with the inverse-square law. Estimates indicate that the interaction of solar particles with the neutral hydrogen will produce an extended lunar ionosphere with a density of the order of 400 protons/cu cm in the vicinity of the moon.

  15. Flank solar wind interaction

    NASA Technical Reports Server (NTRS)

    Moses, Stewart L.; Greenstadt, Eugene W.

    1992-01-01

    This report summarizes the results of the first 12 months of our program to study the interaction of the Earth's magnetosphere with the solar wind on the far flanks of the bow shock. This study employs data from the ISEE-3 spacecraft during its traversals of the Earth's magnetotail and correlative data from spacecraft monitoring the solar wind upstream. Our main effort to date has involved assembling data sets and developing new plotting programs. Two talks were given at the Spring Meeting of the American Geophysical Union describing our initial results from analyzing data from the far flank foreshock and magnetosheath. The following sections summarize our results.

  16. Acceleration of the solar wind

    NASA Technical Reports Server (NTRS)

    Barnes, Aaron

    1992-01-01

    Different approaches to understanding the physics of solar wind acceleration are reviewed. Particular attention is given to fundamental reasons for a supersonic wind concept; the concept of thermal conduction as the primary energy transport mechanism in the solar wind; coronal holes as the source of wind and alternative acceleration mechanisms; and the state of closure of theory and observation.

  17. Genesis Radiation Environment

    NASA Technical Reports Server (NTRS)

    Minow, Joseph I.; Altstatt, Richard L.; Skipworth, William C.

    2007-01-01

    The Genesis spacecraft launched on 8 August 2001 sampled solar wind environments at L1 from 2001 to 2004. After the Science Capsule door was opened, numerous foils and samples were exposed to the various solar wind environments during periods including slow solar wind from the streamer belts, fast solar wind flows from coronal holes, and coronal mass ejections. The Survey and Examination of Eroded Returned Surfaces (SEERS) program led by NASA's Space Environments and Effects program had initiated access for the space materials community to the remaining Science Capsule hardware after the science samples had been removed for evaluation of materials exposure to the space environment. This presentation will describe the process used to generate a reference radiation Genesis Radiation Environment developed for the SEERS program for use by the materials science community in their analyses of the Genesis hardware.

  18. 75 FR 69458 - Notice of Availability of the Record of Decision for the Genesis Solar Energy Project and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-12

    ... Bureau of Land Management Notice of Availability of the Record of Decision for the Genesis Solar Energy... Genesis Solar Energy Project (GSEP). The GSEP is a concentrated solar electrical generating facility using...-mail: CAPSSolarNextEraFPL@blm.gov . SUPPLEMENTARY INFORMATION: Genesis Solar, LLC, a wholly owned...

  19. Composition of the Solar Wind

    NASA Technical Reports Server (NTRS)

    Suess, S. T.

    2007-01-01

    The solar wind reflects the composition of the Sun and physical processes in the corona. Analysis produces information on how the solar system was formed and on physical processes in the corona. The analysis can also produce information on the local interstellar medium, galactic evolution, comets in the solar wind, dust in the heliosphere, and matter escaping from planets.

  20. Personal overview of solar wind 6

    SciTech Connect

    Gosling, J.T.

    1987-01-01

    The author reviews papers presented at the Solar Wind 6 Proceedings. The particular topics discussed are solar wind acceleration theory, heliosphere production of solar winds, coronal mass ejections, interplanetary shock disturbance, and solar wind ionic composition. A concern for the steady decline in solar wind observations is expressed. (LSP)

  1. Corona and solar wind

    NASA Technical Reports Server (NTRS)

    Withbroe, G. L.

    1986-01-01

    The Pinhole/Occulter Facility is a powerful tool for studying the physics of the extended corona and origins of the solar wind. Spectroscopic data acquired by the P/OF coronal instruments can greatly expand empirical information about temperatures, densities, flow velocities, magnetic fields, and chemical abundances in the corona out to r or approx. 10 solar radii. Such information is needed to provide tight empirical constraints on critical physical processes involved in the transport and dissipation of energy and momentum, the heating and acceleration of plasma, and the acceleration of energetic particles. Because of its high sensitivity, high spatial and temporal resolutions, and powerful capabilities for plasma diagnostics, P/OF can significantly increase our empirical knowledge about coronal streamers and transients and thereby advance the understanding of the physics of these phenomena. P/OF observations can be used to establish the role in solar wind generation, if any, of small-scale dynamical phenomena, such as spicules, macrospicules and coronal bullets, and the role of the fine-scale structures, such as polar plumes. Finally, simultaneous measurements by the P/OF coronal and hard X-ray instruments can provide critical empirical information concerning nonthermal energy releases and acceleration of energetic particles in the corona.

  2. Venus: Interaction with Solar Wind

    NASA Astrophysics Data System (ADS)

    Russell, C.; Luhmann, J.; Murdin, P.

    2002-07-01

    The solar wind interaction with VENUS provides the archetypal interaction of a flowing magnetized PLASMA with a PLANETARY IONOSPHERE. Mars interacts with the solar wind in much the same way as does Venus, while the rotating plasma in the Saturnian magnetosphere is believed to interact similarly with its moon, Titan (see SATURN: MAGNETOSPHERE INTERACTION WITH TITAN). The interaction of the Jovian ...

  3. Solar wind photoplate study

    NASA Technical Reports Server (NTRS)

    Scott, B. W.; Voorhies, H. G.

    1972-01-01

    An ion sensitive emulsion detection system has been considered for use in a cycloidal focusing mass spectrometer to measure the various atomic species which comprise the solar plasma. The responses of Ilford Q2 and Kodak SC7 emulsions were measured with N(+) ions at 6 keV to 10 keV, He(++) ions at 750 eV to 2500 eV, and H(+) ions at 550 eV to 1400 eV. These ions have the approximate range of velocities (about 300-500 km/sec) encountered in the solar wind. The work was carried out on a specially prepared magnetic sector mass analyzer. Characteristic response curves were generated, each one utilizing approximately 50 data points at three or more current densities. In addition to the ion response, measurements of the response of these emulsions to a photon flux simulating the visible portion of the solar spectrum were made. The results obtained will be presented in detail and interpreted in relation to other data available for these emulsions.

  4. Forecasting Solar Wind Speeds

    NASA Astrophysics Data System (ADS)

    Suzuki, Takeru K.

    2006-03-01

    By explicitly taking into account the effects of Alfvén waves, I derive from a simple energetics argument a fundamental relation that predicts solar wind (SW) speeds in the vicinity of Earth from physical properties on the Sun. Kojima et al. recently found from observations that the ratio of surface magnetic field strength to the expansion factor of open magnetic flux tubes is a good indicator of the SW speed. I show by using the derived relation that this nice correlation is evidence of Alfvén wave acceleration of the SW in expanding flux tubes. The observations further require that the fluctuation amplitudes of magnetic field lines at the surface be almost universal in different coronal holes, which needs to be tested with future observations.

  5. Genesis Failure Investigation Report

    NASA Technical Reports Server (NTRS)

    Klein, John

    2004-01-01

    The-Genesis mission to collect solar-wind samples and return them to Earth for detailed analysis proceeded successfully for 3.5 years. During reentry on September 8, 2004, a failure in the entry, descent and landing sequence resulted in a crash landing of the Genesis sample return capsule. This document describes the findings of the avionics sub-team that supported the accident investigation of the JPL Failure Review Board.

  6. Wind and solar powered turbine

    NASA Technical Reports Server (NTRS)

    Wells, I. D.; Koh, J. L.; Holmes, M. (Inventor)

    1984-01-01

    A power generating station having a generator driven by solar heat assisted ambient wind is described. A first plurality of radially extendng air passages direct ambient wind to a radial flow wind turbine disposed in a centrally located opening in a substantially disc-shaped structure. A solar radiation collecting surface having black bodies is disposed above the fist plurality of air passages and in communication with a second plurality of radial air passages. A cover plate enclosing the second plurality of radial air passages is transparent so as to permit solar radiation to effectively reach the black bodies. The second plurality of air passages direct ambient wind and thermal updrafts generated by the black bodies to an axial flow turbine. The rotating shaft of the turbines drive the generator. The solar and wind drien power generating system operates in electrical cogeneration mode with a fuel powered prime mover.

  7. Measuring the Turbulent Solar Wind

    NASA Astrophysics Data System (ADS)

    DeForest, Craig; Matthaeus, William; Howard, Tim

    2015-04-01

    The slow solar wind is turbulent, a fact that may explain the variability of the slow wind at Earth. But the nature and strength of the turbulence has been hard to quantify because measurements have been limited to in-situ detection of variations in measurable parameters. Remote imaging of comet tails offers a unique opportunity to study the paths of localized "test particles" in the solar wind, and to analyze the motion in the same way that hydrodynamicists might study turbulence in water with test particles. We report on a careful analysis of the motion of 230 individually tracked features in the tail of a comet observed with STEREO/HI-1, which interacted strongly with the solar wind between 0.2 and 0.3 AU during the observation period, and draw deep conclusions about the nature of solar wind variability.

  8. Anisotropy of solar wind fluctuations: fast wind vs slow wind.

    NASA Astrophysics Data System (ADS)

    Dasso, S.; Milano, L. J.; Matthaeus, W. H.; Smith, C. W.

    2004-12-01

    The fluctuations in the solar wind are often modeled in terms of two distinct populations: (a) a 'wave-like' population with quasi-parallel wavenumbers and (b) a quasi-two dimensional 'turbulent-like' fluctuations with perpendicular wavenumbers. Here the qualification "quasi-parallel" or "quasi-2D" means that nearby wavevectors are grouped together in an idealzed way, for simplicity. The relative abundance of these two populations is important in gaining insight on the dynamics of waves or turbulence in the solar wind, and also in understanding the transport of energetic particle populations, as turbulence geometry has a major impact on scattering. It has been established in the literature that turbulence is, generally speaking, more developed in the slow solar wind, with power spectra closer to the kolmogorov value at 1AU, while the fast solar wind is more "Alfvenic", typically with higher values of the cross helicity. It seems natural therefore to investigate the anisotropy structure of solar wind fluctuations as a function of wind speed. We present here our preliminary results in this regard, obtained from magnetic and plasma data from the ACE specraft, at 1AU, essentially in the ecliptic plane. We also discuss possible implications for the modeling the evolution of waves and turbulence in the solar wind.

  9. Solar Wind and Interplanetary Disturbances

    NASA Technical Reports Server (NTRS)

    Watari, Shinichi

    2002-01-01

    This report describes basic knowledge of solar wind and interplanetary disturbances first, and then it discussed recent results from new observations and theories. At the end it presented research activities to predict interplanetary disturbances for space weather forecast.

  10. Highly Alfvenic Slow Solar Wind

    NASA Technical Reports Server (NTRS)

    Roberts, D. Aaron

    2010-01-01

    It is commonly thought that fast solar wind tends to be highly Alfvenic, with strong correlations between velocity and magnetic fluctuations, but examples have been known for over 20 years in which slow wind is both Alfvenic and has many other properties more typically expected of fast solar wind. This paper will present a search for examples of such flows from more recent data, and will begin to characterize the general characteristics of them. A very preliminary search suggests that such intervals are more common in the rising phase of the solar cycle. These intervals are important for providing constraints on models of solar wind acceleration, and in particular the role waves might or might not play in that process.

  11. Solar wind acceleration in the solar corona

    NASA Technical Reports Server (NTRS)

    Giordano, S.; Antonucci, E.; Benna, C.; Kohl, J. L.; Noci, G.; Michels, J.; Fineschi, S.

    1997-01-01

    The intensity ratio of the O VI doublet in the extended area is analyzed. The O VI intensity data were obtained with the ultraviolet coronagraph spectrometer (UVCS) during the SOHO campaign 'whole sun month'. The long term observations above the north pole of the sun were used for the polar coronal data. Using these measurements, the solar wind outflow velocity in the extended corona was determined. The 100 km/s level is running along the streamer borders. The acceleration of the solar wind is found to be high in regions between streamers. In the central part of streamers, the outflow velocity of the coronal plasma remains below 100 km/s at least within 3.8 solar radii. The regions at the north and south poles, characterized by a more rapid acceleration of the solar wind, correspond to regions where the UVCS observes enhanced O VI line broadenings.

  12. STATIONARITY IN SOLAR WIND FLOWS

    SciTech Connect

    Perri, S.; Balogh, A. E-mail: a.balogh@imperial.ac.u

    2010-05-01

    By using single-point measurements in space physics it is possible to study a phenomenon only as a function of time. This means that we cannot have direct access to information about spatial variations of a measured quantity. However, the investigation of the properties of turbulence and of related phenomena in the solar wind widely makes use of an approximation frequently adopted in hydrodynamics under certain conditions, the so-called Taylor hypothesis; indeed, the solar wind flow has a bulk velocity along the radial direction which is much higher than the velocity of a single turbulent eddy embedded in the main flow. This implies that the time of evolution of the turbulent features is longer than the transit time of the flow through the spacecraft position, so that the turbulent field can be considered frozen into the solar wind flow. This assumption allows one to easily associate time variations with spatial variations and stationarity to homogeneity. We have investigated, applying criteria for weak stationarity to Ulysses magnetic field data in different solar wind regimes, at which timescale and under which conditions the hypothesis of stationarity, and then of homogeneity, of turbulence in the solar wind is well justified. We extend the conclusions of previous studies by Matthaeus and Goldstein to different parameter ranges in the solar wind. We conclude that the stationarity assumption in the inertial range of turbulence on timescales of 10 minutes to 1 day is reasonably satisfied in fast and uniform solar wind flows, but that in mixed, interacting fast, and slow solar wind streams the assumption is frequently only marginally valid.

  13. Solar wind collisional heating

    NASA Astrophysics Data System (ADS)

    Pezzi, Oreste

    2017-06-01

    To properly describe heating in weakly collisional turbulent plasmas such as the solar wind, interparticle collisions should be taken into account. Collisions can convert ordered energy into heat by means of irreversible relaxation towards the thermal equilibrium. Recently, Pezzi et al. (Phys. Rev. Lett., vol. 116, 2016a, 145001) showed that the plasma collisionality is enhanced by the presence of fine structures in velocity space. Here, the analysis is extended by directly comparing the effects of the fully nonlinear Landau operator and a linearized Landau operator. By focusing on the relaxation towards the equilibrium of an out of equilibrium distribution function in a homogeneous force-free plasma, here it is pointed out that it is significant to retain nonlinearities in the collisional operator to quantify the importance of collisional effects. Although the presence of several characteristic times associated with the dissipation of different phase space structures is recovered in both the cases of the nonlinear and the linearized operators, the influence of these times is different in the two cases. In the linearized operator case, the recovered characteristic times are systematically larger than in the fully nonlinear operator case, this suggesting that fine velocity structures are dissipated more slowly if nonlinearities are neglected in the collisional operator.

  14. Comparison of algorithms for determination of solar wind regimes

    NASA Astrophysics Data System (ADS)

    Neugebauer, Marcia; Reisenfeld, Daniel; Richardson, Ian G.

    2016-09-01

    This study compares the designation of different solar wind flow regimes (transient, coronal hole, and streamer belt) according to two algorithms derived from observations by the Solar Wind Ion Composition Spectrometer, the Solar Wind Electron Proton Alpha Monitor, and the Magnetometer on the ACE spacecraft, with a similar regime determination performed on board the Genesis spacecraft. The comparison is made for the interval from late 2001 to early 2004 when Genesis was collecting solar wind ions for return to Earth. The agreement between hourly regime assignments from any pair of algorithms was less than two thirds, while the simultaneous agreement between all three algorithms was only 49%. When the results of the algorithms were compared to a catalog of interplanetary coronal mass ejection events, it was found that almost all the events in the catalog were confirmed by the spacecraft algorithms. On the other hand, many short transient events, lasting 1 to 13 h, that were unanimously selected as transient like by the algorithms, were not included in the catalog.

  15. Measurement of Damage Profiles from Solar Wind Implantation

    NASA Technical Reports Server (NTRS)

    McNamara, K. M.; Synowicki, R. A.; Tiwald, T. E.

    2007-01-01

    NASA's Genesis Mission launched from Cape Canaveral in August of 2001 with the goal of collecting solar wind in ultra-pure materials. The samples were returned to Earth more than three years later for subsequent analysis. Although the solar wind is comprised primarily of protons, it also contains ionized species representing the entire periodic table. The Genesis mission took advantage of the natural momentum of these ionized species to implant themselves in specialized collectors including single crystal Si and SiC. The collectors trapped the solar wind species of interest and sustained significant damage to the surface crystal structure as a result of the ion bombardment. In this work, spectroscopic ellipsometry has been used to evaluate the extent of this damage in Si and SiC samples. These results and models are compared for artificially implanted samples and pristine non-flight material. In addition, the flown samples had accumulated a thin film of molecular contamination as a result of outgassing in flight, and we demonstrate that this layer can be differentiated from the material damage. In addition to collecting bulk solar wind samples (continuous exposure), the Genesis mission actually returned silicon exposed to four different solar wind regimes: bulk, high speed, low speed, and coronal mass ejections. Each of these solar wind regimes varies in energy, but may vary in composition as well. While determining the composition is a primary goal of the mission, we are also interested in the variation in depth and extent of the damage layer as a function of solar wind regime. Here, we examine flight Si from the bulk solar wind regime and compare the results to both pristine and artificially implanted Si. Finally, there were four samples which were mounted in an electrostatic "concentrator" designed to reject a large fraction (>85%) of incoming protons while enhancing the concentration of ions mass 4-28 amu by a factor of at least 20. Two of these samples were

  16. Measurement of Damage Profiles from Solar Wind Implantation

    NASA Technical Reports Server (NTRS)

    McNamara, K. M.; Synowicki, R. A.; Tiwald, T. E.

    2007-01-01

    NASA's Genesis Mission launched from Cape Canaveral in August of 2001 with the goal of collecting solar wind in ultra-pure materials. The samples were returned to Earth more than three years later for subsequent analysis. Although the solar wind is comprised primarily of protons, it also contains ionized species representing the entire periodic table. The Genesis mission took advantage of the natural momentum of these ionized species to implant themselves in specialized collectors including single crystal Si and SiC. The collectors trapped the solar wind species of interest and sustained significant damage to the surface crystal structure as a result of the ion bombardment. In this work, spectroscopic ellipsometry has been used to evaluate the extent of this damage in Si and SiC samples. These results and models are compared for artificially implanted samples and pristine non-flight material. In addition, the flown samples had accumulated a thin film of molecular contamination as a result of outgassing in flight, and we demonstrate that this layer can be differentiated from the material damage. In addition to collecting bulk solar wind samples (continuous exposure), the Genesis mission actually returned silicon exposed to four different solar wind regimes: bulk, high speed, low speed, and coronal mass ejections. Each of these solar wind regimes varies in energy, but may vary in composition as well. While determining the composition is a primary goal of the mission, we are also interested in the variation in depth and extent of the damage layer as a function of solar wind regime. Here, we examine flight Si from the bulk solar wind regime and compare the results to both pristine and artificially implanted Si. Finally, there were four samples which were mounted in an electrostatic "concentrator" designed to reject a large fraction (>85%) of incoming protons while enhancing the concentration of ions mass 4-28 amu by a factor of at least 20. Two of these samples were

  17. Wind in the Solar System

    ERIC Educational Resources Information Center

    McIntosh, Gordon

    2010-01-01

    As an astronomy instructor I am always looking for commonly experienced Earthly phenomena to help my students and me understand and appreciate similar occurrences elsewhere in the solar system. Recently I wrote short "TPT" articles on frost and precipitation. The present article is on winds in the solar system. A windy day or storm might…

  18. Wind in the Solar System

    ERIC Educational Resources Information Center

    McIntosh, Gordon

    2010-01-01

    As an astronomy instructor I am always looking for commonly experienced Earthly phenomena to help my students and me understand and appreciate similar occurrences elsewhere in the solar system. Recently I wrote short "TPT" articles on frost and precipitation. The present article is on winds in the solar system. A windy day or storm might…

  19. Solar cycle variations in the solar wind

    NASA Technical Reports Server (NTRS)

    Freeman, John W.; Lopez, Ramon E.

    1986-01-01

    The solar cycle variations of various solar wind parameters are reviewed. It is shown that there is a gradual decrease in the duration of high-speed streams from the declining phase of solar cycle 20 through the ascending phase of cycle 21 and a corresponding decrease in the annual average of the proton speed toward solar maximum. Beta, the ratio of the proton thermal pressure to magnetic pressure, undergoes a significant solar cycle variation, as expected from the variation in the IMF. Individual hourly averages of beta often exceed unity with 20 cases exceeding 10 and one case as high as 25. The Alfven Mach number shows a solar cycle variation similar to beta, lower aboard solar maximum. High-speed streams can be seen clearly in epsilon and the y component of the interplanetary magnetic field.

  20. Constraints on neon and argon isotopic fractionation in solar wind.

    PubMed

    Meshik, Alex; Mabry, Jennifer; Hohenberg, Charles; Marrocchi, Yves; Pravdivtseva, Olga; Burnett, Donald; Olinger, Chad; Wiens, Roger; Reisenfeld, Dan; Allton, Judith; McNamara, Karen; Stansbery, Eileen; Jurewicz, Amy J G

    2007-10-19

    To evaluate the isotopic composition of the solar nebula from which the planets formed, the relation between isotopes measured in the solar wind and on the Sun's surface needs to be known. The Genesis Discovery mission returned independent samples of three types of solar wind produced by different solar processes that provide a check on possible isotopic variations, or fractionation, between the solar-wind and solar-surface material. At a high level of precision, we observed no significant inter-regime differences in 20Ne/22Ne or 36Ar/38Ar values. For 20Ne/22Ne, the difference between low- and high-speed wind components is 0.24 +/- 0.37%; for 36Ar/38Ar, it is 0.11 +/- 0.26%. Our measured 36Ar/38Ar ratio in the solar wind of 5.501 +/- 0.005 is 3.42 +/- 0.09% higher than that of the terrestrial atmosphere, which may reflect atmospheric losses early in Earth's history.

  1. Cutting of Gold Foil in the Genesis Laboratory

    NASA Image and Video Library

    2005-02-15

    The facility for storing and examining Genesis solar wind samples consists of two adjacent laboratories. In these laboratories, the cutting of gold foil to be used in the gathering of the solar wind dust aboard the Genesis spacecraft. Views include: The process of cutting gold foil to be used aboard the Genesis spacecraft. The technicians use Gore-Tex suits with filters as to not contaminate the items.

  2. Solar wind precipitation on Mars

    NASA Astrophysics Data System (ADS)

    Stenberg, G.; Dieval, C.; Nilsson, H.; Kallio, E.; Barabash, S.; Futaana, Y.; Shematovich, V.; Bisikalo, D.

    2011-10-01

    We have found that solar wind particles frequently precipitate onto the atmosphere of Mars [1,2]. The precipitating particles contribute to the energy and matter flux into the ionosphere. We use ion data from the ASPERA-3 instrument onboard Mars Express to investigate the precipitation patterns, processes and the total transfer of energy and matter from the solar wind to the atmosphere. The main reason for the proton and alpha particle precipitation is likely the large gyroradii of hot particles compared to the size of the induced magnetosphere/magnetic barrier. We find that the particle penetration depends on the direction of the convection electric field in the solar wind but that the crustal magnetic fields have very little influence. The total energy flux is low compared to the solar radiation heating on the dayside, but a significant energy source on the nightside. We also believe that the solar wind alphaparticles precipitating into the atmosphere is an important source of the neutral helium in the Martian atmosphere. We combine our observations with computer modeling [3,4]. We have applied a Direct Simulation Monte Carlo method to solve the kinetic equation for the H/H+ transport in the upper Martian atmosphere including CO2, N2 and O. We conclude that the induced magnetic field around Mars plays the crucial role in the transport of charged particles in the upper atmosphere, and it determines the energy deposition of the solar wind.

  3. Genesis Halo Orbit Station Keeping Design

    NASA Technical Reports Server (NTRS)

    Lo, M.; Williams, K.; Wilson, R.; Howell, K.; Barden, B.

    2000-01-01

    As the fifth mission of NASA's Directory Program, Genesis is designed to collect solar wind samples for approximately two years in a halo orbit near the Sun-Earth L(sub 1) Lagrange point for return to the Earth.

  4. Genesis Halo Orbit Station Keeping Design

    NASA Technical Reports Server (NTRS)

    Lo, M.; Williams, K.; Wilson, R.; Howell, K.; Barden, B.

    2000-01-01

    As the fifth mission of NASA's Directory Program, Genesis is designed to collect solar wind samples for approximately two years in a halo orbit near the Sun-Earth L(sub 1) Lagrange point for return to the Earth.

  5. PHOTOIONIZATION IN THE SOLAR WIND

    SciTech Connect

    Landi, E.; Lepri, S. T.

    2015-10-20

    In this work we investigate the effects of photoionization on the charge state composition of the solar wind. Using measured solar EUV and X-ray irradiance, the Michigan Ionization Code and a model for the fast and slow solar wind, we calculate the evolution of the charge state distribution of He, C, N, O, Ne, Mg, Si, S, and Fe with and without including photoionization for both types of wind. We find that the solar radiation has significant effects on the charge state distribution of C, N, and O, causing the ionization levels of these elements to be higher than without photoionization; differences are largest for oxygen. The ions commonly observed for elements heavier than O are much less affected, except in ICMEs where Fe ions more ionized than 16+ can also be affected by the solar radiation. We also show that the commonly used O{sup 7+}/O{sup 6+} density ratio is the most sensitive to photoionization; this sensitivity also causes the value of this ratio to depend on the phase of the solar cycle. We show that the O{sup 7+}/O{sup 6+} ratio needs to be used with caution for solar wind classification and coronal temperature estimates, and recommend the C{sup 6+}/C{sup 4+} ratio for these purposes.

  6. Periodic solar wind density structures

    NASA Astrophysics Data System (ADS)

    Viall, Nicholeen Mary

    2010-01-01

    This dissertation addresses a specific aspect of the Sun-Earth connection: we show that coronal activity creates periodic density structures in the solar wind which convect radially outward and interact with Earth's magnetosphere. First, we analyze 11 years (1995-2005) of in situ solar wind density observations from the Wind spacecraft and find that periodic density structures occur at particular sets of radial length-scales more often than others. This indicates that these density fluctuations, which have radial length-scales of hundreds of megameters, cannot be attributed entirely to turbulence. Next, we analyze their effect on Earth's magnetosphere. Though these structures are not waves in the solar wind rest frame, they appear at discrete frequencies in Earth's reference frame. They compress the magnetosphere as they convect past, driving global magnetospheric oscillations at the same discrete frequencies as the periodic density structures. Last, we investigate source regions and mechanisms of the periodic solar wind density structures. We analyze the alpha particle to proton abundance ratio during events of periodic density structures. In many events, the proton and alpha density fluctuations are anti- correlated, which strongly argues for either temporally or spatially varying coronal source plasma. We examine white light images of the solar wind taken with SECCHI HI1 on the STEREO spacecraft and find periodic density structures as near to the Sun as 15 solar radii. The smallest resolvable periodic structures that we identify are of comparable length to those found at 1 AU, providing further evidence that at least some periodic density structures are generated in the solar corona as the solar wind is formed. Guided by the properties observed during previous studies and the characteristics established through the work presented here, we examine possible candidate mechanisms in the solar corona that can form periodic density structures. We conclude that

  7. Geoeffectiveness of Extreme Solar Winds

    NASA Astrophysics Data System (ADS)

    Alleyne, H.; Nanan, B.; Walker, S.; Reme, H.; Lucek, E.; Andre, M.; Cornilleau-Wehrlin, N.; Fazakerley, A.; Decreau, P.; McCrea, I.; Zhang, S.; van Eyken, A.

    2006-12-01

    The geoeffectiveness of the extreme solar winds that flowed pass the Earth on 24 October 2003, 07 November 2004 and 09 November 2004 are presented using Cluster (FGM, CIS, PEACE, STAFF and EFW) and ground- based (EISCAT radars at 69.6N, 19.2E and IMAGE magnetometer network at 68-79N)observations. The Cluster observations suggest that magnetic reconnection need not be the main process for solar wind entry into the magnetosphere during extreme solar winds. The ion velocity in the magnetosheath-cusp region remains strongly anti-sunward and poleward and ion density remains high irrespective of IMF Bz is negative or positive. The ion velocity components are also found to agree with the ExB velocities. The ground-based observations indicate that the extreme solar winds directly affect the high latitude ionosphere. The solar wind plasma is found to enter the ionosphere through an afternoon cusp that descends to low latitudes during negative IMF Bz period when a westward electrojet is also found to ascend to high latitudes.

  8. Persistence of solar wind features

    NASA Technical Reports Server (NTRS)

    Rucker, H. O.; Rabl, G. K. F.; Desch, M. D.

    1986-01-01

    Using data from the plasma and magnetometer experiments on board the Voyagers 1 and 2 during the approach to Jupiter, solar wind persistence is investigated over the period from January 1978 (Voyager 1 passing by Voyager 2) through February 1979. The trajectories of both spacecraft provided a unique opportunity to study the radial evolution and variation of the solar wind over about 3 AU, and to analyze the persistence of solar wind features along the radially increasing separation distance of both Voyagers. Some emphasis is placed on a period of DOY (day of year) 152 through 212, 1978, in which the observed propagation delay time of solar wind signatures between both Voyagers significantly deviates from the expected delay time. A decrease in the correlation coefficient of the corresponding Voyager 1 and 2 data profiles indicates a remarkable change of the solar wind flow. This period in question coincides to a great extent with the interval V of June-July 1978, selected by STIP (Study of Travelling Interplanetary Phenomena).

  9. Solar-wind velocity decreases

    NASA Astrophysics Data System (ADS)

    Geranios, A.

    1980-08-01

    A model is developed to account for the solar wind electron and proton temperature decreases observed following the passage of an interplanetary shock wave and during the velocity decrease of a solar wind stream. The equations of mass and energy conservation are solved for a fully ionized, electrically neutral plasma expanding radially and spherically symmetrically, taking into account the heat flux from the solor corona to the plasma along the open magnetic field lines, and the electron thermal conductivity. An analytical relationship between the temperature and the velocity of the solar wind plasma is obtained which is found to be in agreement with experimental measurements made by the Vela 5 and 6 and IMP 6 satellites from August 1969-May 1974. It is thus proposed that the observed low plasma temperatures are due to the fact that the temperature decrease of the expanding plasma exceeds the heat gain due to thermal conduction from the corona.

  10. ASYMMETRIC SOLAR WIND ELECTRON DISTRIBUTIONS

    SciTech Connect

    Yoon, Peter H.; Kim, Sunjung; Lee, Junggi; Lee, Junhyun; Park, Jongsun; Park, Kyungsun; Seough, Jungjoon; Hong, Jinhy

    2012-08-20

    The present paper provides a possible explanation for the solar wind electron velocity distribution functions possessing asymmetric energetic tails. By numerically solving the electrostatic weak turbulence equations that involve nonlinear interactions among electrons, Langmuir waves, and ion-sound waves, it is shown that different ratios of ion-to-electron temperatures lead to the generation of varying degrees of asymmetric tails. The present finding may be applicable to observations in the solar wind near 1 AU and in other regions of the heliosphere and interplanetary space.

  11. A Career in the Solar Wind

    NASA Technical Reports Server (NTRS)

    Neugebauer, Marcia

    1997-01-01

    This is a personal history of the author's experiences, starting with the earliest direct measurements of the solar wind and continuing through later experiments to investigate the physics of the solar wind and its interaction with comets.

  12. The solar wind throughout the solar cycle

    NASA Astrophysics Data System (ADS)

    von Steiger, Rudolf

    The existence of solar corpuscular radiation (SCR) was conjectured by Biermann (1951) based on the fact that the ion tails of comets always point radially away from the Sun. Earlier it had been thought that this was due to solar radiation pressure, but when the relevant cross-sections were measured it became clear that these were far too small. This is visible in Figure 3.1, where stars can be seen shining through the ion tail of comet Hale-Bopp, one of the more spectacular sights in the sky of the 20th century. Parker (1958) provided the first theoretical description of the SCR in terms of a supersonic magnetized fluid. He coined the term "solar wind" in order to set it apart from other ideas of a (subsonic) solar breeze that were around at the time. The solar wind was ultimately observed in the early 1960s by the Soviets and independently with the American Mariner 2 mission to Venus (Gringauz et al., 1961; Neugebauer and Snyder, 1962). An excellent account of these early developments is given by Parker (2001).

  13. Imaging the Variable Solar Wind

    NASA Astrophysics Data System (ADS)

    DeForest, C.; Howard, T. A.; Matthaeus, W. H.

    2013-05-01

    With the advent of wide-field Thomson scattering imagery from STEREO/SECCHI, it is possible to image the solar wind continuously from its origin in the low corona to large fractions of 1AU from the Sun. Although it is sensitive only to non-stationary density structures, Thomson imaging yields morphological insight and global perspective that are not directly available from in-situ data. I will review recent work on both large and small scale analysis. On large scales, it is now possible to track well-presented CMEs from the pre-eruptive structure to impact with in-situ probes, yielding positive identification of flux rope structure based on both positively tracked morphology and direct magnetic measurement. In some cases, plasma detected in-situ can be positively identified with particular pieces of pre-eruptive anatomy in the low corona. Some observed large-scale features are as-yet unexplained. In quiet solar wind, small ejecta and blobs are readily distinguished from disconnection events that may be identified by their morphology, and all can be tracked through the Alfvén surface boundary at 20-50 Rs into the solar wind proper. In the HI-1 field of view, the solar wind takes on a flocculated appearance, though most of the individual features lose image structure and cannot be tracked across the entire field of view. Analysis of individual ejecta and of the statistical properties of the flocculation pattern is yielding insights into the nature of fluctuations and origin of variability in the slow solar wind.

  14. 78 FR 49507 - Genesis Solar, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-14

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Genesis Solar, LLC; Supplemental Notice That Initial Market- Based Rate...-referenced proceeding of Genesis Solar, LLC's application for market-based rate authority, with...

  15. The solar wind-magnetosphere-ionosphere system

    PubMed

    Lyon

    2000-06-16

    The solar wind, magnetosphere, and ionosphere form a single system driven by the transfer of energy and momentum from the solar wind to the magnetosphere and ionosphere. Variations in the solar wind can lead to disruptions of space- and ground-based systems caused by enhanced currents flowing into the ionosphere and increased radiation in the near-Earth environment. The coupling between the solar wind and the magnetosphere is mediated and controlled by the magnetic field in the solar wind through the process of magnetic reconnection. Understanding of the global behavior of this system has improved markedly in the recent past from coordinated observations with a constellation of satellite and ground instruments.

  16. Solar Wind Speed Charged Dust

    NASA Astrophysics Data System (ADS)

    Russell, C. T.; Weimer, D.; Jian, L. K.; Luhmann, J. G.; Omidi, N.

    2009-04-01

    The correlation of the occurrence of magnetic disturbances, known as interplanetary field enhancements (IFEs), with the asteroid 2201 Oljato can only be explained as the interaction with charged dust in the asteroid's orbit, because the events occurred both before and after alignment with the asteroid. These single spacecraft observations did not determine how fast the dust was accelerated, or if they were affected at all by the solar wind. Shortly after STEREO A and B were launched, an IFE crossed the two spacecraft as well as ACE and Wind. This four-spacecraft configuration allowed us to determine that the disturbance was moving radially outward at 700 km/s, the solar wind speed. The conventional wisdom is that only the smallest dust particles can be affected by the solar wind, but examination of periods on STEREO when the spacecraft is being sprayed with multiple beta-meteoroid strikes shows no obvious correlation. Further, the IFEs are much less frequent than the "beta-meteoroid" impacts. Hence, it is possible that IFEs are associated with much larger dust particles, perhaps 1 micron-sized dust. If true, then those particles may be very dangerous albeit rare, possessing about 104 ergs.

  17. Solar wind ion precipitation on Mars

    NASA Astrophysics Data System (ADS)

    Stenberg, Gabriella; Dieval, Catherine; Nilsson, Hans; Barabash, Stas; Futaana, Yoshifumi

    2013-04-01

    Solar wind ions (protons and alpha-particles) frequently precipitate onto the atmosphere of Mars. The precipitating particles contribute to the energy and matter flux into the ionosphere. The main reason for the solar-wind precipitation is likely the large gyroradii of hot particles in the magnetosheath compared to the size of the induced magnetosphere/magnetic barrier. Precipitating particles may modify the composition of the neutral atmosphere. As an example solar wind alpha-particles have been suggested to be an important source of neutral helium in the Martian atmosphere. We use ion data from the ASPERA-3 instrument onboard Mars Express to estimate the net transfer of energy and matter from the solar wind to the atmosphere. Our results indicate that the Martian ionosphere is better protected from penetrating solar wind ions than previously thought, at least during solar minimum conditions. In addition, our findings suggest that the contribution of solar wind alpha-particles to the helium balance of the atmosphere is smaller than expected. We also compare the ion precipitation during periods of quiet solar wind conditions and periods of solar wind pressure pulses. We show that the occurrence frequency of precipitation events is reduced by a factor 2-3 during periods when a solar wind pressure pulse reaches Mars, suggesting that the during this time the magnetic barrier becomes thicker in terms of solar wind ion gyroradii, making it more difficult for ions to precipitate.

  18. The Colorado Solar Wind Experiment

    NASA Astrophysics Data System (ADS)

    Munsat, Tobin; Han, Jia; Horanyi, Mihaly; Ulibarri, Zach; Wang, Xu; Yeo, Lihsia

    2016-10-01

    The Colorado Solar Wind Experiment (CSWE) is a new device developed at the Institute for Modeling Plasma, Atmospheres, and Cosmic Dust (IMPACT) at the University of Colorado. This large ion source is for studies of the interaction of solar wind plasma with planetary surfaces and cosmic dust, and for the investigation of plasma wake physics. With a plasma beam diameter of 12 cm at the source, ion energies of up to 1 keV, and ion flows of up to 1 mA/cm2, a large cross-section Kaufman Ion Source is used to create steady state plasma flow to model the solar wind in an experimental vacuum chamber. Chamber pressure can be reduced to 3e-5 Torr under operating conditions to suppress ion-neutral collisions and create a uniform ion velocity distribution. Diagnostic instruments such as a double Langmuir probe and an ion energy analyzer are mounted on a two-dimensional translation stage that allow the beam to be characterized throughout the chamber. Early experiments include the measurement of dust grain charging from the interaction with flowing plasma, and measurements of the plasma sheath created by the interaction of the flowing plasma impinging on a surface with a dipole magnetic field. This poster will describe the facility and the scientific results obtained to date.

  19. Characterizing the Solar Wind at L1

    NASA Astrophysics Data System (ADS)

    Jahn, J.; Elliott, H. A.

    2008-12-01

    The nature of solar wind-magnetosphere energy transfer plays a big role in understanding the time history and types of global-scale magnetospheric phenomena. However, systematic approaches to quantifying how the specific magnetospheric "modes" (if they can be called that) of substorms, SMCs, sawtooth events, and geomagnetic storms could be controlled by the solar wind are still difficult. We present a fresh approach to characterizing the solar wind and its time history using self-organizing maps. The thrust of this effort is geared towards detecting and classifying solar wind structure on time scales relevant for the magnetospheric responses of interest. Performing this characterization at the L1 point is ideal for uncovering solar wind- magnetosphere relationships. It also provides a very long, contiguous time series that helps us explore these relationships over a complete solar cycle. We present the technique and initial results of solar wind comparisons during and leading up to SMCs and sawtooth events.

  20. 77 FR 61597 - Avalon Wind, LLC; Avalon Wind 2, LLC; Catalina Solar, LLC; Catalina Solar 2, LLC; Pacific Wind...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-10

    ... Energy Regulatory Commission Avalon Wind, LLC; Avalon Wind 2, LLC; Catalina Solar, LLC; Catalina Solar 2, LLC; Pacific Wind Lessee, LLC; Pacific Wind 2, LLC; Valentine Solar, LLC; EDF Renewable Development, Inc.; Notice of Petition for Declaratory Order Take notice that on September 27, 2012, Avalon...

  1. Astrospheres and Solar-like Stellar Winds.

    PubMed

    Wood, Brian E

    Stellar analogs for the solar wind have proven to be frustratingly difficult to detect directly. However, these stellar winds can be studied indirectly by observing the interaction regions carved out by the collisions between these winds and the interstellar medium (ISM). These interaction regions are called "astrospheres", analogous to the "heliosphere" surrounding the Sun. The heliosphere and astrospheres contain a population of hydrogen heated by charge exchange processes that can produce enough H I Lyα absorption to be detectable in UV spectra of nearby stars from the Hubble Space Telescope (HST). The amount of astrospheric absorption is a diagnostic for the strength of the stellar wind, so these observations have provided the first measurements of solar-like stellar winds. Results from these stellar wind studies and their implications for our understanding of the solar wind are reviewed here. Of particular interest are results concerning the past history of the solar wind and its impact on planetary atmospheres.

  2. Distributed Wind Cost Reduction: Learning from Solar

    SciTech Connect

    Tegen, Suzanne

    2016-02-23

    The distributed wind energy industry can learn several lessons from the solar industry regarding reducing soft costs. Suzanne Tegen presented this overview at the 2016 Distributed Wind Energy Association Business Conference in Washington, D.C., on February 23, 2016.

  3. The Distribution of Solar Wind Speeds During Solar Minimum: Calibration for Numerical Solar Wind Modeling Constraints on the Source of the Slow Solar Wind (Postprint)

    DTIC Science & Technology

    2012-03-05

    2003], and that the solar wind speed/ magnetic field expansion relationship is coinci- dental and is merely a result of the coronal geometry. [ 3 ] Wang... field component is 300 nT. The azimuthal magnetic field com- MCGREGOR ET AL.: MODELING SOLAR MINIMUM SOLAR WIND SPEEDS A03101A03101 3 of 11 Approved for...superradial expansion of the magnetic field to account for the observed solar wind speed variation. We investigate the solar wind in the inner corona using

  4. Comet Borrelly Slows Solar Wind

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Over 1300 energy spectra taken on September 22, 2001 from the ion and electron instruments on NASA's Deep Space 1 span a region of 1,400,000 kilometers (870,000 miles) centered on the closest approach to the nucleus of comet Borrelly. A very strong interaction occurs between the solar wind (horizontal red bands to left and right in figure) and the comet's surrounding cloud of dust and gas, the coma. Near Deep Space 1's closest approach to the nucleus, the solar wind picked up charged water molecules from the coma (upper green band near the center), slowing the wind sharply and creating the V-shaped energy structure at the center.

    Deep Space 1 completed its primary mission testing ion propulsion and 11 other advanced, high-risk technologies in September 1999. NASA extended the mission, taking advantage of the ion propulsion and other systems to undertake this chancy but exciting, and ultimately successful, encounter with the comet. More information can be found on the Deep Space 1 home page at http://nmp.jpl.nasa.gov/ds1/ .

    Deep Space 1 was launched in October 1998 as part of NASA's New Millennium Program, which is managed by JPL for NASA's Office of Space Science, Washington, D.C. The California Institute of Technology manages JPL for NASA.

  5. Numerical modeling of the solar wind turbulence

    DOE PAGES

    Kryukov, I.A.; Pogorelov, N.V.; Zank, G.P.; ...

    2012-05-21

    Here we describe an extension of the Multi-Scale Fluid-Kinetic Simulation Suite (MSFLUKSS) by adding a solar wind turbulence model and a fluid treatment of pickup ions. Numerical results are presented of the time-dependent solar wind modeling with the boundary conditions provided by the OMNI data. The distributions of plasma properties and interplanetary magnetic field are compared with the Voyager 2 observations in the distant solar wind.

  6. Correlations Between Neutral and Ionized Solar Wind

    NASA Astrophysics Data System (ADS)

    Collier, M.; Pilkerton, B.; Moore, T.

    The Low Energy Neutral Atom (LENA) Imager on the IMAGE spacecraft has observed the neutral component of the solar wind (JGR, 106, 24,893, 2001) independently adumbrated by Akasofu and Dessler about forty years ago. Neutral solar wind is formed by solar wind charge exchange with interstellar neutrals, dust and the Earth's exosphere, in addition to any intrinsically neutral component. Here we report the results of a statistical study correlating the solar wind fluxes observed by ACE during late 2000 and throughout 2001 with neutral solar wind fluxes observed by LENA. The average correlation coefficient between the neutral and ionized solar wind is 0.66 with "good" correlations (peak correlation coefficient above 0.80) occurring about 28% of the time. The results are similar to those obtained by in-situ multi-spacecraft correlation studies. In this study, however, IMAGE is almost never in the solar wind or magnetosheath. The slope of the relationship between the neutral solar wind flux and the solar wind flux shows a peak in the upstream direction, but shifted toward higher ecliptic longitudes than the interstellar neutral (ISN) flow direction by about 20 degrees. The estimated peak interstellar neutral upstream density is about 10-2 cm-3.

  7. Wind loading on solar collectors

    NASA Astrophysics Data System (ADS)

    Bhaduri, S.; Murphy, L. M.

    1985-06-01

    The present design methodology for the determination of wind loading on the various solar collectors were reviewed and assessed. The total force coefficients of flat plates of aspect ratios 1.0 and 3.0, respectively, at various angles of attack obtained by using the guidelines of the ANSI A58.1-1982, were compared with those obtained by using the methodology of the ASCE Task Committee, 1961, and the experimental results of the full-scale test of heliostats by Peglow. The turbulent energy spectra, currently employed in the building code, are compared with those of Kaimal et al., Lumley, and Ponofsky for wind velocities of 20.0 m/s and 40.24 m/s at an elevation of 9.15 m. The longitudinal spectra of the building code overestimates the Kaimal spectra in the frequency range of 0.007 Hz to 0.08 Hz and underestimates beyond the frequency of 0.08 Hz. The peak angles of attack, on the heliostat, stowed in horizontal position, due to turbulent vertical and lateral components of wind velocity, were estimated by using Daniel's methodology for three wind velocities and compared with the value suggested by the code. The experimental results of a simple test in the laboratory indicate the feasibility of decreasing the drag forces of the flat plate by reducing the solidity ratio.

  8. The Solar Wind Ion Composition Spectrometer

    NASA Technical Reports Server (NTRS)

    Gloeckler, G.; Geiss, J.; Balsiger, H.; Bedini, P.; Cain, J. C.; Fisher, J.; Fisk, L. A.; Galvin, A. B.; Gliem, F.; Hamilton, D. C.

    1992-01-01

    The Solar Wind Ion Composition Spectrometer (SWICS) on Ulysses is designed to determine uniquely the elemental and ionic-charge composition, and the temperatures and mean speeds of all major solar-wind ions, from H through Fe, at solar wind speeds ranging from 175 km/s (protons) to 1280 km/s (Fe(8+)). The instrument, which covers an energy per charge range from 0.16 to 59.6 keV/e in about 13 min, combines an electrostatic analyzer with postacceleration, followed by a time-of-flight and energy measurement. The measurements made by SWICS will have an impact on many areas of solar and heliospheric physics, in particular providing essential and unique information on: (1) conditions and processes in the region of the corona where the solar wind is accelerated; (2) the location of the source regions of the solar wind in the corona; (3) coronal heating processes; (4) the extent and causes of variations in the composition of the solar atmosphere; (5) plasma processes in the solar wind; (6) the acceleration of energetic particles in the solar wind; (7) the thermalization and acceleration of interstellar ions in the solar wind, and their composition; and (8) the composition, charge states, and behavior of the plasma in various regions of the Jovian magnetosphere.

  9. The Solar Wind Ion Composition Spectrometer

    NASA Technical Reports Server (NTRS)

    Gloeckler, G.; Geiss, J.; Balsiger, H.; Bedini, P.; Cain, J. C.; Fisher, J.; Fisk, L. A.; Galvin, A. B.; Gliem, F.; Hamilton, D. C.

    1992-01-01

    The Solar Wind Ion Composition Spectrometer (SWICS) on Ulysses is designed to determine uniquely the elemental and ionic-charge composition, and the temperatures and mean speeds of all major solar-wind ions, from H through Fe, at solar wind speeds ranging from 175 km/s (protons) to 1280 km/s (Fe(8+)). The instrument, which covers an energy per charge range from 0.16 to 59.6 keV/e in about 13 min, combines an electrostatic analyzer with postacceleration, followed by a time-of-flight and energy measurement. The measurements made by SWICS will have an impact on many areas of solar and heliospheric physics, in particular providing essential and unique information on: (1) conditions and processes in the region of the corona where the solar wind is accelerated; (2) the location of the source regions of the solar wind in the corona; (3) coronal heating processes; (4) the extent and causes of variations in the composition of the solar atmosphere; (5) plasma processes in the solar wind; (6) the acceleration of energetic particles in the solar wind; (7) the thermalization and acceleration of interstellar ions in the solar wind, and their composition; and (8) the composition, charge states, and behavior of the plasma in various regions of the Jovian magnetosphere.

  10. Solar wind thermal electron distributions

    SciTech Connect

    Phillips, J.L.; Gosling, J.T.

    1991-01-01

    Solar wind thermal electron distributions exhibit distinctive trends which suggest Coulomb collisions and geometric expansion in the interplanetary magnetic field play keys roles in electron transport. We introduce a simple numerical model incorporating these mechanisms, discuss the ramifications of model results, and assess the validity of the model in terms of ISEE-3 and Ulysses observations. Although the model duplicates the shape of the electron distributions, and explains certain other observational features, observed gradients in total electron temperature indicate the importance of additional heating mechanisms. 5 refs., 7 figs.

  11. Simulations of Solar Wind Turbulence

    NASA Technical Reports Server (NTRS)

    Goldstein, Melvyn L.; Usmanov, A. V.; Roberts, D. A.

    2008-01-01

    Recently we have restructured our approach to simulating magnetohydrodynamic (MHD) turbulence in the solar wind. Previously, we had defined a 'virtual' heliosphere that contained, for example, a tilted rotating current sheet, microstreams, quasi-two-dimensional fluctuations as well as Alfven waves. In this new version of the code, we use the global, time-stationary, WKB Alfven wave-driven solar wind model developed by Usmanov and described in Usmanov and Goldstein [2003] to define the initial state of the system. Consequently, current sheets, and fast and slow streams are computed self-consistently from an inner, photospheric, boundary. To this steady-state configuration, we add fluctuations close to, but above, the surface where the flow become super-Alfvenic. The time-dependent MHD equations are then solved using a semi-discrete third-order Central Weighted Essentially Non-Oscillatory (CWENO) numerical scheme. The computational domain now includes the entire sphere; the geometrical singularity at the poles is removed using the multiple grid approach described in Usmanov [1996]. Wave packets are introduced at the inner boundary such as to satisfy Faraday's Law [Yeh and Dryer, 1985] and their nonlinear evolution are followed in time.

  12. Average thermal characteristics of solar wind electrons

    NASA Technical Reports Server (NTRS)

    Montgomery, M. D.

    1972-01-01

    Average solar wind electron properties based on a 1 year Vela 4 data sample-from May 1967 to May 1968 are presented. Frequency distributions of electron-to-ion temperature ratio, electron thermal anisotropy, and thermal energy flux are presented. The resulting evidence concerning heat transport in the solar wind is discussed.

  13. Magnetospheric balance of solar wind dynamic pressure

    NASA Astrophysics Data System (ADS)

    Lopez, Ramon E.; Gonzalez, Walter D.

    2017-04-01

    The magnetopause is the boundary established by pressure balance between the solar wind flow in the magnetosheath and the magnetosphere. Generally, this pressure balance is represented to be between the solar wind, the dynamic pressure, and the magnetic pressure of Earth's dipole field. The plasma actually in contact with the magnetosphere is the slowed, compressed, and heated solar wind downstream of the shock. The force exerted on the magnetosheath plasma is the J × B force produced by the Chapman-Ferraro current that flows on the magnetopause. Under typical solar wind conditions of relatively high magnetosonic Mach number flow (>6), this simple picture is a reasonable description of the situation. However, under conditions of low solar wind magnetosonic Mach number flow ( 2) the force on the solar wind plasma is not exerted at the magnetopause and must be exerted at the bow shock by currents that connect to the Region 1 currents. In this paper we present observations from two magnetopause crossings observed by the Time History of Events and Macroscale Interactions during Substorms spacecraft to compare and contrast the force balance with the solar wind for two situations with very different solar wind magnetosonic Mach numbers.

  14. Solar wind influence on Jupiter's aurora

    NASA Astrophysics Data System (ADS)

    Gyalay, Szilard; Vogt, Marissa F.; Withers, Paul; Bunce, Emma J.

    2016-10-01

    Jupiter's main auroral emission is driven by a system of corotation enforcement currents that arises to speed up outflowing Iogenic plasma and is not due to the magnetosphere-solar wind interaction like at Earth. The solar wind is generally expected to have only a small influence on Jupiter's magnetosphere and aurora compared to the influence of rotational stresses due to the planet's rapid rotation. However, there is considerable observational evidence that the solar wind does affect the magnetopause standoff distance, auroral radio emissions, and the position and brightness of the UV auroral emissions. Using the Michigan Solar Wind Model (mSWiM) to predict the solar wind conditions upstream of Jupiter we have identified intervals of high and low solar wind dynamic pressure in the Galileo dataset, and use this information to quantify how a magnetospheric compression affects the magnetospheric field configuration. We have developed separate spatial fits to the compressed and nominal magnetic field data, accounting for variations with radial distance and local time. These two fits can be used to update the flux equivalence mapping model of Vogt et al. (2011), which links auroral features to source regions in the middle and outer magnetosphere. The updated version accounts for changing solar wind conditions and provides a way to quantify the expected solar wind-induced variability in the ionospheric mapping of the main auroral emission, satellite footprints, and other auroral features. Our results are highly relevant to interpretation of the new auroral observations from the Juno mission.

  15. Sources of solar wind over the solar activity cycle

    PubMed Central

    Poletto, Giannina

    2012-01-01

    Fast solar wind has been recognized, about 40 years ago, to originate in polar coronal holes (CHs), that, since then, have been identified with sources of recurrent high speed wind streams. As of today, however, there is no general consensus about whether there are, within CHs, preferential locations where the solar wind is accelerated. Knowledge of slow wind sources is far from complete as well. Slow wind observed in situ can be traced back to its solar source by backward extrapolation of magnetic fields whose field lines are streamlines of the outflowing plasma. However, this technique often has not the necessary precision for an indisputable identification of the region where wind originates. As the Sun progresses through its activity cycle, different wind sources prevail and contribute to filling the heliosphere. Our present knowledge of different wind sources is here summarized. Also, a Section addresses the problem of wind acceleration in the low corona, as inferred from an analysis of UV data, and illustrates changes between fast and slow wind profiles and possible signatures of changes along the solar cycle. A brief reference to recent work about the deep roots of solar wind and their changes over different solar cycles concludes the review. PMID:25685421

  16. Sources of solar wind over the solar activity cycle.

    PubMed

    Poletto, Giannina

    2013-05-01

    Fast solar wind has been recognized, about 40 years ago, to originate in polar coronal holes (CHs), that, since then, have been identified with sources of recurrent high speed wind streams. As of today, however, there is no general consensus about whether there are, within CHs, preferential locations where the solar wind is accelerated. Knowledge of slow wind sources is far from complete as well. Slow wind observed in situ can be traced back to its solar source by backward extrapolation of magnetic fields whose field lines are streamlines of the outflowing plasma. However, this technique often has not the necessary precision for an indisputable identification of the region where wind originates. As the Sun progresses through its activity cycle, different wind sources prevail and contribute to filling the heliosphere. Our present knowledge of different wind sources is here summarized. Also, a Section addresses the problem of wind acceleration in the low corona, as inferred from an analysis of UV data, and illustrates changes between fast and slow wind profiles and possible signatures of changes along the solar cycle. A brief reference to recent work about the deep roots of solar wind and their changes over different solar cycles concludes the review.

  17. Locating solar and wind energy sources

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    Renewable energy sources such as solar and wind power hold out the promise of providing energy that does not produce greenhouse gases. One obstacle to realizing production of energy from the Sun and from wind, however, has been determining where these energy sources can best be tapped.A new project called the Solar and Wind Energy Survey Assessment (SWERA) plans to map the solar and wind resources of 13 developing countries, and link these findings with a Geographical Information System so that potential developers can find sites online.

  18. Titan Observed Naked in the Solar Wind

    NASA Image and Video Library

    2015-01-28

    This diagram depicts conditions observed by NASA's Cassini spacecraft during a flyby in Dec. 2013, when Saturn's magnetosphere was highly compressed, exposing Titan to the full force of the solar wind. In analyzing data from the encounter, scientists with Cassini's magnetometer team observed that the giant moon interacted with the solar wind much like the planets Mars and Venus, or a comet -- none of which possess their own internal magnetic field. Specifically, they saw that the solar wind draped itself around Titan, creating a shockwave that formed around Titan where the full-force solar wind rammed into the moon's atmosphere. Previously, researchers had thought Titan would have a different sort of interaction with the solar wind because of the moon's complex atmospheric chemistry. http://photojournal.jpl.nasa.gov/catalog/PIA19055

  19. The abundances of elements and isotopes in the solar wind

    NASA Technical Reports Server (NTRS)

    Gloeckler, George; Geiss, Johannes

    1988-01-01

    Studies of the chemical and isotopic composition of the solar wind are reviewed. Solar wind abundance measurements are discussed and solar wind, coronal, and photospheric abundances for elements between H and Fe are presented. Also, consideration is given to the determination of the solar wind isotopic composition of the noble gases using foil collection techniques and the observation of solar wind heavy ions with the mass per charge spectrometer on ISEE-3. Other topics include solar wind observations with solid state detectors, solar wind abundances in the magnetosheath and the plasma sheet, and high-mass resolution measurements of chemical elements and isotopes in the solar wind.

  20. Solar energy system with wind vane

    DOEpatents

    Grip, Robert E

    2015-11-03

    A solar energy system including a pedestal defining a longitudinal axis, a frame that is supported by the pedestal and that is rotateable relative to the pedestal about the longitudinal axis, the frame including at least one solar device, and a wind vane operatively connected to the frame to urge the frame relative to the pedestal about the longitudinal axis in response to wind acting on the wind vane.

  1. The quiescent corona and slow solar wind

    NASA Technical Reports Server (NTRS)

    Noci, G.; Kohl, J. L.; Antonucci, E.; Tondello, G.; Huber, M. C. E.; Fineschi, S.; Gardner, L. D.; Korendyke, C. M.; Nicolosi, P.; Romoli, M.; hide

    1997-01-01

    The observations of the ultraviolet coronagraph spectrometer (UVCS), operating onboard the Solar and Heliospheric Observatory (SOHO) spacecraft, are discussed. The purpose of the UVCS is the study of the quiescent coronal streamer and the slow solar wind. The observations started in January 1996. Polarized radiance data in the visible continuum were obtained. Some characteristics of the coronal streamer from the UVCS recorded data are discussed. A model for the source of the slow solar wind in the inner corona is proposed.

  2. The quiescent corona and slow solar wind

    NASA Technical Reports Server (NTRS)

    Noci, G.; Kohl, J. L.; Antonucci, E.; Tondello, G.; Huber, M. C. E.; Fineschi, S.; Gardner, L. D.; Korendyke, C. M.; Nicolosi, P.; Romoli, M.; Spadaro, D.; Maccari, L.; Raymond, J. C.; Siegmund, O. H. W.; Benna, C.; Ciaravella, A.; Giordano, S.; Michels, J.; Modigliani, A.; Naletto, G.

    1997-01-01

    The observations of the ultraviolet coronagraph spectrometer (UVCS), operating onboard the Solar and Heliospheric Observatory (SOHO) spacecraft, are discussed. The purpose of the UVCS is the study of the quiescent coronal streamer and the slow solar wind. The observations started in January 1996. Polarized radiance data in the visible continuum were obtained. Some characteristics of the coronal streamer from the UVCS recorded data are discussed. A model for the source of the slow solar wind in the inner corona is proposed.

  3. Global Network of Slow Solar Wind

    NASA Technical Reports Server (NTRS)

    Crooker, N. U.; Antiochos, S. K.; Zhao, X.; Neugebauer, M.

    2012-01-01

    The streamer belt region surrounding the heliospheric current sheet (HCS) is generally treated as the primary or sole source of the slow solar wind. Synoptic maps of solar wind speed predicted by the Wang-Sheeley-Arge model during selected periods of solar cycle 23, however, show many areas of slow wind displaced from the streamer belt. These areas commonly have the form of an arc that is connected to the streamer belt at both ends. The arcs mark the boundaries between fields emanating from different coronal holes of the same polarity and thus trace the paths of belts of pseudostreamers, i.e., unipolar streamers that form over double arcades and lack current sheets. The arc pattern is consistent with the predicted topological mapping of the narrow open corridor or singular separator line that must connect the holes and, thus, consistent with the separatrix-web model of the slow solar wind. Near solar maximum, pseudostreamer belts stray far from the HCS-associated streamer belt and, together with it, form a global-wide web of slow wind. Recognition of pseudostreamer belts as prominent sources of slow wind provides a new template for understanding solar wind stream structure, especially near solar maximum.

  4. Bimodal Solar Wind-Magnetosphere-Ionosphere Coupling

    NASA Astrophysics Data System (ADS)

    Siscoe, G.

    2005-05-01

    Regarding its coupling to the solar wind, the magnetosphere-ionosphere system appears to be schizophrenic. That is, it seems to manifest two modes with contradictory qualities, modes that alternate depending on solar wind conditions. Normal conditions elicit the normal mode (aka the solar wind-dominated mode). But extreme conditions bring out the un-normal mode (aka the ionosphere-dominated mode). This talk emphasizes the un-normal, ionosphere-dominated mode, which makes its presence during great magnetic storms. Then the magnetosphere-confining Chapman-Ferraro current system fades away to be replaced by the region 1 currents system which links the now dominant ionosphere to the whole of geospace out to and including the bow shock. Dst no longer responds to the ram pressure of the solar wind. The electrical potential across the polar cap stops growing as solar wind driving strengthens. Instead, it becomes bound to ionospheric conductance, which as the storm intensifies transforms under local instability. The ionosphere appears to lose its grip on magnetospheric convection, although this is not certain. The plasmasphere is stripped away, most likely to feed (by global circulation) an intensifying ring current. The outer magnetosphere begins a series of slow, macroscale convulsions. Huge parallel potentials possibly develop in the magnetosphere's outer regions, reacting against the ionosphere's domination. Compared to the solar wind-dominated magnetosphere, the ionosphere-dominated magnetosphere is comparatively unknown and, so, provides opportunities for significantly advancing our understanding of the coupled solar wind-magnetosphere-ionosphere system.

  5. Wave Modeling of the Solar Wind.

    PubMed

    Ofman, Leon

    The acceleration and heating of the solar wind have been studied for decades using satellite observations and models. However, the exact mechanism that leads to solar wind heating and acceleration is poorly understood. In order to improve the understanding of the physical mechanisms that are involved in these processes a combination of modeling and observational analysis is required. Recent models constrained by satellite observations show that wave heating in the low-frequency (MHD), and high-frequency (ion-cyclotron) range may provide the necessary momentum and heat input to coronal plasma and produce the solar wind. This review is focused on the results of several recent solar modeling studies that include waves explicitly in the MHD and the kinetic regime. The current status of the understanding of the solar wind acceleration and heating by waves is reviewed.

  6. Radial Evolution of the Solar Wind

    NASA Astrophysics Data System (ADS)

    Elliott, H. A.; Delamere, P. A.

    2016-12-01

    New Horizons now provides another radial slice of solar wind measurements in the ecliptic in the 11 to 36 AU distance range. We extend our prior analysis of the radial evolution of the solar wind by including recent New Horizon observations and analyzing Ulysses, and Voyagers 1 & 2 observations using the same techniques. Most of the Ulysses observations between 3 and 5.4 AU were out of the ecliptic, but the Voyager observations were close to the ecliptic from 1 to 40 AU. Another key difference between is that the Voyager and Ulysses measurements were collected in more active solar cycles than the New Horizons ones. We examine how the dynamic interaction of the fast and slow wind, which creates compressions and rarefactions, impacts the radial evolution of the temperature-speed relationship. No clear signatures of slowing and heating of the solar wind owing to interaction with the interstellar material is observed, when one collectively analyzes the radial profiles of the solar wind parameters inside of 40 AU using data from one of these missions. However, comparisons of 1 AU and outer heliospheric wind observations reveals that solar wind structures are significantly worn down and/or merge together with increasing distance from the Sun. We speculate that compression regions may have additional slowing and heating of the wind compared to rarefactions since the compressions are more dense and have elevated levels of interstellar pickup. Such a difference would not be obvious if the solar wind observations were collectively analyzed without first sorting the compressions and rarefactions. We perform such sorting and use hybrid simulations of dense compression regions (in the 20-36 AU distance range) to assess if there is enhanced slowing or heating owing to interaction of the solar wind with interstellar material in the compression regions.

  7. Solar Wind Earth Exchange Project (SWEEP)

    DTIC Science & Technology

    2016-10-28

    and highly charged ions of the solar wind. The main challenge in predicting the resultant photon flux in the X-ray energy bands is due to the...AFRL-AFOSR-UK-TR-2016-0035 Solar Wind Earth Exchange Project 140200 Steven Sembay UNIVERSITY OF LEICESTER Final Report 10/28/2016 DISTRIBUTION A...To) 01 Sep 2014 to 31 Aug 2016 4. TITLE AND SUBTITLE Solar Wind Earth Exchange Project (SWEEP) 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA9550-14-1

  8. On periodicity of solar wind phenomena

    NASA Technical Reports Server (NTRS)

    Verma, V. K.; Joshi, G. C.

    1995-01-01

    We have investigated the rate of occurrence of solar wind phenomena observed between 1972-1984 using power spectrum analysis. The data have been taken from the high speed solar wind (HSSW) streams catalogue published by Mavromichalaki et al. (1988). The power spectrum analysis of HSSW events indicate that HSSW stream events have a periodicity of 9 days. This periodicity of HSSW events is 1/3 of the 27 days period of coronal holes which are the major source of solar wind events. In our opinion the 9 days period may be the energy build up time to produce the HSSW stream events.

  9. DSCOVR High Time Resolution Solar Wind Measurements

    NASA Technical Reports Server (NTRS)

    Szabo, Adam

    2012-01-01

    The Deep Space Climate Observatory (DSCOVR), previously known as Triana, spacecraft is expected to be launched in late 2014. It will carry a fluxgate magnetometer, Faraday Cup solar wind detector and a top-hat electron electrostatic analyzer. The Faraday Cup will provide an unprecedented 10 vectors/sec time resolution measurement of the solar wind proton and alpha reduced distribution functions. Coupled with the 40 vector/sec vector magnetometer measurements, the identification of specific wave modes in the solar wind will be possible for the first time. The science objectives and data products of the mission will be discussed.

  10. Verification of high-speed solar wind stream forecasts using operational solar wind models

    NASA Astrophysics Data System (ADS)

    Reiss, Martin A.; Temmer, Manuela; Veronig, Astrid M.; Nikolic, Ljubomir; Vennerstrom, Susanne; Schöngassner, Florian; Hofmeister, Stefan J.

    2016-07-01

    High-speed solar wind streams emanating from coronal holes are frequently impinging on the Earth's magnetosphere causing recurrent, medium-level geomagnetic storm activity. Modeling high-speed solar wind streams is thus an essential element of successful space weather forecasting. Here we evaluate high-speed stream forecasts made by the empirical solar wind forecast (ESWF) and the semiempirical Wang-Sheeley-Arge (WSA) model based on the in situ plasma measurements from the Advanced Composition Explorer (ACE) spacecraft for the years 2011 to 2014. While the ESWF makes use of an empirical relation between the coronal hole area observed in Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) images and solar wind properties at the near-Earth environment, the WSA model establishes a link between properties of the open magnetic field lines extending from the photosphere to the corona and the background solar wind conditions. We found that both solar wind models are capable of predicting the large-scale features of the observed solar wind speed (root-mean-square error, RMSE ≈100 km/s) but tend to either overestimate (ESWF) or underestimate (WSA) the number of high-speed solar wind streams (threat score, TS ≈ 0.37). The predicted high-speed streams show typical uncertainties in the arrival time of about 1 day and uncertainties in the speed of about 100 km/s. General advantages and disadvantages of the investigated solar wind models are diagnosed and outlined.

  11. Solar wind tans young asteroids

    NASA Astrophysics Data System (ADS)

    2009-04-01

    A new study published in Nature this week reveals that asteroid surfaces age and redden much faster than previously thought -- in less than a million years, the blink of an eye for an asteroid. This study has finally confirmed that the solar wind is the most likely cause of very rapid space weathering in asteroids. This fundamental result will help astronomers relate the appearance of an asteroid to its actual history and identify any after effects of a catastrophic impact with another asteroid. ESO PR Photo 16a/09 Young Asteroids Look Old "Asteroids seem to get a ‘sun tan' very quickly," says lead author Pierre Vernazza. "But not, as for people, from an overdose of the Sun's ultraviolet radiation, but from the effects of its powerful wind." It has long been known that asteroid surfaces alter in appearance with time -- the observed asteroids are much redder than the interior of meteorites found on Earth [1] -- but the actual processes of this "space weathering" and the timescales involved were controversial. Thanks to observations of different families of asteroids [2] using ESO's New Technology Telescope at La Silla and the Very Large Telescope at Paranal, as well as telescopes in Spain and Hawaii, Vernazza's team have now solved the puzzle. When two asteroids collide, they create a family of fragments with "fresh" surfaces. The astronomers found that these newly exposed surfaces are quickly altered and change colour in less than a million years -- a very short time compared to the age of the Solar System. "The charged, fast moving particles in the solar wind damage the asteroid's surface at an amazing rate [3]", says Vernazza. Unlike human skin, which is damaged and aged by repeated overexposure to sunlight, it is, perhaps rather surprisingly, the first moments of exposure (on the timescale considered) -- the first million years -- that causes most of the aging in asteroids. By studying different families of asteroids, the team has also shown that an asteroid

  12. Genesis SW-Oxygen Corrected for SW/SUN Isotopic Fractionation is Closer to Earth Oxygen than to CAI

    NASA Astrophysics Data System (ADS)

    Ozima, M.; Suzuki, T. K.; Yamada, A.

    2012-03-01

    The Genesis project gave a convincing isotopic composition of oxygen in bulk solar wind sample, but correction for putative isotopic fractionation between SW and the Sun is still needed to conclude the solar oxygen-isotopic composition.

  13. Genesis Recovery Processing

    NASA Technical Reports Server (NTRS)

    Stansbery, E. K.

    2005-01-01

    The Genesis spacecraft, launched in August 2001 to collect samples of the solar wind, returned to Earth on 8 September 2004. The Sample Return Capsule (SRC) failed to deploy its drogue parachute and parafoil and subsequently impacted the Utah Test and Training Range (UTTR) at an estimated 310 kph (193 mph). The goal of the Genesis mission to collect and return samples of the solar wind for precise elemental and isotopic analysis provides the scientific community with a unique set of materials to aid in understanding the origin of our solar system. The spacecraft orbited the Earth-Sun L1 point for 29 months exposing a suite of fifteen types of ultrapure, ultraclean materials in several different locations. Most of the materials were mounted on fixed or deployable wafer panels called collector arrays . A few materials were mounted as targets in the focal spot of an electrostatic mirror (the concentrator ). Other materials were strategically placed to maximize the area for solar-wind collection.

  14. Interplanetary shocks and solar wind extremes

    NASA Astrophysics Data System (ADS)

    Vats, Hari

    The interplanetary shocks have a very high correlation with the annual sunspot numbers during the solar cycle; however the correlation falls very low on shorter time scale. Thus poses questions and difficulty in the predictability. Space weather is largely controlled by these interplanetary shocks, solar energetic events and the extremes of solar wind. In fact most of the solar wind extremes are related to the solar energetic phenomena. It is quite well understood that the energetic events like flares, filament eruptions etc. occurring on the Sun produce high speed extremes both in terms of density and speed. There is also high speed solar wind steams associated with the coronal holes mainly because the magnetic field lines are open there and the solar plasma finds it easy to escape from there. These are relatively tenuous high speed streams and hence create low intensity geomagnetic storms of higher duration. The solar flares and/or filament eruptions usually release excess coronal mass into the interplanetary medium and thus these energetic events send out high density and high speed solar wind which statistically found to produce more intense storms. The other extremes of solar wind are those in which density and speed are much lower than the normal values. Several such events have been observed and are found to produce space weather consequences of different kind. It is found that such extremes are more common around the maximum of solar cycle 20 and 23. Most of these have significantly low Alfven Mach number. This article is intended to outline the interplanetary and geomagnetic consequences of observed by ground based and satellite systems for the solar wind extremes.

  15. Properties of the very slow solar wind

    NASA Astrophysics Data System (ADS)

    Sanchez-Diaz, Eduardo; Segura, Kevin; Rouillard, Alexis P.; Lavraud, Benoit

    2015-04-01

    Solar wind plasma data taken between 0.29-0.9 AU by the twin HELIOS spacecraft reveals the frequent occurrence of very low radial wind speeds (200 < V < 300 km/s), very rarely measured near 1 AU. By analysing the occurrence as a function of heliocentric distance and time, we show that it is primarly measured inside 0.5 AU and mostly during solar maximum, although some very slow wind events were also measured during short periods at solar minimum. We show that the very slow wind is frequently measured during the passage of the solar wind plasma sheet usually detected in the vicinity of the heliospheric current sheet. By tracing these slow events back to the Sun and using a potential field reconstruction of the coronal magnetic field based on magnetograms taken by Mount Wilson Observatory, we compare the speed of the very slow wind with the geometry of the magnetic flux tube at its source. We discuss theoretical mechanisms that could explain the abundance and origin of this very slow wind, we also stress the importance of these findings for our understanding of solar wind structure. This study was carried out as part of the HELCATS FP7 project.

  16. Solar Wind Overview of Cycle 24

    NASA Astrophysics Data System (ADS)

    Galvin, Antoinette; Farrugia, Charles; Kucharek, Harald; Yu, Wenyuan

    2017-04-01

    The STEREO observatories were commissioned in early 2007, near the end of solar cycle 23, and has continued (outside of the solar conjunction blackout period) providing data into the present phase of cycle 24. During the approach to solar minimum (2007-2008), there are two well-delineated regions of higher speed solar wind (> 500 km/s), associated with the central meridian passage of coronal holes and correlated with lower densities, lower iron ionic charge states, and uniform magnetic polarity. Preceding these regions are higher density ridges associated with stream interaction regions. During the recent solar minimum (2008-2010) there were significant intervals of slow speed solar wind, including small transients (Yu et al., 2016) and slow interplanetary coronal mass ejections. ICMEs characterized by higher speeds and higher iron charge states became more prevalent as the cycle reached solar maximum (2013-2014). We are currently in the declining phase of solar activity in this cycle, though ICME events are still being observed. We present overview synoptic solar wind data as seen at STEREO A for the mission to date and frequency distributions of solar wind iron charge states over time.

  17. Prospects for future solar-wind missions

    NASA Technical Reports Server (NTRS)

    Bochsler, P.; Moebius, E.

    1993-01-01

    Possible activities and future goals for solar wind research in the post Soho era are discussed. Two major enterprises which will open up important fields in the future study of the Sun are addressed. The first deals with in situ study of the solar corona, a region that has not been accessible for direct study in the past. This exploratory work will include the coronal heating and the acceleration of the solar wind much closer to its origin and the determination of the charge states of a large number of ions as a diagnostic tool for fractionation processes in these regions. The second major goal will be the setting up of a baseline for the isotopic composition in the solar system by studying a sample from the Sun in detail. These studies will be complemented by a direct comparison with extra solar samples of interstellar pick up ions, which become accessible with the same instrumentation as is necessary for the detailed investigation of the solar wind's isotopic composition. In order to achieve these goals, advanced composition experiments are developed to investigate the solar wind with enhanced mass resolution, considerably increased geometrical factor, and improved time resolution. The placing of sophisticated mass/charge spectrometers, with the ability to investigate both charge and velocity distributions with enhanced time resolution, in the solar wind acceleration region, is also proposed.

  18. The solar wind interaction with Venus

    NASA Technical Reports Server (NTRS)

    Luthmann, J. G.

    1992-01-01

    The Pioneer Venus Orbiter (PVO) mission has played a key role in establishing the nature of the solar wind interaction with Venus. Although earlier probes had determined that Venus presented an obstacle much smaller than the size of earth's magnetosphere to the solar wind, they did not carry out in situ measurements pertaining to solar wind interaction studies at low enough altitudes to determine why. They also did not provide datasets of sufficient duration to study the variability of the interaction of both short (one day) and long (solar cycle) timescales. The first 600 of the nearly 5000 orbits of PVO magnetometer data have been used to determine a very low upper limit on the intrinsic dipolar magnetic moment of Venus. The consequence of that low magnetic moment is that the solar wind interacts directly with the upper atmosphere and ionosphere. Relative to a dipolar field obstacle, the ionospheric obstacle is rather incompressible. A bow shock is observed to stand in front of the nearly Venus-sized ionospheric obstacle at a comparatively steady subsolar altitude of approximately 1.5 R(v) (Venus radii). This shock decelerates the supersonic solar wind plasma so that it can flow around the obstacle. It was found to change its average position in the terminator plane from about 2.4 R(v) to 2.1 R(v) as the solar cycle progressed from the 1978 orbit insertion near solar maximum through the 1986-87 solar minimum, and back again during the latest solar activity increase. Between the bow shock and the ionosphere proper, the slowed solar wind plasma flow diverges near the subsolar point and makes its way across the terminator where it reaccelerates and continues anti-Sunward. The solar wind magnetic field, which is in effect frozen into the flowing plasma, is distorted in this 'magnetosheath' region so that it appears to hang up or drape over the dayside ionosphere before it slips around with the flow. These features of the solar wind interaction are also seen when the

  19. Electrostatic Solitary Waves in the Solar Wind: Evidence for Instability at Solar Wind Current Sheets

    NASA Technical Reports Server (NTRS)

    Malaspina, David M.; Newman, David L.; Wilson, Lynn Bruce; Goetz, Keith; Kellogg, Paul J.; Kerstin, Kris

    2013-01-01

    A strong spatial association between bipolar electrostatic solitary waves (ESWs) and magnetic current sheets (CSs) in the solar wind is reported here for the first time. This association requires that the plasma instabilities (e.g., Buneman, electron two stream) which generate ESWs are preferentially localized to solar wind CSs. Distributions of CS properties (including shear angle, thickness, solar wind speed, and vector magnetic field change) are examined for differences between CSs associated with ESWs and randomly chosen CSs. Possible mechanisms for producing ESW-generating instabilities at solar wind CSs are considered, including magnetic reconnection.

  20. Solar and Wind Site Screening Decision Trees

    EPA Pesticide Factsheets

    EPA and NREL created a decision tree to guide state and local governments and other stakeholders through a process for screening sites for their suitability for future redevelopment with solar photovoltaic (PV) energy and wind energy.

  1. Turbulence in solar wind and laboratory plasmas

    SciTech Connect

    Carbone, V.

    2010-06-16

    Recent studies of plasma turbulence based on measurements within solar wind and laboratory plasmas has been discussed. Evidences for the presence of a turbulent energy cascade, using the Yaglom's law for MHD turbulence, has been provided through data from the Ulysses spacecraft. This allows, for the first time, a direct estimate of the turbulent energy transfer rate, which can contribute to the in situ heating of the solar wind. The energy cascade has been evidenced also for ExB electrostatic turbulence in laboratory magnetized plasmas using measurements of intermittent transport (bursty turbulence) at the edge of the RFX-mod reversed field pinch plasma device. Finally the problem of the dispersive region of turbulence in solar wind above the ion-cyclotron frequency, where a spectral break is usually observed, and the problem of dissipation in a collisionless fluid as the solar wind, are briefly discussed.

  2. An MHD Model of the Solar Corona and Solar Wind

    NASA Astrophysics Data System (ADS)

    Mikic, Z.; Linker, J. A.; Colborn, J. A.

    1996-05-01

    The structure of the heliosphere, especially the regions of fast and slow solar wind, are strongly influenced by coronal magnetic structure near the Sun. Favorable comparisons between three-dimensional MHD models of the solar corona and eclipse observations have shown that it is possible to model the structure of the large-scale solar corona. However, these models use a simplified energy equation, in which the plasma is assumed to obey an adiabatic energy equation with a reduced polytropic index. As a consequence, even though the predicted streamer structure in the corona agrees fairly well with eclipse observations, the predicted solar wind speed is not realistic. We have improved this model by adding important dynamic and thermodynamic effects, including the presence of a transition region, thermal conduction, radiation, coronal heating, and Alfven wave acceleration. We will present results obtained with this improved model on the structure of the solar corona and solar wind.

  3. Magnetic energy flow in the solar wind.

    NASA Technical Reports Server (NTRS)

    Modisette, J. L.

    1972-01-01

    Discussion of the effect of rotation (tangential flow) of the solar wind on the conclusions of Whang (1971) suggesting an increase in the solar wind velocity due to the conversion of magnetic energy to kinetic energy. It is shown that the effect of the rotation of the sun on the magnetic energy flow results in most of the magnetic energy being transported by magnetic shear stress near the sun.

  4. Efforts to Simulate Solar Wind Turbulence

    NASA Technical Reports Server (NTRS)

    Goldstein, Melvyn L.

    2007-01-01

    A three-dimensional integration of the MHD equations in spherical coordinates has been developed that attempts to simulate a variety of solar wind conditions. These include the interaction of Alfven wave packets and the development of a turbulent cascade, the role of the heliospheric current sheet, the role of quasi-two-dimensional fluctuations in determining how magnetic field lines meander throughout the heliosphere, and the role of interstellar pickup ions in perturbing the solar wind in the outer heliosphere.

  5. Quantifying Solar Wind-Polar Cap Interactions

    NASA Astrophysics Data System (ADS)

    Urban, K. D.; Gerrard, A. J.; Lanzerotti, L. J.; Weatherwax, A. T.; Huang, Y.

    2015-12-01

    It is well known that the solar wind is a major driver of ultra-low frequency [ULF] power at ground locations from low to high latitudes. However, due to the scarcity of deep polar cap magnetometer sites, it is not clear when, where, or if this is true deep inside the polar cap on open field lines where interplanetary magnetic field [IMF] ULF waves could possibly be directly detected. Given recent observations of very large Joule heating estimates from DMSP data, together with the large heating reported by the CHAMP satellite, it is important to understand the degree to which ULF waves in the solar wind can directly cause such heating. Using a time series of lagged correlation sequences ("dynamic correlograms") between GSM Bz ULF power (computed via data obtained from NASA's Advanced Composition Explorer [ACE] ahead of Earth in the solar wind) and the horizontal ULF power (H^2=N^2+E^2) from ground-based magnetometers in Earth's southern polar cap, we investigate the direct penetration of ULF waves from the solar wind into the polar ionosphere during a gamut of space weather conditions at a distributed network of Automated Geophysical Observatories [AGOs] in Antarctica. To infer causation, a predicted lag correlation maximum at each time step is computed by simply dividing the associated distance of ACE from Earth by the concurrent bulk solar wind speed. This technique helps parse out direct penetration of solar wind ULF waves from other sources (e.g., via leakage from closed field line resonances due to the bulk solar wind plasma viscously interacting at dawn/dusk flanks inducing Kelvin-Helmholtz instabilities [KHI] or compressional modes induced by impulses in solar wind dynamic pressure). The identified direct-penetrating ULF waves are related to the DMSP-derived Poynting fluxes by regression analysis, and conclusions are drawn for the importance of the ULF source for the measured heating.

  6. The interaction of the solar wind with the interstellar medium

    NASA Technical Reports Server (NTRS)

    Axford, W. I.

    1972-01-01

    The expected characteristics of the solar wind, extrapolated from the vicinity of the earth are described. Several models are examined for the interaction of the solar wind with the interstellar plasma and magnetic field. Various aspects of the penetration of neutral interstellar gas into the solar wind are considered. The dynamic effects of the neutral gas on the solar wind are described. Problems associated with the interaction of cosmic rays with the solar wind are discussed.

  7. Correlations between neutral and ionized solar wind

    NASA Astrophysics Data System (ADS)

    Pilkerton, B. M.; Collier, M. R.; Moore, T. E.

    We report results of a statistical study correlating ionized solar wind (ISW) fluxes observed by ACE during late 2000 and throughout 2001 with neutral solar wind (NSW) fluxes observed by IMAGE/LENA over the same period. The average correlation coefficient between the neutral and ionized solar wind is 0.66 with correlations greater than 0.80 occurring about 29% of the time. Correlations appear to be driven by high solar wind flux variability, similar to results obtained by in situ multi-spacecraft correlation studies. In this study, however, IMAGE remains inside the magnetosphere on over 95% of its orbits. As a function of day of year, or equivalently ecliptic longitude, the slope of the relationship between the neutral solar wind flux and the ionized solar wind flux shows an enhancement near the upstream direction, but the symmetry point appears shifted toward higher ecliptic longitudes than the interstellar neutral (ISN) flow direction by about 20°. The estimated peak interstellar neutral upstream density inside of 1 AU is about 7 × 10 -3 cm -3.

  8. BMSW - Fast solar wind monitor in operation

    NASA Astrophysics Data System (ADS)

    Safrankova, J.; Nemecek, Z.; Prech, L.; Zastenker, G. N.

    2012-04-01

    The Spektr-R spacecraft was launched on a Zenit-3F rocket into the Earth orbit with a perigee of 10,000 kilometers and apogee of 390,000 km on July 18, 2011. The spacecraft operational lifetime would exceed five years. The main task of the mission is investigation of distant sources of electromagnetic emissions but, as a supporting measurement, the spacecraft carries a complex of the devices for solar wind monitoring. The main task of the solar wind monitor (BMSW) is to provide the fast measurements of the solar wind density, velocity, and temperature with a time resolution of 32 ms. Such time resolution was obtained using simultaneous measurements of several Faraday cups oriented permanently approximately in the solar wind direction. We describe briefly basic principles of the measurements, bring several examples of observations that demonstrate necessity of fast measurements for a better understanding of solar wind processes and compare BMSW observations with other available solar wind spacecraft. We explain the data strategy and processing and present the data products that are already available for the broad scientific community via web page of the project.

  9. Origin of the Ubiquitous Fast Solar Wind

    NASA Technical Reports Server (NTRS)

    Habbal, S. R.; Woo, R.; Fineschi, S.; O'Neal, R.; Kohl, J.; Noci, G.

    1997-01-01

    The solar wind is a direct manifestation of the coronal heating processes which continue to elude us. For over three decades, observations in interplanetary space have identified two types of wind: a slow component with highly variable physical properties also characterized by speeds typically beow 500 kn/s, and a much less variable fast wind flowing on average at 750 km/s1.

  10. Sulfur abundances in the solar wind measured by SWICS on Ulysses. [Solar Wind Ion Composition Spectrometer

    NASA Technical Reports Server (NTRS)

    Shafer, C. M.; Gloeckler, G.; Galvin, A. B.; Ipavich, F. M.; Geiss, J.; Von Steiger, R.; Ogilvie, K.

    1993-01-01

    One of the nine experiments on Ulysses (launched October, 1990), the Solar Wind Ion Composition Spectrometer, utilizes an energy per charge deflection system along with time of flight technology to uniquely determine the mass and mass per charge of solar wind particles. Thus the composition of various solar wind types can be analyzed. Using the SWICS data accumulated during the in-ecliptic phase of the mission, we have determined the sulfur abundance, relative to silicon, in two different types of solar wind: transient and coronal hole associated flows. Sulfur is of extreme interest because it is one of the few elements that lies in the transitional region of the FIP-dependent relative abundance enrichment function, observed for solar energetic particles and some types of solar wind flows.

  11. Mars ionospheric response to solar wind variability

    NASA Astrophysics Data System (ADS)

    Opgenoorth, H. J.; Andrews, D. J.; Fränz, M.; Lester, M.; Edberg, N. J. T.; Morgan, D.; Duru, F.; Witasse, O.; Williams, A. O.

    2013-10-01

    planets with induced magnetospheres, the coupling between the ionosphere, the weak draped magnetosphere, and the solar wind is very direct in comparison to Earth. The weak induced magnetosphere itself is created by the prevailing Solar wind conditions and therefore in its shape and strength dynamically depending on it. In early 2010, Mars was located behind Earth in the Solar wind; thus, we can use coordinated data from multiple near-Earth spacecraft (Stereo, Wind) to evaluate what kind of Solar wind disturbances have passed by Earth and might consecutively hit Mars, and when. We employ plasma data from the ESA Mars-Express mission, the ASPERA-3 particle instrument, and the MARSIS Active Ionospheric Sounder (AIS) to investigate, for a number of isolated events in March and April 2010, how the ionosphere and the induced magnetosphere at Mars develop and decay in response to Solar wind variability in the magnetic field, density, and velocity. In a dedicated campaign mode, we use frequent long-duration MARSIS AIS operations for several consecutive orbits, to monitor for the first time the long-term development of the Martian plasma environment during solar wind disturbances. We find that the magnetosphere and ionosphere of Mars can become considerably compressed by solar wind dynamic pressure variations, which usually are also associated with changes in the magnetic draping of the interplanetary magnetic field around the planet. These are typically associated with corotating interaction regions and coronal mass ejections, and can last for several days. During such episodes of compression, we see signatures of increased plasma transport over the terminator and enhanced ion outflow from the upper atmosphere.

  12. A Comparison of the Propagated Solar Wind with Near-Earth Solar Wind Observations

    NASA Astrophysics Data System (ADS)

    Hsu, T. S.

    2015-12-01

    Magneotospheric dynamics are primarily controlled by the solar wind and its interplanetary magnetic field (IMF). Majority of the magnetospheric studies relied on observation of the solar wind frequently taken as far away as the L1 Lagrange point approximately 230 RE upstream. The quality of the empirical or theoretical modeling depends on how accurately the solar wind observation at L1 can be propagated to the magnetosphere and drives the magnetospheric dynamics. It has been more than two decades that researchers seek to determine the structures and evolution of the solar wind observationally in order to characterize the propagated solar wind parcels that interact with the Earth. Russell et al. [1980] used solar wind data at the Earth and L1 without considering the type of solar wind structures and found that the Bz correlations varied from 0.0 to 1.0. Although the most probable correlation was 0.85, half of the time the correlation was less than 0.5. The scale of IMF correlations was reexamined by Collier et al. [1998] using data from Wind and IMP 8. It should be noted that Collier et al. [1998] examined data during solar minimum and Russell et al. [1980] examined data during solar maximum. The scales of solar wind plasma and magnetic field were further examined by Richardson and Paularena [2001]. The found that the transverse scale for a decrease in density correlation by 0.1 is 120 Re and for velocity about 70 Re. In contrast the transverse scales for the components of the IMF are about 50 Re. Using ISEE 2 and IMP8 from 1978 to 1985, Hsu and McPherron [2009] found that a small transvers IMF structure of about 15 Re can occur only about 5%~13% . Most of the recent studies examining Sun-Earth coupling using OMNI solar data which is propagated to the Earth-Sun line by a method based upon minimum variance analysis [Weimer et al., 2003; Bargatze et al., 2005]. The important question of how often a near-earth IMF structure is absent from the propagated solar wind and

  13. Dynamics of solar wind speed: Cycle 23

    NASA Astrophysics Data System (ADS)

    Sarkar, Tushnik; Khondekar, Mofazzal H.; Banerjee, Subrata

    2017-04-01

    A statistical signal processing approach has been made to study the dynamics of the speed of steady flow of hot plasma from the corona of sun known as solar wind generated in Solar Cycle 23. A long time series of solar wind speed of length 2492 days from 1st Jan, 1997 to 28th October, 2003 collected from Coordinated Heliospheric Observations (COHO) data base at NASA's National Space Science Data Center (NSSDC) is investigated for this purpose. Detection of nonlinearity and chaos in dynamics of solar wind speed is the prime objective of this work. In the present analysis delay vector variance (DVV) method is used to detect the existence of nonlinearity within the dynamics of solar wind speed. To explore the signature of the chaos in it multiple statistical methodologies like '0-1' test, the correlation dimension analysis, computation of Information Entropy of the time series and Largest Lyapunov Exponent method have been applied. It has been observed that though the coronal plasma i.e. solar wind flow rate has a nonlinear dynamics but without any chaos. The absence of chaos indicates a probable regular behaviour of the series. The unit magnitude of the Correlation dimension indicates the presence of the deterministic component of the series. Embedding Dimension obtained argues that the deterministic component has dimension of six. The nearly zero value of the Lyapunov exponent claims that the system is conservative and exhibits Lyapunov stability. These revelations establish that not only the solar wind speed alone but the solar wind-magnetosphere coupling is also contributing towards the complexity of the magnetospheric plasma dynamics.

  14. Are There Natural Categories of Solar Wind?

    NASA Astrophysics Data System (ADS)

    Roberts, D. A.; Sipes, T.; Karimabadi, H.

    2014-12-01

    What seem to be the most obvious categories of solar wind, such as fast and slow, often turn out to be difficult to pin down on closer examination. For example, while slow winds tend to be dense and nonAlfvenic, there are significant exceptions, with some slow winds being not only very Alfvenic but also exhibiting many fast wind traits. Here we use "unsupervised" data mining to look for "natural" solar wind types. We use a set of variables to represent the state of the system and apply what are now standard algorithms to look for natural clustering of these variables. We have done this process for the solar wind density, speed, a carbon charge state ratio (6+ to 5+), the cross-helicity, and the "residual energy." When using the first three of these, we find two groups that tend to be slow and fast, but with the boundary between the groups that is a combination of speed and density. When all five variables are used, the best characterization of the states is as three basic groups in the cross-helicity vs residual energy space, i.e., in terms of "turbulence" measures rather than simple parameters. The three-variable case is largely but not completely reproduced in its subspace. We will suggest what the results could mean for the understanding of issues such as solar wind acceleration.

  15. Solar wind origin in coronal funnels.

    PubMed

    Tu, Chuan-Yi; Zhou, Cheng; Marsch, Eckart; Xia, Li-Dong; Zhao, Liang; Wang, Jing-Xiu; Wilhelm, Klaus

    2005-04-22

    The origin of the solar wind in solar coronal holes has long been unclear. We establish that the solar wind starts flowing out of the corona at heights above the photosphere between 5 megameters and 20 megameters in magnetic funnels. This result is obtained by a correlation of the Doppler-velocity and radiance maps of spectral lines emitted by various ions with the force-free magnetic field as extrapolated from photospheric magnetograms to different altitudes. Specifically, we find that Ne7+ ions mostly radiate around 20 megameters, where they have outflow speeds of about 10 kilometers per second, whereas C3+ ions with no average flow speed mainly radiate around 5 megameters. Based on these results, a model for understanding the solar wind origin is suggested.

  16. Evidence of active region imprints on the solar wind structure

    NASA Technical Reports Server (NTRS)

    Hick, P.; Jackson, B. V.

    1995-01-01

    A common descriptive framework for discussing the solar wind structure in the inner heliosphere uses the global magnetic field as a reference: low density, high velocity solar wind emanates from open magnetic fields, with high density, low speed solar wind flowing outward near the current sheet. In this picture, active regions, underlying closed magnetic field structures in the streamer belt, leave little or no imprint on the solar wind. We present evidence from interplanetary scintillation measurements of the 'disturbance factor' g that active regions play a role in modulating the solar wind and possibly contribute to the solar wind mass output. Hence we find that the traditional view of the solar wind, though useful in understanding many features of solar wind structure, is oversimplified and possibly neglects important aspects of solar wind dynamics

  17. Genesis Field Recovery

    NASA Technical Reports Server (NTRS)

    McNamara, K. M.

    2005-01-01

    The Genesis mission returned to Earth on September 8, 2004 after a nearly flawless three-year mission to collect solar matter. The intent was to deploy a drogue chute and parafoil high over the Utah desert and to catch the fragile payload capsule in mid-air by helicopter. The capsule would then be opened in a clean-room constructed for that purpose at UTTR, and a nitrogen purge was to be installed before transporting the science canister to JSC. Unfortunately, both chutes failed to deploy, causing the capsule to fall to the desert floor at a speed of nearly 200 MPH. Still, Genesis represents a milestone in the US space program, comprising the first sample return since the Apollo Missions as well as the first return of materials exposed to the space environment outside of low Earth orbit and beyond the Earth s magnetosphere for an extended period. We have no other comparable materials in all of our collections on Earth. The goal of the Genesis Mission was to collect a representative sample of the composition of the solar wind and thus, the solar nebula from which our solar system originated. This was done by allowing the naturally accelerated species to implant shallowly in the surfaces of ultra-pure, ultra-clean collector materials. These collectors included single crystal silicon (FZ and CZ), sapphire, silicon carbide; those materials coated with aluminum, silicon, diamond like carbon, and gold; and isotopically enriched polycrystalline diamond and amorphous carbon. The majority of these materials were distributed on five collector arrays. Three of the materials were housed in an electrostatic concentrator designed to increase the flux of low-mass ions. There was also a two-inch diameter bulk metallic glass collector and a gold foil, polished aluminum, and molybdenum coated platinum foil collector. An excellent review of the Genesis collector materials is offered in reference [1].

  18. Clouds blown by the solar wind

    NASA Astrophysics Data System (ADS)

    Voiculescu, M.; Usoskin, I.; Condurache-Bota, S.

    2013-12-01

    In this letter we investigate possible relationships between the cloud cover (CC) and the interplanetary electric field (IEF), which is modulated by the solar wind speed and the interplanetary magnetic field. We show that CC at mid-high latitudes systematically correlates with positive IEF, which has a clear energetic input into the atmosphere, but not with negative IEF, in general agreement with predictions of the global electric circuit (GEC)-related mechanism. Thus, our results suggest that mid-high latitude clouds might be affected by the solar wind via the GEC. Since IEF responds differently to solar activity than, for instance, cosmic ray flux or solar irradiance, we also show that such a study allows distinguishing one solar-driven mechanism of cloud evolution, via the GEC, from others.

  19. Slow Solar Wind: Observations and Modeling

    NASA Technical Reports Server (NTRS)

    Abbo, L.; Ofman, L.; Antiochos, S. K.; Hansteen, V. H.; Harra, L.; Ko, Y.-K.; Lapenta, G.; Li, B.; Riley, P.; Strachan, L.; hide

    2016-01-01

    While it is certain that the fast solar wind originates from coronal holes, where and how the slow solar wind (SSW) is formed remains an outstanding question in solar physics even in the post-SOHO era. The quest for the SSW origin forms a major objective for the planned future missions such as the Solar Orbiter and Solar Probe Plus. Nonetheless, results from spacecraft data, combined with theoretical modeling, have helped to investigate many aspects of the SSW. Fundamental physical properties of the coronal plasma have been derived from spectroscopic and imaging remote-sensing data and in situ data, and these results have provided crucial insights for a deeper understanding of the origin and acceleration of the SSW. Advanced models of the SSW in coronal streamers and other structures have been developed using 3D MHD and multi-fluid equations.

  20. Slow Solar Wind: Observations and Modeling

    NASA Technical Reports Server (NTRS)

    Abbo, L.; Ofman, L.; Antiochos, S. K.; Hansteen, V. H.; Harra, L.; Ko, Y.-K.; Lapenta, G.; Li, B.; Riley, P.; Strachan, L.; Von Steiger, R.; Wang, Y.-M.

    2016-01-01

    While it is certain that the fast solar wind originates from coronal holes, where and how the slow solar wind (SSW) is formed remains an outstanding question in solar physics even in the post-SOHO era. The quest for the SSW origin forms a major objective for the planned future missions such as the Solar Orbiter and Solar Probe Plus. Nonetheless, results from spacecraft data, combined with theoretical modeling, have helped to investigate many aspects of the SSW. Fundamental physical properties of the coronal plasma have been derived from spectroscopic and imaging remote-sensing data and in situ data, and these results have provided crucial insights for a deeper understanding of the origin and acceleration of the SSW. Advanced models of the SSW in coronal streamers and other structures have been developed using 3D MHD and multi-fluid equations.

  1. Slow Solar Wind: Observations and Modeling

    NASA Astrophysics Data System (ADS)

    Abbo, L.; Ofman, L.; Antiochos, S. K.; Hansteen, V. H.; Harra, L.; Ko, Y.-K.; Lapenta, G.; Li, B.; Riley, P.; Strachan, L.; von Steiger, R.; Wang, Y.-M.

    2016-11-01

    While it is certain that the fast solar wind originates from coronal holes, where and how the slow solar wind (SSW) is formed remains an outstanding question in solar physics even in the post-SOHO era. The quest for the SSW origin forms a major objective for the planned future missions such as the Solar Orbiter and Solar Probe Plus. Nonetheless, results from spacecraft data, combined with theoretical modeling, have helped to investigate many aspects of the SSW. Fundamental physical properties of the coronal plasma have been derived from spectroscopic and imaging remote-sensing data and in situ data, and these results have provided crucial insights for a deeper understanding of the origin and acceleration of the SSW. Advanced models of the SSW in coronal streamers and other structures have been developed using 3D MHD and multi-fluid equations.

  2. SOLAR METALLICITY DERIVED FROM IN SITU SOLAR WIND COMPOSITION

    SciTech Connect

    Von Steiger, R.; Zurbuchen, T. H. E-mail: thomasz@umich.edu

    2016-01-01

    We use recently released solar wind compositional data to determine the metallicity of the Sun—the fraction per unit mass that is composed of elements heavier than He. We focus on a present-day solar sample available to us, which is the least fractionated solar wind from coronal holes near the poles of the Sun. Using these data, we derive a metallicity of Z = 0.0196 ± 0.0014, which is significantly larger than recent published values based on photospheric spectroscopy, but consistent with results from helioseismology.

  3. Ancient solar wind in lunar microbreccias

    NASA Technical Reports Server (NTRS)

    Thiemens, M. H.; Clayton, R. N.

    1980-01-01

    Possible components of the ancient solar wind, particularly the N-15/N-14 ratio, are investigated on the basis of lunar microbreccia studies. Nitrogen contents and isotope ratios were determined for Apollo 11 and 15 microbreccia samples by means of vacuum pyrolysis techniques. The Apollo 11 soil breccias, which had been closed to the addition of recent solar wind due to their compaction, are found to contain the lowest N-15/N-14 ratios yet reported for the solar wind, extending the range of variation of the ratio to between a delta N-15 of -190% in the past to +120% at present. Nitrogen isotope analysis of the Apollo 15 drill core, which had undergone two episodes of solar wind exposure, also support the secular variation in the N-15 content of the solar wind, which is attributed to spallation reactions in the sun. The formation of the breccias at the Apollo 11 and 15 sites is discussed on the basis of the observed nitrogen systematics, and differences between N-15 and Ne-21 cosmic ray exposure ages implied are attributed to the diffusive loss of neon from lunar soils.

  4. Laboratory Facility for Simulating Solar Wind Sails

    SciTech Connect

    Funaki, Ikkoh; Ayabe, Tomohiro; Horisawa, Hideyuki; Yamakawa, Hiroshi

    2008-12-31

    Magnetic sail (MagSail) is a deep space propulsion system, in which an artificial magnetic cavity captures the energy of the solar wind to propel a spacecraft in the direction leaving the sun. For a scale-model experiment of the plasma flow of MagSail, we employed a magnetoplasmadynamic arcjet as a solar wind simulator. It is observed that a plasma flow from the solar wind simulator reaches a quasi-steady state of about 0.8 ms duration after a transient phase when initiating the discharge. During this initial phase of the discharge, a blast-wave was observed to develop radially in a vacuum chamber. When a solenoidal coil (MagSail scale model) is immersed into the quasi-steady flow where the velocity is 45 km/s, and the number density is 10{sup 19} m-3, a bow shock as well as a magnetic cavity were formed in front of the coil. As a result of the interaction between the plasma flow and the magnetic cavity, the momentum of the simulated solar wind is decreased, and it is found from the thrust measurement that the solar wind momentum is transferred to the coil simulating MagSail.

  5. Pluto-Charon solar wind interaction dynamics

    NASA Astrophysics Data System (ADS)

    Hale, J. P. M.; Paty, C. S.

    2017-05-01

    This work studies Charon's effects on the Pluto-solar wind interaction using a multifluid MHD model which simulates the interactions of Pluto and Charon with the solar wind as well as with each other. Specifically, it investigates the ionospheric dynamics of a two body system in which either one or both bodies possess an ionosphere. Configurations in which Charon is directly upstream and directly downstream of Pluto are considered. Depending on ionospheric and solar wind conditions, Charon could periodically pass into the solar wind flow upstream of Pluto. The results of this study demonstrate that in these circumstances Charon modifies the upstream flow, both in the case in which Charon possesses an ionosphere, and in the case in which Charon is without an ionosphere. This modification amounts to a change in the gross structure of the interaction region when Charon possesses an ionosphere but is more localized when Charon lacks an ionosphere. Furthermore, evidence is shown that supports Charon acting to partially shield Pluto from the solar wind when it is upstream of Pluto, resulting in a decrease in ionospheric loss by Pluto.

  6. Mars Ionospheric Response to Solar Wind Variability

    NASA Astrophysics Data System (ADS)

    Opgenoorth, H. J.; Edberg, N.; Lester, M.; Williams, A.; Fränz, M.; Witasse, O.; Duru, F.; Morgan, D.

    2011-10-01

    At planets with induced magnetospheres the coupling between the ionosphere, the small draped magnetosphere and the solar wind is in a way much more direct than at Earth. On the other hand it is also much more complicated as the magnetosphere itself is created and in its total shape and strength dynamically depending on the prevailing Solar wind conditions. In early 2010 Mars was located behind Earth in the Solar wind. In this study we have utilized coordinated data from multiple near-Earth spacecraft (Stereo, ACE, Cluster, and even Earth groundbased data) to evaluate what kind of Solar wind disturbances have passed by Earth and might hit Mars consecutively (and when). We use plasma data from the ESA Mars- Express mission (mainly from the ASPERA particle instrument and the MARSIS topside ionospheric sounder) to investigate what kind of ionospheric and magnetospheric response is triggered at Mars in response to Solar wind variability in the magnetic field, density and velocity for a number of isolated events in March and April 2010.

  7. Solar wind propagation by magnetic lasso

    NASA Astrophysics Data System (ADS)

    Dósa, Melinda; Opitz, Andrea

    2017-04-01

    Concerning the increasing number of heliospheric space missions it is a key issue to foresee space weather conditions in the spacecraft's and the target object's neighborhood. Solar wind parameters are propagated to outer orbits by several ballistic and magnetohydrodynamic (MHD) methods. MHD models describe the underlying physical processes more realistic, but computations are time-demanding. Ballistic models are simple, computationally fast and need only input data. They work quite well closer to the Sun, where MHD effects have smaller amplitudes. The ballistic model presented here is enhanced by adjusting for the target movement during the propagation time through the following method: First, a dataring is created around the Sun containing solar wind parameters for each Carrington longitude, based on ACE data. It is assumed that solar wind parameters from the same source are constant for one solar rotation. The second step is the actual propagation where we are trying to find the exact magnetic field line connecting the target object with a certain longitude of the source surface at the Sun. This is carried out by a minimum variance analysis. By this step a correction is applied for the movement of the target object during solar wind travel time. Once the proper magnetic field line is found, solar wind velocity and magnetic field polarity is propagated assuming no change during travel time. The method was tested successfully during the Rosetta mission. While the spacecraft was investigating the close environment of the comet Churyumov-Gerasimenko it was necessary to know the properties of the ambient solar wind in order to evaluate data and account for the dynamic changes.

  8. Solar wind ion composition and charge states

    NASA Technical Reports Server (NTRS)

    vonSteiger, R.

    1995-01-01

    The solar wind, a highly tenuous plasma streaming from the Sun into interplanetary space at supersonic speed, is roughly composed of 95% hydrogen and 5% helium by number. All other, heavy elements contribute less than 0.1% by number and thus are truly test particles Nevertheless, these particles provide valuable information not present in the main components. We first discuss the importance of the heavy ions as tracers for processes in the solar atmosphere. Specifically, their relative abundances are found to be different in the solar wind as compared to the photosphere. This fractionation, which is best organized as a function of the first ionization time (FIT) of the elements under solar surface conditions, provides information on the structure of the chromosphere. where it is imparted on the partially ionized material by an atom-ion separation mechanism. Moreover, the charge states of the heavy ions can be used to infer the coronal temperature, since they are frozen-in near the altitude where the expansion time scale overcomes the ionization/recombination time scales. Next, we review the published values of ion abundances in the solar wind, concentrating on the recent results of the SWICS instrument on Ulysses. About 8 elements and more than 20 charge states can be routinely analyzed by this sensor. There is clear evidence that both the composition and the charge state distribution is significantly different in the fast solar wind from the south polar coronal hole, traversed by Ulysses in 1993/94, as compared to the solar wind normally encountered near the ecliptic plane. The fractionation between low- and high-FIT elements is reduced, and the charge states indicate a lower, more uniform coronal temperature in the hole. Finally, we discuss these results in the framework of existing theoretical models of the chromosphere and corona, attempting to identify differences between the low- and high-latitude regions of the solar atmosphere.

  9. The Genesis Trajectory and Heteroclinic Cycles

    NASA Technical Reports Server (NTRS)

    Lo, M.; Koon, W.; Ross, S.; Marsden, J.

    1999-01-01

    The Genesis Mission will be NASA's first robotic sample return mission. The purpose of this mission is to collect solar wind samples for two years in L1 halo orbit and return it to the Utah Test and Training Range (UTTR) for mid-air retrieval by helicopters.

  10. Complexity induced solar wind turbulence and evolution

    NASA Astrophysics Data System (ADS)

    Chang, T.

    2003-04-01

    "Complexity" has become a hot topic in nearly every field of modern physics. Solar wind plasmas are of no exception. Recently, Chang [2002], in analogy with theories developed for phenomena observed in the magnetotail and the auroral zone [Chang, 1999; 2001], demonstrated that the sporadic and localized interactions of magnetic coherent structures arising from plasma resonances could be the origin of "complexity" of nonresonant pseudo-2D spatiotemporal fluctuations in solar wind turbulence and in the coronal hole base. Such nonresonant fluctuations were shown to exist in the solar wind by Matthaeus et al. [1990] in terms of the two-dimensional correlation as a function of distance parallel and perpendicular to the mean magnetic field based on the ISEE-3 magnetometer data. Other evidences indicating the existence of such type of fluctuations in the solar wind have been reported by Tu et al. [1989], Tu and Marsch [1990, 1991], Bruno and Bavassano [1991], Bavassano and Bruno [1992], Bruno et al. [2001], and others. These results explain [Tu and Marsch, 1991] why the Alfvén ratio (a quantitative measure of Alfvénicity) is often found to be less than one in the solar wind [Belcher and Davis 1971, Solodyna et al., 1977, Bruno et al, 1985, Roberts et al., 1990], particularly for the space range farther than 0.3 AU. The above observational results are also consistent with the conclusions obtained from 2D MHD numerical simulations [Matthaeus and Larkin, 1986, Roberts and Goldstein, 1988, Goldstein et al., 1989, Roberts et al., 1991, and Roberts, 1992]. Such findings have led Chang [2002] to suggest the following evolutional scenario for the plasma turbulence in the generic fast solar wind. In and near the coronal hole base, the turbulent fluctuations are predominantly nonresonantly generated by pseudo-2D nonlinear interactions. As the fluctuations emerge from the coronal hole base, they propagate resonantly in the field-aligned direction primarily as Alfvén waves

  11. Solar wind charge exchange during geomagnetic storms

    NASA Astrophysics Data System (ADS)

    Robertson, I. P.; Cravens, T. E.; Sibeck, D. G.; Collier, M. R.; Kuntz, K. D.

    2012-04-01

    On 2001 March 31 a coronal mass ejection pushed the subsolar magnetopause to the vicinity of geosynchronous orbit at 6.6 R_E. The NASA/GSFC Community Coordinated Modeling Center (CCMC) employed a global magnetohydrodynamic (MHD) model to simulate the solar wind-magnetosphere interaction during the peak of this geomagnetic storm. Robertson et al. then modeled the expected soft X-ray emission due to solar wind charge exchange with geocoronal neutrals in the dayside cusp and magnetosheath. The locations of the bow shock, magnetopause and cusps were clearly evident in their simulations. Another geomagnetic storm took place on 2000 July 14 (Bastille Day). We again modeled X-ray emission due to solar wind charge exchange, but this time as observed from a moving spacecraft. This paper discusses the impact of spacecraft location on observed X-ray emission and the degree to which the locations of the bow shock and magnetopause can be detected in images.

  12. Magnetofluid Turbulence in the Solar Wind

    NASA Technical Reports Server (NTRS)

    Goldstein, Melvyn L.

    2008-01-01

    The solar wind shows striking characteristics that suggest that it is a turbulent magnetofluid, but the picture is not altogether simple. From the earliest observations, a strong correlation between magnetic fluctuations and plasma velocity fluctuations was noted. The high corrections suggest that the fluctuations are Alfven waves. In addition, the power spectrum of the magnetic fluctuation showed evidence of an inertial range that resembled that seen in fully-developed fluid turbulence. Alfven waves, however, are exact solutions of the equations of incompressible magnetohydrodynamics. Thus, there was a puzzle: how can a magnetofluid consisting of Alfven waves be turbulent? The answer lay in the role of velocity shears in the solar wind that could drive turbulent evolution. Puzzles remain: for example, the power spectrum of the velocity fluctuations is less steep than the slope of the magnetic fluctuations, nor do we understand even now why the solar wind appears to be nearly incompressible with a -5/3 power-spectral index.

  13. Solar wind proton temperature-velocity relationship

    NASA Technical Reports Server (NTRS)

    Lopez, R. E.; Freeman, J. W.

    1986-01-01

    Helios 1 data are analyzed to find an experimental fit for the temperature-velocity relationship at 1 AU. It is shown that the proton temperature-velocity changes at a velocity of approximately 500 km/s. Interplanetary dynamic processes, i.e., stream interactions, are shown to affect the temperature-velocity relationships less than 22 percent; the functional form of these relationships appears to be preserved throughout the solar cycle. It is pointed out that any comprehensive model of the solar wind will have to address the difference in the temperature-velocity relationship between the low- and high-speed wind, since this is a product of the acceleration and subsequent heating process generating the solar wind.

  14. Magnetofluid Turbulence in the Solar Wind

    NASA Technical Reports Server (NTRS)

    Goldstein, Melvyn L.

    2008-01-01

    The solar wind shows striking characteristics that suggest that it is a turbulent magnetofluid, but the picture is not altogether simple. From the earliest observations, a strong correlation between magnetic fluctuations and plasma velocity fluctuations was noted. The high corrections suggest that the fluctuations are Alfven waves. In addition, the power spectrum of the magnetic fluctuation showed evidence of an inertial range that resembled that seen in fully-developed fluid turbulence. Alfven waves, however, are exact solutions of the equations of incompressible magnetohydrodynamics. Thus, there was a puzzle: how can a magnetofluid consisting of Alfven waves be turbulent? The answer lay in the role of velocity shears in the solar wind that could drive turbulent evolution. Puzzles remain: for example, the power spectrum of the velocity fluctuations is less steep than the slope of the magnetic fluctuations, nor do we understand even now why the solar wind appears to be nearly incompressible with a -5/3 power-spectral index.

  15. ENERGY DISSIPATION PROCESSES IN SOLAR WIND TURBULENCE

    SciTech Connect

    Wang, Y.; Wei, F. S.; Feng, X. S.; Sun, T. R.; Zuo, P. B.; Xu, X. J.; Zhang, J.

    2015-12-15

    Turbulence is a chaotic flow regime filled by irregular flows. The dissipation of turbulence is a fundamental problem in the realm of physics. Theoretically, dissipation ultimately cannot be achieved without collisions, and so how turbulent kinetic energy is dissipated in the nearly collisionless solar wind is a challenging problem. Wave particle interactions and magnetic reconnection (MR) are two possible dissipation mechanisms, but which mechanism dominates is still a controversial topic. Here we analyze the dissipation region scaling around a solar wind MR region. We find that the MR region shows unique multifractal scaling in the dissipation range, while the ambient solar wind turbulence reveals a monofractal dissipation process for most of the time. These results provide the first observational evidences for intermittent multifractal dissipation region scaling around a MR site, and they also have significant implications for the fundamental energy dissipation process.

  16. Escape for the Slow Solar Wind

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2017-05-01

    Plasma from the Sun known as the slow solar wind has been observed far away from where scientists thought it was produced. Now new simulations may have resolved the puzzle of where the slow solar wind comes from and how it escapes the Sun to travel through our solar system.An Origin PuzzleA full view of a coronal hole (dark portion) from SDO. The edges of the coronal hole mark the boundary between open and closed magnetic field lines. [SDO; adapted from Higginson et al. 2017]The Suns atmosphere, known as the corona, is divided into two types of regions based on the behavior of magnetic field lines. In closed-field regions, the magnetic field is firmly anchored in the photosphere at both ends of field lines, so traveling plasma is confined to coronal loops and must return to the Suns surface. In open-field regions, only one end of each magnetic field line is anchored in the photosphere, so plasma is able to stream from the Suns surface out into the solar system.This second type of region known as a coronal hole is thought to be the origin of fast-moving plasma measured in our solar system and known as the fast solar wind. But we also observe a slow solar wind: plasma that moves at speeds of less than 500 km/s.The slow solar wind presents a conundrum. Its observational properties strongly suggest it originates in the hot, closed corona rather than the cooler, open regions. But if the slow solar wind plasma originates in closed-field regions of the Suns atmosphere, then how does it escape from the Sun?Slow Wind from Closed FieldsA team of scientists led by Aleida Higginson (University of Michigan) has now used high-resolution, three-dimensional magnetohydrodynamic simulations to show how the slow solar wind can be generated from plasma that starts outin closed-field parts of the Sun.A simulated heliospheric arc, composed of open magnetic field lines. [Higginson et al. 2017]Motions on the Suns surface near the boundary between open and closed-field regions the boundary

  17. Solar wind turbulence: Observations of MHD effects

    NASA Technical Reports Server (NTRS)

    Bavassano, B.

    1995-01-01

    Since the first in-situ observations it was realized that the solar wind is permeated by large-amplitude variations on a very extended range of scales. In this paper an overview of our present state of knowledge for fluctuations in the magnetohydrodynamic (MHD) regime is given. These fluctuations are an important component of the solar wind variability and notably contribute to the overall energy and momentum flux. They generally have a turbulent character and their amplitude is large enough to suggest the presence of nonlinear effects. In recent years the use of high time-resolution data on an extended range of heliocentric distances has allowed major steps towards a satisfactory understanding of the solar wind MHD fluctuations. Their radial evolution in the expanding wind has been determined through detailed analyses of the variations in their spectral features. correlations. and anisotropics. The role of interplanetary sources has been carefully investigated. The influence of interactions with structures convected by the solar wind has been examined. Fluctuations have been studied in the light of theories developed to draw together the effects of both incompressibility and compressibility. Increasing attention has been devoted to the intermittent character of the turbulence. Finally, very recent observations by Ulysses at high heliographic latitudes have allowed the first in-situ analysis of turbulence features in polar regions of the heliosphere.

  18. Solar Wind Change Exchange from the Magnetosheath

    NASA Technical Reports Server (NTRS)

    Snowden, Steve

    2008-01-01

    We report the results of a long (approximately 100 ks) XMM-Newton observation designed to observe solar wind charge exchange emission (SWCX) from Earth's magnetosheath. By luck, the observation took place during a period of minimal solar wind flux so the SWCX emission was also minimal. Never-the-less, there is a significant if not stunning correlation between the observed O VIII count rate and our model for magnetosheath emission. We also report on the observed O VII and O VII emission.

  19. Solar wind controls on Mercury's magnetospheric cusp

    NASA Astrophysics Data System (ADS)

    He, Maosheng; Vogt, Joachim; Heyner, Daniel; Zhong, Jun

    2017-06-01

    This study assesses the response of the cusp to solar wind changes comprehensively, using 2848 orbits of MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) observation. The assessment entails four steps: (1) propose and validate an approach to estimate the solar wind magnetic field (interplanetary magnetic field (IMF)) for MESSENGER's cusp transit; (2) define an index σ measuring the intensity of the magnetic disturbance which significantly peaks within the cusp and serves as an indicator of the cusp activity level; (3) construct an empirical model of σ as a function of IMF and Mercury's heliocentric distance rsun, through linear regression; and (4) use the model to estimate and compare the polar distribution of the disturbance σ under different conditions for a systematic comparison. The comparison illustrates that the disturbance peak over the cusp is strongest and widest extending in local time for negative IMF Bx and negative IMF Bz, and when Mercury is around the perihelion. Azimuthal shifts are associated with both IMF By and rsun: the cusp moves toward dawn when IMF By or rsun decrease. These dependences are explained in terms of the IMF Bx-controlled dayside magnetospheric topology, the component reconnection model applied to IMF By and Bz, and the variability of solar wind ram pressure associated with heliocentric distance rsun. The applicability of the component reconnection model on IMF By indicates that at Mercury reconnection occurs at lower shear angles than at Earth.Plain Language SummaryMercury's magnetosphere was suggested to be particularly sensitive to <span class="hlt">solar</span> <span class="hlt">wind</span> conditions. This study investigates the response of the magnetospheric cusp to <span class="hlt">solar</span> <span class="hlt">wind</span> conditions systematically. For this purpose, we analyze the statistical predictability of interplanetary magnetic field (IMF) at Mercury, develop an approach for estimating the <span class="hlt">solar</span> <span class="hlt">wind</span> magnetic field (IMF) for MErcury Surface</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080043891&hterms=snowden&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsnowden','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080043891&hterms=snowden&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsnowden"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Change Exchange from the Magnetosheath</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Snowden, Steve</p> <p>2008-01-01</p> <p>We report the results of a long (approximately 100 ks) XMM-Newton observation designed to observe <span class="hlt">solar</span> <span class="hlt">wind</span> charge exchange emission (SWCX) from Earth's magnetosheath. By luck, the observation took place during a period of minimal <span class="hlt">solar</span> <span class="hlt">wind</span> flux so the SWCX emission was also minimal. Never-the-less, there is a significant if not stunning correlation between the observed O VIII count rate and our model for magnetosheath emission. We also report on the observed O VII and O VII emission.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994AdSpR..14..161B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994AdSpR..14..161B"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> composition from the Moon;</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bochsler, P.</p> <p>1994-06-01</p> <p>The lunar regolith contains the best accessible record of the <span class="hlt">solar</span> <span class="hlt">wind</span> composition of the past few billion years. Interpreting this record crucially depends on our understanding of the implantation mechanisms, potential alternative sources other than the <span class="hlt">solar</span> <span class="hlt">wind</span>, storage and degradation processes, and transport- and loss-mechanisms of trapped particles in the regolith. We therefore suggest that a future mission to the Moon should contain the following objectives: (1) A thorough in-situ investigation of the contemporary <span class="hlt">solar</span> <span class="hlt">wind</span> composition by means of long-duration exposure experiments with various techniques as baseline for investigation of the historic and ancient <span class="hlt">solar</span> <span class="hlt">wind</span>. (2) A multidisciplinary program, involving an experimental investigation of implantation-, storage- and loss-processes of <span class="hlt">solar</span> particles at the conditions of the lunar environment. This program is complementary to an elaborated systematic sampling of all layers of the lunar regolith, based on the experience from the Apollo- and the Luna-missions. Difficulties with the interpretation of the lunar record are illuminated in the case of surface correlated nitrogen. (3) A complementary goal for the extensive sampling of the lunar surface is the documentation of the lunar regolith for future generations, prior to extended human activites which could have detrimental effects to the lunar environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009LNP...778..223I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009LNP...778..223I"><span>Diagnostics of the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Plasma</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Issautier, K.</p> <p></p> <p>The <span class="hlt">solar</span> <span class="hlt">wind</span> is a fully ionized plasma, coming from the outer atmosphere of the Sun, the so-called <span class="hlt">solar</span> corona, which expands as a supersonic flow into the interplanetary medium [55]. The first observations indicating that the Sun might be emitting a <span class="hlt">wind</span> were made by Biermann in 1946 of comet tails [1], which are observed to point away from the Sun. Comets usually exhibit two tails: a dust tail driven by the radiation pressure and a plasma tail, which points in slightly different directions pushed by the “<span class="hlt">solar</span> corpuscular radiation” of the Sun. In 1958, E.N. Parker explained theoretically this “particle radiation” using a simple fluid model [55], showing that the <span class="hlt">solar</span> atmosphere is not in hydrostatic equilibrium but must expand into the interplanetary medium as a <span class="hlt">wind</span>. The existence of this <span class="hlt">solar</span> <span class="hlt">wind</span> was debated until it was indeed confirmed by spacecraft Lunik 2 and 3 [16] and continuously observed by Mariner 2 [53]. The Parker theory is discussed fully in Chap. 7 (Velli).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170005311','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170005311"><span>Marshall Space Flight Center's <span class="hlt">Solar</span> <span class="hlt">Wind</span> Facility</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wright, K. H.; Schneider, T. A.; Vaughn, J. A.; Whittlesey, P. L.</p> <p>2017-01-01</p> <p>Historically, NASA's Marshall Space Flight Center (MSFC) has operated a <span class="hlt">Solar</span> <span class="hlt">Wind</span> Facility (SWF) to provide long term particle and photon exposure to material samples. The requirements on the particle beam details were not stringent as the cumulative fluence level is the test goal. Motivated by development of the faraday cup instrument on the NASA <span class="hlt">Solar</span> Probe Plus (SPP) mission, the MSFC SWF has been upgraded to included high fidelity particle beams providing broadbeam ions, broadbeam electrons, and narrow beam protons or ions, which cover a wide dynamic range of <span class="hlt">solar</span> <span class="hlt">wind</span> velocity and flux conditions. The large vacuum chamber with integrated cryo-shroud, combined with a 3-axis positioning system, provides an excellent platform for sensor development and qualification. This short paper provides some details of the SWF charged particle beams characteristics in the context of the <span class="hlt">Solar</span> Probe Plus program requirements. Data will be presented on the flux and energy ranges as well as beam stability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21700868','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21700868"><span>The oxygen isotopic composition of the Sun inferred from captured <span class="hlt">solar</span> <span class="hlt">wind</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McKeegan, K D; Kallio, A P A; Heber, V S; Jarzebinski, G; Mao, P H; Coath, C D; Kunihiro, T; Wiens, R C; Nordholt, J E; Moses, R W; Reisenfeld, D B; Jurewicz, A J G; Burnett, D S</p> <p>2011-06-24</p> <p>All planetary materials sampled thus far vary in their relative abundance of the major isotope of oxygen, (16)O, such that it has not been possible to define a primordial <span class="hlt">solar</span> system composition. We measured the oxygen isotopic composition of <span class="hlt">solar</span> <span class="hlt">wind</span> captured and returned to Earth by NASA's <span class="hlt">Genesis</span> mission. Our results demonstrate that the Sun is highly enriched in (16)O relative to the Earth, Moon, Mars, and bulk meteorites. Because the <span class="hlt">solar</span> photosphere preserves the average isotopic composition of the <span class="hlt">solar</span> system for elements heavier than lithium, we conclude that essentially all rocky materials in the inner <span class="hlt">solar</span> system were enriched in (17)O and (18)O, relative to (16)O, by ~7%, probably via non-mass-dependent chemistry before accretion of the first planetesimals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930067663&hterms=ion+Composition+Experiment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dion%2BComposition%2BExperiment','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930067663&hterms=ion+Composition+Experiment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dion%2BComposition%2BExperiment"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> composition measurements by the Ulysses SWICS experiment during transient <span class="hlt">solar</span> <span class="hlt">wind</span> flows</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Galvin, A. B.; Gloeckler, G.; Ipavich, F. M.; Shafer, C. M.; Geiss, J.; Ogilvie, K.</p> <p>1993-01-01</p> <p>For the March/April 1991 time period, the alpha/proton abundance ratio, the proton kinetic temperature and speed distributions, and the relative abundance of O(+7) to O(+6) is determined over each 13-minute duty cycle of the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Ion Composition Spectrometer (SWICs) experiment on Ulysses. The ratio O(+7)/O(+6) (as a relative measure of ionization temperature) is shown to be useful in identifying possible coronal mass ejection (CME) events. We report measurements of silicon/oxygen abundance ratios and silicon and oxygen charge state distributions in the <span class="hlt">solar</span> <span class="hlt">wind</span> during a CME event and compare these compositions to a 'normal' <span class="hlt">solar</span> <span class="hlt">wind</span> time period.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920017194','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920017194"><span>Workshop on <span class="hlt">Solar</span> Activity, <span class="hlt">Solar</span> <span class="hlt">Wind</span>, Terrestrial Effects, and <span class="hlt">Solar</span> Acceleration</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1992-01-01</p> <p>A summary of the proceedings from the workshop are presented. The areas covered were <span class="hlt">solar</span> activity, <span class="hlt">solar</span> <span class="hlt">wind</span>, terrestrial effects, and <span class="hlt">solar</span> acceleration. Specific topics addressed include: (1) <span class="hlt">solar</span> cycle manifestations, both large and small scale, as well as long-term and short-term changes, including transients such as flares; (2) sources of <span class="hlt">solar</span> <span class="hlt">wind</span>, as identified by interplanetary observations including coronal mass ejections (CME's) or x-ray bright points, and the theory for and evolution of large-scale and small-scale structures; (3) magnetosphere responses, as observed by spacecraft, to variable <span class="hlt">solar</span> <span class="hlt">wind</span> and transient energetic particle emissions; and (4) origin and propagation of <span class="hlt">solar</span> cosmic rays as related to <span class="hlt">solar</span> activity and terrestrial effects, and <span class="hlt">solar</span> <span class="hlt">wind</span> coronal-hole relationships and dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/570069','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/570069"><span><span class="hlt">Wind/solar</span> resource in Texas</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nelson, V.; Starcher, K.; Gaines, H.</p> <p>1997-12-31</p> <p>Data are being collected at 17 sites to delineate a baseline for the <span class="hlt">wind</span> and <span class="hlt">solar</span> resource across Texas. <span class="hlt">Wind</span> data are being collected at 10, 25, and 40 m (in some cases at 50 m) to determine <span class="hlt">wind</span> shear and power at hub heights of large turbines. Many of the sites are located in areas of predicted terrain enhancement. The typical day in a month for power and <span class="hlt">wind</span> turbine output was calculated for selected sites and combination of sites; distributed systems. Major result to date is that there is the possibility of load matching in South Texas during the summer months, even though the average values by month indicate a low <span class="hlt">wind</span> potential.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MNRAS.463....2S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MNRAS.463....2S"><span>Implications of <span class="hlt">solar</span> <span class="hlt">wind</span> measurements for <span class="hlt">solar</span> models and composition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Serenelli, Aldo; Scott, Pat; Villante, Francesco L.; Vincent, Aaron C.; Asplund, Martin; Basu, Sarbani; Grevesse, Nicolas; Peña-Garay, Carlos</p> <p>2016-11-01</p> <p>We critically examine recent claims of a high <span class="hlt">solar</span> metallicity by von Steiger & Zurbuchen (2016, vSZ16) based on in situ measurements of the <span class="hlt">solar</span> <span class="hlt">wind</span>, rather than the standard spectroscopically inferred abundances (Asplund et al. 2009, hereafter AGSS09). We test the claim by Vagnozzi et al. (2016) that a composition based on the <span class="hlt">solar</span> <span class="hlt">wind</span> enables one to construct a standard <span class="hlt">solar</span> model in agreement with helioseismological observations and thus solve the decades-old <span class="hlt">solar</span> modelling problem. We show that, although some helioseismological observables are improved compared to models computed with spectroscopic abundances, most are in fact worse. The high abundance of refractory elements leads to an overproduction of neutrinos, with a predicted 8B flux that is nearly twice its observed value, and 7Be and CNO fluxes that are experimentally ruled out at high confidence. A combined likelihood analysis shows that models using the vSZ16 abundances are worse than AGSS09 despite a higher metallicity. We also present astrophysical and spectroscopic arguments showing the vSZ16 composition to be an implausible representation of the <span class="hlt">solar</span> interior, identifying the first ionization potential effect in the outer <span class="hlt">solar</span> atmosphere and <span class="hlt">wind</span> as the likely culprit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20110016220&hterms=solar+wind&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsolar%2Bwind','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20110016220&hterms=solar+wind&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsolar%2Bwind"><span>Coronal Plumes in the Fast <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Velli, Marco; Lionello, Roberto; Linker, Jon A.; Mikic, Zoran</p> <p>2011-01-01</p> <p>The expansion of a coronal hole filled with a discrete number of higher density coronal plumes is simulated using a time-dependent two-dimensional code. A <span class="hlt">solar</span> <span class="hlt">wind</span> model including an exponential coronal heating function and a flux of Alfven waves propagating both inside and outside the structures is taken as a basic state. Different plasma plume profiles are obtained by using different scale heights for the heating rates. Remote sensing and <span class="hlt">solar</span> <span class="hlt">wind</span> in situ observations are used to constrain the parameter range of the study. Time dependence due to plume ignition and disappearance is also discussed. Velocity differences of the order of approximately 50 km/s, such as those found in microstreams in the high-speed <span class="hlt">solar</span> <span class="hlt">wind</span>, may be easily explained by slightly different heat deposition profiles in different plumes. Statistical pressure balance in the fast <span class="hlt">wind</span> data may be masked by the large variety of body and surface waves which the higher density filaments may carry, so the absence of pressure balance in the microstreams should not rule out their interpretation as the extension of coronal plumes into interplanetary space. Mixing of plume-interplume material via the Kelvin-Helmholtz instability seems to be possible within the parameter ranges of the models defined here, only at large di stances from the Sun, beyond 0.2-0.3 AU. Plasma and composition measurements in the inner heliosphere, such as those which will become available with <span class="hlt">Solar</span> Orbiter and <span class="hlt">Solar</span> Probe Plus, should therefore definitely be able to identify plume remnants in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20110016220&hterms=solar+wind&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsolar%2Bwind','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20110016220&hterms=solar+wind&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsolar%2Bwind"><span>Coronal Plumes in the Fast <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Velli, Marco; Lionello, Roberto; Linker, Jon A.; Mikic, Zoran</p> <p>2011-01-01</p> <p>The expansion of a coronal hole filled with a discrete number of higher density coronal plumes is simulated using a time-dependent two-dimensional code. A <span class="hlt">solar</span> <span class="hlt">wind</span> model including an exponential coronal heating function and a flux of Alfven waves propagating both inside and outside the structures is taken as a basic state. Different plasma plume profiles are obtained by using different scale heights for the heating rates. Remote sensing and <span class="hlt">solar</span> <span class="hlt">wind</span> in situ observations are used to constrain the parameter range of the study. Time dependence due to plume ignition and disappearance is also discussed. Velocity differences of the order of approximately 50 km/s, such as those found in microstreams in the high-speed <span class="hlt">solar</span> <span class="hlt">wind</span>, may be easily explained by slightly different heat deposition profiles in different plumes. Statistical pressure balance in the fast <span class="hlt">wind</span> data may be masked by the large variety of body and surface waves which the higher density filaments may carry, so the absence of pressure balance in the microstreams should not rule out their interpretation as the extension of coronal plumes into interplanetary space. Mixing of plume-interplume material via the Kelvin-Helmholtz instability seems to be possible within the parameter ranges of the models defined here, only at large di stances from the Sun, beyond 0.2-0.3 AU. Plasma and composition measurements in the inner heliosphere, such as those which will become available with <span class="hlt">Solar</span> Orbiter and <span class="hlt">Solar</span> Probe Plus, should therefore definitely be able to identify plume remnants in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRA..119.2978P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRA..119.2978P"><span>Substorm occurrence during quiet <span class="hlt">solar</span> <span class="hlt">wind</span> driving</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pulkkinen, T. I.; Partamies, N.; Kilpua, E. K. J.</p> <p>2014-04-01</p> <p>We examine the OMNI database and International Monitor for Auroral Geomagnetic Effects (IMAGE) magnetometer chain records to study the substorm occurrence and characteristics during quiet <span class="hlt">solar</span> driving periods, especially during the <span class="hlt">solar</span> minimum period in 2009. We define substorm-like activations as periods where the hourly average AL is below -200 nT. Using the OMNI data set, we demonstrate that there are limiting <span class="hlt">solar</span> <span class="hlt">wind</span> speed, interplanetary magnetic field magnitude, and driving electric field values below which substorm-like activations (AL < 200 nT, intensification and decay of the electrojet) do not occur. These minimum parameter values are V < 266 km/s, B < 1.4 nT, and E < 0.025 mV/m such low values are observed less than 1% of the time. We also show that for the same level of driving <span class="hlt">solar</span> <span class="hlt">wind</span> electric field, the electrojet intensity is smaller (by few tens of nT), and the electrojet resides farther poleward (by over 1°) during extended quiet <span class="hlt">solar</span> driving in 2009 than during average <span class="hlt">solar</span> activity conditions. During the <span class="hlt">solar</span> minimum period in 2009, we demonstrate that substorm-like activations can be identified from the IMAGE magnetometer chain observations during periods when the hourly average IL index is below -100 nT. When the hourly IL activity is smaller than that, which covers 87% of the nighttime observations, the electrojet does not show coherent behavior. We thus conclude that substorm recurrence time during very quiet <span class="hlt">solar</span> <span class="hlt">wind</span> driving conditions is about 5-8 h, which is almost double that of the average <span class="hlt">solar</span> activity conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17742848','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17742848"><span>Apollo 11 <span class="hlt">solar</span> <span class="hlt">wind</span> composition experiment: first results.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bühler, F; Eberhardt, P; Geiss, J; Meister, J; Signer, P</p> <p>1969-12-19</p> <p>The helium-4 <span class="hlt">solar</span> <span class="hlt">wind</span> flux during the Apollo 11 lunar surface excursion was (6.3 +/- 1.2) x 10(6) atoms per square centimeter per second. The <span class="hlt">solar</span> <span class="hlt">wind</span> direction and energy are essentially not perturbed by the moon. Evidence for a lunar <span class="hlt">solar</span> <span class="hlt">wind</span> albedo was found.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AIPC.1203.1025T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AIPC.1203.1025T"><span>Combined <span class="hlt">Solar</span> and <span class="hlt">Wind</span> Energy Systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tripanagnostopoulos, Y.; Souliotis, M.; Makris, Th.</p> <p>2010-01-01</p> <p>In this paper we present the new concept of combined <span class="hlt">solar</span> and <span class="hlt">wind</span> energy systems for buildings applications. Photovoltaics (PV) and small <span class="hlt">wind</span> turbines (WTs) can be install on buildings, in case of sufficient <span class="hlt">wind</span> potential, providing the building with electricity. PVs can be combined with thermal collectors to form the hybrid photovoltaic/thermal (PV/T) systems. The PVs (or the PV/Ts) and WT subsystems can supplement each other to cover building electrical load. In case of using PV/T collectors, the surplus of electricity, if not used or stored in batteries, can increase the temperature of the thermal storage tank of the <span class="hlt">solar</span> thermal unit. The description of the experimental set-up of the suggested PV/T/WT system and experimental results are presented. In PV/T/WT systems the output from the <span class="hlt">solar</span> part depends on the sunshine time and the output of the <span class="hlt">wind</span> turbine part depends on the <span class="hlt">wind</span> speed and is obtained any time of day or night. The use of the three subsystems can cover a great part of building energy load, contributing to conventional energy saving and environment protection. The PV/T/WT systems are considered suitable in rural and remote areas with electricity supply from stand-alone units or mini-grid connection. PV/T/WT systems can also be used in typical grid connected applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1062443','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1062443"><span>Identifying <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Ramping Events: Preprint</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Florita, A.; Hodge, B. M.; Orwig, K.</p> <p>2013-01-01</p> <p><span class="hlt">Wind</span> and <span class="hlt">solar</span> power are playing an increasing role in the electrical grid, but their inherent power variability can augment uncertainties in power system operations. One solution to help mitigate the impacts and provide more flexibility is enhanced <span class="hlt">wind</span> and <span class="hlt">solar</span> power forecasting; however, its relative utility is also uncertain. Within the variability of <span class="hlt">solar</span> and <span class="hlt">wind</span> power, repercussions from large ramping events are of primary concern. At the same time, there is no clear definition of what constitutes a ramping event, with various criteria used in different operational areas. Here the Swinging Door Algorithm, originally used for data compression in trend logging, is applied to identify variable generation ramping events from historic operational data. The identification of ramps in a simple and automated fashion is a critical task that feeds into a larger work of 1) defining novel metrics for <span class="hlt">wind</span> and <span class="hlt">solar</span> power forecasting that attempt to capture the true impact of forecast errors on system operations and economics, and 2) informing various power system models in a data-driven manner for superior exploratory simulation research. Both allow inference on sensitivities and meaningful correlations, as well as the ability to quantify the value of probabilistic approaches for future use in practice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM42B..02R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM42B..02R"><span>Hemispheric differences in <span class="hlt">solar</span> <span class="hlt">wind</span> - magnetosphere interactions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reistad, J. P.; Ostgaard, N.; Laundal, K.; Snekvik, K.; Tenfjord, P.; Oksavik, K.</p> <p>2014-12-01</p> <p>Although the aurora to a large degree behave similar in the two hemispheres, recent simultaneous observations of the global aurora from space have revealed that sometimes rather large intensity and location asymmetries are present in the global aurora. From event studies using e.g. conjugate imaging, multiple mechanisms have been proposed to be responsible for the asymmetric aurora. However, we know very little about their general importance. We have investigated the general importance of an asymmetric <span class="hlt">solar</span> <span class="hlt">wind</span> dynamo. It has been suggested that the radial component of the IMF can modify the energy conversion between the <span class="hlt">solar</span> <span class="hlt">wind</span> and magnetosphere differently in the two hemispheres in a general sense. By looking at the global aurora using IMAGE WIC during carefully selected events minimally contaminated by other mechanisms affecting the two hemispheres differently, we find that the dusk side aurora depend oppositely on the radial IMF direction in the two hemispheres. These results are consistent with an asymmetric <span class="hlt">solar</span> <span class="hlt">wind</span> dynamo where the hemispheric preference is controlled by the radial IMF. This is the first study indicating the importance of the asymmetric <span class="hlt">solar</span> <span class="hlt">wind</span> dynamo in a general sense. A different mechanism, the asymmetric loading of magnetic flux during IMF By conditions is also expected to account for North-South asymmetries in the nightside global aurora. This will be investigated using a similar approach to establish the general importance of of this IMF By mechanism on the global aurora in the two hemispheres.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=biomass&pg=7&id=ED114270','ERIC'); return false;" href="https://eric.ed.gov/?q=biomass&pg=7&id=ED114270"><span>Energy Primer: <span class="hlt">Solar</span>, Water, <span class="hlt">Wind</span>, and Biofuels.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Portola Inst., Inc., Menlo Park, CA.</p> <p></p> <p>This is a comprehensive, fairly technical book about renewable forms of energy--<span class="hlt">solar</span>, water, <span class="hlt">wind</span>, and biofuels. The biofuels section covers biomass energy, agriculture, aquaculture, alcohol, methane, and wood. The focus is on small-scale systems which can be applied to the needs of the individual, small group, or community. More than one-fourth…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Biomass+AND+energy&pg=3&id=ED114270','ERIC'); return false;" href="http://eric.ed.gov/?q=Biomass+AND+energy&pg=3&id=ED114270"><span>Energy Primer: <span class="hlt">Solar</span>, Water, <span class="hlt">Wind</span>, and Biofuels.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Portola Inst., Inc., Menlo Park, CA.</p> <p></p> <p>This is a comprehensive, fairly technical book about renewable forms of energy--<span class="hlt">solar</span>, water, <span class="hlt">wind</span>, and biofuels. The biofuels section covers biomass energy, agriculture, aquaculture, alcohol, methane, and wood. The focus is on small-scale systems which can be applied to the needs of the individual, small group, or community. More than one-fourth…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730002063','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730002063"><span>Magnetic field merging in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schindler, K.</p> <p>1972-01-01</p> <p>Magnetic field merging in the <span class="hlt">solar</span> <span class="hlt">wind</span> is discussed in terms of steady-state merging, which involves a steady flow field, and of spontaneous merging, which involves an instability such as the tearing instability. Spontaneous merging is found to be more effective than steady-state merging.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.4843L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.4843L"><span>THOR Cold <span class="hlt">Solar</span> <span class="hlt">Wind</span> (CSW) instrument</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lavraud, Benoit</p> <p>2017-04-01</p> <p>Turbulence Heating ObserveR (THOR) is the first mission concept dedicated to the study of plasma turbulence. We present the Cold <span class="hlt">Solar</span> <span class="hlt">Wind</span> (CSW) instrument that is being designed for THOR. CSW will measure the full three dimensional distribution function of <span class="hlt">solar</span> <span class="hlt">wind</span> protons and alphas with unprecedented accuracies. It will measure <span class="hlt">solar</span> <span class="hlt">wind</span> proton distributions down to at least 50 ms with energy resolution of 7% and angular resolution of 1.5°. CSW is based on a top-hat electrostatic analyzer (with very large geometric factor) design with deflectors at the entrance. The particle detection system uses Channel Electron Multipliers (CEM) associated with an analog front end Application-Specific Integrated Circuit (ASIC). CSW electronics comprises a fast sweeping high voltage board, as well as an FPGA and low voltage power supply boards to perform its operations. CSW is designed to address many of the key science objectives of THOR, in particular regarding ion-scale kinetic aspects of <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080019653&hterms=wind+night+day&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dwind%2Bnight%2Bday','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080019653&hterms=wind+night+day&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dwind%2Bnight%2Bday"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Drivers for Steady Magnetospheric Convection</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>McPherron, Robert L.; O'Brien, T. Paul; Thompson, Scott; Lui, A. T. Y. (Editor)</p> <p>2005-01-01</p> <p>Steady magnetospheric convection (SMC) also known as convection bays, is a particular mode of response of the magnetosphere to <span class="hlt">solar</span> <span class="hlt">wind</span> coupling. It is characterized by convection lasting for times longer than a typical substorm recovery during which no substorms expansions can be identified. It is generally believed that the <span class="hlt">solar</span> <span class="hlt">wind</span> must be unusually steady for the magnetosphere to enter this state. However, most previous studies have assumed this is true and have used such conditions to identify events. In a preliminary investigation using only the AE and AL indices to select events we have shown that these expectations are generally correct. SMC events seem to be associated with slow speed <span class="hlt">solar</span> <span class="hlt">wind</span> and moderate, stable IMF Bz. In this report we extend our previous study including additional parameters and the time variations in various statistical quantities. For the intervals identified as SMCs we perform a detailed statistical analysis of the properties of different <span class="hlt">solar</span> <span class="hlt">wind</span> variables. We compare these statistics to those determined from all data, and from intervals in which substorms but not SMCs are present. We also consider the question of whether substorms are required to initiate and terminate an SMC. We conclude that the intervals we have identified as SMC are likely to be examples of the original Dungey concept of balanced reconnection at a pair of x-lines on the day and night side of the Earth.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080019653&hterms=LUI&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DLUI','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080019653&hterms=LUI&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DLUI"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Drivers for Steady Magnetospheric Convection</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>McPherron, Robert L.; O'Brien, T. Paul; Thompson, Scott; Lui, A. T. Y. (Editor)</p> <p>2005-01-01</p> <p>Steady magnetospheric convection (SMC) also known as convection bays, is a particular mode of response of the magnetosphere to <span class="hlt">solar</span> <span class="hlt">wind</span> coupling. It is characterized by convection lasting for times longer than a typical substorm recovery during which no substorms expansions can be identified. It is generally believed that the <span class="hlt">solar</span> <span class="hlt">wind</span> must be unusually steady for the magnetosphere to enter this state. However, most previous studies have assumed this is true and have used such conditions to identify events. In a preliminary investigation using only the AE and AL indices to select events we have shown that these expectations are generally correct. SMC events seem to be associated with slow speed <span class="hlt">solar</span> <span class="hlt">wind</span> and moderate, stable IMF Bz. In this report we extend our previous study including additional parameters and the time variations in various statistical quantities. For the intervals identified as SMCs we perform a detailed statistical analysis of the properties of different <span class="hlt">solar</span> <span class="hlt">wind</span> variables. We compare these statistics to those determined from all data, and from intervals in which substorms but not SMCs are present. We also consider the question of whether substorms are required to initiate and terminate an SMC. We conclude that the intervals we have identified as SMC are likely to be examples of the original Dungey concept of balanced reconnection at a pair of x-lines on the day and night side of the Earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060026059','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060026059"><span>Material Interactions with <span class="hlt">Solar</span> <span class="hlt">Wind</span> Ion Environments</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Minow, Joseph I.; McWilliams, Brett</p> <p>2006-01-01</p> <p><span class="hlt">Solar</span> <span class="hlt">wind</span> composition is dominated by hydrogen (approx.96%) and helium (approx.3 to 4%) with a minor fraction (less than or equal to 1%) of heavy ions. Hydrogen (helium) ions impact spacecraft surfaces with energies from 0.5 to 5 keV (1.8 to 21 keV) due to variations in <span class="hlt">solar</span> <span class="hlt">wind</span> velocity from 300 km/s to 1000 km/sec with extremes of a few 10 s keV during periods of extremely high <span class="hlt">solar</span> <span class="hlt">wind</span> velocity exceeding 1000 km/sec. Mean impact energies are typically on the order of approximately 1 keV and 4 keV for hydrogen ions and helium ions, respectively. These energies are typically of the peak of the energy dependent light ion sputter yields for hydrogen and helium on many metals. In addition, light ions with kilovolt energies have been shown to produce blister (or exfoliation) damage to metal surfaces due to formation of high pressure gas bubbles within the materials when exposed to ion fluences on the order of 10(exp 16 to (10(exp 17 ions/sq cm. A number of spacecraft designs for current and future missions include gossamer polymer structures with thin metallic reflection coatings to shield instruments from the Sun or <span class="hlt">solar</span> sail propulsion systems for use in a variety of locations in the inner <span class="hlt">solar</span> system from 0.5 to 1 AU. In addition, there is interest in designing spacecraft for <span class="hlt">solar</span> physics missions requiring operations as close to the Sun as 0.16 to 0.2 AU. Integrity of the metallic coatings is critical in many of these applications since degradation will result in modification of material thermal properties or exposure of polymers to <span class="hlt">solar</span> UV photons which can compromise mission requirements. This paper will evaluate the relative contributions of sputtering and blister formation to material degradation in <span class="hlt">solar</span> <span class="hlt">wind</span> environments over a range of radial distances from the Sun to demonstrate where <span class="hlt">solar</span> <span class="hlt">wind</span> environments become important for materials selection. We will first review the physics and results from laboratory measurements of light ion sputtering</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19800058887&hterms=Turley&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DTurley','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19800058887&hterms=Turley&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DTurley"><span><span class="hlt">Solar</span> cycle changes in the polar <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Coles, W. A.; Rickett, B. J.; Rumsey, V. H.; Kaufman, J. J.; Turley, D. G.; Ananthakrishnan, S.; Armstrong, J. W.; Harmons, J. K.; Scott, S. L.; Sime, D. G.</p> <p>1980-01-01</p> <p>It is noted that although the 11 year <span class="hlt">solar</span> cycle was first recognized in 1843, it is still only poorly understood. Further, while there are satisfactory models for the magnetic variations, the underlying physics is still obscure. New observations on the changing three-dimensional form of the <span class="hlt">solar</span> <span class="hlt">wind</span> are presented which help relate some of the modulations observed in geomagnetic activity, the ionosphere, and the flux of galactic cosmic rays.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021273&hterms=solar+energy+generated&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsolar%2Benergy%2Bgenerated','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021273&hterms=solar+energy+generated&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsolar%2Benergy%2Bgenerated"><span>The origin of the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Axford, W. I.; McKenzie, J. F.</p> <p>1995-01-01</p> <p>The high speed <span class="hlt">solar</span> <span class="hlt">wind</span>, which is associated with coronal holes and unipolar interplanetary magnetic field, has now been observed in situ beyond 0.3 a.u. and at latitudes up to 80 degrees. Its important characteristics are that it is remarkably steady in terms of flow properties and composition and that the ions, especially minor species, are favored in terms of heating and acceleration. We have proposed that the high speed <span class="hlt">wind</span>, with its associated coronal holes, forms the basic mode of <span class="hlt">solar</span> <span class="hlt">wind</span> flow. In contrast, the low speed <span class="hlt">wind</span> is inherently non-stationary, filamentary and not in equilibrium with conditions at the coronal base. It is presumably the result of continual reconfigurations of the force-free magnetic field in the low-latitude closed corona which allow trapped plasma to drain away along transiently open flux tubes. Observations of high speed <span class="hlt">solar</span> <span class="hlt">wind</span> close to its source are hampered by the essential heterogeneity of the corona, even at sunspot minimum. In particular it is difficult to determine more than limits to the density, temperature and wave amplitude near the coronal base as a result of contamination from fore- and back-ground plasma. We interpret the observations as indicating that the high speed <span class="hlt">solar</span> <span class="hlt">wind</span> originates in the chromospheric network, covering only about 1% of the surface of the sun, where the magnetic field is complex and not unipolar. As a result of small-scale reconnection events in this 'furnace', Alfven waves are generated with a flat spectrum covering the approximate range 10 kHz to 10 Hz. The plasma is likely to be produced as a result of downwards thermal conduction and possibly photoionization at the top of the low density chromospheric interface to the furnace, thus controlling the mass flux in the <span class="hlt">wind</span>. The immediate source of free (magnetic) energy is in the form of granule-sized loops which are continually carried into the network from the sides. The resulting wave spectrum is such that energy can be</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AmSci..90..532W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AmSci..90..532W"><span>The Origin of the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Woo, Richard; Habbal, Shadia Rifai</p> <p>2002-12-01</p> <p>Nearly 1,400 years ago, Chinese astronomers noticed that comet tails always point away from the Sun. They concluded that the Sun must have chi</em>—a basic life force—that blows the tails away. It wasn't until the middle of the 20th century that scientists understood that this "force" actually consisted of little pieces of the sun itself—protons and electrons—blowing out into the <span class="hlt">solar</span> system as a "<span class="hlt">wind</span>" at more than a million kilometers per hour. The traditional view of the <span class="hlt">solar</span> <span class="hlt">wind</span>'s origins suggests that it originates from special regions on the Sun, called coronal holes. Woo and Habbal present new evidence showing that the <span class="hlt">wind</span> actually emanates from all regions on the Sun.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SpWea..14..724B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SpWea..14..724B"><span>Decoding <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere coupling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beharrell, M. J.; Honary, F.</p> <p>2016-10-01</p> <p>We employ a new NARMAX (Nonlinear Auto-Regressive Moving Average with eXogenous inputs) code to disentangle the time-varying relationship between the <span class="hlt">solar</span> <span class="hlt">wind</span> and SYM-H. The NARMAX method has previously been used to formulate a Dst model, using a preselected <span class="hlt">solar</span> <span class="hlt">wind</span> coupling function. In this work, which uses the higher-resolution SYM-H in place of Dst, we are able to reveal the individual components of different <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere interaction processes as they contribute to the geomagnetic disturbance. This is achieved with a graphics processing unit (GPU)-based NARMAX code that is around 10 orders of magnitude faster than previous efforts from 2005, before general-purpose programming on GPUs was possible. The algorithm includes a composite cost function, to minimize overfitting, and iterative reorthogonalization, which reduces computational errors in the most critical calculations by a factor of ˜106. The results show that negative deviations in SYM-H following a southward interplanetary magnetic field (IMF) are first a measure of the increased magnetic flux in the geomagnetic tail, observed with a delay of 20-30 min from the time the <span class="hlt">solar</span> <span class="hlt">wind</span> hits the bow shock. Terms with longer delays are found which represent the dipolarization of the magnetotail, the injections of particles into the ring current, and their subsequent loss by flowout through the dayside magnetopause. Our results indicate that the contribution of magnetopause currents to the storm time indices increase with <span class="hlt">solar</span> <span class="hlt">wind</span> electric field, E = v × B. This is in agreement with previous studies that have shown that the magnetopause is closer to the Earth when the IMF is in the tangential direction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21535178','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21535178"><span>Numerical simulations to study <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sharma, R. P.; Sharma, Nidhi; Kumar, Sanjay; Kumar, Sachin; Singh, H. D.</p> <p>2011-02-15</p> <p>Numerical simulation of coupled equations of kinetic Alfven wave (KAW) and ion acoustic wave is presented in the <span class="hlt">solar</span> <span class="hlt">wind</span>. The nonlinear dynamical equations satisfy the modified Zakharov system of equations by taking the nonadiabatic response of the background density. The ponderomotive nonlinearity is incorporated in the wave dynamics. The effect of Landau damping of KAW is taken into account. Localization of magnetic field intensity and the wavenumber spectra (perpendicular and parallel) of magnetic fluctuations are studied in <span class="hlt">solar</span> plasmas around 1 a.u. Our results reveal the formation of damped localized structures and the steeper spectra that are in good agreement with the observations. These damped structures and steeper turbulent spectra can be responsible for plasma heating and particle acceleration in <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040200985&hterms=IMP&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DIMP','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040200985&hterms=IMP&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DIMP"><span><span class="hlt">Wind</span> and IMP 8 <span class="hlt">Solar</span> <span class="hlt">Wind</span>, Magnetosheath and Shock Data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2004-01-01</p> <p>The purpose of this project was to provide the community access to magnetosheath data near Earth. We provided 27 years of IMP 8 magnetosheath proton velocities, densities, and temperatures with our best (usually 1-min.) time resolution. IMP 8 crosses the magnetosheath twice each 125 day orbit, and we provided magnetosheath data for the roughly 27 years of data for which magnetometer data are also available (which are needed to reliably pick boundaries). We provided this 27 years of IMP 8 magnetosheath data to the NSSDC; this data is now integrated with the IMP 8 <span class="hlt">solar</span> <span class="hlt">wind</span> data with flags indicating whether each data point is in the <span class="hlt">solar</span> <span class="hlt">wind</span>, magnetosheath, or at the boundary between the two regions. The plasma speed, density, and temperature are provided for each magnetosheath point. These data are also available on the MIT web site ftp://space .mit.edu/pub/plasma/imp/www/imp.html. We provide ASCII time-ordered rows of data giving the observation time, the spacecraft position in GSE, the velocity is GSE, the density and temperature for protons. We also have analyzed and archived on our web site the <span class="hlt">Wind</span> magnetosheath plasma parameters. These consist of ascii files of the proton and alpha densities, speeds, and thermal speeds. These data are available at ftp://space.mit.edu/pub/plasma/<span class="hlt">wind</span>/sheath These are the two products promised in the work statement and they have been completed in full.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040200985&hterms=ftp&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dftp','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040200985&hterms=ftp&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dftp"><span><span class="hlt">Wind</span> and IMP 8 <span class="hlt">Solar</span> <span class="hlt">Wind</span>, Magnetosheath and Shock Data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2004-01-01</p> <p>The purpose of this project was to provide the community access to magnetosheath data near Earth. We provided 27 years of IMP 8 magnetosheath proton velocities, densities, and temperatures with our best (usually 1-min.) time resolution. IMP 8 crosses the magnetosheath twice each 125 day orbit, and we provided magnetosheath data for the roughly 27 years of data for which magnetometer data are also available (which are needed to reliably pick boundaries). We provided this 27 years of IMP 8 magnetosheath data to the NSSDC; this data is now integrated with the IMP 8 <span class="hlt">solar</span> <span class="hlt">wind</span> data with flags indicating whether each data point is in the <span class="hlt">solar</span> <span class="hlt">wind</span>, magnetosheath, or at the boundary between the two regions. The plasma speed, density, and temperature are provided for each magnetosheath point. These data are also available on the MIT web site ftp://space .mit.edu/pub/plasma/imp/www/imp.html. We provide ASCII time-ordered rows of data giving the observation time, the spacecraft position in GSE, the velocity is GSE, the density and temperature for protons. We also have analyzed and archived on our web site the <span class="hlt">Wind</span> magnetosheath plasma parameters. These consist of ascii files of the proton and alpha densities, speeds, and thermal speeds. These data are available at ftp://space.mit.edu/pub/plasma/<span class="hlt">wind</span>/sheath These are the two products promised in the work statement and they have been completed in full.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130011126','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130011126"><span>Cleaning Study of <span class="hlt">Genesis</span> Sample 60487</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kuhlman, Kim R.; Rodriquez, M. C.; Gonzalez, C. P.; Allton, J. H.; Burnett, D. S.</p> <p>2013-01-01</p> <p>The <span class="hlt">Genesis</span> mission collected <span class="hlt">solar</span> <span class="hlt">wind</span> and brought it back to Earth in order to provide precise knowledge of <span class="hlt">solar</span> isotopic and elemental compositions. The ions in the <span class="hlt">solar</span> <span class="hlt">wind</span> were stopped in the collectors at depths on the order of 10 to a few hundred nanometers. This shallow implantation layer is critical for scientific analysis of the composition of the <span class="hlt">solar</span> <span class="hlt">wind</span> and must be preserved throughout sample handling, cleaning, processing, distribution, preparation and analysis. Particles of <span class="hlt">Genesis</span> wafers, brine from the Utah Testing Range and an organic film have deleterious effects on many of the high-resolution instruments that have been developed to analyze the implanted <span class="hlt">solar</span> <span class="hlt">wind</span>. We have conducted a correlative microscopic study of the efficacy of cleaning <span class="hlt">Genesis</span> samples with megasonically activated ultrapure water and UV/ozone cleaning. Sample 60487, the study sample, is a piece of float-zone silicon from the B/C array approximately 4.995mm x 4.145 mm in size</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18..416S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18..416S"><span>Martian ionosphere response to <span class="hlt">solar</span> <span class="hlt">wind</span> variability during <span class="hlt">solar</span> minimum</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sanchez-Cano, Beatriz; Lester, Mark; Witasse, Olivier; Mays, M. Leila; Hall, Benjamin E. S.; Milan, Stephen E.; Cartacci, Marco; Blelly, Pierre-Louis; Andrews, David; Opgenoorth, Hermann; Odstrcil, Dusan</p> <p>2016-04-01</p> <p><span class="hlt">Solar</span> cycle variations in <span class="hlt">solar</span> radiation create notable density changes in the Martian ionosphere. In addition to this long-term variability, there are numerous short-term and non-recurrent <span class="hlt">solar</span> events that hit Mars which need to be considered, such as Interplanetary Coronal Mass Ejections (ICMEs), Co-Rotation Interaction Regions (CIRs), <span class="hlt">solar</span> flares, or <span class="hlt">solar</span> <span class="hlt">wind</span> high speed streams. The response of the Martian plasma system to each of these events is often unusual, especially during the long period of extreme low <span class="hlt">solar</span> activity in 2008 and 2009. This work shows the long-term <span class="hlt">solar</span> cycle impact on the ionosphere of Mars using data from The Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS), and The Analyzer of Space Plasma and Energetic Atoms (ASPERA-3), and with empirical and numerical models on Mars Express. Particular attention is given to the different ionospheric responses observed during the last, extended <span class="hlt">solar</span> minimum. Mars' ionospheric response followed a similar pattern to the response observed in the Earth's ionosphere, despite the large differences related to the inner-origin of the magnetic field of both planets. The ionospheric temperature was cooler, the topside scale height was smaller and almost constant with altitude, the secondary ionospheric layer practically disappeared and the whole atmospheric total electron content (TEC) suffered an extreme reduction of about 30-40%, not predicted before by models. Moreover, there is a larger probability for the induced magnetic field to be present in the ionosphere, than in other phases of the <span class="hlt">solar</span> cycle. The short-term variability is also addressed with the study of an ICME followed by a fast stream that hit Mars in March 2008, where <span class="hlt">solar</span> <span class="hlt">wind</span> data are provided by ACE and STEREO-B and supported by simulations using the WSA-ENLIL Model. The <span class="hlt">solar</span> <span class="hlt">wind</span> conditions lead to the formation of a CIR centred on the interface of the fast and the slow <span class="hlt">solar</span> <span class="hlt">wind</span> streams. Mars' system reacted to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20100024507&hterms=atmosphere+super+earth&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Datmosphere%2Bsuper%2Bearth','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20100024507&hterms=atmosphere+super+earth&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Datmosphere%2Bsuper%2Bearth"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Ablation of Terrestrial Planet Atmospheres</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moore, Thomas Earle; Fok, Mei-Ching H.; Delcourt, Dominique C.</p> <p>2009-01-01</p> <p>Internal plasma sources usually arise in planetary magnetospheres as a product of stellar ablation processes. With the ignition of a new star and the onset of its ultraviolet and stellar <span class="hlt">wind</span> emissions, much of the volatiles in the stellar system undergo a phase transition from gas to plasma. Condensation and accretion into a disk is replaced by radiation and stellar <span class="hlt">wind</span> ablation of volatile materials from the system- Planets or smaller bodies that harbor intrinsic magnetic fields develop an apparent shield against direct stellar <span class="hlt">wind</span> impact, but UV radiation still ionizes their gas phases, and the resulting internal plasmas serve to conduct currents to and from the central body along reconnected magnetic field linkages. Photoionization and thermalization of electrons warms the ionospheric topside, enhancing Jeans' escape of super-thermal particles, with ambipolar diffusion and acceleration. Moreover, observations and simulations of auroral processes at Earth indicate that <span class="hlt">solar</span> <span class="hlt">wind</span> energy dissipation is concentrated by the geomagnetic field by a factor of 10-100, enhancing heavy species plasma and gas escape from gravity, and providing more current carrying capacity. Thus internal plasmas enable coupling with the plasma, neutral gas and by extension, the entire body. The stellar <span class="hlt">wind</span> is locally loaded and slowed to develop the required power. The internal source plasma is accelerated and heated, inflating the magnetosphere as it seeks escape, and is ultimately blown away in the stellar <span class="hlt">wind</span>. Bodies with little sensible atmosphere may still produce an exosphere of sputtered matter when exposed to direct <span class="hlt">solar</span> <span class="hlt">wind</span> impact. Bodies with a magnetosphere and internal sources of plasma interact more strongly with the stellar <span class="hlt">wind</span> owing to the magnetic linkage between the two created by reconnection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999AIPC..471..585P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999AIPC..471..585P"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> correlations: Statistical and case studies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Paularena, K. I.; Richardson, J. D.; Zastenker, G. N.; Dalin, P. A.</p> <p>1999-06-01</p> <p>Recent work on <span class="hlt">solar</span> <span class="hlt">wind</span> plasma correlations using data from several widely-separated spacecraft (IMP 8, INTERBALL-1, <span class="hlt">WIND</span>, and ISEE-3) has shown that, for 6-hour periods, the average plasma correlation is ~0.7. The focus of these studies has been directed toward a statistical understanding of gross <span class="hlt">solar</span> <span class="hlt">wind</span> correlation behavior. In all correlations examined, lower average correlations are caused by the presence of many points from the low correlation subpopulation; nevertheless, data points from the high correlation population are still present. No single organizational factor has yet been found which adequately separates low-correlation periods from high-correlation periods. Some of the spread in correlations is due to the spatial orientations and dimensions of <span class="hlt">solar</span> <span class="hlt">wind</span> structures, and thus to the locational alignments of the spacecraft being correlated, but this does not adequately explain all the good or poor correlations since sometimes three nearby spacecraft show poor correlations, while sometimes three widely-separated space-craft show good correlations. Thus, in order to understand the underlying physics, detailed investigation of individual cases has been undertaken. These results will be important in assigning quality measures to space weather predictions using satellite measurements taken at L1, for example.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730002078','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730002078"><span>Corotation of an intermittent <span class="hlt">solar</span> <span class="hlt">wind</span> source</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Croft, T. A.</p> <p>1972-01-01</p> <p>The measured electron content of the <span class="hlt">solar</span> <span class="hlt">wind</span> in mid-1970 exhibited a region of relatively high electron density that reappeared at intervals of about 27.8 days. It is shown that the repeating event cannot be reconciled with the concept of a long-enduring steady flow, even though the recurrence period is close to the rotation period of the sun. This evidence of transients is inferred from the short duration of each appearance of the interval of higher density; each should last for roughly one corotation interval if it is caused by a steady stream. The radio path was approximately 0.8 AU long, and the corotation interval exceeded 3 days. Other aspects of the content data patterns support the view that such transient events are common in the <span class="hlt">solar</span> <span class="hlt">wind</span>. The mid-1970 repeating event is an unusually good example of the intermittent character of flow regions in the <span class="hlt">solar</span> <span class="hlt">wind</span> that fluctuate on a time scale of days but endure as identifiable regions for many months. A sputtering corotating source of thin <span class="hlt">solar</span> plasma streams could explain this series of events; it could also be explained in terms of a stream that is steady in density and speed but undulating north-south so that it passes into and out of the 0.8 AU radio path in a matter of a day or less.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016cosp...41E1604P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016cosp...41E1604P"><span>Magnetosheath influence on <span class="hlt">solar</span> <span class="hlt">wind</span> - magnetosphere coupling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pulkkinen, Tuija; Kilpua, Emilia; Dimmock, Andrew; Myllys, Minna; Osmane, Adnane; Nykyri, Katariina; Lakka, Antti</p> <p>2016-07-01</p> <p>We have shown that the <span class="hlt">solar</span> <span class="hlt">wind</span> - magnetosphere - ionosphere coupling is different during due northward IMF from that during due southward IMF, and that the Poynting flux at the magnetopause is not a simple function of the upstream <span class="hlt">solar</span> <span class="hlt">wind</span> conditions upstream of the bow shock. These results are indicative of multiple transport processes taking place on various temporal and spatial scales, and therefore more detailed analysis is required to identify these mechanisms and quantify their contributions to <span class="hlt">solar</span> <span class="hlt">wind</span> - magnetosphere coupling. We combine the OMNI, IMAGE and THEMIS observations to statistically examine the properties incident at the magnetopause in the quasi-perpendicular and quasi-parallel shock sides separately. We use local and global MHD simulations to examine the energy and plasma transport properties across the bow shock, in the magnetosheath, and across the magnetopause. We focus especially on the anomalously quiet period during the deep <span class="hlt">solar</span> minimum in 2008-2010, comparing the results with steady but stronger drivers during magnetic cloud events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1914278P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1914278P"><span>The magnetosphere of Venus under unusual <span class="hlt">Solar</span> <span class="hlt">Wind</span> conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pope, Simon A.; Siung Chong, Ghai; Collinson, Glyn A.; Zhang, Tielong; Balikhin, Michael A.</p> <p>2017-04-01</p> <p>Due to its lack of an intrinsic magnetic field, the structure of the induced magnetosphere and associated plasma processes in and near Venus can be strongly influenced by the prevailing <span class="hlt">solar</span> <span class="hlt">wind</span> conditions. Examples include the shock structure/location, the occurrence of reconnection in the <span class="hlt">solar</span> <span class="hlt">wind</span> and tail and the occurrence of the Kelvin-Helmholtz instability at the ionopause. However, the interaction of the <span class="hlt">solar</span> <span class="hlt">wind</span> with Venus is a complex processes and with observations being limited to single spacecraft missions with restricted orbit, it can be difficult to link observations with particular <span class="hlt">solar</span> <span class="hlt">wind</span> conditions. To better understand this relationship, Venus Express magnetic field and plasma data is used to identify and analyse changes to the structure of the magnetosphere and local plasma processes that are related to unusual <span class="hlt">solar</span> <span class="hlt">wind</span> conditions. By examining Venus under unusual <span class="hlt">solar</span> <span class="hlt">wind</span> conditions the resulting changes, if out of the ordinary, can be more directly linked to particular <span class="hlt">solar</span> <span class="hlt">wind</span> conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSM41C2457P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSM41C2457P"><span>The magnetosphere of Venus under unusual <span class="hlt">Solar</span> <span class="hlt">Wind</span> condition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pope, S. A.; Chong, G. S.; Collinson, G.; Zhang, T.; Balikhin, M. A.</p> <p>2016-12-01</p> <p>Due to its lack of an intrinsic magnetic field, the structure of the induced magnetosphere and associated plasma processes in and near Venus can be strongly influenced by the prevailing <span class="hlt">solar</span> <span class="hlt">wind</span> conditions. Examples include the shock structure/location, the occurrence of reconnection in the <span class="hlt">solar</span> <span class="hlt">wind</span> and tail and the occurrence of the Kelvin-Helmholtz instability at the ionopause. However, the interaction of the <span class="hlt">solar</span> <span class="hlt">wind</span> with Venus is a complex processes and with observations being limited to single spacecraft missions with restricted orbit, it can be difficult to link observations with particular <span class="hlt">solar</span> <span class="hlt">wind</span> conditions. To better understand this relationship, Venus Express magnetic field and plasma data is used to identify and analyse changes to the structure of the magnetosphere and local plasma processes that are related to unusual <span class="hlt">solar</span> <span class="hlt">wind</span> conditions. By examining Venus under unusual <span class="hlt">solar</span> <span class="hlt">wind</span> conditions the resulting changes, if out of the ordinary, can be more directly linked to particular <span class="hlt">solar</span> <span class="hlt">wind</span> conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040074203','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040074203"><span>Properties of Minor Ions in the <span class="hlt">Solar</span> <span class="hlt">Wind</span> and Implications for the Background <span class="hlt">Solar</span> <span class="hlt">Wind</span> Plasma</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wagner, William (Technical Monitor); Esser, Ruth</p> <p>2004-01-01</p> <p>The scope of the investigation is to extract information on the properties of the bulk <span class="hlt">solar</span> <span class="hlt">wind</span> from the minor ion observations that are provided by instruments on board NASA space craft and theoretical model studies. Ion charge states measured in situ in interplanetary space are formed in the inner coronal regions below 5 <span class="hlt">solar</span> radii, hence they carry information on the properties of the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma in that region. The plasma parameters that are important in the ion forming processes are the electron density, the electron temperature and the flow speeds of the individual ion species. In addition, if the electron distribution function deviates from a Maxwellian already in the inner corona, then the enhanced tail of that distribution function, also called halo, greatly effects the ion composition. This study is carried out using <span class="hlt">solar</span> <span class="hlt">wind</span> models, coronal observations, and ion calculations in conjunction with the in situ observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSH43A4168P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSH43A4168P"><span>Characteristics of <span class="hlt">solar</span> <span class="hlt">wind</span> density depletions during <span class="hlt">solar</span> cycles 23 and 24</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Park, K.; Lee, J.; Oh, S.; Yi, Y.</p> <p>2014-12-01</p> <p><span class="hlt">Solar</span> <span class="hlt">wind</span> density depletions are generally believed to be caused by the interplanetary (IP) shocks. However, there are other cases that are hardly associated with IP shocks. To better understand the cause of the density depletions, we investigate the <span class="hlt">solar</span> <span class="hlt">wind</span> parameters and interplanetary magnetic field (IMF) data related to the <span class="hlt">solar</span> <span class="hlt">wind</span> density depletion events during the period from 1996 to 2013 that are obtained with the Advanced Composition Explorer (ACE) and the <span class="hlt">WIND</span> satellite. As a result, we found that the <span class="hlt">solar</span> <span class="hlt">wind</span> density has an anti-correlation with IMF strength during all events of <span class="hlt">solar</span> <span class="hlt">wind</span> density depletion, regardless of the presence of IP shocks. We thus argue that IMF strength is an important factor in understanding the nature of <span class="hlt">solar</span> <span class="hlt">wind</span> density depletion. Since IMF strength varies with <span class="hlt">solar</span> cycle, we also investigate the characteristics of <span class="hlt">solar</span> <span class="hlt">wind</span> density depletion events in different phases of <span class="hlt">solar</span> cycle as an attempt to find its connection to the sun.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17755527','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17755527"><span>Deimos: an obstacle to the <span class="hlt">solar</span> <span class="hlt">wind</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sauer, K; Dubinin, E; Baumgärtel, K; Bogdanov, A</p> <p>1995-08-25</p> <p>Two isolated <span class="hlt">solar</span> <span class="hlt">wind</span> disturbances about 5 minutes in duration were detected aboard the Russian spacecraft Phobos-2 upon its crossing the wake of the martian moon Deimos about 15,000 kilometers downstream from the moon on 1 February 1989. These plasma and magnetic events are interpreted as the inbound and outbound crossings of a Mach cone that is formed as a result of an effective interaction of the <span class="hlt">solar</span> <span class="hlt">wind</span> with Deimos. Possible mechanisms such as remanent magnetization, cometary type interaction caused by heavy ion or charged dust production, and unipolar induction resulting from the finite conductivity of the body are discussed. Although none of the present models is fully satisfactory, neutral gas emission through water loss by Deimos at a rate of about 10(23) molecules per second, combined with a charged dust coma, is favored.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19750035055&hterms=infancy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dinfancy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19750035055&hterms=infancy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dinfancy"><span>The <span class="hlt">solar</span> <span class="hlt">wind</span> and magnetospheric dynamics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Russell, C. T.</p> <p>1974-01-01</p> <p>The dynamic processes involved in the interaction between the <span class="hlt">solar</span> <span class="hlt">wind</span> and the earth's magnetosphere are reviewed. The evolution of models of the magnetosphere is first surveyed. The existence of the auroral substorm and the cyclical polar magnetic substorm is evidence that the magnetosphere is a dynamic system. The dynamic changes occurring in the magnetosphere, including erosion of the magnetopause, changes in the size of the polar cap, variations in the flaring angle of the tail, neutral point formation, plasma sheet motions, and the inward collapse of the midnight magnetosphere, are discussed. The cyclical variations of geomagnetic activity are explained in terms of the control of the <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere interaction by the north-south component of the interplanetary magnetic field. Present phenomenological models allow prediction of geomagnetic activity from interplanetary measurements, but modeling of detailed magnetospheric processes is still in its infancy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760018046','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760018046"><span><span class="hlt">Solar-wind</span> interaction with planetary ionospheres</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cloutier, P. A.</p> <p>1976-01-01</p> <p>Planetary encounters by numerous spacecraft have furnished information concerning the <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with the planets Mercury, Venus, Mars, and Jupiter. While direct measurements have indicated a wide range of atmospheric densities and intrinsic magnetic field strengths, the data seem to indicate that the flow pattern around nonmagnetized or weakly magnetized planets with atmospheres optically thick at ionizing wavelengths is basically the same as that around a strongly magnetized planet's magnetosphere, such as the earth's. The planetary ionosphere apparently presents a hard obstacle to the flow, with bow shock formation required in the supersonic, super-Alfvenic flow to slow and direct most of the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma around the planetary ionosphere. Various aspects of the interaction are examined in the context of theoretical models in an attempt to explain observed details of the interaction regions of Venus and Mars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24996092','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24996092"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> thermally induced magnetic fluctuations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Navarro, R E; Moya, P S; Muñoz, V; Araneda, J A; F-Viñas, A; Valdivia, J A</p> <p>2014-06-20</p> <p>A kinetic description of Alfvén-cyclotron magnetic fluctuations for anisotropic electron-proton quasistable plasmas is studied. An analytical treatment, based on the fluctuation-dissipation theorem, consistently shows that spontaneous fluctuations in plasmas with stable distributions significantly contribute to the observed magnetic fluctuations in the <span class="hlt">solar</span> <span class="hlt">wind</span>, as seen, for example, in [S. D. Bale et al., Phys. Rev. Lett. 103, 211101 (2009)], even far below from the instability thresholds. Furthermore, these results, which do not require any adjustable parameters or wave excitations, are consistent with the results provided by hybrid simulations. It is expected that this analysis contributes to our understanding of the nature of magnetic fluctuations in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25848082','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25848082"><span>Anisotropy in <span class="hlt">solar</span> <span class="hlt">wind</span> plasma turbulence.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Oughton, S; Matthaeus, W H; Wan, M; Osman, K T</p> <p>2015-05-13</p> <p>A review of spectral anisotropy and variance anisotropy for <span class="hlt">solar</span> <span class="hlt">wind</span> fluctuations is given, with the discussion covering inertial range and dissipation range scales. For the inertial range, theory, simulations and observations are more or less in accord, in that fluctuation energy is found to be primarily in modes with quasi-perpendicular wavevectors (relative to a suitably defined mean magnetic field), and also that most of the fluctuation energy is in the vector components transverse to the mean field. Energy transfer in the parallel direction and the energy levels in the parallel components are both relatively weak. In the dissipation range, observations indicate that variance anisotropy tends to decrease towards isotropic levels as the electron gyroradius is approached; spectral anisotropy results are mixed. Evidence for and against wave interpretations and turbulence interpretations of these features will be discussed. We also present new simulation results concerning evolution of variance anisotropy for different classes of initial conditions, each with typical background <span class="hlt">solar</span> <span class="hlt">wind</span> parameters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA201119','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA201119"><span>Corona-<span class="hlt">Solar</span> <span class="hlt">Wind</span> Coupling Review</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1987-06-01</p> <p>Spitzer which should be valid if the magne:ic field is radial and the plasma is collision dominated. Although both of these conditions are expected to hold...conduction has been studied by introducing a heat flux density given by the classical Spitzer value times the square of the cosine of the angle...Broussard, R. M., N. R. Shecley, Jr ., R. Tousey, and J. H. Underwood. A survey of coronal holes and their <span class="hlt">solar</span> <span class="hlt">wind</span> associations throughout sunspot cycle</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993EM%26P...60...23K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993EM%26P...60...23K"><span>Interplanetary dust particles and <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klacka, J.; Saniga, M.</p> <p>1993-01-01</p> <p>An effect of the <span class="hlt">solar</span> <span class="hlt">wind</span> on the motion of interplanetary dust particles is investigated. An equation of motion is derived. It is pointed out that the 'Pseudo-Poynting-Robertson effect' (and its special case - a 'corpuscular drag') and the 'corpuscular sputtering' represent in reality one and the same effect within the framework of special relativity. In this context perturbation equations of celestial mechanics are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5030602','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5030602"><span>Turbulence and waves in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Roberts, D.A.; Goldstein, M.L. )</p> <p>1991-01-01</p> <p>Studies of turbulence and waves in the <span class="hlt">solar</span> <span class="hlt">wind</span> is discussed. Consideration is given to the observations and theory concerning the origin and evolution of interplanetary MHD fluctuations and to the observations, theory, and simulations of compressive fluctuations. Particular attention is given to extrapolations to near-sun and polar fields regions. Results obtained on turbulence at comets and magnetic turbulence of low-frequency waves excited by unstable distributions of ions are discussed. 230 refs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017IAUS..328..162J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017IAUS..328..162J"><span><span class="hlt">Solar</span> and stellar coronae and <span class="hlt">winds</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jardine, Moira</p> <p>2017-10-01</p> <p><span class="hlt">Solar</span>-like stars influence their environments through their coronal emis- sion and <span class="hlt">winds</span>. These processes are linked through the physics of the stellar magnetic field, whose strength and geometry has now been explored for a large number of stars through spectropolarimetric observations. We have now detected trends with mass and rotation rate in the distribution of magnetic energies in different geometries and on also different length scales. This has implications both for the dynamo processes that generate the fields and also for the dynamics and evolution of the coronae and <span class="hlt">winds</span>. Modelling of the surface driving processes on stars of various masses and rotation rates has revealed tantalising clues about the dynamics of stellar coronae and their ejecta. These new observations have also prompted a resurgence in the modelling of stellar <span class="hlt">winds</span>, which is now uncovering the range of different interplanetary conditions that exoplanets might experience as they evolve.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...838...50F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...838...50F"><span>Kinetic Properties of the Neutral <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Florinski, V.; Heerikhuisen, J.</p> <p>2017-03-01</p> <p>Charge-exchange collisions between the <span class="hlt">solar</span> <span class="hlt">wind</span> protons and interstellar hydrogen produce a distinctive population of neutral hydrogen streaming radially at nearly the <span class="hlt">solar-wind</span> speed. This tenuous population, known as the neutral <span class="hlt">solar</span> <span class="hlt">wind</span> (NSW) is thought to play a key role in the appearance of the Interplanetary Boundary EXplorer ribbon, a bright circular band in the sky that is the source of neutral hydrogen with energies near 1 keV. According to the leading model of the ribbon, the velocity distribution of NSW hydrogen is imparted on the pickup ions (PUIs) generated via charge exchange with the interstellar protons beyond the heliopause, and in this way controls the stability of the resulting ring distribution of PUIs against hydromagnetic wave generation. In this paper, we examine the velocity distributions of the NSW atoms in the heliosphere and the outer heliosheath regions by following the phase-space trajectories of the Boltzmann equation. It is demonstrated that these distributions are highly anisotropic, with the parallel (radial) temperature greatly exceeding the perpendicular temperature. Ions picked up near 90° from the anisotropic NSW would form a stable ring distribution capable of generating the ribbon flux. We also discuss a second population of neutrals born in charge transfer collisions with interstellar PUIs, the so-called neutralized pickup ion (NPI) component. Their high thermal velocities translate into large parallel velocity spread of the daughter ribbon PUIs, which would adversely affect plasma stability in local interstellar space.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20120011917&hterms=storm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dstorm','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20120011917&hterms=storm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dstorm"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Charge Exchange During Geomagnetic Storms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Robertson, Ina P.; Cravens, Thomas E.; Sibeck, David G.; Collier, Michael R.; Kuntz, K. D.</p> <p>2012-01-01</p> <p>On March 31st. 2001, a coronal mass ejection pushed the subsolar magnetopause to the vicinity of geosynchronous orbit at 6.6 RE. The NASA/GSFC Community Coordinated Modeling Center (CCMe) employed a global magnetohydrodynamic (MHD) model to simulate the <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere interaction during the peak of this geomagnetic storm. Robertson et aL then modeled the expected 50ft X-ray emission due to <span class="hlt">solar</span> <span class="hlt">wind</span> charge exchange with geocoronal neutrals in the dayside cusp and magnetosheath. The locations of the bow shock, magnetopause and cusps were clearly evident in their simulations. Another geomagnetic storm took place on July 14, 2000 (Bastille Day). We again modeled X-ray emission due to <span class="hlt">solar</span> <span class="hlt">wind</span> charge exchange, but this time as observed from a moving spacecraft. This paper discusses the impact of spacecraft location on observed X-ray emission and the degree to which the locations of the bow shock and magnetopause can be detected in images.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20120011917&hterms=solar+storms&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsolar%2Bstorms','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20120011917&hterms=solar+storms&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsolar%2Bstorms"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Charge Exchange During Geomagnetic Storms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Robertson, Ina P.; Cravens, Thomas E.; Sibeck, David G.; Collier, Michael R.; Kuntz, K. D.</p> <p>2012-01-01</p> <p>On March 31st. 2001, a coronal mass ejection pushed the subsolar magnetopause to the vicinity of geosynchronous orbit at 6.6 RE. The NASA/GSFC Community Coordinated Modeling Center (CCMe) employed a global magnetohydrodynamic (MHD) model to simulate the <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere interaction during the peak of this geomagnetic storm. Robertson et aL then modeled the expected 50ft X-ray emission due to <span class="hlt">solar</span> <span class="hlt">wind</span> charge exchange with geocoronal neutrals in the dayside cusp and magnetosheath. The locations of the bow shock, magnetopause and cusps were clearly evident in their simulations. Another geomagnetic storm took place on July 14, 2000 (Bastille Day). We again modeled X-ray emission due to <span class="hlt">solar</span> <span class="hlt">wind</span> charge exchange, but this time as observed from a moving spacecraft. This paper discusses the impact of spacecraft location on observed X-ray emission and the degree to which the locations of the bow shock and magnetopause can be detected in images.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840005052','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840005052"><span>Quasi-steady <span class="hlt">solar</span> <span class="hlt">wind</span> dynamics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pizzo, V. J.</p> <p>1983-01-01</p> <p>Progress in understanding the large scale dynamics of quasisteady, corotating <span class="hlt">solar</span> <span class="hlt">wind</span> structure was reviewed. The nature of the <span class="hlt">solar</span> <span class="hlt">wind</span> at large heliocentric distances preliminary calculations from a 2-D MHD model are used to demonstrate theoretical expectations of corotating structure out to 30 AU. It is found that the forward and reverse shocks from adjacent CIR's begin to interact at about 10 AU, producing new shock pairs flanking secondary CIR's. These sawtooth secondary CIR's interact again at about 20 AU and survive as visible entities to 30 AU. The model predicts the velocity jumps at the leading edge of the secondary CIR's at 30 AU should be very small but there should still be sizable variations in the thermodynamic and magnetic parameters. The driving dynamic mechanism in the distant <span class="hlt">solar</span> <span class="hlt">wind</span> is the relaxation of pressure gradients. The second topic is the influence of weak, nonimpulsive time dependence in quasisteady dynamics. It is suggested that modest large scale variations in the coronal flow speed on periods of several hours to a day may be responsible for many of the remaining discrepancies between theory and observation. Effects offer a ready explanation for the apparent rounding of stream fronts between 0.3 and 1.0 AU discovered by Helios.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1052886','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1052886"><span>Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study (Fact Sheet)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Not Available</p> <p>2012-09-01</p> <p>Initiated in 2007 to examine the operational impact of up to 35% penetration of <span class="hlt">wind</span>, photovoltaic (PV), and concentrating <span class="hlt">solar</span> power (CSP) energy on the electric power system, the Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study (WWSIS) is one of the largest regional <span class="hlt">wind</span> and <span class="hlt">solar</span> integration studies to date. The goal is to understand the effects of variability and uncertainty of <span class="hlt">wind</span>, PV, and CSP on the grid. In the Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study Phase 1, <span class="hlt">solar</span> penetration was limited to 5%. Utility-scale PV was not included because of limited capability to model sub-hourly, utility-scale PV output . New techniques allow the Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study Phase 2 to include high penetrations of <span class="hlt">solar</span> - not only CSP and rooftop PV but also utility-scale PV plants.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760018041','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760018041"><span><span class="hlt">Solar-wind</span> control of the extent of planetary ionospheres</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bauer, S. J.</p> <p>1976-01-01</p> <p>In our <span class="hlt">solar</span> system there are at least four magnetic planets: Earth, Jupiter, Mercury, and Mars; while at least one planet, Venus, appears to be essentially nonmagnetic. The ionospheres of the magnetic planets are imbedded in their magnetosphere and thus shielded from the <span class="hlt">solar</span> <span class="hlt">wind</span>, whereas the ionosphere of Venus, at least, interacts directly with the <span class="hlt">solar</span> <span class="hlt">wind</span>. However, the <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with the planetary environment, in both cases, affects the behavior of their ionospheres. The role the <span class="hlt">solar</span> <span class="hlt">wind</span> interaction plays in limiting the extent of the ionospheres of both magnetic and nonmagnetic planets is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050172136','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050172136"><span>Status of <span class="hlt">Genesis</span> Mo-Pt Foils</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nishiizumi, K.; Allton, J. H.; Burnett, D. S.; Butterworth, A. L.; Caffee, M. W.; Clark, B.; Jurewicz, A. J. G.; Komura, K.; Westphal, A. J.; Welten, K. C.</p> <p>2005-01-01</p> <p>A total of 8,000 sq cm of Mo-coated Pt foils were exposed to <span class="hlt">solar</span> <span class="hlt">wind</span> for 884 days by the <span class="hlt">Genesis</span> mission. <span class="hlt">Solar</span> <span class="hlt">wind</span> ions were captured in the surface of the Mo. Our objective is the measurement of long-lived radionuclides, such as Be-10, Al-26, Cl-36, and Mn-53, and short-lived radionuclides, such as Na-22 and Mn-54, in the captured sample of <span class="hlt">solar</span> <span class="hlt">wind</span>. The expected flux of these nuclides in the <span class="hlt">solar</span> <span class="hlt">wind</span> is 100 atom/sq cm yr or less. The hard landing of the SRC (Sample Return Capsule) at UTTR (Utah Test and Training Range) has resulted in contaminated and crumpled foils. Here we present a status report and revised plan for processing the foils.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19720029841&hterms=directed+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Ddirected%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720029841&hterms=directed+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Ddirected%2Benergy"><span>Electron energy flux in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ogilvie, K. W.; Scudder, J. D.; Sugiura, M.</p> <p>1971-01-01</p> <p>Description of studies of electrons between 10 eV and 9.9 keV in the <span class="hlt">solar</span> <span class="hlt">wind</span>. The transport of energy in the rest frame of the plasma is evaluated and shown to be parallel to the interplanetary magnetic field. The presence of electrons from <span class="hlt">solar</span> events causes this energy-flux density to exceed the heat flow due to thermal electrons. In one such event, the observations are shown to be consistent with the <span class="hlt">solar</span>-electron observations made at higher energies. When observations are made at a point connected to the earth's bow shock by an interplanetary-field line, a comparatively large energy flux along the field toward the sun is observed, but the heat flow remains outwardly directed during this time interval. In either situation the heat flow is found to be consistent with measurements made on Vela satellites by a different method. These values, less than .01 ergs/sq cm/sec, are sufficiently low to require modifications to the Spitzer-Harm conductivity formula for use in <span class="hlt">solar-wind</span> theories.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1981AdSpR...1....3S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1981AdSpR...1....3S"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> and its interaction with the magnetosphere - Measured parameters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schwenn, R.</p> <p></p> <p>The sun and the <span class="hlt">solar</span> <span class="hlt">wind</span> are considered in terms of the 'ballerina' model first proposed by Alfven (1977), taking into account high speed streams, the slow <span class="hlt">solar</span> <span class="hlt">wind</span>, stream-stream interactions, the relation of streams and magnetic structure, and transients caused by <span class="hlt">solar</span> activity. The main features of the <span class="hlt">solar</span> <span class="hlt">wind</span> behavior are illustrated with the aid of data, covering one complete <span class="hlt">solar</span> rotation in 1974/1975, which were obtained with instruments aboard the Helios-1 <span class="hlt">solar</span> probe. It is pointed out that the <span class="hlt">solar</span> <span class="hlt">wind</span> acts like a huge buffer pushing onto the earth's magnetosphere with a highly variable pressure. Of the energy in the highly variable <span class="hlt">solar</span> <span class="hlt">wind</span> reservoir only a tiny fraction is absorbed by the magnetosphere in an obviously very nonstationary way.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMSH43B..07A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMSH43B..07A"><span>Topological Origins of the Slow <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Antiochos, S.</p> <p>2008-12-01</p> <p>Although the slow <span class="hlt">solar</span> <span class="hlt">wind</span> has been studied for decades with both in situ and remote sensing observations, its origin is still a matter of intense debate. In the standard quasi-steady model, the slow <span class="hlt">wind</span> is postulated to originate near coronal hole boundaries that define topologically well-behaved separatrices between open and closed field regions. In the interchange model, on the other hand, the slow <span class="hlt">wind</span> is postulated to originate on open flux that is dynamically diffusing throughout the seemingly closed-field corona. We argue in favor of the quasi-steady scenario and propose that the slow <span class="hlt">wind</span> is due to two effects: First, the open-closed boundary is highly complex due to the complexity of the photospheric flux distribution. Second, this boundary is continuously driven by the transport of magnetic helicity from the closed field region into the open. The implications of this model for the structure and dynamics of the corona and slow <span class="hlt">wind</span> are discussed, and observational tests of the model are presented. This work has been supported, in part, by the NASA LWS, HTP, and SR&T programs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20090006612&hterms=Debate&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DDebate','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20090006612&hterms=Debate&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DDebate"><span>Topological Origins of the Slow <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Antiochos, Spiro</p> <p>2008-01-01</p> <p>Although the slow <span class="hlt">solar</span> <span class="hlt">wind</span> has been studied for decades with both in situ and remote sensing observations, its origin is still a matter of intense debate. In the standard quasi-steady model, the slow <span class="hlt">wind</span> is postulated to originate near coronal hole boundaries that define topologically well-behaved separatrices between open and closed field regions. In the interchange model, on the other hand, the slow <span class="hlt">wind</span> is postulated to originate on open flux that is dynamically diffusing throughout the seemingly closed-field corona. We argue in favor of the quasi-steady scenario and propose that the slow <span class="hlt">wind</span> is due to two effects: First, the open-closed boundary is highly complex due to the complexity of the photospheric flux distribution. Second, this boundary is continuously driven by the transport of magnetic helicity from the closed field region into the open. The implications of this model for the structure and dynamics of the corona and slow <span class="hlt">wind</span> are discussed, and observational tests of the mode</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007SoPh..240..315V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007SoPh..240..315V"><span>Coronal Holes and <span class="hlt">Solar</span> <span class="hlt">Wind</span> High-Speed Streams: I. Forecasting the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Parameters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vršnak, Bojan; Temmer, Manuela; Veronig, Astrid M.</p> <p>2007-02-01</p> <p>We analyze the relationship between the coronal hole (CH) area/position and physical characteristics of the associated corotating high-speed stream (HSS) in the <span class="hlt">solar</span> <span class="hlt">wind</span> at 1 AU. For the analysis we utilize the data in the period DOY 25 125 of 2005, characterized by a very low coronal mass ejection (CME) activity. Distinct correlations between the daily averaged CH parameters and the <span class="hlt">solar</span> <span class="hlt">wind</span> characteristics are found, which allows us to forecast the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity v, proton temperature T, proton density n, and magnetic field strength B, several days in advance in periods of low CME activity. The forecast is based on monitoring fractional areas A, covered by CHs in the meridional slices embracing the central meridian distance ranges [-40°,-20°], [-10°,10°], and [20°,40°]. On average, the peaks in the daily values of n, B, T, and v appear delayed by 1, 2, 3, and 4 days, respectively, after the area A attains its maximum in the central-meridian slice. The peak values of the <span class="hlt">solar</span> <span class="hlt">wind</span> parameters are correlated to the peak values of A, which provides also forecasting of the peak values of n, B, T, and v. The most accurate prediction can be obtained for the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity, for which the average relative difference between the calculated and the observed peak values amounts to overline{\\vertδ\\vert}≈10 %. The forecast reliability is somewhat lower in the case of T, B, and n ( overline{\\vertδ\\vert}≈20 , 30, and 40%, respectively). The space weather implications are discussed, including the perspectives for advancing the real-time calculation of the Sun Earth transit times of coronal mass ejections and interplanetary shocks, by including more realistic real-time estimates of the <span class="hlt">solar</span> <span class="hlt">wind</span> characteristics.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19800009702&hterms=silverman&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsilverman','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19800009702&hterms=silverman&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsilverman"><span>Variations of the <span class="hlt">solar</span> <span class="hlt">wind</span> and <span class="hlt">solar</span> cycle in the last 300 years</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Feynman, J.; Silverman, S.</p> <p>1980-01-01</p> <p>The past history of the <span class="hlt">solar</span> <span class="hlt">wind</span> and <span class="hlt">solar</span> cycle, inferred from records of geomagnetics and aurora, is examined. Records show that the <span class="hlt">solar</span> <span class="hlt">wind</span> apparently varied in a systematic manner throughout the period from 1770 to 1857 and that the period around 1810 resembled the 1901 minimum geomagnetic disturbance. Results show that the <span class="hlt">solar</span> <span class="hlt">wind</span> and hence the Sun changes on a time scale long compared to a <span class="hlt">solar</span> cycle and short compared to the Maunder minimum. The inclusion of a study on the <span class="hlt">solar</span> <span class="hlt">wind</span> and <span class="hlt">solar</span> cycle variations for the SCADM mission is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19720019110&hterms=helium+neon&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dhelium%2Bneon','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720019110&hterms=helium+neon&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dhelium%2Bneon"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> rare gas analysis: Trapped <span class="hlt">solar</span> <span class="hlt">wind</span> helium and neon in Surveyor 3 material</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Buehler, F.; Eberhardt, P.; Geiss, J.; Schwarzmueller, J.</p> <p>1972-01-01</p> <p>The He-4 and Ne-20 contents in sections of the Surveyor 3 support strut samples were determined by optical and scanning electron microscopy and are compared to the results of the Apollo <span class="hlt">solar</span> <span class="hlt">wind</span> composition (SWC) experiments. The He-4/Ne-20 ratio in the samples from the sunlit side of the strut was approximately 300; the ratios determined in Apollo 12 lunar fines and SWC foil were below 100. The He-4/He-3 ratios were also determined, and the ratio obtained from Surveyor 3 material is higher than those found with Apollo 11 and 12 SWC experiments. The effects of spallation by cosmic rays or <span class="hlt">solar</span> protons, stripping by cosmic ray or energetic <span class="hlt">solar</span> alpha particles, recycling of <span class="hlt">solar</span> <span class="hlt">wind</span> He and radiogenic Ne, He from terrestrial atmosphere, mass discrimination near the moon, mass dependence of trapping probability, diffusion, and contamination by lunar dust are considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19720019110&hterms=Helium+gas&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DHelium%2Bgas','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720019110&hterms=Helium+gas&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DHelium%2Bgas"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> rare gas analysis: Trapped <span class="hlt">solar</span> <span class="hlt">wind</span> helium and neon in Surveyor 3 material</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Buehler, F.; Eberhardt, P.; Geiss, J.; Schwarzmueller, J.</p> <p>1972-01-01</p> <p>The He-4 and Ne-20 contents in sections of the Surveyor 3 support strut samples were determined by optical and scanning electron microscopy and are compared to the results of the Apollo <span class="hlt">solar</span> <span class="hlt">wind</span> composition (SWC) experiments. The He-4/Ne-20 ratio in the samples from the sunlit side of the strut was approximately 300; the ratios determined in Apollo 12 lunar fines and SWC foil were below 100. The He-4/He-3 ratios were also determined, and the ratio obtained from Surveyor 3 material is higher than those found with Apollo 11 and 12 SWC experiments. The effects of spallation by cosmic rays or <span class="hlt">solar</span> protons, stripping by cosmic ray or energetic <span class="hlt">solar</span> alpha particles, recycling of <span class="hlt">solar</span> <span class="hlt">wind</span> He and radiogenic Ne, He from terrestrial atmosphere, mass discrimination near the moon, mass dependence of trapping probability, diffusion, and contamination by lunar dust are considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20090006630&hterms=Goldstein&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DGoldstein','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20090006630&hterms=Goldstein&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DGoldstein"><span>Variations of Strahl Properties with Fast and Slow <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Figueroa-Vinas, Adolfo; Goldstein, Melvyn L.; Gurgiolo, Chris</p> <p>2008-01-01</p> <p>The interplanetary <span class="hlt">solar</span> <span class="hlt">wind</span> electron velocity distribution function generally shows three different populations. Two of the components, the core and halo, have been the most intensively analyzed and modeled populations using different theoretical models. The third component, the strahl, is usually seen at higher energies, is confined in pitch-angle, is highly field-aligned and skew. This population has been more difficult to identify and to model in the <span class="hlt">solar</span> <span class="hlt">wind</span>. In this work we make use of the high angular, energy and time resolution and three-dimensional data of the Cluster/PEACE electron spectrometer to identify and analyze this component in the ambient <span class="hlt">solar</span> <span class="hlt">wind</span> during high and slow speed <span class="hlt">solar</span> <span class="hlt">wind</span>. The moment density and fluid velocity have been computed by a semi-numerical integration method. The variations of <span class="hlt">solar</span> <span class="hlt">wind</span> density and drift velocity with the general build <span class="hlt">solar</span> <span class="hlt">wind</span> speed could provide some insight into the source, origin, and evolution of the strahl.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20090006630&hterms=Goldstein&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DGoldstein','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20090006630&hterms=Goldstein&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DGoldstein"><span>Variations of Strahl Properties with Fast and Slow <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Figueroa-Vinas, Adolfo; Goldstein, Melvyn L.; Gurgiolo, Chris</p> <p>2008-01-01</p> <p>The interplanetary <span class="hlt">solar</span> <span class="hlt">wind</span> electron velocity distribution function generally shows three different populations. Two of the components, the core and halo, have been the most intensively analyzed and modeled populations using different theoretical models. The third component, the strahl, is usually seen at higher energies, is confined in pitch-angle, is highly field-aligned and skew. This population has been more difficult to identify and to model in the <span class="hlt">solar</span> <span class="hlt">wind</span>. In this work we make use of the high angular, energy and time resolution and three-dimensional data of the Cluster/PEACE electron spectrometer to identify and analyze this component in the ambient <span class="hlt">solar</span> <span class="hlt">wind</span> during high and slow speed <span class="hlt">solar</span> <span class="hlt">wind</span>. The moment density and fluid velocity have been computed by a semi-numerical integration method. The variations of <span class="hlt">solar</span> <span class="hlt">wind</span> density and drift velocity with the general build <span class="hlt">solar</span> <span class="hlt">wind</span> speed could provide some insight into the source, origin, and evolution of the strahl.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19750032355&hterms=wind+night+day&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dwind%2Bnight%2Bday','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19750032355&hterms=wind+night+day&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dwind%2Bnight%2Bday"><span>Steady state asymmetric planetary electrical induction. [by <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Horning, B. L.; Schubert, G.</p> <p>1974-01-01</p> <p>An analytic solution is presented for the steady state electric and magnetic fields induced by the motional electric field of the <span class="hlt">solar</span> <span class="hlt">wind</span> in the atmosphere or interior of a planet that is asymmetrically surrounded by <span class="hlt">solar</span> <span class="hlt">wind</span> plasma. The electrically conducting ionosphere or interior must be in direct electrical contact with the <span class="hlt">solar</span> <span class="hlt">wind</span> over the day side of the planet. The conducting region of the planet is modeled by a sphere or a spherical shell of arbitrarily stratified electrical conductivity. A monoconducting cylindrical cavity is assumed to extend downstream on the night side of the planet. The <span class="hlt">solar</span> <span class="hlt">wind</span> is assumed to be highly conducting so that the induced fields are confined to the planet and cavity. Induced currents close as sheet currents at the <span class="hlt">solar</span> <span class="hlt">wind</span>-cavity and <span class="hlt">solar</span> <span class="hlt">wind</span>-planet interfaces. Numerical evaluations of the analytic formulas are carried out for a uniformly conducting spherical model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980018115','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980018115"><span>Interpretation of <span class="hlt">Solar</span> <span class="hlt">Wind</span> Ion Composition Measurements from Ulysses</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Esser, Ruth</p> <p>1998-01-01</p> <p>The ion compositions measured in situ in the <span class="hlt">solar</span> <span class="hlt">wind</span> are important since the ion fractions carry information on the plasma conditions in the inner corona. The conditions in the inner corona define the properties of the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma flow. Thus, if the ion fraction measurements can be used to unravel some of the plasma parameters in the inner corona, they will provide a valuable contribution to solving the heating and acceleration problem of the <span class="hlt">solar</span> <span class="hlt">wind</span>. The ion charge states in the <span class="hlt">solar</span> <span class="hlt">wind</span> carry information on electron temperature, electron density and ion flow speed. They are also sensitive to the shape of the electron distribution function. Through carefully modeling the <span class="hlt">solar</span> <span class="hlt">wind</span> and calculating the ion fractions predicted for different <span class="hlt">solar</span> <span class="hlt">wind</span> conditions, constraints on the electron temperature and ion flow speeds can be placed if the electron density is measured using polarization brightness measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...837...75S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...837...75S"><span>Turbulent Transport in a Three-dimensional <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shiota, D.; Zank, G. P.; Adhikari, L.; Hunana, P.; Telloni, D.; Bruno, R.</p> <p>2017-03-01</p> <p>Turbulence in the <span class="hlt">solar</span> <span class="hlt">wind</span> can play essential roles in the heating of coronal and <span class="hlt">solar</span> <span class="hlt">wind</span> plasma and the acceleration of the <span class="hlt">solar</span> <span class="hlt">wind</span> and energetic particles. Turbulence sources are not well understood and thought to be partly enhanced by interaction with the large-scale inhomogeneity of the <span class="hlt">solar</span> <span class="hlt">wind</span> and the interplanetary magnetic field and/or transported from the <span class="hlt">solar</span> corona. To investigate the interaction with background inhomogeneity and the turbulence sources, we have developed a new 3D MHD model that includes the transport and dissipation of turbulence using the theoretical model of Zank et al. We solve for the temporal and spatial evolution of three moments or variables, the energy in the forward and backward fluctuating modes and the residual energy and their three corresponding correlation lengths. The transport model is coupled to our 3D model of the inhomogeneous <span class="hlt">solar</span> <span class="hlt">wind</span>. We present results of the coupled <span class="hlt">solar</span> <span class="hlt">wind</span>-turbulence model assuming a simple tilted dipole magnetic configuration that mimics <span class="hlt">solar</span> minimum conditions, together with several comparative intermediate cases. By considering eight possible <span class="hlt">solar</span> <span class="hlt">wind</span> and turbulence source configurations, we show that the large-scale <span class="hlt">solar</span> <span class="hlt">wind</span> and IMF inhomogeneity and the strength of the turbulence sources significantly affect the distribution of turbulence in the heliosphere within 6 au. We compare the predicted turbulence distribution results from a complete <span class="hlt">solar</span> minimum model with in situ measurements made by the Helios and Ulysses spacecraft, finding that the synthetic profiles of the turbulence intensities show reasonable agreement with observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160003153','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160003153"><span>Small Particulate Contamination Survey Of <span class="hlt">Genesis</span> Flight Sample 61423</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kuhlman, K. R.; Schmeling, M.; Gonzalez, C. P.; Allums, K. K.; Allton, J. H.; Burnett, D. S.</p> <p>2016-01-01</p> <p>The <span class="hlt">Genesis</span> mission collected <span class="hlt">solar</span> <span class="hlt">wind</span> and brought it back to Earth in order to provide precise knowledge of <span class="hlt">solar</span> isotopic and elemental compositions. The ions in the <span class="hlt">solar</span> <span class="hlt">wind</span> stop in the collectors at depths on the order of 10 to a few hundred nanometers. This shallow implantation layer is critical for scientific analysis of the composition of the <span class="hlt">solar</span> <span class="hlt">wind</span> and must be preserved throughout sample handling, cleaning, processing, distribution, preparation and analysis. We continue to work with the community of scientists analyzing <span class="hlt">Genesis</span> samples using our unique laboratory facilities -- and, where needed, our unique cleaning techniques -- to significantly enhance the science return from the <span class="hlt">Genesis</span> mission. This work is motivated by the need to understand the submicron contamination on the collectors in the <span class="hlt">Genesis</span> payload as recovered from the crash site in the Utah desert, and -- perhaps more importantly -- how to remove it. We continue to evaluate the effectiveness of the wet-chemical "cleaning" steps used by various investigators, to enable them to design improved methods of stripping spacecraft and terrestrial contamination from surfaces while still leaving the <span class="hlt">solar-wind</span> signal intact.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730002081','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730002081"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> helium enhancements following major <span class="hlt">solar</span> flares</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hirshberg, J.</p> <p>1972-01-01</p> <p>The observations of <span class="hlt">solar</span> <span class="hlt">wind</span> helium enhancements following major <span class="hlt">solar</span> flares are reviewed, and the hypothesis that helium enhancements often mark flare piston plasma is confirmed. Helium enhancements were observed during each of the three periods (March 1966, July 1966, August/September 1966) of major <span class="hlt">solar</span> activity that occurred from October 1965 to October 1966. No enhancements were seen during the long quiet periods that occurred that year. At 1 AU, the helium-enhanced plasma pistons had slowed so that the velocity was 80 percent of the mean transit velocity, in general agreement with theoretical models of the propagation of flare disturbances. A qualitative model, in which the piston plasma is accelerated from the flare site deep in the corona, is discussed briefly. If the model is valid in general outline, the piston plasmas provide samples of material from the lower levels of the corona.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021499&hterms=solar+energy+you&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsolar%2Benergy%2Byou','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021499&hterms=solar+energy+you&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsolar%2Benergy%2Byou"><span>Radial evolution of the energy density of <span class="hlt">solar</span> <span class="hlt">wind</span> fluctuations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zank, G. P.; Matthaeus, W. H.; Smith, C. W.</p> <p>1995-01-01</p> <p>On the basis of transport theories appropriate to a radially expanding <span class="hlt">solar</span> <span class="hlt">wind</span>, we describe new results for the radial evolution of the energy density in <span class="hlt">solar</span> <span class="hlt">wind</span> fluctuations at MHD scales. These models include the effects of 'mixing' and driving as well as the possibility of non-isotropic MHD turbulence. Implications of these results for <span class="hlt">solar</span> <span class="hlt">wind</span> heating, cosmic ray diffusion and interstellar pick-up ions will also be addressed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021499&hterms=evolution+theory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Devolution%2Btheory','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021499&hterms=evolution+theory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Devolution%2Btheory"><span>Radial evolution of the energy density of <span class="hlt">solar</span> <span class="hlt">wind</span> fluctuations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zank, G. P.; Matthaeus, W. H.; Smith, C. W.</p> <p>1995-01-01</p> <p>On the basis of transport theories appropriate to a radially expanding <span class="hlt">solar</span> <span class="hlt">wind</span>, we describe new results for the radial evolution of the energy density in <span class="hlt">solar</span> <span class="hlt">wind</span> fluctuations at MHD scales. These models include the effects of 'mixing' and driving as well as the possibility of non-isotropic MHD turbulence. Implications of these results for <span class="hlt">solar</span> <span class="hlt">wind</span> heating, cosmic ray diffusion and interstellar pick-up ions will also be addressed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730020094','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730020094"><span>The large scale structure of the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wolfe, J. H.</p> <p>1971-01-01</p> <p>The <span class="hlt">solar</span> <span class="hlt">wind</span> structure is reviewed based on experimental space measurements acquired over approximately the last decade. The character of the interplanetary medium is considered from the viewpoint of the temporal behavior of the <span class="hlt">solar</span> <span class="hlt">wind</span> over increasingly longer time intervals, the average properties of the various <span class="hlt">solar</span> <span class="hlt">wind</span> parameters and their interrelationships. A brief discussion is included of interplanetary-terrestrial relationships and the expected effects of heliographic latitude and radial distance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021279&hterms=Bern&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DBern','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021279&hterms=Bern&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DBern"><span>Elemental and charge state composition of the fast <span class="hlt">solar</span> <span class="hlt">wind</span> observed with SMS instruments on <span class="hlt">WIND</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gloeckler, G.; Galvin, A. B.; Ipavich, F. M.; Hamilton, D. C.; Bochsler, P.; Geiss, J.; Fisk, L. A.; Wilken, B.</p> <p>1995-01-01</p> <p>The elemental composition and charge state distributions of heavy ions of the <span class="hlt">solar</span> <span class="hlt">wind</span> provide essential information about: (1) atom-ion separation processes in the <span class="hlt">solar</span> atmosphere leading to the 'FIP effect' (the overabundance of low First Ionization potential (FIP) elements in the <span class="hlt">solar</span> <span class="hlt">wind</span> compared to the photosphere); and (2) coronal temperature profiles, as well as mechanisms which heat the corona and accelerate the <span class="hlt">solar</span> <span class="hlt">wind</span>. This information is required for <span class="hlt">solar</span> <span class="hlt">wind</span> acceleration models. The SWICS instrument on Ulysses measures for all <span class="hlt">solar</span> <span class="hlt">wind</span> flow conditions the relative abundance of about 8 elements and 20 charge states of the <span class="hlt">solar</span> <span class="hlt">wind</span>. Furthermore, the Ulysses high-latitude orbit provides an unprecedented look at the <span class="hlt">solar</span> <span class="hlt">wind</span> from the polar coronal holes near <span class="hlt">solar</span> minimum conditions. The MASS instrument on the <span class="hlt">WIND</span> spacecraft is a high-mass resolution <span class="hlt">solar</span> <span class="hlt">wind</span> ion mass spectrometer that will provide routinely not only the abundances and charge state of all elements easily measured with SWICS, but also of N, Mg, S. The MASS sensor was fully operational at the end of 1994 and has sampled the in-ecliptic <span class="hlt">solar</span> <span class="hlt">wind</span> composition in both the slow and the corotating fast streams. This unique combination of SWICS on Ulysses and MASS on <span class="hlt">WIND</span> allows us to view for the first time the <span class="hlt">solar</span> <span class="hlt">wind</span> from two regions of the large coronal hole. Observations with SWICS in the coronal hole <span class="hlt">wind</span>: (1) indicate that the FIP effect is small; and (2) allow us determine the altitude of the maximum in the electron temperature profile, and indicate a maximum temperature of approximately 1.5 MK. New results from the SMS instruments on <span class="hlt">Wind</span> will be compared with results from SWICS on Ulysses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPD....47.0324P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPD....47.0324P"><span>Morphology of Pseudostreamers and <span class="hlt">Solar</span> <span class="hlt">Wind</span> Properties</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Panasenco, Olga; Velli, Marco</p> <p>2016-05-01</p> <p>The <span class="hlt">solar</span> dynamo and photospheric convection lead to three main types of structures extending from the <span class="hlt">solar</span> surface into the corona - active regions, <span class="hlt">solar</span> filaments (prominences when observed at the limb) and coronal holes. These structures exist over a wide range of scales, and are interlinked with each other in evolution and dynamics. Active regions can form clusters of magnetic activity and the strongest overlie sunspots. In the decay of active regions, the boundaries separating opposite magnetic polarities (neutral lines) develop the specific structures called filament channels above which filaments form. In the presence of flux imbalance decaying active regions can also give birth to lower latitude coronal holes. The accumulation of magnetic flux at coronal hole boundaries also creates the conditions for filament formation: polar crown filaments are permanently present at the boundaries of the polar coronal holes. Middle-latitude and equatorial coronal holes - the result of active region evolution - can create pseudostreamers (PSs) if other coronal holes of the same polarity are present. While helmet streamers form between open fields of opposite polarities, the pseudostreamer, characterized by a smaller coronal imprint, typically shows a more prominent straight ray or stalk extending from the corona. The pseudostreamer base at photospheric heights is multipolar; often one observes tripolar magnetic configurations with two neutral lines - where filaments can form - separating the coronal holes. Here we discuss the specific role of filament channels on pseudostreamer topology and on <span class="hlt">solar</span> <span class="hlt">wind</span> properties. 1D numerical analysis of PSs shows that the properties of the <span class="hlt">solar</span> <span class="hlt">wind</span> from around PSs depend on the presence/absence of filament channels, number of channels and chirality at the PS base low in the corona.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFMSH23A1164M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFMSH23A1164M"><span>Eigenmode Structure in <span class="hlt">Solar</span> <span class="hlt">Wind</span> Langmuir Waves</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Malaspina, D. M.; Ergun, R.; Bougeret, J.; Kaiser, M. L.; Bale, S.; Cairns, I. H.; Cattell, C. A.; Kellogg, P. J.; Newman, D. L.</p> <p>2007-12-01</p> <p>Bursty Langmuir waves associated with space plasma phenomena including type II and type III <span class="hlt">solar</span> radio bursts, auroral field-aligned electrons, and radiation from shocks often exhibit localized beat-type waveforms. A consensus view on the modulation mechanism remains elusive. Current theories include multi-wave interactions, turbulence, or non-linear growth such as kinetic localization. Most of these theories start with the assumption that the density of the background plasma is near-uniform, in spite of numerous observations to the contrary. An alternative approach is to start with the assumption that density perturbations pre-exist. We construct an analytical electric field solution, describing Langmuir waves as a combination of trapped eigenmodes within a parabolic density well. This hypothesis is supported by discreet frequency structure in auroral Langmuir wave observations observed to be associated with density fluctuations, and by the high degree of localization observed in <span class="hlt">solar</span> <span class="hlt">wind</span> borne Langmuir waves. This simple, one-dimensional model can reproduce waveform and frequency structure of localized Langmuir waves observed by STEREO/SWAVES. The waveforms can be reasonably reproduced using linear combinations of only a few low-mode eigenmode solutions. The eigenmode solutions are sensitive to plasma environmental parameters such as the electron temperature and <span class="hlt">solar</span> <span class="hlt">wind</span> velocity. The trapped-eigenmode solutions can form a theoretical basis to explore the non-linear behavior of Langmuir waves which may allow for efficient conversion and escape of electromagnetic emissions and second harmonic production.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUSMSH24A..04S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUSMSH24A..04S"><span>What Determines the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Speed ?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Suzuki, T. K.; Fujiki, K.; Kojima, M.; Tokumaru, M.; Hirano, M.; Baba, D.; Yamasita, M.; Hakamada, K.</p> <p>2005-05-01</p> <p>Recent observations by Interplanetary Scintillation measurements by Nagoya-STEL group (Hirano et al.2003; Kojima et al.2004) show that <span class="hlt">solar</span> <span class="hlt">wind</span> speed is well-correlated with B/f, where B is radial magnetic field strength at the <span class="hlt">solar</span> surface and f is a super-radial expansion factor of open flux tubes. We show that this correlation is nicely explained by dissipation of Alfven waves no matter what types of the wave dissipation processes operate. B determines the input energy flux of Alfven waves and f controls adiabatic loss of the wave energy, so that B/f is an important control parameter which determines the <span class="hlt">solar</span> <span class="hlt">wind</span> speed. (reference ) [1] Hirano, M., Kojima, M., Tokumaru, M., Fujiki, K., Ohmi, T., Yamashita, M, Hakamada, K., and Hayashi, K. 2003,, Eos Trans. AGU, 84(46), Fall Meet. Suppl., Abstract SH21B-0164 [2] Kojima, M., K. Fujiki, M. Hirano, M. Tokumaru, T. Ohmi, and K. Hakamada, 2004, "The Sun and the heliosphere as an Integrated System", Giannina Poletto and Steven T. Suess, Eds. Kluwer Academic Publishers, in press</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.1156V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.1156V"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> influence on Jupiter's magnetosphere and aurora</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vogt, Marissa; Gyalay, Szilard; Withers, Paul</p> <p>2016-04-01</p> <p>Jupiter's magnetosphere is often said to be rotationally driven, with strong centrifugal stresses due to large spatial scales and a rapid planetary rotation period. For example, the main auroral emission at Jupiter is not due to the magnetosphere-<span class="hlt">solar</span> <span class="hlt">wind</span> interaction but is driven by a system of corotation enforcement currents that arises to speed up outflowing Iogenic plasma. Additionally, processes like tail reconnection are also thought to be driven, at least in part, by processes internal to the magnetosphere. While the <span class="hlt">solar</span> <span class="hlt">wind</span> is generally expected to have only a small influence on Jupiter's magnetosphere and aurora, there is considerable observational evidence that the <span class="hlt">solar</span> <span class="hlt">wind</span> does affect the magnetopause standoff distance, auroral radio emissions, and the position and brightness of the UV auroral emissions. We will report on the results of a comprehensive, quantitative study of the influence of the <span class="hlt">solar</span> <span class="hlt">wind</span> on various magnetospheric data sets measured by the Galileo mission from 1996 to 2003. Using the Michigan <span class="hlt">Solar</span> <span class="hlt">Wind</span> Model (mSWiM) to predict the <span class="hlt">solar</span> <span class="hlt">wind</span> conditions upstream of Jupiter, we have identified intervals of high and low <span class="hlt">solar</span> <span class="hlt">wind</span> dynamic pressure. We can use this information to quantify how a magnetospheric compression affects the magnetospheric field configuration, which in turn will affect the ionospheric mapping of the main auroral emission. We also consider whether there is evidence that reconnection events occur preferentially during certain <span class="hlt">solar</span> <span class="hlt">wind</span> conditions or that the <span class="hlt">solar</span> <span class="hlt">wind</span> modulates the quasi-periodicity seen in the magnetic field dipolarizations and flow bursts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840010164&hterms=balsiger&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dbalsiger','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840010164&hterms=balsiger&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dbalsiger"><span>The ISPM <span class="hlt">solar-wind</span> ion composition spectrometer</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gloeckler, G.; Geiss, J.; Balsiger, H.; Fisk, L. A.; Gliem, F.; Ipavich, F. M.; Ogilvie, K. W.; Stuedemann, W.; Wilken, B.</p> <p>1983-01-01</p> <p>The International <span class="hlt">Solar</span> Polar Mission (ISPM) <span class="hlt">Solar-Wind</span> Ion Composition Spectrometer which determines elemental and ionic-charge composition, and the temperatures and mean speeds of all major <span class="hlt">solar-wind</span> ions, from H through Fe, at <span class="hlt">solar</span> <span class="hlt">wind</span> speeds ranging from 145 km/sec (protons) to 1352 km/sec (Fe+8) is described. The instrument, which covers an energy per charge range from 110 eV/q to 66.7 keV/q in 13 min, combines an electrostatic analyzer with postacceleration, followed by a time-of-flight and energy measurement. Conditions and processes in the region of the corona where the <span class="hlt">solar</span> <span class="hlt">wind</span> is accelerated; location of the source regions of the <span class="hlt">solar</span> <span class="hlt">wind</span> in the corona; coronal heating processes; the extent and causes of variations in the composition of the <span class="hlt">solar</span> atmosphere; plasma processes in the <span class="hlt">solar</span> <span class="hlt">wind</span>; acceleration of energetic particles in the <span class="hlt">solar</span> <span class="hlt">wind</span>; the thermalization and acceleration of interstellar ions in the <span class="hlt">solar</span> <span class="hlt">wind</span>, and their composition; and the composition and behavior of the plasma in the Jovian magnetosphere are studied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EGSGA..27.6304I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27.6304I"><span>Time Variable <span class="hlt">Solar</span> <span class="hlt">Wind</span> Interaction of Mercury</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ip, W.-H.; Kopp, A.</p> <p></p> <p>A three-dimensional MHD code was used to simulate the solr <span class="hlt">wind</span> interaction of Mercury's magnetosphere with interplanetary magnetic field (IMF) of different orien- tations. It can be shown that for northward pointing IMF, the Hermean magnetosphere is nearly closed with the polar cap shrinking to a small area. On the other hand, the boundary of the polar cap expands to mid-latitude region (about 30 degrees latitude) for south-pointing IMF. Such large changes in the size and morphology of the polar cap in response to directional variations of the IMF could be related to the observed temporal variabilities of the atomic sodium emission on Mercury's disk. That is, the production rate of the sodium atoms could be significantly modulated i.e., weak for northward IMF and large for southward IMF) if <span class="hlt">solar</span> <span class="hlt">wind</span> sputtering of the surface material is an important source mechanism of the sodium atoms.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUFMSM42A0828T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUFMSM42A0828T"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Disturbances Related to Geomagnetic Storms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tan, A.; Lyatsky, W. B.</p> <p>2001-12-01</p> <p>We used the superposed epoch method to reconstruct a typical behavior of <span class="hlt">solar</span> <span class="hlt">wind</span> parameters before and during strong isolated geomagnetic storms. For this analysis we used 130 such geomagnetic storms during the period of 1966-2000. The results obtained show that a typical disturbance in the <span class="hlt">solar</span> <span class="hlt">wind</span> responsible for geomagnetic storm generation is associated with the propagation of high-speed plasma flow compressing ambient <span class="hlt">solar</span> <span class="hlt">wind</span> plasma and interplanetary magnetic field (IMF) ahead of this high-speed flow. This gives rise to enhanced magnetic field, plasma density, plasma turbulence and temperature, which start to increase several hours before geomagnetic storm onset. However, the IMF Bz (responsible for geomagnetic storm onset) starts to increase significantly later (approximately 6-7 hours after maximal variations in plasma density and IMF By). The time delay between peaks in IMF Bz and plasma density (and IMF By) may be a result of draping of high-speed plasma streams with ambient magnetic field in the (z-y) plane as discussed by some authors. This leads to an increase first in plasma density and IMF By ahead of a high-speed flow, which is followed by an increase in IMF Bz. This simple model allows us to predict that the probability for geomagnetic storm generation should depend on which edge of a high-speed flow encounters the Earth's magnetosphere. The probability for geomagnetic storm generation is expected to be maximal when the flow encounters the magnetosphere by its north-west edge for negative IMF By and south-west edge for positive IMF By.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840005003','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840005003"><span>Spectroscopic measurements of <span class="hlt">solar</span> <span class="hlt">wind</span> generation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kohl, J. L.; Withbroe, G. L.; Zapata, C. A.; Noci, G.</p> <p>1983-01-01</p> <p>Spectroscopically observable quantities are described which are sensitive to the primary plasma parameters of the <span class="hlt">solar</span> <span class="hlt">wind</span>'s source region. The method is discussed in which those observable quantities are used as constraints in the construction of empirical models of various coronal structures. Simulated observations are used to examine the fractional contributions to observed spectral intensities from coronal structures of interest which co-exist with other coronal structures along simulated lines-of-sight. The sensitivity of spectroscopic observables to the physical parameters within each of those structures is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740013297','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740013297"><span>Sweet's mechanism in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burlaga, L. F.; Scudder, J. D.</p> <p>1974-01-01</p> <p>Sweet's mechanism occurs in the <span class="hlt">solar</span> <span class="hlt">wind</span>, at D-sheets near 1 AU. Conductivities on the order of 10,000 esu are obtained, which is on the order of the local plasma frequency. This implies that the effective collision frequency is on the order of the plasma frequency. The lateral extent of D-sheets is approximately 0.01 AU to 0.001 AU. Hundreds of such D-sheets are probably present between the orbits of Venus and Earth at any instant.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720003183','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720003183"><span>Dynamics of the <span class="hlt">solar</span> <span class="hlt">wind</span> and its interaction with bodies in the <span class="hlt">solar</span> system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Spreiter, J. R.</p> <p>1971-01-01</p> <p>A discussion of the <span class="hlt">solar</span> <span class="hlt">wind</span> and its interaction with bodies of the <span class="hlt">solar</span> system is presented. An overall unified account of the role of shock waves in the heating of the <span class="hlt">solar</span> corona, the transmission of <span class="hlt">solar</span> disturbances to the <span class="hlt">solar</span> system, the flow fields of planets and natural satellites, and biological effects are provided. An analysis of magnetometer data from Explorer 33 and Vela 3A satellites to identify characteristics of <span class="hlt">solar</span> <span class="hlt">wind</span> shock waves is included.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880001356','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880001356"><span>A numerical study of transient, thermally-conductive <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Han, S. M.; Wu, S. T.; Dryer, M.</p> <p>1987-01-01</p> <p>A numerical analysis of transient <span class="hlt">solar</span> <span class="hlt">wind</span> starting at the <span class="hlt">solar</span> surface and arriving at 1 AU is performed by an implicit numerical method. The model hydrodynamic equations include thermal conduction terms for both steady and unsteady simulations. Simulation results show significant influence of thermal conduction on both steady and time-dependent <span class="hlt">solar</span> <span class="hlt">wind</span>. Higher thermal conduction results in higher <span class="hlt">solar</span> <span class="hlt">wind</span> speed, higher temperature, but lower plasma density at 1 AU. Higher base temperature at the <span class="hlt">solar</span> surface gives lower plasma speed, lower temperature, but higher density at 1 AU. Higher base density, on the other hand, gives lower velocity, lower temperature, but higher density at 1 AU.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820033354&hterms=forces+distance&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dforces%2Bdistance','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820033354&hterms=forces+distance&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dforces%2Bdistance"><span>On rotational forces in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hollweg, J. V.; Isenberg, P. A.</p> <p>1981-01-01</p> <p><span class="hlt">Solar</span> rotational forces affecting the flow of minor ions in the <span class="hlt">solar</span> <span class="hlt">wind</span> are considered as corotating with the sun. Cold, noninteracting charged particles in the magnetic and gravitational fields of the sun rotate with the angular velocity of the sun, and calculations of lowest bulk order velocities show that differences in particle velocities decrease with increasing distance from the sun. A centrifugal potential in the corotating frame implies that ion motion is independent of protons, with velocities determined by the potential, which monotonically decreases without limit. The potential dominates the initial kinetic energy of the particles, and the equality of velocities within the potential is not due to interactions between particles as claimed by Mackenzie et al. (1979).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1914789H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1914789H"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> controls on Mercury's magnetospheric cusp</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>He, Maosheng; Vogt, Joachim; Heyner, Daniel; Zhong, Jun</p> <p>2017-04-01</p> <p>Mercury's magnetospheric cusp results from the interaction between the planetary intrinsic magnetic field and the <span class="hlt">solar</span> <span class="hlt">wind</span>. In this study, we assemble 2848 orbits of MESSENGER data for a comprehensive assessment of <span class="hlt">solar</span> <span class="hlt">wind</span> control on Mercury's cusp. We propose and validate an IMF estimation approach for the cusp transit, and construct an index to measure the magnetic disturbance. The index maximizes within the cusp, more intense than in the adjacent magnetosphere by several orders of magnitude. We develop an empirical model of the index as a function of IMFvector and Mercury's <span class="hlt">solar</span> orbital phase. The model is used to study the cusp activity under different conditions. Comparisons reveal the cusp activity is more intense and extends further in local time, under antisunward IMF (IMFx<0) than sunward (IMFx>0), under southward IMF (IMFz<0) than northward (IMFz>0), and when Mercury orbits at its perihelion than at aphelion. Besides, the cusp shifts azimuthally towards dawn when IMF reverses from westward (IMFy<0) to eastward (IMFy>0), and when Mercury approaches its perihelion. The IMFx dependence is consistent with existing observations and simulations which are ascribed to the asymmetry of dayside magnetospheric configuration between sunward and anti-sunward IMF conditions. We explain the IMFy and IMFz dependences in terms of component reconnection of the magnetospheric field merging with By-dominant and Bz-dominant IMF, respectively. The control of the Mercury <span class="hlt">solar</span> orbit phase on the intensity and local time location of the disturbance peak are possibly arising from the modulations of the heliocentric distance on the <span class="hlt">solar</span> <span class="hlt">wind</span> ram pressure. The existence of significant IMF dependence suggests the IMF orientation plays a role in the convection configuration at Mercury. The IMFy-dependence at Mercury is opposite to that at Earth, suggesting that component reconnection at the dayside magnetopause is more important in the Hermean system than in the terrestrial</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ASPC..484..263Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ASPC..484..263Z"><span>Latitudinal Dependence of Coronal Hole-Associated Fast <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, L.; Landi, E.</p> <p>2014-05-01</p> <p>The fast <span class="hlt">solar</span> <span class="hlt">wind</span> can have at least two different coronal sources: high-latitude, polar coronal holes (PCH) and low-latitude, equatorial coronal holes (ECH). The in-situ differences in the PCH and ECH <span class="hlt">winds</span> have not been well studied, nor have the differences in their evolution over the <span class="hlt">solar</span> cycles. Ulysses' 19 years of observations from 1990 to 2009, combined with ACE observations from 1998 to the present, provide us with measurements of <span class="hlt">solar</span> <span class="hlt">wind</span> properties that span two entire <span class="hlt">solar</span> cycles, which allow us to study the in-situ properties and evolution of the coronal hole-associated <span class="hlt">solar</span> <span class="hlt">wind</span> at different latitudes. In this work, we focus on the PCH and ECH <span class="hlt">solar</span> <span class="hlt">winds</span> during the minima between <span class="hlt">solar</span> cycles 22-23 and 23-24. We use data from SWICS, SWOOPS, and VHM/FGM on board Ulysses, and SWICS, SWEPAM, and MAG on board ACE to analyze the proton dynamics, heavy ion composition, elemental abundance, and magnetic field properties of the PCH <span class="hlt">wind</span> and ECH <span class="hlt">wind</span>, with a special focus on their differences during the recent two <span class="hlt">solar</span> minima. We also include the slow and hot, streamer-associated (ST) <span class="hlt">wind</span> as a reference in the comparison. The comparison of PCH and ECH <span class="hlt">wind</span> shows that: 1) the in-situ properties of ECH and PCH <span class="hlt">winds</span> are significantly different during the two <span class="hlt">solar</span> minima, and 2) the two types of coronal hole-associated <span class="hlt">solar</span> <span class="hlt">wind</span> respond differently to changes in <span class="hlt">solar</span> activity strength from cycle 23 to cycle 24.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSH42A..02D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSH42A..02D"><span>Alfvénic Slow <span class="hlt">Solar</span> <span class="hlt">Wind</span>: characteristics and origin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>D'Amicis, R.</p> <p>2016-12-01</p> <p>The <span class="hlt">solar</span> <span class="hlt">wind</span> is a turbulent medium whose behavior is mostly determined by the nonlinear interaction between inward and outward propagating Alfvén waves. The purest examples of Alfvénic fluctuations are found in the trailing edges of fast <span class="hlt">solar</span> <span class="hlt">wind</span> streams. The slow <span class="hlt">wind</span> usually has a lower degree of Alfvénicity being more strongly intermixed with structures of non-Alfvénic nature. However, as already found in the past, our recent analysis shows that under certain circumstances, even slow <span class="hlt">wind</span> can be highly Alfvénic with fluctuations sometimes as wide as that of the fast <span class="hlt">wind</span>. In this study we explore many facets of the Alfvénic slow <span class="hlt">solar</span> <span class="hlt">wind</span> spanning from the study of the source regions and their connection to coronal structures, to the micro-physics of distribution functions, anisotropies, to the role of turbulence and wave-particle interactions in <span class="hlt">solar</span> <span class="hlt">wind</span> heating, which are among the main topics of this session. It has been found that the Alfvénic slow <span class="hlt">wind</span> is more similar to the fast <span class="hlt">wind</span> rather than to the typical slow <span class="hlt">wind</span> suggesting a similar origin for the two types of <span class="hlt">solar</span> <span class="hlt">wind</span>. Actually the Alfvénic slow <span class="hlt">wind</span> does not originate from active regions or the cusp of the helmet streamers as the typical slow <span class="hlt">wind</span> rather from the boundary between streamers and coronal holes. This would determine the similarities with the fast <span class="hlt">solar</span> <span class="hlt">wind</span> suggesting a major role played by the super-radial expansion responsible for the lower velocity. These new findings have relevant implications for the upcoming <span class="hlt">Solar</span> Orbiter and <span class="hlt">Solar</span> Probe Plus missions, and for turbulence measurements close to the Sun.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003SSRv..105..627B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003SSRv..105..627B"><span>The Plasma Ion and Electron Instruments for the <span class="hlt">Genesis</span> Mission</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barraclough, B. L.; Dors, E. E.; Abeyta, R. A.; Alexander, J. F.; Ameduri, F. P.; Baldonado, J. R.; Bame, S. J.; Casey, P. J.; Dirks, G.; Everett, D. T.; Gosling, J. T.; Grace, K. M.; Guerrero, D. R.; Kolar, J. D.; Kroesche, J. L., Jr.; Lockhart, W. L.; McComas, D. J.; Mietz, D. E.; Roese, J.; Sanders, J.; Steinberg, J. T.; Tokar, R. L.; Urdiales, C.; Wiens, R. C.</p> <p>2003-01-01</p> <p>The <span class="hlt">Genesis</span> Ion Monitor (GIM) and the <span class="hlt">Genesis</span> Electron Monitor (GEM) provide 3-dimensional plasma measurements of the <span class="hlt">solar</span> <span class="hlt">wind</span> for the <span class="hlt">Genesis</span> mission. These measurements are used onboard to determine the type of plasma that is flowing past the spacecraft and to configure the <span class="hlt">solar</span> <span class="hlt">wind</span> sample collection subsystems in real-time. Both GIM and GEM employ spherical-section electrostatic analyzers followed by channel electron multiplier (CEM) arrays for detection and angle and energy/charge analysis of incident ions and electrons. GIM is of a new design specific to <span class="hlt">Genesis</span> mission requirements whereas the GEM sensor is an almost exact copy of the plasma electron sensors currently flying on the ACE and Ulysses spacecraft, albeit with new electronics and programming. Ions are detected at forty log-spaced energy levels between ˜ 1 eV and 14 keV by eight CEM detectors, while electrons with energies between ˜ 1 eV and 1.4 keV are measured at twenty log-spaced energy levels using seven CEMs. The spin of the spacecraft is used to sweep the fan-shaped fields-of-view of both instruments across all areas of the sky of interest, with ion measurements being taken forty times per spin and samples of the electron population being taken twenty four times per spin. Complete ion and electron energy spectra are measured every ˜ 2.5 min (four spins of the spacecraft) with adequate energy and angular resolution to determine fully 3-dimensional ion and electron distribution functions. The GIM and GEM plasma measurements are principally used to enable the operational <span class="hlt">solar</span> <span class="hlt">wind</span> sample collection goals of the <span class="hlt">Genesis</span> mission but they also provide a potentially very useful data set for studies of <span class="hlt">solar</span> <span class="hlt">wind</span> phenomena, especially if combined with other <span class="hlt">solar</span> <span class="hlt">wind</span> data sets from ACE, <span class="hlt">WIND</span>, SOHO and Ulysses for multi-spacecraft investigations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19810056379&hterms=isophotes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Disophotes','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19810056379&hterms=isophotes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Disophotes"><span>Coronal streamers in the <span class="hlt">solar</span> <span class="hlt">wind</span> at 1 AU</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gosling, J. T.; Asbridge, J. R.; Bame, S. J.; Feldman, W. C.; Borrini, G.; Hansen, R. T.</p> <p>1981-01-01</p> <p>Virtually all <span class="hlt">solar</span> <span class="hlt">wind</span> observing groups have reported substantial variations in the <span class="hlt">solar</span> <span class="hlt">wind</span> helium-hydrogen abundance ratio (A(He)). A study of Los Alamos Imp <span class="hlt">solar</span> <span class="hlt">wind</span> data has revealed an association between low A(He) and high proton density that occurs at low flow speeds and that is correlated with polarity reversals of the interplanetary magnetic field. The current investigation has the objective to present further examples of the low A(He), high proton density, low speed, magnetic field polarity association, and to document the common occurrence of multiple events lasting approximately 3-7 days. The results are presented of attempts to relate these events directly to maps or isophotes of <span class="hlt">solar</span> coronal brightness at 1.5 <span class="hlt">solar</span> radii. The results of the investigation suggest that a substantial fraction of the low-speed <span class="hlt">solar</span> <span class="hlt">wind</span> originates in coronal streamers, particularly near <span class="hlt">solar</span> minimum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760017036','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760017036"><span>The 3-D <span class="hlt">solar</span> radioastronomy and the structure of the corona and the <span class="hlt">solar</span> <span class="hlt">wind</span>. [<span class="hlt">solar</span> probes of <span class="hlt">solar</span> activity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Steinberg, J. L.; Caroubalos, C.</p> <p>1976-01-01</p> <p>The mechanism causing <span class="hlt">solar</span> radio bursts (1 and 111) is examined. It is proposed that a nonthermal energy source is responsible for the bursts; nonthermal energy is converted into electromagnetic energy. The advantages are examined for an out-of-the-ecliptic <span class="hlt">solar</span> probe mission, which is proposed as a means of stereoscopically viewing <span class="hlt">solar</span> radio bursts, <span class="hlt">solar</span> magnetic fields, coronal structure, and the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840010163&hterms=Temple&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DTemple','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840010163&hterms=Temple&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DTemple"><span>The ISPM <span class="hlt">solar-wind</span> plasma experiment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bame, S. J.; Glore, J. P.; Mccomas, D. J.; Moore, K. R.; Chavez, J. C.; Ellis, T. J.; Peterson, G. R.; Temple, J. H.; Wymer, F. J.</p> <p>1983-01-01</p> <p>The ISPM <span class="hlt">solar</span> <span class="hlt">wind</span> plasma experiment accurately characterizes the bulk flow and internal state conditions of the interplanetary plasma in three dimensions at all heliographic distances and heliographic latitudes reached by the spacecraft. <span class="hlt">Solar</span> <span class="hlt">wind</span> electrons, protons, alpha particles, and heavier ions are measured. Oxygen, silicon, and iron ions at various charge levels are resolved. Electrons and ions are measured simultaneously with independent curved-plate electrostatic analysers equipped with multiple continuous channel electron multipliers arranged so that particle velocity distributions are suitably resolved without gaps in spacecraft polar-angle space. Electrons with energies between 1 and 900 eV are detected at 7 polar angles and various combinations of azimuth angle to cover the unit sphere comprehensively. Ions are detected between 257 eV/Q and 35 keV/Q. Data matrices are obtained every 4 min when the spacecraft is actively transmitting and every 8 min during storage periods. These matrices contain sufficient energy and angle resolution to permit detailed calculations of ion velocity distributions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007NPGeo..14..695M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007NPGeo..14..695M"><span>Multifractality and intermittency in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Macek, W. M.</p> <p>2007-11-01</p> <p>Within the complex dynamics of the <span class="hlt">solar</span> <span class="hlt">wind</span>'s fluctuating plasma parameters, there is a detectable, hidden order described by a chaotic strange attractor which has a multifractal structure. The multifractal spectrum has been investigated using Voyager (magnetic field) data in the outer heliosphere and using Helios (plasma) data in the inner heliosphere. We have also analyzed the spectrum for the <span class="hlt">solar</span> <span class="hlt">wind</span> attractor. The spectrum is found to be consistent with that for the multifractal measure of the self-similar one-scale weighted Cantor set with two parameters describing uniform compression and natural invariant probability measure of the attractor of the system. In order to further quantify the multifractality, we also consider a generalized weighted Cantor set with two different scales describing nonuniform compression. We investigate the resulting multifractal spectrum depending on two scaling parameters and one probability measure parameter, especially for asymmetric scaling. We hope that this generalized model will also be a useful tool for analysis of intermittent turbulence in space plasmas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18596802','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18596802"><span>An asymmetric <span class="hlt">solar</span> <span class="hlt">wind</span> termination shock.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stone, Edward C; Cummings, Alan C; McDonald, Frank B; Heikkila, Bryant C; Lal, Nand; Webber, William R</p> <p>2008-07-03</p> <p>Voyager 2 crossed the <span class="hlt">solar</span> <span class="hlt">wind</span> termination shock at 83.7 au in the southern hemisphere, approximately 10 au closer to the Sun than found by Voyager 1 in the north. This asymmetry could indicate an asymmetric pressure from an interstellar magnetic field, from transient-induced shock motion, or from the <span class="hlt">solar</span> <span class="hlt">wind</span> dynamic pressure. Here we report that the intensity of 4-5 MeV protons accelerated by the shock near Voyager 2 was three times that observed concurrently by Voyager 1, indicating differences in the shock at the two locations. (Companion papers report on the plasma, magnetic field, plasma-wave and lower energy particle observations at the shock.) Voyager 2 did not find the source of anomalous cosmic rays at the shock, suggesting that the source is elsewhere on the shock or in the heliosheath. The small intensity gradient of Galactic cosmic ray helium indicates that either the gradient is further out in the heliosheath or the local interstellar Galactic cosmic ray intensity is lower than expected.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4394683','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4394683"><span>Anisotropy in <span class="hlt">solar</span> <span class="hlt">wind</span> plasma turbulence</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Oughton, S.; Matthaeus, W. H.; Wan, M.; Osman, K. T.</p> <p>2015-01-01</p> <p>A review of spectral anisotropy and variance anisotropy for <span class="hlt">solar</span> <span class="hlt">wind</span> fluctuations is given, with the discussion covering inertial range and dissipation range scales. For the inertial range, theory, simulations and observations are more or less in accord, in that fluctuation energy is found to be primarily in modes with quasi-perpendicular wavevectors (relative to a suitably defined mean magnetic field), and also that most of the fluctuation energy is in the vector components transverse to the mean field. Energy transfer in the parallel direction and the energy levels in the parallel components are both relatively weak. In the dissipation range, observations indicate that variance anisotropy tends to decrease towards isotropic levels as the electron gyroradius is approached; spectral anisotropy results are mixed. Evidence for and against wave interpretations and turbulence interpretations of these features will be discussed. We also present new simulation results concerning evolution of variance anisotropy for different classes of initial conditions, each with typical background <span class="hlt">solar</span> <span class="hlt">wind</span> parameters. PMID:25848082</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=MSFC-6903621&hterms=parking+Solar&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dparking%2BSolar','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=MSFC-6903621&hterms=parking+Solar&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dparking%2BSolar"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Spectrometer on Lunar Surface</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1969-01-01</p> <p>Sitting on the lunar surface, this <span class="hlt">Solar</span> <span class="hlt">Wind</span> Spectrometer is measuring the energies of the particles that make up the <span class="hlt">solar</span> <span class="hlt">wind</span>. This was one of the instruments used during the Apollo 12 mission. The second manned lunar landing mission, Apollo 12 launched from launch pad 39-A at Kennedy Space Center in Florida on November 14, 1969 via a Saturn V launch vehicle. The Saturn V vehicle was developed by the Marshall Space Flight Center (MSFC) under the direction of Dr. Wernher von Braun. Aboard Apollo 12 was a crew of three astronauts: Alan L. Bean, pilot of the Lunar Module (LM), Intrepid; Richard Gordon, pilot of the Command Module (CM), Yankee Clipper; and Spacecraft Commander Charles Conrad. The LM, Intrepid, landed astronauts Conrad and Bean on the lunar surface in what's known as the Ocean of Storms while astronaut Richard Gordon piloted the CM, Yankee Clipper, in a parking orbit around the Moon. Lunar soil activities included the deployment of the Apollo Lunar Surface Experiments Package (ALSEP), finding the unmanned Surveyor 3 that landed on the Moon on April 19, 1967, and collecting 75 pounds (34 kilograms) of rock samples. Apollo 12 safely returned to Earth on November 24, 1969.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhDT........77L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhDT........77L"><span>The structure of the <span class="hlt">solar</span> <span class="hlt">wind</span> in the inner heliosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Christina On-Yee</p> <p>2010-12-01</p> <p>This dissertation is devoted to expanding our understanding of the <span class="hlt">solar</span> <span class="hlt">wind</span> structure in the inner heliosphere and variations therein with <span class="hlt">solar</span> activity. Using spacecraft observations and numerical models, the origins of the large-scale structures and long-term trends of the <span class="hlt">solar</span> <span class="hlt">wind</span> are explored in order to gain insights on how our Sun determines the space environments of the terrestrial planets. I use long term measurements of the <span class="hlt">solar</span> <span class="hlt">wind</span> density, velocity, interplanetary magnetic field, and particles, together with models based on <span class="hlt">solar</span> magnetic field data, to generate time series of these properties that span one <span class="hlt">solar</span> rotation (˜27 days). From these time series, I assemble and obtain the synoptic overviews of the <span class="hlt">solar</span> <span class="hlt">wind</span> properties. The resulting synoptic overviews show that the <span class="hlt">solar</span> <span class="hlt">wind</span> around Mercury, Venus, Earth, and Mars is a complex co-rotating structure with recurring features and occasional transients. During quiet <span class="hlt">solar</span> conditions, the heliospheric current sheet, which separates the positive interplanetary magnetic field from the negative, usually has a remarkably steady two- or four-sector structure that persists for many <span class="hlt">solar</span> rotations. Within the sector boundaries are the slow and fast speed <span class="hlt">solar</span> <span class="hlt">wind</span> streams that originate from the open coronal magnetic field sources that map to the ecliptic. At the sector boundaries, compressed high-density and the related high-dynamic pressure ridges form where streams from different coronal source regions interact. High fluxes of energetic particles also occur at the boundaries, and are seen most prominently during the quiet <span class="hlt">solar</span> period. The existence of these recurring features depends on how long-lived are their source regions. In the last decade, 3D numerical <span class="hlt">solar</span> <span class="hlt">wind</span> models have become more widely available. They provide important scientific tools for obtaining a more global view of the inner heliosphere and of the relationships between conditions at Mercury, Venus, Earth, and Mars. When</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRA..122.2740L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRA..122.2740L"><span>Centennial evolution of monthly <span class="hlt">solar</span> <span class="hlt">wind</span> speeds: Fastest monthly <span class="hlt">solar</span> <span class="hlt">wind</span> speeds from long-duration coronal holes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lukianova, Renata; Holappa, Lauri; Mursula, Kalevi</p> <p>2017-03-01</p> <p>High-speed <span class="hlt">solar</span> <span class="hlt">wind</span> streams (HSSs) are very efficient drivers of geomagnetic activity at high latitudes. In this paper we use a recently developed ΔH parameter of geomagnetic activity, calculated from the nightside hourly magnetic field measurements of the Sodankylä observatory, as a proxy for <span class="hlt">solar</span> <span class="hlt">wind</span> (SW) speed at monthly time resolution in 1914-2014 (<span class="hlt">solar</span> cycles 15-24). The seasonal variation in the relation between monthly ΔH and <span class="hlt">solar</span> <span class="hlt">wind</span> speed is taken into account by calculating separate regressions between ΔH and SW speed for each month. Thereby, we obtain a homogeneous series of proxy values for monthly <span class="hlt">solar</span> <span class="hlt">wind</span> speed for the last 100 years. We find that the strongest HSS-active months of each <span class="hlt">solar</span> cycle occur in the declining phase, in years 1919, 1930, 1941, 1952, 1959, 1973, 1982, 1994, and 2003. Practically all these years are the same or adjacent to the years of annual maximum <span class="hlt">solar</span> <span class="hlt">wind</span> speeds. This implies that the most persistent coronal holes, lasting for several <span class="hlt">solar</span> rotations and leading to the highest annual SW speeds, are also the sources of the highest monthly SW speeds. Accordingly, during the last 100 years, there were no coronal holes of short duration (of about one <span class="hlt">solar</span> rotation) that would produce faster monthly (or <span class="hlt">solar</span> rotation) averaged <span class="hlt">solar</span> <span class="hlt">wind</span> than the most long-living coronal holes in each <span class="hlt">solar</span> cycle produce.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850026753','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850026753"><span>The <span class="hlt">solar</span> <span class="hlt">wind</span> effect on cosmic rays and <span class="hlt">solar</span> activity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fujimoto, K.; Kojima, H.; Murakami, K.</p> <p>1985-01-01</p> <p>The relation of cosmic ray intensity to <span class="hlt">solar</span> <span class="hlt">wind</span> velocity is investigated, using neutron monitor data from Kiel and Deep River. The analysis shows that the regression coefficient of the average intensity for a time interval to the corresponding average velocity is negative and that the absolute effect increases monotonously with the interval of averaging, tau, that is, from -0.5% per 100km/s for tau = 1 day to -1.1% per 100km/s for tau = 27 days. For tau 27 days the coefficient becomes almost constant independently of the value of tau. The analysis also shows that this tau-dependence of the regression coefficiently is varying with the <span class="hlt">solar</span> activity.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21163510','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21163510"><span>The <span class="hlt">solar</span> <span class="hlt">wind</span> in the third dimension</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Neugebauer, M.</p> <p>1996-07-20</p> <p>For many years, <span class="hlt">solar-wind</span> physicists have been using plasma and field data acquired near the ecliptic plane together with data on the scintillation of radio sources and remote sensing of structures in the <span class="hlt">solar</span> corona to estimate the properties of the high-latitude <span class="hlt">solar</span> <span class="hlt">wind</span>. Because of the highly successful Ulysses mission, the moment of truth is now here. This paper summarizes the principal agreements and differences between the Ulysses observations and expectations. The speed of the high-latitude <span class="hlt">solar</span> <span class="hlt">wind</span> was even greater than anticipated. The strength of the radial component of the interplanetary magnetic field was found to be independent of latitude. The tilt of the heliospheric current sheet caused reverse corotating shocks to be observed to higher latitudes than forward corotating shocks. The energetic particles accelerated in these shocks were detected well poleward of the latitudes at which Ulysses observed the interaction regions themselves. As anticipated, there was a strong flux of outward propagating Alfven waves throughout the polar flow. Those waves were probably largely responsible for the smaller-than-anticipated increase of galactic cosmic rays with increasing latitude. As expected, the charge state or ionization temperature of heavy ions was lower in the polar flow than in low-latitude interstream flows. What was not anticipated was the correlation of elemental abundances with ionization temperatures; the Ulysses data revealed a connection between the first ionization time in the upper chromosphere and the final ionization state in the corona. As expected, transient events were detected to {approx}60 deg. latitude, but the properties of those high latitude transient flows held some surprises. At high latitudes, the speeds of the transient interplanetary plasma clouds were approximately the same as the speed of the ambient plasma and the expansion of the clouds drove forward and reverse shock pairs that had never been seen at low latitudes. At</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JASS...34..105P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JASS...34..105P"><span>Characteristics of <span class="hlt">Solar</span> <span class="hlt">Wind</span> Density Depletions During <span class="hlt">Solar</span> Cycles 23 and 24</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Park, Keunchan; Lee, Jeongwoo; Yi, Yu; Lee, Jaejin; Sohn, Jongdae</p> <p>2017-06-01</p> <p><span class="hlt">Solar</span> <span class="hlt">wind</span> density depletions are phenomena that <span class="hlt">solar</span> <span class="hlt">wind</span> density is rapidly decreased and keep the state. They are generally believed to be caused by the interplanetary (IP) shocks. However, there are other cases that are hardly associated with IP shocks. We set up a hypothesis for this phenomenon and analyze this study. We have collected the <span class="hlt">solar</span> <span class="hlt">wind</span> parameters such as density, speed and interplanetary magnetic field (IMF) data related to the <span class="hlt">solar</span> <span class="hlt">wind</span> density depletion events during the period from 1996 to 2013 that are obtained with the advanced composition explorer (ACE) and the <span class="hlt">Wind</span> satellite. We also calculate two pressures (magnetic, dynamic) and analyze the relation with density depletion. As a result, we found total 53 events and the most these phenomena’s sources caused by IP shock are interplanetary coronal mass ejection (ICME). We also found that <span class="hlt">solar</span> <span class="hlt">wind</span> density depletions are scarcely related with IP shock’s parameters. The <span class="hlt">solar</span> <span class="hlt">wind</span> density is correlated with <span class="hlt">solar</span> <span class="hlt">wind</span> dynamic pressure within density depletion. However, the <span class="hlt">solar</span> <span class="hlt">wind</span> density has an little anti-correlation with IMF strength during all events of <span class="hlt">solar</span> <span class="hlt">wind</span> density depletion, regardless of the presence of IP shocks. Additionally, In 47 events of IP shocks, we find 6 events that show a feature of blast wave. The quantities of IP shocks are weaker than blast wave from the Sun, they are declined in a short time after increasing rapidly. We thus argue that IMF strength or dynamic pressure are an important factor in understanding the nature of <span class="hlt">solar</span> <span class="hlt">wind</span> density depletion. Since IMF strength and <span class="hlt">solar</span> <span class="hlt">wind</span> speed varies with <span class="hlt">solar</span> cycle, we will also investigate the characteristics of <span class="hlt">solar</span> <span class="hlt">wind</span> density depletion events in different phases of <span class="hlt">solar</span> cycle as an additional clue to their physical nature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JGRA..118.2834Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JGRA..118.2834Z"><span>Association of <span class="hlt">solar</span> <span class="hlt">wind</span> proton flux extremes with pseudostreamers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, L.; Gibson, S. E.; Fisk, L. A.</p> <p>2013-06-01</p> <p>We investigate the characteristics and <span class="hlt">solar</span> origins of a subpopulation of the <span class="hlt">solar</span> <span class="hlt">wind</span> that possesses extreme values of proton flux. Ulysses observations including <span class="hlt">solar</span> <span class="hlt">wind</span> magnetic flux, proton flux, number density and velocity, and ionic composition are examined in this study. We find that the departures of <span class="hlt">solar</span> <span class="hlt">wind</span> proton flux from its constancy occur for time intervals leading up to and encompassing the past two <span class="hlt">solar</span> minima, and the extreme-proton-flux <span class="hlt">wind</span> possesses the following characteristics: (1) it generally originates from sources middle-distant from the Heliospheric Current Sheet (HCS); (2) it is associated with a broad range of velocities and electron temperatures but excludes very fast/cold <span class="hlt">wind</span>; (3) it exhibits anticorrelation between electron temperature and proton velocity, as does the rest of the <span class="hlt">solar</span> <span class="hlt">wind</span>; (4) it has extreme proton density values relative to the rest of the <span class="hlt">solar</span> <span class="hlt">wind</span>; and (5) the extreme-high-proton-flux <span class="hlt">wind</span> has radial component of open magnetic flux (Br) greater than the rest of the <span class="hlt">solar</span> <span class="hlt">wind</span>, and both extreme-high and extreme-low <span class="hlt">wind</span> do not possess the lowest values of Br flux. Comparing with SOHO EIT 195 Å coronal images, we find the observed extreme-proton-flux <span class="hlt">wind</span> has temporal and spatial coincidence with the appearance of low-latitude coronal holes present in the recent two <span class="hlt">solar</span> minima; the magnetic field lines extrapolated by the Potential Field Source Surface model confirm there are coronal pseudostreamer structures involved. So we propose that these extreme-proton-flux <span class="hlt">winds</span> can be associated with mid- to low-latitude coronal holes and "pseudostreamer" structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUSMSH23A..01Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUSMSH23A..01Z"><span>Association of <span class="hlt">Solar</span> <span class="hlt">Wind</span> Proton Flux Extremes with Pseudostreamers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, L.; Gibson, S. E.; Fisk, L. A.</p> <p>2013-05-01</p> <p>We investigate the characteristics and <span class="hlt">solar</span> origins of a sub-population of the <span class="hlt">solar</span> <span class="hlt">wind</span> that possesses extreme values of proton flux. Ulysses observations including <span class="hlt">solar</span> <span class="hlt">wind</span> magnetic flux, proton flux, number density and velocity, and ionic composition are examined in this study. We find the departures of <span class="hlt">solar</span> <span class="hlt">wind</span> proton flux from its constancy occur for time intervals leading up to and encompassing the past two <span class="hlt">solar</span> minima, and the extreme-proton-flux <span class="hlt">wind</span> possesses the following characteristics: 1) it generally originates from sources middle-distant from the Heliospheric Current Sheet (HCS); 2) it is associated with a broad range of velocities and electron temperatures, but excludes very fast/cold <span class="hlt">wind</span>; 3) it exhibits anticorrelation between electron temperature and proton velocity, as does the rest of the <span class="hlt">solar</span> <span class="hlt">wind</span>; 4) it has extreme proton density values relative to the rest of the <span class="hlt">solar</span> <span class="hlt">wind</span>; and 5) the extreme-high-proton-flux <span class="hlt">wind</span> has radial component of open magnetic flux (Br) greater than the rest of the <span class="hlt">solar</span> <span class="hlt">wind</span> and both extreme-high and extreme-low <span class="hlt">wind</span> do not possess the lowest values of Br flux. Comparing with SOHO EIT 195 A coronal images, we find the observed extreme-proton-flux <span class="hlt">wind</span> has temporal and special coincidence with the appearance of low latitude coronal holes present in the recent two <span class="hlt">solar</span> minima; and the magnetic field lines extrapolated by the Potential Field Source Surface (PFSS) model confirm there are coronal pseudostreamer structures involved. So we propose that these extreme-proton-flux <span class="hlt">wind</span> can be associated with mid-to-low-latitude coronal holes and "pseudostreamer" structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000057278','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000057278"><span><span class="hlt">Genesis</span> Trajectory Design</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bell, Julia L.; Lo, Martin W.; Wilson, Roby S.</p> <p>2000-01-01</p> <p>The <span class="hlt">Genesis</span> mission will launch in 2001, sending the spacecraft into a halo orbit about the Sun-Earth L1 point to collect and return <span class="hlt">solar</span> <span class="hlt">wind</span> samples to the Earth for analysis in 2003. One of the most constraining aspects of the mission design is the requirement to return to the designated landing site (the Utah Test and Training Range, UTTR) during daylight hours. The ongoing mission design has led the development of a family of solutions that characterize a broad range of conditions at Earth entry. Characterizing this family provides insight into the possible existence of additional trajectories while also helping to narrow the search space by indicating where additional solutions are unlikely to exist; this contributes to a more efficient utilization of mission design resources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSH31C2434S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSH31C2434S"><span>The very slow <span class="hlt">solar</span> <span class="hlt">wind</span> in the Inner Heliosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sanchez-Diaz, E.; Segura, K.; Rouillard, A.; Lavraud, B.; Tao, C.; Blelly, P. L.</p> <p>2015-12-01</p> <p>Measurements near 1AU of the bulk and compositional properties of the interplanetary plasma point to the existence of two <span class="hlt">solar</span> <span class="hlt">winds</span> that can be classified by their speeds, V, the fast (V>400 km s-1) and slow <span class="hlt">winds</span> (V<400 km s-1). The slow <span class="hlt">solar</span> <span class="hlt">wind</span> is seldom observed slower than 300 km s-1 at 1 AU. We show that, closer to the Sun, there is a big amount of <span class="hlt">solar</span> <span class="hlt">wind</span> slower than 300 km s-1, hereafter very slow <span class="hlt">solar</span> <span class="hlt">wind</span> (VSSW). It is mostly detected inside 0.7 AU by the HELIOS spacecraft during <span class="hlt">solar</span> maximum (1979-1980). The closer to the Sun the slower it can be observed, reaching velocities of 200 kms-1 near 0.3 AU. This very slow <span class="hlt">wind</span> usually contains the very dense heliospheric plasma sheet as well as the heliospheric current sheet. The very low speeds disappear by 1AU likely due to the interaction with the faster plasma. <span class="hlt">Solar</span> Probe Plus will measure in-situ how low in the inner Heliosphere this interaction starts and whether even lower velocities are observed inside 0.3 AU. The VSSW has higher density and lower temperature than regular slow <span class="hlt">solar</span> <span class="hlt">wind</span>, qualitatively extending the known scaling laws for the <span class="hlt">solar</span> <span class="hlt">wind</span> over 300 km s-1(Lopez & Freeman, 1986) (Hundhausen, Bame, Asbridge, & Sydoriak, 1970). Like the rest of the slow <span class="hlt">solar</span> <span class="hlt">wind</span>, the helium abundance of the VSSW increase with <span class="hlt">solar</span> activity, approaching to the fast <span class="hlt">wind</span> composition at <span class="hlt">solar</span> maximum. Combining a Potential Field Source Surface (PFSS) to a ballistic backmapping, we relate the ins-situ measurements to the <span class="hlt">solar</span> surface. We compute the proton density flux just above the photosphere and find much higher fluxes in the VSSW than in the faster <span class="hlt">winds</span> at <span class="hlt">solar</span> maximum. Based on this, we propose a likely mechanism for the <span class="hlt">solar</span> cycle variability of the helium abundance of the VSSW and slow <span class="hlt">solar</span> <span class="hlt">wind</span>, which will be tested by combining <span class="hlt">Solar</span> Orbiter and <span class="hlt">Solar</span> Probe Plus measurements of the VSSW with high resolution and high cadence Carrington maps. This work was funded by the EU FP7 HELCATS</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820028333&hterms=1087&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%25231087','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820028333&hterms=1087&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%25231087"><span>Correlations between <span class="hlt">solar</span> <span class="hlt">wind</span> parameters and auroral kilometric radiation intensity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gallagher, D. L.; Dangelo, N.</p> <p>1981-01-01</p> <p>The relationship between <span class="hlt">solar</span> <span class="hlt">wind</span> properties and the influx of energy into the nightside auroral region as indicated by the intensity of auroral kilometric radiation is investigated. Smoothed Hawkeye satellite observations of auroral radiation at 178, 100 and 56.2 kHz for days 160 through 365 of 1974 are compared with <span class="hlt">solar</span> <span class="hlt">wind</span> data from the composite <span class="hlt">Solar</span> <span class="hlt">Wind</span> Plasma Data Set, most of which was supplied by the IMP-8 spacecraft. Correlations are made between smoothed daily averages of <span class="hlt">solar</span> <span class="hlt">wind</span> ion density, bulk flow speed, total IMF strength, electric field, <span class="hlt">solar</span> <span class="hlt">wind</span> speed in the southward direction, <span class="hlt">solar</span> <span class="hlt">wind</span> speed multiplied by total IMF strength, the substorm parameter epsilon and the Kp index. The greatest correlation is found between <span class="hlt">solar</span> <span class="hlt">wind</span> bulk flow speed and auroral radiation intensity, with a linear correlation coefficient of 0.78 for the 203 daily averages examined. A possible mechanism for the relationship may be related to the propagation into the nightside magnetosphere of low-frequency long-wavelength electrostatic waves produced in the magnetosheath by the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1226489','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1226489"><span>Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study Phase 3: Technical Overview</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p></p> <p>2015-11-01</p> <p>Technical fact sheet outlining the key findings of Phase 3 of the Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study (WWSIS-3). NREL and GE find that with good system planning, sound engineering practices, and commercially available technologies, the Western grid can maintain reliability and stability during the crucial first minute after grid disturbances with high penetrations of <span class="hlt">wind</span> and <span class="hlt">solar</span> power.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021363&hterms=Properties+wave+function&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DProperties%2Bwave%2Bfunction','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021363&hterms=Properties+wave+function&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DProperties%2Bwave%2Bfunction"><span>Three-fluid <span class="hlt">solar</span> <span class="hlt">wind</span> model with Alfven waves</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Esser, Ruth; Habbal, Shadia R.; Hu, You Q.</p> <p>1995-01-01</p> <p>We present a study of a three-fluid <span class="hlt">solar</span> <span class="hlt">wind</span> model. with continuity, momentum and separate energy equations for protons. alpha particles and electrons. Allowing separate coronal heat sources for all three species, we study the flow properties of the <span class="hlt">solar</span> <span class="hlt">wind</span> as a function of heat input, Alfven wave energy input, and alpha particle abundance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1217837','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1217837"><span><span class="hlt">Solar</span> and <span class="hlt">Wind</span> Technologies for Hydrogen Production Report to Congress</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>None, None</p> <p>2005-12-01</p> <p>DOE's <span class="hlt">Solar</span> and <span class="hlt">Wind</span> Technologies for Hydrogen Production Report to Congress summarizes the technology roadmaps for <span class="hlt">solar</span>- and <span class="hlt">wind</span>-based hydrogen production. Published in December 2005, it fulfills the requirement under section 812 of the Energy Policy Act of 2005.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021292&hterms=solar+wind+power&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dsolar%2Bwind%2Bpower','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021292&hterms=solar+wind+power&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dsolar%2Bwind%2Bpower"><span>Turbulence in the <span class="hlt">solar</span> <span class="hlt">wind</span>: Kinetic effects</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Goldstein, M. L.</p> <p>1995-01-01</p> <p>Although a casual look at the fluctuating magnetic and velocity fields in the <span class="hlt">solar</span> <span class="hlt">wind</span> may be reminiscent of a chaotic and disordered flow, there is, nonetheless. considerable organization and structure in the temporal and spatial evolution of those fluctuations. Much of that evolution is controlled by processes operating on rather large scales for example, in the inner heliosphere, the fluctuations in magnetic and velocity are highly correlated in the sense of outward propagating Alfven waves. This correlation can be destroyed both in time and distance by the velocity gradients present between fast and slow streams and by other nonlinear processes which stir the medium, producing a turbulent cascade of energy from large to small scales. Many aspects of this turbulent evolution can be described using fluid models; however, at some scale the fluid approximation breaks down and a more detailed paradigm is necessary. The breakdown is evident in the power spectrum of magnetic fluctuations at scales approaching the wavelength of ion cyclotron waves. At those scales, as evident in Mariner 10 and other magnetometer data, the spectrum bends over and the fluctuations damp, possibly heating the ambient plasma. Some evidence for heating of the <span class="hlt">solar</span> <span class="hlt">wind</span> is present in the Voyager data. Fluid models can be modified to some extent to incorporate aspects of a kinetic treatment. This is done by modifying the dissipation terms in the fluid equations and by including extra terms, such as the Hall term. As the scale lengths of phenomena shrink further and approach the spatial and temporal scales characteristic of electron phenomena, the fluid description must be abandoned altogether and a fully kinetic treatment is required. One example is the generation of Langmuir solitons produced by the electron beams that generate type 3 <span class="hlt">solar</span> radio bursts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1215160R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1215160R"><span>The Electrodynamics of the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Interaction with Venus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Russell, C. T.; Ma, Y. J.; Luhman, J. G.</p> <p>2010-05-01</p> <p>Venus has a thick atmosphere whose upper reaches are ionized by <span class="hlt">solar</span> EUV. The temperature and density of this ionosphere provide sufficient pressure that, at <span class="hlt">solar</span> maximum for normal <span class="hlt">solar</span> <span class="hlt">wind</span> pressures, the <span class="hlt">solar</span> <span class="hlt">wind</span> is deflected at altitudes far above the region of significant ion-neutral collisions. Hence when the interplanetary field changes, a current is induced at the ionopause that excludes the magnetic field from the ionosphere. A magnetic barrier of magnetic field draped around the ionosphere builds up and forms the obstacle to the <span class="hlt">solar</span> <span class="hlt">wind</span> flow. Since the size of the Venus obstacle vastly exceeds that of the ion-gyro motion, a bow shock forms that slows, heats, and deflects the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma. This interaction is the epitome of the induced magnetosphere. At times though, the <span class="hlt">solar</span> <span class="hlt">wind</span> pressure is too strong to be stood off by the ionosphere, and the ionopause drops to collisional altitudes. At this point, the ionosphere becomes magnetized throughout. Venus also has an H and O exosphere that extends into the <span class="hlt">solar</span> <span class="hlt">wind</span>. These can lead to the occurrence of cometary processes like mass pickup and deceleration of the flow. In short, the <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with Venus has many facets and is sufficiently complex to continue to fuel new discoveries and a little controversy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22167597','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22167597"><span>OBSERVATION OF FLUX-TUBE CROSSINGS IN THE <span class="hlt">SOLAR</span> <span class="hlt">WIND</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Arnold, L.; Li, G.; Li, X.; Yan, Y.</p> <p>2013-03-20</p> <p>Current sheets are ubiquitous in the <span class="hlt">solar</span> <span class="hlt">wind</span>. They are a major source of the <span class="hlt">solar</span> <span class="hlt">wind</span> MHD turbulence intermittency. They may result from nonlinear interactions of the <span class="hlt">solar</span> <span class="hlt">wind</span> MHD turbulence or are the boundaries of flux tubes that originate from the <span class="hlt">solar</span> surface. Some current sheets appear in pairs and are the boundaries of transient structures such as magnetic holes and reconnection exhausts or the edges of pulsed Alfven waves. For an individual current sheet, discerning whether it is a flux-tube boundary or due to nonlinear interactions or the boundary of a transient structure is difficult. In this work, using data from the <span class="hlt">Wind</span> spacecraft, we identify two three-current-sheet events. Detailed examination of these two events suggests that they are best explained by the flux-tube-crossing scenario. Our study provides convincing evidence supporting the scenario that the <span class="hlt">solar</span> <span class="hlt">wind</span> consists of flux tubes where distinct plasmas reside.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19810060080&hterms=solar+wind+power&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsolar%2Bwind%2Bpower','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19810060080&hterms=solar+wind+power&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsolar%2Bwind%2Bpower"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> control of auroral zone geomagnetic activity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Clauer, C. R.; Mcpherron, R. L.; Searls, C.; Kivelson, M. G.</p> <p>1981-01-01</p> <p><span class="hlt">Solar</span> <span class="hlt">wind</span> magnetosphere energy coupling functions are analyzed using linear prediction filtering with 2.5 minute data. The relationship of auroral zone geomagnetic activity to <span class="hlt">solar</span> <span class="hlt">wind</span> power input functions are examined, and a least squares prediction filter, or impulse response function is designed from the data. Computed impulse response functions are observed to have characteristics of a low pass filter with time delay. The AL index is found well related to <span class="hlt">solar</span> <span class="hlt">wind</span> energy functions, although the AU index shows a poor relationship. High frequency variations of auroral indices and substorm expansions are not predictable with <span class="hlt">solar</span> <span class="hlt">wind</span> information alone, suggesting influence by internal magnetospheric processes. Finally, the epsilon parameter shows a poorer relationship with auroral geomagnetic activity than a power parameter, having a VBs <span class="hlt">solar</span> <span class="hlt">wind</span> dependency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1095399','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1095399"><span>The Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study Phase 2</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lew, D.; Brinkman, G.; Ibanez, E.; Hodge, B. M.; Hummon, M.; Florita, A.; Heaney, M.</p> <p>2013-09-01</p> <p>The electric grid is a highly complex, interconnected machine, and changing one part of the grid can have consequences elsewhere. Adding <span class="hlt">wind</span> and <span class="hlt">solar</span> affects the operation of the other power plants and adding high penetrations can induce cycling of fossil-fueled generators. Cycling leads to wear-and-tear costs and changes in emissions. Phase 2 of the Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study (WWSIS-2) evaluated these costs and emissions and simulated grid operations for a year to investigate the detailed impact of <span class="hlt">wind</span> and <span class="hlt">solar</span> on the fossil-fueled fleet. This built on Phase 1, one of the largest <span class="hlt">wind</span> and <span class="hlt">solar</span> integration studies ever conducted, which examined operational impacts of high <span class="hlt">wind</span> and <span class="hlt">solar</span> penetrations in the West.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1220243','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1220243"><span>The Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study Phase 2</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lew, Debra; Brinkman, Greg; Ibanez, E.; Florita, A.; Heaney, M.; Hodge, B. -M.; Hummon, M.; Stark, G.; King, J.; Lefton, S. A.; Kumar, N.; Agan, D.; Jordan, G.; Venkataraman, S.</p> <p>2013-09-01</p> <p>The electric grid is a highly complex, interconnected machine, and changing one part of the grid can have consequences elsewhere. Adding <span class="hlt">wind</span> and <span class="hlt">solar</span> affects the operation of the other power plants and adding high penetrations can induce cycling of fossil-fueled generators. Cycling leads to wear-and-tear costs and changes in emissions. Phase 2 of the Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study (WWSIS-2) evaluated these costs and emissions and simulated grid operations for a year to investigate the detailed impact of <span class="hlt">wind</span> and <span class="hlt">solar</span> on the fossil-fueled fleet. This built on Phase 1, one of the largest <span class="hlt">wind</span> and <span class="hlt">solar</span> integration studies ever conducted, which examined operational impacts of high <span class="hlt">wind</span> and <span class="hlt">solar</span> penetrations in the West(GE Energy 2010).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22039422','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22039422"><span>INTERPRETING MAGNETIC VARIANCE ANISOTROPY MEASUREMENTS IN THE <span class="hlt">SOLAR</span> <span class="hlt">WIND</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>TenBarge, J. M.; Klein, K. G.; Howes, G. G.; Podesta, J. J.</p> <p>2012-07-10</p> <p>The magnetic variance anisotropy (A{sub m}) of the <span class="hlt">solar</span> <span class="hlt">wind</span> has been used widely as a method to identify the nature of <span class="hlt">solar</span> <span class="hlt">wind</span> turbulent fluctuations; however, a thorough discussion of the meaning and interpretation of the A{sub m} has not appeared in the literature. This paper explores the implications and limitations of using the A{sub m} as a method for constraining the <span class="hlt">solar</span> <span class="hlt">wind</span> fluctuation mode composition and presents a more informative method for interpreting spacecraft data. The paper also compares predictions of the A{sub m} from linear theory to nonlinear turbulence simulations and <span class="hlt">solar</span> <span class="hlt">wind</span> measurements. In both cases, linear theory compares well and suggests that the <span class="hlt">solar</span> <span class="hlt">wind</span> for the interval studied is dominantly Alfvenic in the inertial and dissipation ranges to scales of k{rho}{sub i} {approx_equal} 5.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSH21B2526J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSH21B2526J"><span>Magnetic Signatures of Nano Dust in the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jia, Y. D.; Lai, H.; Russell, C. T.</p> <p>2016-12-01</p> <p>Nano dust particles become charged and therefore accelerate once they are created and released into the <span class="hlt">solar</span> <span class="hlt">wind</span>. However, it takes hours to accelerate EVEN the lightest dust particles. To study their interaction with the <span class="hlt">solar</span> <span class="hlt">wind</span>, we numerically model the <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with charged dust at several stages in the dust acceleration process: at release; after the dust particles gain 20% of the <span class="hlt">solar</span> <span class="hlt">wind</span> speed; after the dust particles gain 50% of the <span class="hlt">solar</span> <span class="hlt">wind</span> speed; and a subsonic interaction. In addition, we model such interactions on dust particles weighing 3000, 10,000, and 100,000 amu/proton charge. Lastly, we compare such interactions when the dust is released at different heliocentric distances: 0.3 AU, 0.7 AU, and 1 AU. We use these models to predict what a magnetometer will detect at 1 AU when such dust clouds are released upstream.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996AAS...188.4905G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996AAS...188.4905G"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Composition: First Results from SOHO and Future Expectations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Galvin, A. B.; Ipavich, F. M.; Gloeckler, G.; Coplan, M.; Hovestadt, D.; Hilchenbach, M.; Buergi, A.; Klecker, B.; Scholer, M.; Bochsler, P.; Balsiger, H.; Geiss, J.; Kallenbach, R.; Wurz, P.; Gruenwaldt, H.; Axford, W. I.; Livi, S.; Marsch, E.; Wilken, B.; Gliem, F.; Reiche, K.-U.; Lee, M. A.; Moebius, E.; Hsieh, K. C.; Neugebauer, M.; Managadze, G. G.; Verigin, M. I.</p> <p>1996-05-01</p> <p>The SOHO payload includes three experiments designed to make "in situ" particle measurements of the <span class="hlt">solar</span> <span class="hlt">wind</span> and <span class="hlt">solar</span> energetic particles (CELIAS, D. Hovestadt PI; COSTEP, H. Kunow PI; ERNE, J. Torsti PI). The <span class="hlt">solar</span> <span class="hlt">wind</span> measurements that are the focus of this talk are primarily provided by the CELIAS CTOF and MTOF sensors. (CELIAS/STOF and COSTEP-ERNE measure <span class="hlt">solar</span> and interplanetary suprathermal and energetic particle populations.) CELIAS/CTOF measures <span class="hlt">solar</span> <span class="hlt">wind</span> heavy ion elemental and charge state abundances, information which is used (for example) in identifying the type of <span class="hlt">solar</span> <span class="hlt">wind</span> flow and the ionization processes in the corona where the <span class="hlt">solar</span> <span class="hlt">wind</span> charge states become "frozen-in". CELIAS/MTOF provides heavy ion elemental and isotopic abundances that are important (for example) in the study of fractionation factors in coronal abundances (as in the so-called "FIP-effect") for the rarer elements not resolvable in conventional <span class="hlt">solar</span> <span class="hlt">wind</span> composition instruments, and in determining the isotopic make-up of the <span class="hlt">solar</span> corona. MTOF is, by far, the most powerful <span class="hlt">solar</span> <span class="hlt">wind</span> mass spectrometer flown to date, and already has new science to report at the time of this writing. This happenstance is due to a combination of (1) advanced technology in obtaining high mass resolution for ions at <span class="hlt">solar</span> <span class="hlt">wind</span> energies, and (2) increased statistics. The excellent counting statistics are largely due to continuous <span class="hlt">solar</span> <span class="hlt">wind</span> monitoring (with its position at L1, ``the Sun never sets on SOHO''), and the continuous sampling of the <span class="hlt">solar</span> <span class="hlt">wind</span> by the 3-axis stabilized spacecraft further enhanced by MTOF's novel, never previously flown deflection system that encompasses a very large dynamic range. As might be expected, this unique opportunity has allowed MTOF to identify a number of elements for the first time in the <span class="hlt">solar</span> <span class="hlt">wind</span> (e.g., P, Ti, Cr and Ni). A rich assortment of <span class="hlt">solar</span> <span class="hlt">wind</span> isotopes have been identified for the first time, many of which (e.g., Fe 54 and 56; Ni 58,60,62) have</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22342040','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22342040"><span>Short-scale variations of the <span class="hlt">solar</span> <span class="hlt">wind</span> helium abundance</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Šafránková, J.; Němeček, Z.; Cagaš, P.; Přech, L.; Pavlů, J.; Zastenker, G. N.; Riazantseva, M. O.; Koloskova, I. V.</p> <p>2013-11-20</p> <p>Abrupt changes of the relative He abundance in the <span class="hlt">solar</span> <span class="hlt">wind</span> are usually attributed to encounters with boundaries dividing <span class="hlt">solar</span> <span class="hlt">wind</span> streams from different sources in the <span class="hlt">solar</span> corona. This paper presents a systematic study of fast variations of the He abundance that supports the idea that a majority of these variations on short timescales (3-30 s) are generated by in-transit turbulence that is probably driven by the speed difference between the ion species. This turbulence contributes to the <span class="hlt">solar</span> <span class="hlt">wind</span> heating and leads to a correlation of the temperature with He abundance.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730002047','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730002047"><span>The large-scale structure of the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wolfe, J. H.</p> <p>1972-01-01</p> <p>The large-scale structure of the <span class="hlt">solar</span> <span class="hlt">wind</span> is reviewed on the basis of experimental space measurements acquired over approximately the last decade. The observations cover the fading portion of the last <span class="hlt">solar</span> cycle up through the maximum of the present cycle. The character of the interplanetary medium is considered from the viewpoint of the temporal behavior of the <span class="hlt">solar</span> <span class="hlt">wind</span> over increasingly longer time intervals, the average properties of the various <span class="hlt">solar</span> <span class="hlt">wind</span> parameters and their interrelationships. Interplanetary-terrestrial relationships and the expected effects of heliographic lattitude and radial distance are briefly discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19780062796&hterms=tritium&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dtritium','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19780062796&hterms=tritium&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dtritium"><span><span class="hlt">Solar-wind</span> tritium limit and nuclear processes in the <span class="hlt">solar</span> atmosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fireman, E. L.; Damico, J.; Defelice, J.</p> <p>1975-01-01</p> <p>Tritium in Surveyor 3 material is measured, and the resulting H-3/H-1 ratio for the <span class="hlt">solar</span> <span class="hlt">wind</span> is applied in a <span class="hlt">solar</span> flare-<span class="hlt">solar</span> <span class="hlt">wind</span> relation to investigate the mixing requirements for the <span class="hlt">solar</span> atmosphere. The flare-<span class="hlt">wind</span> relation is derived. None of the tritium can be attributed to <span class="hlt">solar-wind</span> implantation. The upper limit for the H-3/He ratio in the <span class="hlt">solar</span> <span class="hlt">wind</span> is 4 times 10 to the minus tenth power and corresponds to a H-3/H-1 limit of 2 times 10 to the minus eleventh power. This limit imposes a requirement on the mixing rate in the <span class="hlt">solar</span> atmosphere if the H-3 production rate in <span class="hlt">solar</span>-surface nuclear reactions is greater than 160/sq cm per sec.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760007453','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760007453"><span>Geomagnetic responses to the <span class="hlt">solar</span> <span class="hlt">wind</span> and the <span class="hlt">solar</span> activity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Svalgaard, L.</p> <p>1975-01-01</p> <p>Following some historical notes, the formation of the magnetosphere and the magnetospheric tail is discussed. The importance of electric fields is stressed and the magnetospheric convection of plasma and magnetic field lines under the influence of large-scale magnetospheric electric fields is outlined. Ionospheric electric fields and currents are intimately related to electric fields and currents in the magnetosphere and the strong coupling between the two regions is discussed. The energy input of the <span class="hlt">solar</span> <span class="hlt">wind</span> to the magnetosphere and upper atmosphere is discussed in terms of the reconnection model where interplanetary magnetic field lines merge or connect with the terrestrial field on the sunward side of the magnetosphere. The merged field lines are then stretched behind earth to form the magnetotail so that kinetic energy from the <span class="hlt">solar</span> <span class="hlt">wind</span> is converted into magnetic energy in the field lines in the tail. Localized collapses of the crosstail current, which is driven by the large-scale dawn/dusk electric field in the magnetosphere, divert part of this current along geomagnetic field lines to the ionosphere, causing substorms with auroral activity and magnetic disturbances. The collapses also inject plasma into the radiation belts and build up a ring current. Frequent collapses in rapid succession constitute the geomagnetic storm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1913340P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1913340P"><span>Simulating and cataloguing the background <span class="hlt">solar</span> <span class="hlt">wind</span> conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pinto, Rui; Rouillard, Alexis; Odstrcil, Dusan; Mays, Leila</p> <p>2017-04-01</p> <p>I will present a new series of <span class="hlt">solar</span> <span class="hlt">wind</span> simulations used to build a catalogue of the background <span class="hlt">solar</span> <span class="hlt">wind</span> from the surface of the Sun to 1 AU. We used a new <span class="hlt">solar</span> <span class="hlt">wind</span> model, called MULTI-VP, which takes a coronal magnetic field map as input and calculates the dynamical and thermal properties of the <span class="hlt">solar</span> <span class="hlt">wind</span> from the chromosphere up to about 30 Rsun. MULTI-VP supplies the full set of physical inner boundary conditions required to initiate the model ENLIL, which was then used to calculate the properties of the <span class="hlt">wind</span> flow in the heliosphere (from 21.5 Rsun to 1AU). This combined modelling strategy does not rely on semi-empirical assumptions for the state of the <span class="hlt">solar</span> <span class="hlt">wind</span> at the high corona, and provides new estimates of the state of the background <span class="hlt">wind</span> which are based only on physical principles. MULTI-VP was initiated using Potential Field Source-Surface extrapolations from WSO synoptic maps covering several Carrington rotations both at <span class="hlt">solar</span> minimum and at <span class="hlt">solar</span> maximum (CR 2055 - 2079 and CR 2130 - 2149; see https://stormsweb.irap.omp.eu/doku.php?id=windmaptable). Our solutions were calibrated against in-situ measurements of different spacecrafts, white-light J-Maps and coronal/heliospheric imagery in order to provide better predictions than the classical methods. These <span class="hlt">wind</span> solution will be available as HELCATS catalogues (http://www.helcats-fp7.eu/).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43.4089K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43.4089K"><span>Implications of L1 observations for slow <span class="hlt">solar</span> <span class="hlt">wind</span> formation by <span class="hlt">solar</span> reconnection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kepko, L.; Viall, N. M.; Antiochos, S. K.; Lepri, S. T.; Kasper, J. C.; Weberg, M.</p> <p>2016-05-01</p> <p>While the source of the fast <span class="hlt">solar</span> <span class="hlt">wind</span> is known to be coronal holes, the source of the slow <span class="hlt">solar</span> <span class="hlt">wind</span> has remained a mystery. Long time scale trends in the composition and charge states show strong correlations between <span class="hlt">solar</span> <span class="hlt">wind</span> velocity and plasma parameters, yet these correlations have proved ineffective in determining the slow <span class="hlt">wind</span> source. We take advantage of new high time resolution (12 min) measurements of <span class="hlt">solar</span> <span class="hlt">wind</span> composition and charge state abundances at L1 and previously identified 90 min quasiperiodic structures to probe the fundamental timescales of slow <span class="hlt">wind</span> variability. The combination of new high temporal resolution composition measurements and the clearly identified boundaries of the periodic structures allows us to utilize these distinct <span class="hlt">solar</span> <span class="hlt">wind</span> parcels as tracers of slow <span class="hlt">wind</span> origin and acceleration. We find that each 90 min (2000 Mm) parcel of slow <span class="hlt">wind</span> has near-constant speed yet exhibits repeatable, systematic charge state and composition variations that span the entire range of statistically determined slow <span class="hlt">solar</span> <span class="hlt">wind</span> values. The classic composition-velocity correlations do not hold on short, approximately hourlong, time scales. Furthermore, the data demonstrate that these structures were created by magnetic reconnection. Our results impose severe new constraints on slow <span class="hlt">solar</span> <span class="hlt">wind</span> origin and provide new, compelling evidence that the slow <span class="hlt">wind</span> results from the sporadic release of closed field plasma via magnetic reconnection at the boundary between open and closed flux in the Sun's atmosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021367&hterms=Structural+Equation+Modeling&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DStructural%2BEquation%2BModeling','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021367&hterms=Structural+Equation+Modeling&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DStructural%2BEquation%2BModeling"><span>Coronal roots of <span class="hlt">solar</span> <span class="hlt">wind</span> streams: 3-D MHD modeling</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pisanko, Yu. V.</p> <p>1995-01-01</p> <p>Weak (discontinuous) solutions of the 3-D MHD equations look like a promising tool to model the transonic <span class="hlt">solar</span> <span class="hlt">wind</span> with structural elements: current sheets, coronal plumes etc. Using the observational information about various coronal emissions one can include these structural elements into the 3-D MHD <span class="hlt">solar</span> <span class="hlt">wind</span> model by embedding the discontinuities of given type. Such 3-D MHD structured <span class="hlt">solar</span> <span class="hlt">wind</span> is calculated self-consistently: variants are examined via numerical experiments. In particular, the behavior of coronal plumes in the transonic <span class="hlt">solar</span> <span class="hlt">wind</span> flow, is modeled. The input information for numerical modeling (for example, the magnetic field map at the very base of the <span class="hlt">solar</span> corona) can be adjusted so that fast stream arises over the center of the coronal hole, over the coronal hole boundaries and, even, over the region with closed magnetic topology. 3-D MHD equations have the analytical solution which can serve as a model of supersonic trans-alfvenic <span class="hlt">solar</span> <span class="hlt">wind</span> in the (5-20) <span class="hlt">solar</span> radii heliocentric distance interval. The transverse, nonradial total (gas + magnetic field) pressure balance in the flow is the corner-stone of this solution. The solution describes the filamentation (ray-like structure of the <span class="hlt">solar</span> corona) and streaming (formation of high-speed streams with velocities up to 800 km/sec) as a consequence of the magnetic field spatial inhomogeneous structure and trans-alfvenic character of the flow. The magnetic field works in the model as a 'controller' for the <span class="hlt">solar</span> <span class="hlt">wind</span> streaming and filamentation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMPA24A..05R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMPA24A..05R"><span>Identifying "Carrington Events" in <span class="hlt">Solar</span>, <span class="hlt">Solar</span> <span class="hlt">Wind</span>, and Magnetospheric Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Russell, C. T.; Riley, P.; Luhmann, J. G.; Lai, H.</p> <p>2016-12-01</p> <p>Extreme space weather begins when extraordinary levels of stored magnetic energy in the photosphere rapidly destabilizes. This destabilization generally releases a rapidly expelled plasma and magnetic flux rope. Large fluxes of highly relativistic particles signal the event and at Earth precede the expelled flux rope. The most recent such <span class="hlt">solar</span> event did not encounter the Earth, but was recorded by STEREO A on July 23, 2012. The energy density in the relativistic particles that preceded the rapidly expanding magnetic cloud was so intense that the compression front expanded with a sub fast mode speed (i.e. `subsonically') and the compression front became a slow mode wave. The peak magnetic field in the rope was 109 nT, larger than any previously reported field at 1 AU in the <span class="hlt">solar</span> <span class="hlt">wind</span>. An equally fast disturbance left the Sun on September 1, 1859, and caused intense induced currents when it reached the Earth. It is likely that at least some of the magnetospheric currents were caused by the accompanying magnetic cloud, but magnetospheric diagnostics were scarce during this event. This first space weather event became the defining occurrence of extreme space weather. A second modern event not generally recognized as "Carrington" class, but arguably super-Carrington, arrived on August 4, 1972. Between the Apollo 16 and 17 missions. It was a strong producer of geomagnetic induced currents, but produced only a weak ring current, possibly because the part of the magnetic cloud in contact with the Earth had a polarity that did not couple the <span class="hlt">solar</span> <span class="hlt">wind</span> momentum flux to the magnetosphere. The pressure wave reached 1 AU in the shortest time of any recorded <span class="hlt">solar</span> event and brought an energetic particle flux that would have harmed the astronauts had they been in space. To identify which <span class="hlt">solar</span> events are capable of producing the most extreme space weather events, we must identify those that are expelled toward the Earth at the highest speeds. How these events manifest their</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910048815&hterms=causes+PTH&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcauses%2BPTH','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910048815&hterms=causes+PTH&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcauses%2BPTH"><span>Intermittent turbulence in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burlaga, L. F.</p> <p>1991-01-01</p> <p>This paper demonstrates the existence of intermittent turbulence in the <span class="hlt">solar</span> <span class="hlt">wind</span> at 8.5 AU. The pth-order velocity structure functions show scaling behavior in the range of periods from 0.85 hour to 13.6 hours for p of less than 20. The exponent of the scaling law s(p) is a quadratic function of p. These observations of s(p) for compressible MHD turbulence on a scale of the order of about 1 AU are consistent with laboratory measurements of s(p) for gasdynamic turbulence on a scale of the order of 1 m, indicating the universal character of intermittent turbulence. The observations are not described by the 'constant beta' model of intermittent turbulence. They are marginally consistent with the lognormal model. The observations are consistent with a random beta model prediction which assumes that the turbulence is a mixture of sheets and space-filling eddies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/924986','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/924986"><span>Innovations in <span class="hlt">Wind</span> and <span class="hlt">Solar</span> PV Financing</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cory, K.; Coughlin, J.; Jenkin, T.; Pater, J.; Swezey, B.</p> <p>2008-02-01</p> <p>There is growing national interest in renewable energy development based on the economic, environmental, and security benefits that these resources provide. Historically, greater development of our domestic renewable energy resources has faced a number of hurdles, primarily related to cost, regulation, and financing. With the recent sustained increase in the costs and associated volatility of fossil fuels, the economics of renewable energy technologies have become increasingly attractive to investors, both large and small. As a result, new entrants are investing in renewable energy and new business models are emerging. This study surveys some of the current issues related to <span class="hlt">wind</span> and <span class="hlt">solar</span> photovoltaic (PV) energy project financing in the electric power industry, and identifies both barriers to and opportunities for increased investment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22365612','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22365612"><span>RELAXATION PROCESSES IN <span class="hlt">SOLAR</span> <span class="hlt">WIND</span> TURBULENCE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Servidio, S.; Carbone, V.; Gurgiolo, C.; Goldstein, M. L.</p> <p>2014-07-10</p> <p>Based on global conservation principles, magnetohydrodynamic (MHD) relaxation theory predicts the existence of several equilibria, such as the Taylor state or global dynamic alignment. These states are generally viewed as very long-time and large-scale equilibria, which emerge only after the termination of the turbulent cascade. As suggested by hydrodynamics and by recent MHD numerical simulations, relaxation processes can occur during the turbulent cascade that will manifest themselves as local patches of equilibrium-like configurations. Using multi-spacecraft analysis techniques in conjunction with Cluster data, we compute the current density and flow vorticity and for the first time demonstrate that these localized relaxation events are observed in the <span class="hlt">solar</span> <span class="hlt">wind</span>. Such events have important consequences for the statistics of plasma turbulence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21929247','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21929247"><span>Nonaxisymmetric anisotropy of <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Turner, A J; Gogoberidze, G; Chapman, S C; Hnat, B; Müller, W-C</p> <p>2011-08-26</p> <p>A key prediction of turbulence theories is frame-invariance, and in magnetohydrodynamic (MHD) turbulence, axisymmetry of fluctuations with respect to the background magnetic field. Paradoxically the power in fluctuations in the turbulent <span class="hlt">solar</span> <span class="hlt">wind</span> are observed to be ordered with respect to the bulk macroscopic flow as well as the background magnetic field. Here, nonaxisymmetry across the inertial and dissipation ranges is quantified using in situ observations from Cluster. The observed inertial range nonaxisymmetry is reproduced by a "fly through" sampling of a direct numerical simulation of MHD turbulence. Furthermore, fly through sampling of a linear superposition of transverse waves with axisymmetric fluctuations generates the trend in nonaxisymmetry with power spectral exponent. The observed nonaxisymmetric anisotropy may thus simply arise as a sampling effect related to Taylor's hypothesis and is not related to the plasma dynamics itself.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19800013734','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800013734"><span>Magnetic clouds in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burlaga, L. F.; Klein, L.</p> <p>1980-01-01</p> <p>Two interplanetary magnetic clouds, characterized by anomalous magnetic field directions and unusually high magnetic field strengths with a scale of the order of 0.25 AU, are identified and described. As the clouds moved past a spacecraft located in the <span class="hlt">solar</span> <span class="hlt">wind</span> near Earth, the magnetic field direction changed by rotating approximately 180 deg nearly parallel to a plane which was essentially perpendicular to the ecliptic. The configuration of the magnetic field in the clouds might be that of a tightly wound cylindrical helix or a series of closed circular loops. One of the magnetic clouds was in a cold stream preceded by a shock, and it caused both a geomagnetic storm and a depression in the galactic cosmic ray intensity. No stream, geomagnetic storm, or large cosmic ray decrease was associated with the other magnetic cloud.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20000073293&hterms=Ulysses&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DUlysses','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20000073293&hterms=Ulysses&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DUlysses"><span>Microstructures in the Polar <span class="hlt">Solar</span> <span class="hlt">Wind</span>: Ulysses</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tsuruyani, Bruce T.; Arballo, J. K.; Galvan, C.; Goldstein, B. E.; Lakhina, G. S.; Sakurai, R.; Smith, E. J.; Neugebauer, M.</p> <p>1999-01-01</p> <p>We find that small (10-200 rP) magnetic decreases comprise a dominant part of the polar <span class="hlt">solar</span> <span class="hlt">wind</span> microstructure at Ulysses distances (2.2 AU). These magnetic field dips are almost always bounded by tangential discontinuities, a feature which is not well understood at this time. Hundreds of these events have been examined in detail and a variety of types have been found. These will be described. It is speculated that these structures have been generated by perpendicular heating of ions closer to the Sun and have then been convected to distances of Ulysses. Such structures may be very important for the rapid cross- field diffusion of ions in the polar regions of the heliosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22215435','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22215435"><span>ASYMMETRIC ELECTRON DISTRIBUTIONS IN THE <span class="hlt">SOLAR</span> <span class="hlt">WIND</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rha, Kicheol; Ryu, Chang-Mo; Yoon, Peter H.</p> <p>2013-09-20</p> <p>A plausible mechanism responsible for producing asymmetric electron velocity distribution functions in the <span class="hlt">solar</span> <span class="hlt">wind</span> is investigated by means of one-dimensional electrostatic particle-in-cell (PIC) simulation. A recent paper suggests that the variation in the ion-to-electron temperature ratio influences the nonlinear wave-particle dynamics such that it results in the formation of asymmetric distributions. The present PIC code simulation largely confirms this finding, but quantitative differences between the weak turbulence formalism and the present PIC simulation are also found, suggesting the limitation of the analytical method. The inter-relationship between the asymmetric electron distribution and the ion-to-electron temperature ratio may be a new useful concept for the observation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhRvE..89e2812M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhRvE..89e2812M"><span>Stationarity of extreme bursts in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moloney, N. R.; Davidsen, J.</p> <p>2014-05-01</p> <p>Recent results have suggested that the statistics of bursts in the <span class="hlt">solar</span> <span class="hlt">wind</span> vary with <span class="hlt">solar</span> cycle. Here, we show that this variation is basically absent if one considers extreme bursts. These are defined as threshold-exceeding events over the range of high thresholds for which their number decays as a power law. In particular, we find that the distribution of duration times and energies of extreme bursts in the <span class="hlt">solar</span> <span class="hlt">wind</span> ɛ parameter and similar observables are independent of the <span class="hlt">solar</span> cycle and in this sense stationary, and show robust asymptotic power laws with exponents that are independent of the specific threshold. This is consistent with what has been observed for <span class="hlt">solar</span> flares and, thus, provides evidence in favor of a link between <span class="hlt">solar</span> flares and extreme bursts in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25353849','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25353849"><span>Stationarity of extreme bursts in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Moloney, N R; Davidsen, J</p> <p>2014-05-01</p> <p>Recent results have suggested that the statistics of bursts in the <span class="hlt">solar</span> <span class="hlt">wind</span> vary with <span class="hlt">solar</span> cycle. Here, we show that this variation is basically absent if one considers extreme bursts. These are defined as threshold-exceeding events over the range of high thresholds for which their number decays as a power law. In particular, we find that the distribution of duration times and energies of extreme bursts in the <span class="hlt">solar</span> <span class="hlt">wind</span> ε parameter and similar observables are independent of the <span class="hlt">solar</span> cycle and in this sense stationary, and show robust asymptotic power laws with exponents that are independent of the specific threshold. This is consistent with what has been observed for <span class="hlt">solar</span> flares and, thus, provides evidence in favor of a link between <span class="hlt">solar</span> flares and extreme bursts in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22365426','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22365426"><span><span class="hlt">Solar</span> energetic particle events in different types of <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kahler, S. W.; Vourlidas, A.</p> <p>2014-08-10</p> <p>We examine statistically some properties of 96 20 MeV gradual <span class="hlt">solar</span> energetic proton (SEP) events as a function of three different types of <span class="hlt">solar</span> <span class="hlt">wind</span> (SW) as classified by Richardson and Cane. Gradual SEP (E > 10 MeV) events are produced in shocks driven by fast (V ≳ 900 km s{sup –1}) and wide (W > 60°) coronal mass ejections (CMEs). We find no differences among the transient, fast, and slow SW streams for SEP 20 MeV proton event timescales. It has recently been found that the peak intensities Ip of these SEP events scale with the ∼2 MeV proton background intensities, which may be a proxy for the near-Sun shock seed particles. Both the intensities Ip and their 2 MeV backgrounds are significantly enhanced in transient SW compared to those of fast and slow SW streams, and the values of Ip normalized to the 2 MeV backgrounds only weakly correlate with CME V for all SW types. This result implies that forecasts of SEP events could be improved by monitoring both the Sun and the local SW stream properties and that the well known power-law size distributions of Ip may differ between transient and long-lived SW streams. We interpret an observed correlation between CME V and the 2 MeV background for SEP events in transient SW as a manifestation of enhanced <span class="hlt">solar</span> activity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JApA...36..185D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JApA...36..185D"><span><span class="hlt">Solar</span> Coronal Plumes and the Fast <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dwivedi, Bhola N.; Wilhelm, Klaus</p> <p>2015-03-01</p> <p>The spectral profiles of the coronal Ne viii line at 77 nm have different shapes in quiet-Sun regions and Coronal Holes (CHs). A single Gaussian fit of the line profile provides an adequate approximation in quiet-Sun areas, whereas, a strong shoulder on the long-wavelength side is a systematic feature in CHs. Although this has been noticed since 1999, no physical reason for the peculiar shape could be given. In an attempt to identify the cause of this peculiarity, we address three problems that could not be conclusively resolved, in a review article by a study team of the International Space Science Institute (ISSI) (Wilhelm et al. 2011): (1) The physical processes operating at the base and inside of plumes, as well as their interaction with the <span class="hlt">Solar</span> <span class="hlt">Wind</span> (SW). (2) The possible contribution of plume plasma to the fast SW streams. (3) The signature of the First-Ionization Potential (FIP) effect between plumes and inter-plume regions (IPRs). Before the spectroscopic peculiarities in IPRs and plumes in Polar Coronal Holes (PCHs) can be further investigated with the instrument <span class="hlt">Solar</span> Ultraviolet Measurements of Emitted Radiation (SUMER) aboard the <span class="hlt">Solar</span> and Heliospheric Observatory (SOHO), it is mandatory to summarize the results of the review to place the spectroscopic observations into context. Finally, a plume model is proposed that satisfactorily explains the plasma flows up and down the plume field lines and leads to the shape of the neon line in PCHs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSH51D4191P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSH51D4191P"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> compressible structures at ion scales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Perrone, D.; Alexandrova, O.; Rocoto, V.; Pantellini, F. G. E.; Zaslavsky, A.; Maksimovic, M.; Issautier, K.; Mangeney, A.</p> <p>2014-12-01</p> <p>In the <span class="hlt">solar</span> <span class="hlt">wind</span> turbulent cascade, the energy partition between fluid and kinetic degrees of freedom, in the vicinity of plasma characteristic scales, i.e. ion and electron Larmor radius and inertial lengths, is still under debate. In a neighborhood of the ion scales, it has been observed that the spectral shape changes and fluctuations become more compressible. Nowadays, a huge scientific effort is directed to the comprehension of the link between macroscopic and microscopic scales and to disclose the nature of compressive fluctuations, meaning that if space plasma turbulence is a mixture of quasi-linear waves (as whistler or kinetic Alfvèn waves) or if turbulence is strong with formation of coherent structures responsible for dissipation. Here we present an automatic method to identify compressible coherent structures around the ion spectral break, using Morlet wavelet decomposition of magnetic signal from Cluster spacecraft and reconstruction of magnetic fluctuations in a selected scale range. Different kind of coherent structures have been detected: from soliton-like one-dimensional structures to current sheet- or wave-like two-dimensional structures. Using a multi-satellite analysis, in order to characterize 3D geometry and propagation in plasma rest frame, we recover that these structures propagate quasi-perpendicular to the mean magnetic field, with finite velocity. Moreover, without using the Taylor hypothesis, the spatial scales of coherent structures have been estimated. Our observations in the <span class="hlt">solar</span> <span class="hlt">wind</span> can provide constraints on theoretical modeling of small scale turbulence and dissipation in collisionless magnetized plasmas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1814950V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1814950V"><span>Evolution of <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence and intermittency over the <span class="hlt">solar</span> cycle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Väisänen, Pauli; Virtanen, Ilpo; Echim, Marius; Munteanu, Costel; Mursula, Kalevi</p> <p>2016-04-01</p> <p><span class="hlt">Solar</span> <span class="hlt">wind</span> is a natural, near-by plasma physics laboratory, which offers possibilities to study plasma physical phenomena over a wide range of parameter values that are difficult to reach in ground-based laboratories. Accordingly, the <span class="hlt">solar</span> <span class="hlt">wind</span> is subject of many studies of, e.g., intermittency, turbulence and other nonlinear space plasma phenomena. Turbulence is an important feature of the <span class="hlt">solar</span> <span class="hlt">wind</span> dynamics, e.g., for the energy transfer mechanisms and their scale invariance, the <span class="hlt">solar</span> <span class="hlt">wind</span> evolution, the structure of the heliospheric magnetic field (HMF), the particle energization and heating, and for phenomena related to <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with the planetary plasma systems. Here we analyse high resolution measurements of the <span class="hlt">solar</span> <span class="hlt">wind</span> and the heliospheric magnetic field provided by several ESA and NASA satellites, including ACE, STEREO, Ulysses and Cluster. This collection of satellites allows us to compile and study nearly 20 years of high-resolution <span class="hlt">solar</span> <span class="hlt">wind</span> and HMF measurements from the start of <span class="hlt">solar</span> cycle 23 to the current declining phase of <span class="hlt">solar</span> cycle 24. Long-term studies require homogeneity and, therefore, we pay great attention to the reliability and consistency of the data, in particular to instrumental defects like spin harmonics, the purity of the <span class="hlt">solar</span> <span class="hlt">wind</span> and its possible contamination in the foreshock by magnetospheric ions. We study how the different key-descriptors of turbulence like the slope of the power law of power spectral density and the kurtosis of the fluctuations of the heliospheric magnetic field vary over the <span class="hlt">solar</span> cycle.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/86287','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/86287"><span><span class="hlt">Solar</span> semidiurnal tidal <span class="hlt">wind</span> oscillations above the CART site</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Whiteman, C.D.; Bian, X.</p> <p>1995-03-01</p> <p>Harmonic analysis of wintertime data from 915- and 404-MHz radar <span class="hlt">wind</span> profilers at four sites in North America has identified coherent semidiurnal <span class="hlt">wind</span> oscillations through the entire depth of the troposphere. These <span class="hlt">winds</span> are readily apparent above the CART site, as evidenced from analyses of data from the Haviland, KS, radar profiler. The characteristics of this <span class="hlt">wind</span> system match the characteristics of <span class="hlt">solar</span> semidiurnal atmospheric tides, as predicted by a simple dynamic model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995arm..meet...20W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995arm..meet...20W"><span><span class="hlt">Solar</span> semidiurnal tidal <span class="hlt">wind</span> oscillations above the CART site</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Whiteman, C. D.; Bian, X.</p> <p>1995-03-01</p> <p>Harmonic analysis of wintertime data from 915- and 404-MHz radar <span class="hlt">wind</span> profilers at four sites in North America has identified coherent semidiurnal <span class="hlt">wind</span> oscillations through the entire depth of the troposphere. These <span class="hlt">winds</span> are readily apparent above the CART site, as evidenced from analyses of data from the Haviland, KS, radar profiler. The characteristics of this <span class="hlt">wind</span> system match the characteristics of <span class="hlt">solar</span> semidiurnal atmospheric tides, as predicted by a simple dynamic model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22127065','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22127065"><span>RESIDUAL ENERGY SPECTRUM OF <span class="hlt">SOLAR</span> <span class="hlt">WIND</span> TURBULENCE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chen, C. H. K.; Bale, S. D.; Salem, C. S.; Maruca, B. A.</p> <p>2013-06-20</p> <p>It has long been known that the energy in velocity and magnetic field fluctuations in the <span class="hlt">solar</span> <span class="hlt">wind</span> is not in equipartition. In this paper, we present an analysis of 5 yr of <span class="hlt">Wind</span> data at 1 AU to investigate the reason for this. The residual energy (difference between energy in velocity and magnetic field fluctuations) was calculated using both the standard magnetohydrodynamic (MHD) normalization for the magnetic field and a kinetic version, which includes temperature anisotropies and drifts between particle species. It was found that with the kinetic normalization, the fluctuations are closer to equipartition, with a mean normalized residual energy of {sigma}{sub r} = -0.19 and mean Alfven ratio of r{sub A} = 0.71. The spectrum of residual energy, in the kinetic normalization, was found to be steeper than both the velocity and magnetic field spectra, consistent with some recent MHD turbulence predictions and numerical simulations, having a spectral index close to -1.9. The local properties of residual energy and cross helicity were also investigated, showing that globally balanced intervals with small residual energy contain local patches of larger imbalance and larger residual energy at all scales, as expected for nonlinear turbulent interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1215270T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1215270T"><span>The Paleoarchean geodynamo, <span class="hlt">solar</span> <span class="hlt">wind</span> and magnetopause</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tarduno, John A.; Cottrell, R. D.; Watkeys, M. K.; Hofmann, A.; Doubrovine, P. V.; Mamajek, E.; Liu, D.; Sibeck, D. G.; Neukirch, L. P.; Usui, Y.</p> <p>2010-05-01</p> <p>The standoff of stellar <span class="hlt">winds</span> by a planetary magnetic field prevents atmospheric erosion and water loss important for the evolution of a habitable planet. But little is known about early magnetic field strength and whether intense radiation from the young, rapidly rotating Sun modified Earth's atmosphere. New paleointensity results from single silicate crystals bearing magnetic inclusions indicate the presence of a geodynamo between 3.4 and 3.45 billion years ago. The field measured is ~30-50% weaker than that of present-day and when combined with a greater <span class="hlt">solar</span> <span class="hlt">wind</span> pressure suggests steady-state Paleoarchean magnetopause standoff distances ≤ 5 Earth radii, similar to values observed during recent coronal mass ejection events. Aurora would have been at lower latitudes and polar cap area is predicted to have been up to 3 times greater than today. Heating, expansion and volatile loss from the exosphere is implied, affecting long-term atmospheric composition. Efforts to examine even older Paleoarchean-Hadean magnetic mineral carriers for geomagnetic paleointensity signatures will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSH14B..07V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSH14B..07V"><span>Flux tubes embedded into reconnection outflows in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Voros, Z.; Zaqarashvili, T.; Sasunov, Y.; Narita, Y.</p> <p>2015-12-01</p> <p>Reconnection exhausts in the <span class="hlt">solar</span> <span class="hlt">wind</span> are usually interpreted in terms of a quasi-stationary Petschek-type reconnection model. Accordingly, within a region of magnetic field reversal, the wedge-shaped, Alfvenic accelerated plasma outflow is bounded by layers containing (anti-) correlated components of speed and magnetic field fluctuations. However, time-dependent impulsive reconnection can generate flux ropes embedded into accelerated outflows. Reconnection associated moving flux ropes or plasmoids are frequently observed in the Earth's magnetotail, while similar observations are missing in the <span class="hlt">solar</span> <span class="hlt">wind</span>. We present the first observations of small-scale magnetic flux ropes associated with reconnection exhausts in the <span class="hlt">solar</span> <span class="hlt">wind</span>, using the data from the <span class="hlt">WIND</span> probe. We argue that the interaction of moving flux ropes with the background plasma can generate turbulence leading finally to the local heating of the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPD....4830106H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPD....4830106H"><span>Slow <span class="hlt">Solar</span> <span class="hlt">Wind</span> from S-Web Arcs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Higginson, Aleida K.; Antiochos, Spiro K.; DeVore, C. Richard; Wyper, Peter; Zurbuchen, Thomas H.</p> <p>2017-08-01</p> <p>A long-standing mystery posed by in-situ heliospheric observations is the large angular extent of slow <span class="hlt">solar</span> <span class="hlt">wind</span> about the heliospheric current sheet (HCS). Measurements of plasma composition strongly imply that much of the slow <span class="hlt">wind</span> consists of plasma from the closed corona that escapes onto open field lines, presumably by field-line opening or by interchange reconnection. Both of these processes are expected to release closed-field plasma into the <span class="hlt">solar</span> <span class="hlt">wind</span> within and immediately adjacent to the HCS. The recently proposed Separatrix-Web (S-Web) Theory postulates that the observations of slow <span class="hlt">wind</span> far from the HCS can be explained by the dynamical interaction of open and closed flux in regions of complex coronal-hole topology. We present the first high-resolution, three-dimensional numerical simulations of the dynamic S-Web. These simulations suggest that photospheric motions at coronal-hole boundaries are responsible for the release of slow <span class="hlt">solar</span> <span class="hlt">wind</span> plasma from the magnetically closed <span class="hlt">solar</span> corona, specifically through prolific interchange magnetic reconnection. The location of this plasma once it is released into the <span class="hlt">solar</span> <span class="hlt">wind</span> depends strongly on the geometry of the coronal-hole flux. We demonstrate how the dynamics at the boundaries of narrow corridors of open flux (coronal hole corridors) can create giant S-Web arcs of slow <span class="hlt">solar</span> <span class="hlt">wind</span> at high latitudes in the heliosphere, far from the HCS, accounting for the long-puzzling slow-<span class="hlt">wind</span> observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001IAUS..203..495H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001IAUS..203..495H"><span>Coronal Heating and the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Acceleration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hirayama, T.</p> <p></p> <p>The twisting magnetic field as the DC energy injection will produce charge separation and consequently an electric field parallel to the magnetic field. Accelerated beam electrons (a few times thermal velocity) due to this electric filed will be stopped by classical collisions with ambient electrons and ions. The beam electrons, 10-3 of the bulk electrons, do not create electric currents due to the back streaming bulk electrons. Hence it is not the normal or anomalous Joule heating, but a co-spatial frictional heating, and yet bulk heating. The heating rate is the kinetic energy density of beams multiplied by the classical collision frequency, and is about 10-4 erg cm-3 s-1. It successfully reproduces observations of quiet and active regions, including the RTV scaling law. In the open field, the damping length of this Alfvénic twist is 0.4 <span class="hlt">solar</span> radii. This is appropriate to produce slow and high-speed <span class="hlt">solar</span> <span class="hlt">winds</span>. Ion-cyclotron waves may be excited due to supra-thermal beams.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011APS..MARV31015P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011APS..MARV31015P"><span>Analysis of <span class="hlt">Wind</span> Forces on Roof-Top <span class="hlt">Solar</span> Panel</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Panta, Yogendra; Kudav, Ganesh</p> <p>2011-03-01</p> <p>Structural loads on <span class="hlt">solar</span> panels include forces due to high <span class="hlt">wind</span>, gravity, thermal expansion, and earthquakes. International Building Code (IBC) and the American Society of Civil Engineers are two commonly used approaches in <span class="hlt">solar</span> industries to address <span class="hlt">wind</span> loads. Minimum Design Loads for Buildings and Other Structures (ASCE 7-02) can be used to calculate <span class="hlt">wind</span> uplift loads on roof-mounted <span class="hlt">solar</span> panels. The present study is primarily focused on 2D and 3D modeling with steady, and turbulent flow over an inclined <span class="hlt">solar</span> panel on the flat based roof to predict the <span class="hlt">wind</span> forces for designing <span class="hlt">wind</span> management system. For the numerical simulation, 3-D incompressible flow with the standard k- ɛ was adopted and commercial CFD software ANSYS FLUENT was used. Results were then validated with <span class="hlt">wind</span> tunnel experiments with a good agreement. <span class="hlt">Solar</span> panels with various aspect ratios for various high <span class="hlt">wind</span> speeds and angle of attacks were modeled and simulated in order to predict the <span class="hlt">wind</span> loads in various scenarios. The present study concluded to reduce the strong <span class="hlt">wind</span> uplift by designing a guide plate or a deflector before the panel. Acknowledgments to Northern States Metal Inc., OH (GK & YP) and School of Graduate Studies of YSU for RP & URC 2009-2010 (YP).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1326077','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1326077"><span>Modeling <span class="hlt">solar</span> <span class="hlt">wind</span> with boundary conditions from interplanetary scintillations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Manoharan, P.; Kim, T.; Pogorelov, N. V.; Arge, C. N.</p> <p>2015-09-30</p> <p>Interplanetary scintillations make it possible to create three-dimensional, time- dependent distributions of the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity. Combined with the magnetic field observations in the <span class="hlt">solar</span> photosphere, they help perform <span class="hlt">solar</span> <span class="hlt">wind</span> simulations in a genuinely time-dependent way. Interplanetary scintillation measurements from the Ooty Radio Astronomical Observatory in India provide directions to multiple stars and may assure better resolution of transient processes in the <span class="hlt">solar</span> <span class="hlt">wind</span>. In this paper, we present velocity distributions derived from Ooty observations and compare them with those obtained with the Wang-Sheeley-Arge (WSA) model. We also present our simulations of the <span class="hlt">solar</span> <span class="hlt">wind</span> flow from 0.1 AU to 1 AU with the boundary conditions based on both Ooty and WSA data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1326077-modeling-solar-wind-boundary-conditions-from-interplanetary-scintillations','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1326077-modeling-solar-wind-boundary-conditions-from-interplanetary-scintillations"><span>Modeling <span class="hlt">solar</span> <span class="hlt">wind</span> with boundary conditions from interplanetary scintillations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Manoharan, P.; Kim, T.; Pogorelov, N. V.; ...</p> <p>2015-09-30</p> <p>Interplanetary scintillations make it possible to create three-dimensional, time- dependent distributions of the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity. Combined with the magnetic field observations in the <span class="hlt">solar</span> photosphere, they help perform <span class="hlt">solar</span> <span class="hlt">wind</span> simulations in a genuinely time-dependent way. Interplanetary scintillation measurements from the Ooty Radio Astronomical Observatory in India provide directions to multiple stars and may assure better resolution of transient processes in the <span class="hlt">solar</span> <span class="hlt">wind</span>. In this paper, we present velocity distributions derived from Ooty observations and compare them with those obtained with the Wang-Sheeley-Arge (WSA) model. We also present our simulations of the <span class="hlt">solar</span> <span class="hlt">wind</span> flow from 0.1 AUmore » to 1 AU with the boundary conditions based on both Ooty and WSA data.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820012230','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820012230"><span>Evidence for <span class="hlt">solar</span> <span class="hlt">wind</span> control of Saturn radio emission</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Desch, M. D.</p> <p>1982-01-01</p> <p>Using data collected by the Voyager 1 and 2 spacecraft in 1980 and 1981, strong evidence is presented for a direct correlation between variations in the <span class="hlt">solar</span> <span class="hlt">wind</span> at Saturn and the level of activity of Saturn's nonthermal radio emission. Correlation coefficients of 57 to 58% are reached at lag times of 0 to 1 days between the arrival at Saturn of high pressure <span class="hlt">solar</span> <span class="hlt">wind</span> streams and the onset of increased radio emission. The radio emission exhibits a long-term periodicity of 25 days, identical to the periodicity seen in the <span class="hlt">solar</span> <span class="hlt">wind</span> at this time and consistent with the <span class="hlt">solar</span> rotation period. The energy coupling efficiency between the <span class="hlt">solar</span> <span class="hlt">wind</span> with the Saturn radio emission is estimated and compared with that for Earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170003051&hterms=Winds&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DWinds','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170003051&hterms=Winds&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DWinds"><span>Implications of L1 Observations for Slow <span class="hlt">Solar</span> <span class="hlt">Wind</span> Formation by <span class="hlt">Solar</span> Reconnection</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kepko, L.; Viall, N. M.; Antiochos, S. K.; Lepri, S. T.; Kasper, J. C.; Weberg, M.</p> <p>2016-01-01</p> <p>While the source of the fast <span class="hlt">solar</span> <span class="hlt">wind</span> is known to be coronal holes, the source of the slow <span class="hlt">solar</span> <span class="hlt">wind</span> has remained a mystery. Long time scale trends in the composition and charge states show strong correlations between <span class="hlt">solar</span> <span class="hlt">wind</span> velocity and plasma parameters, yet these correlations have proved ineffective in determining the slow <span class="hlt">wind</span> source. We take advantage of new high time resolution (12 min) measurements of <span class="hlt">solar</span> <span class="hlt">wind</span> composition and charge state abundances at L1 and previously identified 90 min quasi periodic structures to probe the fundamental timescales of slow <span class="hlt">wind</span> variability. The combination of new high temporal resolution composition measurements and the clearly identified boundaries of the periodic structures allows us to utilize these distinct <span class="hlt">solar</span> <span class="hlt">wind</span> parcels as tracers of slowwind origin and acceleration. We find that each 90 min (2000 Mm) parcel of slow <span class="hlt">wind</span> has near-constant speed yet exhibits repeatable, systematic charge state and composition variations that span the entire range of statistically determined slow <span class="hlt">solar</span> <span class="hlt">wind</span> values. The classic composition-velocity correlations do not hold on short, approximately hour long, time scales. Furthermore, the data demonstrate that these structures were created by magnetic reconnection. Our results impose severe new constraints on slow <span class="hlt">solar</span> <span class="hlt">wind</span> origin and provide new, compelling evidence that the slow <span class="hlt">wind</span> results from the sporadic release of closed field plasma via magnetic reconnection at the boundary between open and closed flux in the Sun's atmosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SoPh..292..128B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SoPh..292..128B"><span>Charge States of Krypton and Xenon in the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bochsler, Peter; Fludra, Andrzej; Giunta, Alessandra</p> <p>2017-09-01</p> <p>We calculate charge state distributions of Kr and Xe in a model for two different types of <span class="hlt">solar</span> <span class="hlt">wind</span> using the effective ionization and recombination rates provided from the OPEN_ADAS data base. The charge states of heavy elements in the <span class="hlt">solar</span> <span class="hlt">wind</span> are essential for estimating the efficiency of Coulomb drag in the inner corona. We find that xenon ions experience particularly low Coulomb drag from protons in the inner corona, comparable to the notoriously weak drag of protons on helium ions. It has been found long ago that helium in the <span class="hlt">solar</span> <span class="hlt">wind</span> can be strongly depleted near interplanetary current sheets, whereas coronal mass ejecta are sometimes strongly enriched in helium. We argue that if the extraordinary variability of the helium abundance in the <span class="hlt">solar</span> <span class="hlt">wind</span> is due to inefficient Coulomb drag, the xenon abundance must vary strongly. In fact, a secular decrease of the <span class="hlt">solar</span> <span class="hlt">wind</span> xenon abundance relative to the other heavier noble gases (Ne, Ar, Kr) has been postulated based on a comparison of noble gases in recently irradiated and ancient samples of ilmenite in the lunar regolith. We conclude that decreasing <span class="hlt">solar</span> activity and decreasing frequency of coronal mass ejections over the <span class="hlt">solar</span> lifetime might be responsible for a secularly decreasing abundance of xenon in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18046399','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18046399"><span>Little or no <span class="hlt">solar</span> <span class="hlt">wind</span> enters Venus' atmosphere at <span class="hlt">solar</span> minimum.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, T L; Delva, M; Baumjohann, W; Auster, H-U; Carr, C; Russell, C T; Barabash, S; Balikhin, M; Kudela, K; Berghofer, G; Biernat, H K; Lammer, H; Lichtenegger, H; Magnes, W; Nakamura, R; Schwingenschuh, K; Volwerk, M; Vörös, Z; Zambelli, W; Fornacon, K-H; Glassmeier, K-H; Richter, I; Balogh, A; Schwarzl, H; Pope, S A; Shi, J K; Wang, C; Motschmann, U; Lebreton, J-P</p> <p>2007-11-29</p> <p>Venus has no significant internal magnetic field, which allows the <span class="hlt">solar</span> <span class="hlt">wind</span> to interact directly with its atmosphere. A field is induced in this interaction, which partially shields the atmosphere, but we have no knowledge of how effective that shield is at <span class="hlt">solar</span> minimum. (Our current knowledge of the <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with Venus is derived from measurements at <span class="hlt">solar</span> maximum.) The bow shock is close to the planet, meaning that it is possible that some <span class="hlt">solar</span> <span class="hlt">wind</span> could be absorbed by the atmosphere and contribute to the evolution of the atmosphere. Here we report magnetic field measurements from the Venus Express spacecraft in the plasma environment surrounding Venus. The bow shock under low <span class="hlt">solar</span> activity conditions seems to be in the position that would be expected from a complete deflection by a magnetized ionosphere. Therefore little <span class="hlt">solar</span> <span class="hlt">wind</span> enters the Venus ionosphere even at <span class="hlt">solar</span> minimum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021391&hterms=balsiger&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbalsiger','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021391&hterms=balsiger&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbalsiger"><span>Iron charge states in the <span class="hlt">solar</span> <span class="hlt">wind</span> as measured by SMS on <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Galvin, A. B.; Cohen, C. M. S.; Ipavich, F. M.; Gloeckler, G.; Hamilton, D. C.; Chotoo, K.; Balsiger, H.; Sheldon, R.</p> <p>1995-01-01</p> <p>The <span class="hlt">Wind</span> spacecraft was launched in November 1994. In the first half of 1995 it was in the interplanetary medium upstream of the Earth. The <span class="hlt">Solar</span> <span class="hlt">Wind</span> and Suprathermal Ion Composition Experiment (SMS) on <span class="hlt">Wind</span> consists of three sensors, the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Ion Composition Spectrometer (SWICS), the Suprathermal Ion Composition Spectrometer (STICS), and the high mass resolution spectrometer (MASS). All three instruments utilize electrostatic deflection combined with time-of-flight measurement. The data from these three sensors allows the determination of the ionic composition of the <span class="hlt">solar</span> <span class="hlt">wind</span> in a variety of <span class="hlt">solar</span> <span class="hlt">wind</span> conditions over a large energy/charge range (0.5 to 230 keV/e). We have examined the <span class="hlt">Wind</span> database for time periods conducive to observing <span class="hlt">solar</span> <span class="hlt">wind</span> iron. With the high mass resolution of the MASS spectrometer (M/Delta-M greater than 100) iron is easily identified while the electrostatic deflection provides information concerning the mass/charge distribution. We present here the relative abundance of iron charge states in the <span class="hlt">solar</span> <span class="hlt">wind</span> near 1 AU.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021391&hterms=Bern&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DBern','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021391&hterms=Bern&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DBern"><span>Iron charge states in the <span class="hlt">solar</span> <span class="hlt">wind</span> as measured by SMS on <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Galvin, A. B.; Cohen, C. M. S.; Ipavich, F. M.; Gloeckler, G.; Hamilton, D. C.; Chotoo, K.; Balsiger, H.; Sheldon, R.</p> <p>1995-01-01</p> <p>The <span class="hlt">Wind</span> spacecraft was launched in November 1994. In the first half of 1995 it was in the interplanetary medium upstream of the Earth. The <span class="hlt">Solar</span> <span class="hlt">Wind</span> and Suprathermal Ion Composition Experiment (SMS) on <span class="hlt">Wind</span> consists of three sensors, the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Ion Composition Spectrometer (SWICS), the Suprathermal Ion Composition Spectrometer (STICS), and the high mass resolution spectrometer (MASS). All three instruments utilize electrostatic deflection combined with time-of-flight measurement. The data from these three sensors allows the determination of the ionic composition of the <span class="hlt">solar</span> <span class="hlt">wind</span> in a variety of <span class="hlt">solar</span> <span class="hlt">wind</span> conditions over a large energy/charge range (0.5 to 230 keV/e). We have examined the <span class="hlt">Wind</span> database for time periods conducive to observing <span class="hlt">solar</span> <span class="hlt">wind</span> iron. With the high mass resolution of the MASS spectrometer (M/Delta-M greater than 100) iron is easily identified while the electrostatic deflection provides information concerning the mass/charge distribution. We present here the relative abundance of iron charge states in the <span class="hlt">solar</span> <span class="hlt">wind</span> near 1 AU.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRA..122.2973B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRA..122.2973B"><span>Substorm occurrence rates, substorm recurrence times, and <span class="hlt">solar</span> <span class="hlt">wind</span> structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Borovsky, Joseph E.; Yakymenko, Kateryna</p> <p>2017-03-01</p> <p>Two collections of substorms are created: 28,464 substorms identified with jumps in the SuperMAG AL index in the years 1979-2015 and 16,025 substorms identified with electron injections into geosynchronous orbit in the years 1989-2007. Substorm occurrence rates and substorm recurrence-time distributions are examined as functions of the phase of the <span class="hlt">solar</span> cycle, the season of the year, the Russell-McPherron favorability, the type of <span class="hlt">solar</span> <span class="hlt">wind</span> plasma at Earth, the geomagnetic-activity level, and as functions of various <span class="hlt">solar</span> and <span class="hlt">solar</span> <span class="hlt">wind</span> properties. Three populations of substorm occurrences are seen: (1) quasiperiodically occurring substorms with recurrence times (waiting times) of 2-4 h, (2) randomly occurring substorms with recurrence times of about 6-15 h, and (3) long intervals wherein no substorms occur. A working model is suggested wherein (1) the period of periodic substorms is set by the magnetosphere with variations in the actual recurrence times caused by the need for a <span class="hlt">solar</span> <span class="hlt">wind</span> driving interval to occur, (2) the mesoscale structure of the <span class="hlt">solar</span> <span class="hlt">wind</span> magnetic field triggers the occurrence of the random substorms, and (3) the large-scale structure of the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma is responsible for the long intervals wherein no substorms occur. Statistically, the recurrence period of periodically occurring substorms is slightly shorter when the ram pressure of the <span class="hlt">solar</span> <span class="hlt">wind</span> is high, when the magnetic field strength of the <span class="hlt">solar</span> <span class="hlt">wind</span> is strong, when the Mach number of the <span class="hlt">solar</span> <span class="hlt">wind</span> is low, and when the polar-cap potential saturation parameter is high.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996KosIs..34..451M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996KosIs..34..451M"><span>Multifractal properties of <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence: theory and observations.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Milovanov, A. V.; Avanov, L. A.; Zastenker, G. N.; Zelenyj, L. M.</p> <p>1996-10-01</p> <p>A fractal model of the <span class="hlt">solar</span> <span class="hlt">wind</span> is presented. This model treats fluctuations of the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity from the viewpoint of nonlinear processes originating in the convective region and photosphere of the Sun. The multifractal structure of proton velocity fluctuations in a region of heliocentric distances from 0.2 to 0.8 AU is a result of these processes. Continuous measurements of <span class="hlt">solar</span> <span class="hlt">wind</span> velocity aboard the ISEE-3 spacecraft during one month were used to compare the theoretical and experimental results. It is shown that fluctuations of proton velocity have a multifractal structure in a frequency range of 10-5 - 10-3Hz.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920048629&hterms=tutorial&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dtutorial','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920048629&hterms=tutorial&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dtutorial"><span>The <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with unmagnetized planets - A tutorial</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Luhmann, J. G.</p> <p>1990-01-01</p> <p>The interaction of the <span class="hlt">solar</span> <span class="hlt">wind</span> with the Venus ionosphere induces currents which can substantially exclude the <span class="hlt">solar</span> <span class="hlt">wind</span> and IMF from the dayside ionosphere beneath the 'ionopause', where ionosphere thermal pressure equals incident <span class="hlt">solar</span> <span class="hlt">wind</span> dynamic pressure. The field then diffuses through the ionopause with increasing speed at decreasing altitudes, and is weakest in the subpolar region. Once within the ionopause, the magnetic field is redistributed by ionospheric convection, and then decays at low altitudes via collisional dissipation of the associated currents. The maximum ionospheric field magnitudes observed, of about 150 nT, furnish magnetic pressures exceeding the ionospheric thermal pressure by a factor of about 3.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.1715M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.1715M"><span><span class="hlt">Solar</span> <span class="hlt">wind</span>, radiation belt electrons and atmospheric vorticity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mironova, Irina; Tinsley, Brian; Zhou, Limin</p> <p></p> <p>The association of atmospheric vorticity changes with <span class="hlt">solar</span> <span class="hlt">wind</span> sector structure explored by John Wilcox and Walter Orr Roberts in the 1970s is examined in terms of the sector related minima in <span class="hlt">solar</span> <span class="hlt">wind</span> speed, and associated minima in relativistic electron precipitation from the outer radiation belt. Stronger correlations of atmospheric vorticity with the relativistic electron flux are found than with either <span class="hlt">solar</span> <span class="hlt">wind</span> speed or the passage of magnetic sector boundaries over the Earth. This is consistent with changes in the ionosphere-earth current density affecting cloud microphysics, with the ionization from the Bremsstrahlung X-rays from the relativistic electron precipitation increasing the conductivity of the stratosphere.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19830016174','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830016174"><span>The relationship between Saturn kilometric radiation and the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Desch, M. D.; Rucker, H. O.</p> <p>1983-01-01</p> <p>Voyager spacecraft radio, interplanetary plasma, and interplanetary magnetic field data are used to show that large amplitude fluctuations in the power generated by the Saturn kilometric radio emission are best correlated with <span class="hlt">solar</span> <span class="hlt">wind</span> ram pressure variation. In all, thirteen <span class="hlt">solar</span> <span class="hlt">wind</span> quantities previously found important in driving terrestrial magnetospheric substorms and other auroral processes were examined for evidence of correlations with the Saturn radio emission. The results are consistent with hydromagnetic wave or eddy diffusion processes driven by large scale <span class="hlt">solar</span> <span class="hlt">wind</span> pressure changes at Saturn's dayside magnetopause.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890052693&hterms=Hom&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DHom','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890052693&hterms=Hom&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DHom"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> control of Jupiter's hectometric radio emission</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Barrow, C. H.; Desch, M. D.</p> <p>1989-01-01</p> <p>Radio, plasma, and magnetic field data obtained by Voyager 1 and Voyager 2 were used to examine the manner in which the Jovian hectometric radio emission (HOM) is controlled by the <span class="hlt">solar</span> <span class="hlt">wind</span>. Using the method of superposed epochs, it was found that the higher energy HOM is correlated with the IMF as well as with the <span class="hlt">solar</span> <span class="hlt">wind</span> density and pressure. However, unlike the Io-independent decametric radio emission (Non-Io DAM), the HOM displayed no correlation with the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity, although this radio component appear to be also influenced by the IMF. The results suggest separate HOM amd Non-Io DAM sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21394380','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21394380"><span>MEASUREMENTS OF RAPID DENSITY FLUCTUATIONS IN THE <span class="hlt">SOLAR</span> <span class="hlt">WIND</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Malaspina, D. M.; Ergun, R. E.; Kellogg, P. J.; Bale, S. D.</p> <p>2010-03-01</p> <p>The power spectrum of density fluctuations in the <span class="hlt">solar</span> <span class="hlt">wind</span> is inferred by tracking small timescale changes in the electron plasma frequency during periods of strong Langmuir wave activity. STEREO electric field waveform data are used to produce time profiles of plasma density from which the density power spectrum is derived. The power spectra obtained by this method extend the observed frequency range by an order of magnitude while remaining consistent with previous results near a few Hertz. Density power spectral indices are found to be organized by the angle between the local magnetic field and the <span class="hlt">solar</span> <span class="hlt">wind</span> direction, indicating significant anisotropy in <span class="hlt">solar</span> <span class="hlt">wind</span> high-frequency density turbulence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008EOSTr..89..212C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008EOSTr..89..212C"><span>Mars: A Richly Complicated Obstacle to the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Crider, Dana H.; Brain, David A.; Lundin, Rickard</p> <p>2008-06-01</p> <p>Chapman Conference on the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Interaction With Mars; San Diego, California, 22-25 January 2008; Although studies of the <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with Mars (SWIM) date back to the mid-1960s, whether Mars possessed a global magnetic field remained uncertain until 1997. We now know that Mars lacks a measurable dynamo; however, it has intense, localized regions of magnetization tied to its crust. With this patchy magnetic field, the <span class="hlt">solar</span> <span class="hlt">wind</span> interacts directly with the upper atmosphere of Mars, driving structural and compositional variations and providing energy for atmospheric escape to space. These processes may have played an important role in the long-term evolution of the Martian climate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1914825O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1914825O"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> parameteres and disturbances in STEREO view</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Opitz, Andrea</p> <p>2017-04-01</p> <p>The twin STEREO spacecraft provided two vantage point <span class="hlt">solar</span> <span class="hlt">wind</span> observations between 2007 and 2014. Instrumentation of the STEREO A and B spacecraft is very nearly identical, hence their measurements are easily comparable. These measurements are visualised and treated with different methods in order to obtain a global view of the in-ecliptic background <span class="hlt">solar</span> <span class="hlt">wind</span> and the disturbances such as CIRs and CMEs. Comparison of the two datasets and exclusion of spatial effects provides information on the in-ecliptic <span class="hlt">solar</span> <span class="hlt">wind</span> structure in the inner heliosphere. These methods and results will be revised in this paper.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920063558&hterms=born+out&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dborn%2Bout','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920063558&hterms=born+out&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dborn%2Bout"><span>Charge-exchange born He(+) ions in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gruntman, Michael A.</p> <p>1992-01-01</p> <p>The effect of charge transfer between <span class="hlt">solar</span> <span class="hlt">wind</span> alpha-particles and hydrogen atoms of interstellar origin is revisited. Singly-charged helium ions born in the charge transfer carry important information on processes in the <span class="hlt">solar</span> <span class="hlt">wind</span> and the heliosphere. The velocity distribution of such He(+) ions is substantially different from that of He(+) pick-up ions due to ionization of the interstellar helium atoms. Estimates of the expected abundances of the charge-exchange born He(+) in the <span class="hlt">solar</span> <span class="hlt">wind</span> are presented, and the possibility of measuring this plasma component on deep space missions is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6517833','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6517833"><span><span class="hlt">Wind</span> loading on <span class="hlt">solar</span> concentrators: some general considerations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Roschke, E. J.</p> <p>1984-05-01</p> <p>A survey has been completed to examine the problems and complications arising from <span class="hlt">wind</span> loading on <span class="hlt">solar</span> concentrators. <span class="hlt">Wind</span> loading is site specific and has an important bearing on the design, cost, performance, operation and maintenance, safety, survival, and replacement of <span class="hlt">solar</span> collecting systems. Emphasis herein is on paraboloidal, two-axis tracking systems. Thermal receiver problems also are discussed. <span class="hlt">Wind</span> characteristics are discussed from a general point of view; current methods for determining design <span class="hlt">wind</span> speed are reviewed. Aerodynamic coefficients are defined and illustrative examples are presented. <span class="hlt">Wind</span> tunnel testing is discussed, and environmental <span class="hlt">wind</span> tunnels are reviewed; recent results on heliostat arrays are reviewed as well. Aeroelasticity in relation to structural design is discussed briefly. <span class="hlt">Wind</span> loads, i.e., forces and moments, are proportional to the square of the mean <span class="hlt">wind</span> velocity. Forces are proportional to the square of concentrator diameter, and moments are proportional to the cube of diameter. Thus, <span class="hlt">wind</span> loads have an important bearing on size selection from both cost and performance standpoints. It is concluded that sufficient information exists so that reasonably accurate predictions of <span class="hlt">wind</span> loading are possible for a given paraboloidal concentrator configuration, provided that reliable and relevant <span class="hlt">wind</span> conditions are specified. Such predictions will be useful to the design engineer and to the systems engineer as well. Information is lacking, however, on <span class="hlt">wind</span> effects in field arrays of paraboloidal concentrators. <span class="hlt">Wind</span> tunnel tests have been performed on model heliostat arrays, but there are important aerodynamic differences between heliostats and paraboloidal dishes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AIPC.1539...94Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AIPC.1539...94Z"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> proton flux extremes and their association with pseudostreamers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, Liang; Gibson, Sarah E.; Fisk, Lennard A.</p> <p>2013-06-01</p> <p>Proton flux, as defined by the product of proton number density and proton speed, while exhibiting remarkable constancy across heliographic latitudes from pole to equator as measured by the Ulysses spacecraft, nevertheless showed obvious departure from this constancy for some mid-latitude <span class="hlt">wind</span> and extended to high heliomagnetic latitudes during the recent two <span class="hlt">solar</span> minima. We examine the <span class="hlt">solar</span> <span class="hlt">wind</span> exclusive of ICMEs from Ulysses and ACE observations, to analyze the <span class="hlt">solar</span> <span class="hlt">wind</span> in-situ data exhibiting extremes in proton flux. We first find these extreme-proton-flux <span class="hlt">winds</span> generally originate in latitudes middle-distant from the heliospheric current sheet (HCS), and they have relatively slower speed than the bulk of the <span class="hlt">solar</span> <span class="hlt">wind</span>. Then we map the in-situ ACE observations in Carrington rotation (CR) 1997 back to the <span class="hlt">solar</span> surface by using the Potential-Field-Source-Surface (PFSS) model, in order to consider the coronal properties at the extreme-proton-flux <span class="hlt">wind</span> sources. We find there is a clear association between these extreme-proton-flux <span class="hlt">solar</span> <span class="hlt">wind</span> and the mid-latitude coronal holes and "pseudostreamer" structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSM41D2461N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSM41D2461N"><span>Diamagnetic effect in the foremoon <span class="hlt">solar</span> <span class="hlt">wind</span> observed by Kaguya</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nishino, M. N.; Saito, Y.; Tsunakawa, H.; Miyake, Y.; Harada, Y.; Yokota, S.; Takahashi, F.; Matsushima, M.; Shibuya, H.; Shimizu, H.</p> <p>2016-12-01</p> <p>Interaction between the lunar surface and incident <span class="hlt">solar</span> <span class="hlt">wind</span> is one of the crucial phenomena of the lunar plasma sciences. Recent observations by lunar orbiters revealed that strength of the interplanetary magnetic field (IMF) at spacecraft altitude increases over crustal magnetic fields on the dayside. In addition, variations of the IMF on the lunar night side have been reported in the viewpoint of diamagnetic effect around the lunar wake. However, few studies have been performed for the IMF over non-magnetized regions on the dayside. Here we show an event where strength of the IMF decreases at 100 km altitude on the lunar dayside (i.e. in the foremoon <span class="hlt">solar</span> <span class="hlt">wind</span>) when the IMF is almost parallel to the incident <span class="hlt">solar</span> <span class="hlt">wind</span> flow, comparing the upstream <span class="hlt">solar</span> <span class="hlt">wind</span> data from ACE and <span class="hlt">WIND</span> with Kaguya magnetometer data. The lunar surface below the Kaguya orbit is not magnetized (or very weakly magnetized), and the sunward-travelling protons show signatures of those back-scattered at the lunar surface. We find that the decrease in the magnetic pressure is compensated by the thermal pressure of the back-scattered protons. In other words, the IMF strength in the foremoon <span class="hlt">solar</span> <span class="hlt">wind</span> decreases by diamagnetic effect of sunward-travelling protons back-scattered at the lunar dayside surface. Such diamagnetic effect would be prominent in the high-beta <span class="hlt">solar</span> <span class="hlt">wind</span> environment, and may be ubiquitous in the environment where planetary surface directly interacts with surrounding space plasma.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1510078M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1510078M"><span>Ionospheric mid-latitude response to <span class="hlt">solar</span> <span class="hlt">wind</span> discontinuities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Munteanu, Costel; Mosna, Zbysek; Kouba, Daniel; Echim, Marius</p> <p>2013-04-01</p> <p>We have compiled a database of 356 discontinuities detected by both the Advanced Composition Explorer ACE) and Cluster satellites in the <span class="hlt">solar</span> <span class="hlt">wind</span> between 2001-2012 and analyzed their ionospheric response. Each discontinuity of the data base is defined by a change of at least 5 nT in less than 5 min in one or more components of the interplanetary magnetic field (IMF). The discontinuities are observed in January-April every year, when Cluster enters the <span class="hlt">solar</span> <span class="hlt">wind</span>. The ionospheric effects of <span class="hlt">solar</span> <span class="hlt">wind</span> discontinuities are investigated by checking the variations of critical frequencies foF2, the heights of the F layer and the ionospheric plasma dynamics recorded using ground measurement with a time resolution of 15 minutes from mid-latitude digisondes located in Czech Republic. The time delay between <span class="hlt">solar</span> <span class="hlt">wind</span> input and the ionospheric response is analyzed using the characteristics and the shape of the ionograms. The geoeffectiveness of the <span class="hlt">solar</span> <span class="hlt">wind</span> discontinuities is expressed as correlation between key plasma parameters (e,g, the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity, magnetic jump across the discontinuity) and the ionospheric variations. <span class="hlt">Solar</span> cycle effects are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSA13D..08C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSA13D..08C"><span>Predicting Inner Heliospheric <span class="hlt">Solar</span> <span class="hlt">Wind</span> Conditions in Advance of <span class="hlt">Solar</span> Probe Plus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Case, A. W.; Kasper, J. C.; Korreck, K. E.; Stevens, M. L.; Cohen, O.; Salem, C. S.; Halekas, J. S.; Larson, D. E.; Maruca, B. A.</p> <p>2012-12-01</p> <p>In advance of the upcoming inner heliospheric missions (<span class="hlt">Solar</span> Orbiter and <span class="hlt">Solar</span> Probe Plus) it is vital to have an accurate prediction of the range of <span class="hlt">solar</span> <span class="hlt">wind</span> conditions that occur between 9.5Rs and 0.7AU. These conditions will place constraints on instrument design and the operational modes that are used. In this paper, we discuss and compare different methods of predicting the <span class="hlt">solar</span> <span class="hlt">wind</span> bulk plasma parameters. One method uses observed 1AU conditions observed with the <span class="hlt">Wind</span> spacecraft combined with scaling laws derived from Helios observations. We extend this simple model by using a more realistic <span class="hlt">solar</span> <span class="hlt">wind</span> velocity profile in addition to the <span class="hlt">Wind</span> and Helios observations. Another method uses 3D MHD simulations from which <span class="hlt">solar</span> <span class="hlt">wind</span> conditions along a spacecraft trajectory can be extracted. We discuss some implications of these models in the design of the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Electrons Alphas and Protons investigation, a suite of <span class="hlt">solar</span> <span class="hlt">wind</span> instruments being designed to fly on <span class="hlt">Solar</span> Probe Plus.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19830002737','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830002737"><span>Stationarity of magnetohydrodynamic fluctuations in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Matthaeus, W. H.; Goldstein, M. L.</p> <p>1982-01-01</p> <p><span class="hlt">Solar</span> <span class="hlt">wind</span> research and studies of charged particle propagation often assume that the interplanetary magnetic field represents a stationary random process. The extent to which ensemble averages of the <span class="hlt">solar</span> <span class="hlt">wind</span> magnetic fields follow the asymptotic behavior predicted by the ergodic theorem was investigated. Several time periods, including a span of nearly two years, are analyzed. Data intervals which span many <span class="hlt">solar</span> rotations satisfy the conditions of weak stationarity if the effects of <span class="hlt">solar</span> rotation are included in the asymptotic analysis. Shorter intervals which include a small integral number of interplanetary sectors also satisfy weak stationarity. The results are illustrated using magnetometer data from the ISEE-3, Voyager and IMP spacecraft.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870007250&hterms=technologie&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dtechnologie','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870007250&hterms=technologie&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dtechnologie"><span><span class="hlt">Solar</span> <span class="hlt">wind</span>-plasma interaction: The AMPTE <span class="hlt">solar</span> <span class="hlt">wind</span> plasma releases</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1986-01-01</p> <p>In situ measurements during AMPTE <span class="hlt">solar</span> <span class="hlt">wind</span> ion releases are described. The creation of a diamagnetic cavity, compression and draping of magnetic field lines, recoil of the entire artificial comet, and ion beam and tail formation are discussed. The wave measurements were used to determine the time variation of the plasma density from the measurement of the electron plasma frequency and to determine the state of cloud expansion and cavity formation. Features found include absence of strong turbulence and anomalous diffusion in the cavity boundary, and the appearance of very intense shock-like emission in front of the plasma clouds. The first effect suggests partially unknowm processes leading to magnetic field penetration into the region of the clouds. The direct observation of the interaction processes between the fast streaming <span class="hlt">solar</span> <span class="hlt">wind</span> plasma and the expanding cloud plasma of the Li and artificial comet releases may have relevance to astrophysical situations as, for instance, encountered in <span class="hlt">solar</span> flares, interstellar clouds, or during accretion of matter onto compact objects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/112936','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/112936"><span>He abundance variations in the <span class="hlt">solar</span> <span class="hlt">wind</span>: Observations from Ulysses</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Barraclough, B.L.; Gosling, J.T.; Phillips, J.L.; McComas, D.J.; Feldman, W.C.; Goldstein, B.E.</p> <p>1995-09-01</p> <p>The Ulysses mission is providing the first opportunity to observe variations in <span class="hlt">solar</span> <span class="hlt">wind</span> plasma parameters at heliographic latitudes far removed from the ecliptic plane. We present an overview of the <span class="hlt">solar</span> <span class="hlt">wind</span> speed and the variability in helium abundance, [He] data on [He] in six high latitude coronal mass ejections (CMEs), and a superposed epoch analysis of [He] variations at the seven heliospheric current sheet (HCS) crossings made during the rapid-latitude-scan portion of the mission. The differences in the variability of the <span class="hlt">solar</span> <span class="hlt">wind</span> speed and [He] in high latitude and equatorial regions are quite striking. <span class="hlt">Solar</span> <span class="hlt">wind</span> speed is generally low but highly variable near the <span class="hlt">solar</span> equator, while at higher latitudes the average speed is quite high with little variability. [He] can vary over nearly two decades at low <span class="hlt">solar</span> latitudes, while at high latitudes it varies only slightly. In contrast to the high [He] that is commonly associated with CMEs observed in the ecliptic, none of the six high-speed CMEs encountered at high southern heliographic latitudes showed any significant variation in helium content. A superposed epoch analysis of the [He] during all seven HCS crossings made as Ulysses passed from the southern to northern <span class="hlt">solar</span> hemisphere shows the expected [He] minimum near the crossing and a broad region of low [He] around the crossing time. We discuss how our <span class="hlt">solar</span> <span class="hlt">wind</span> [He] observations may provide an accurate measure of the helium composition for the entire convective zone of the Sun.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1914406T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1914406T"><span>Alfvénic <span class="hlt">solar</span> <span class="hlt">wind</span> powers substorms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tanskanen, Eija; Hynönen, Reko; Mursula, Kalevi</p> <p>2017-04-01</p> <p>Alfvenic <span class="hlt">solar</span> <span class="hlt">wind</span> fluctuations (ALFs) are known to modulate geomagnetic activity. We have examined high-latitude geomagnetic activity over the <span class="hlt">solar</span> cycle 23 and found out that increase of <span class="hlt">solar</span> <span class="hlt">wind</span> Alfvenicity enhance both auroral substorm intensity and substorm frequency. Alfvénic <span class="hlt">solar</span> <span class="hlt">wind</span> fluctuations are found throughout the <span class="hlt">solar</span> cycle, but they are fastest, most frequent and geo-effective in the declining phase of the cycle, when the number of high-speed streams at the Earth's vicinity increases rapidly. We find a rapid transition from the predominance of slow (< 400 km/s) ALFs in 2002 to fast (> 600 km/s) ALFs in 2003, in coincidence with the rapid increase of substorm activity from late 2002 to early 2003. The Alfvénicity of <span class="hlt">solar</span> <span class="hlt">wind</span> increased by 40% from 2002 to 2003. After the transition the fast ALFs occur twice per <span class="hlt">solar</span> rotation while in previous year only four fast ALF intervals were detected. Increase of <span class="hlt">solar</span> <span class="hlt">wind</span> Alfvénicity by 40% from 2002 to 2003, and transition from slow to fast Alfvén fluctuations coincide with the increase of auroral substorm intensity by 28% and substorm frequency by 43%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1094889','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1094889"><span>Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study Phase 2 (Fact Sheet)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Not Available</p> <p>2013-09-01</p> <p>This is one-page, two-sided fact sheet presents high-level summary results of the Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study Phase 2, which examined operational impacts of high penetrations of variable renewable generation in the West.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060041718&hterms=ubiquitous&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dubiquitous','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060041718&hterms=ubiquitous&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dubiquitous"><span>Origins of the Slow and the Ubiquitous Fast <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Korendyke, Noci C.; Habbal, S. R.</p> <p>1997-01-01</p> <p>We present in this letter the first coordinated radio occultation measurements and ultraviolet observations of the inner corona below 5.5 Rs, obtained during the Galileo <span class="hlt">solar</span> conjunction in January 1997, to establish the origin of the slow <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA19719.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA19719.html"><span>Artist Concept of the Interaction of the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2015-07-17</p> <p>Artist concept of the interaction of the <span class="hlt">solar</span> <span class="hlt">wind</span> the supersonic outflow of electrically charged particles from the Sun with Pluto predominantly nitrogen atmosphere based on NASA New Horizons SWAP instrument.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890054328&hterms=electrodynamics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Delectrodynamics','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890054328&hterms=electrodynamics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Delectrodynamics"><span>Electrodynamics of <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere-ionosphere interactions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kan, Joseph R.; Akasofu, Syun-Ichi</p> <p>1989-01-01</p> <p>The paper presents a coherent picture of fundamental physical processes in three basic elements of the <span class="hlt">solar-wind</span>/magnetosphere/ionosphere coupling system: (1) the field-aligned potential structure which leads to the formation of auroral arcs, (2) the magnetosphere-ionosphere coupling which leads to the onset of magnetospheric substorms, and (3) the <span class="hlt">solar-wind</span>/magnetosphere dynamo which supplies the power driving various magnetospheric processes. Process (1) is forced into existence by the loss-cone constriction effect when the upward field-aligned current density exceeds the loss-cone thermal flux limit. Substorm onset occurs when the ionosphere responds fully to the enhanced magnetospheric convection driven by the <span class="hlt">solar</span> <span class="hlt">wind</span>. Energy is transferred from the <span class="hlt">solar</span> <span class="hlt">wind</span> to the magnetosphere by a dynamo process, primarily on open field lines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMSM13B1604C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMSM13B1604C"><span>Relationship between the sawtooth period and <span class="hlt">solar</span> <span class="hlt">wind</span> drivers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cai, X.; Clauer, C. R.; Weimer, D. R.</p> <p>2009-12-01</p> <p>Cai and Clauer [2009] shows the mean period of sawtooth events has a large variability from 2 to 4 hours, with a mean period around 3 hours. What controls the period, whether by <span class="hlt">solar</span> <span class="hlt">wind</span> drivers or internal magnetospheric parameters, is unknown. In this presentation, we examine the relationship between the <span class="hlt">solar</span> <span class="hlt">wind</span> drivers and the period for each individual tooth. No clear linear trends are found so we conclude that the period of sawtooth events does not depend on any single <span class="hlt">solar</span> <span class="hlt">wind</span> driver exclusively. However sawtooth events driven by stream interaction events have a longer period (~ 180 minutes) than those driven by interplanetary coronal mass ejections (~ 150 minutes). This might suggest the <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere system has different coupling efficiencies during these two types of sawtooth events. We also propose an idea to explain why sawtooth events occur periodically and why the Earth has different response modes.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AGUFM.P32A1066D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AGUFM.P32A1066D"><span>Mass dragged from Mars's atmosphere by the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Durand-Manterola, H. J.</p> <p>2003-12-01</p> <p>In the past Mars had a denser atmosphere, but it lacks a magnetic field to protect the ionosphere and exosphere from the <span class="hlt">solar</span> <span class="hlt">wind</span>. A model describing the loss of atmosphere by the erosion of the <span class="hlt">solar</span> <span class="hlt">wind</span> in geologic time is presented. Recent results shows that the Martian dynamo existed in Early and Middle Noachian. Then <span class="hlt">solar</span> <span class="hlt">wind</span> erosion would have started at the end of Middle Noachian or the beginning of Late Noachian. With this assumption the amount of volatiles dragged by the <span class="hlt">solar</span> <span class="hlt">wind</span>, if the chronology developed by Neukum and Wise is correct, is in the range of 0.472 to 1.89 Terrestrial Atmospheric Masses (TAM). If the chronology developed by Hartmann et al. is correct, the loss remains in the range of 0.0624 to 0.25 TAM.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SpWea..14..973C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SpWea..14..973C"><span>Quantitative evaluation of <span class="hlt">solar</span> <span class="hlt">wind</span> time-shifting methods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cameron, Taylor; Jackel, Brian</p> <p>2016-11-01</p> <p>Nine years of <span class="hlt">solar</span> <span class="hlt">wind</span> dynamic pressure and geosynchronous magnetic field data are used for a large-scale statistical comparison of uncertainties associated with several different algorithms for propagating <span class="hlt">solar</span> <span class="hlt">wind</span> measurements. The MVAB-0 scheme is best overall, performing on average a minute more accurately than a flat time-shift. We also evaluate the accuracy of these time-shifting methods as a function of <span class="hlt">solar</span> <span class="hlt">wind</span> magnetic field orientation. We find that all time-shifting algorithms perform significantly worse (>5 min) due to geometric effects when the <span class="hlt">solar</span> <span class="hlt">wind</span> magnetic field is radial (parallel or antiparallel to the Earth-Sun line). Finally, we present an empirical scheme that performs almost as well as MVAB-0 on average and slightly better than MVAB-0 for intervals with nonradial B.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19740042885&hterms=planet+mars+jupiter&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dplanet%2Bmars%2Bjupiter','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19740042885&hterms=planet+mars+jupiter&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dplanet%2Bmars%2Bjupiter"><span>Magnetic fields of Mars and Venus - <span class="hlt">Solar</span> <span class="hlt">wind</span> interactions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ness, N. F.</p> <p>1974-01-01</p> <p>Recent USSR studies of the magnetic field and <span class="hlt">solar</span> <span class="hlt">wind</span> flow in the vicinity of Mars and Venus confirm earlier U.S. reports of a bow shock wave developed as the <span class="hlt">solar</span> <span class="hlt">wind</span> interacts with these planets. Mars 2 and 3 magnetometer experiments report the existence of an intrinsic planetary magnetic field, sufficiently strong to form a magnetopause, deflecting the <span class="hlt">solar</span> <span class="hlt">wind</span> around the planet and its ionosphere. This is in contrast to the case for Venus, where it is assumed to be the ionosphere and processes therein which are responsible for the <span class="hlt">solar</span> <span class="hlt">wind</span> deflection. An empirical relationship appears to exist between planetary dipole magnetic moments and their angular momentum for the Moon, Mars, Venus, Earth, and Jupiter. Implications for the magnetic fields of Mercury and Saturn are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870027492&hterms=css&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcss','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870027492&hterms=css&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcss"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> flow upstream of the coronal slow shock</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Whang, Y. C.</p> <p>1986-01-01</p> <p>Slow shocks have been predicted to exist embedded in large coronal holes at low altitude. Two or more curved slow shocks may link together to form a composite discontinuity surface around the sun which may be called the coronal slow shock (CSS). Here a <span class="hlt">solar-wind</span> model is studied under the assumption that a standing CSS exists and cororates with the sun at a constant angular velocity. A steady, axisymmetrical one-fluid model is introduced to study the expansion of <span class="hlt">solar</span> <span class="hlt">wind</span> in the open-field region upstream of the CSS. The model requires that the conditions downstream of the CSS near the equatorial plane can produce a <span class="hlt">solar</span> <span class="hlt">wind</span> agreeable with the observations made near the earth's orbit. The paper presents an illustrative calculation in which the polar caps within 60 deg of the polar angle are assumed to be the source region of the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1094881','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1094881"><span>Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study: Phase 2 (Presentation)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lew, D.; Brinkman, G.; Ibanez, E.; Lefton, S.; Kumar, N.; Venkataraman, S.; Jordan, G.</p> <p>2013-09-01</p> <p>This presentation summarizes the scope and results of the Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study Phase 2, which examined operational impacts of high penetrations of variable renewable generation in the West.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSH41F..05K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSH41F..05K"><span>Integrating Multiple Approaches to Solving <span class="hlt">Solar</span> <span class="hlt">Wind</span> Turbulence Problems (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Karimabadi, H.; Roytershteyn, V.</p> <p>2013-12-01</p> <p>The ultimate understanding of the <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence must explain the physical process and their connection at all scales ranging from the largest down to electron kinetic scales. This is a daunting task and as a result a more piecemeal approach to the problem has been followed. For example, the role of each wave has been explored in isolation and in simulations with scales limited to those of the underlying waves. In this talk, we present several issues with this approach and offer an alternative with an eye towards more realistic simulations of <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence. The main simulation techniques used have been MHD, Hall MHD, hybrid, fully kinetic, and gyrokinetic. We examine the limitations of each approach and their viability for studies of <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence. Finally, the effect of initial conditions on the resulting turbulence and their comparison with <span class="hlt">solar</span> <span class="hlt">wind</span> are demonstrated through several kinetic simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19830052897&hterms=accounts+charge&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Daccounts%2Bcharge','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19830052897&hterms=accounts+charge&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Daccounts%2Bcharge"><span>Charge exchange in <span class="hlt">solar</span> <span class="hlt">wind</span>-cometary interactions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gombosi, T. I.; Horanyi, M.; Kecskemety, K.; Cravens, T. E.; Nagy, A. F.</p> <p>1983-01-01</p> <p>A simple model of a cometary spherically symmetrical atmosphere and ionosphere is considered. An analytic solution of the governing equations describing the radial distribution of the neutral and ion densities is found. The new solution is compared to the well-known solution of the equations containing only ionization terms. Neglecting recombination causes a significant overestimate of the ion density in the vicinity of the comet. An axisymmetric model of the <span class="hlt">solar</span> <span class="hlt">wind</span>-cometary interaction is considered, taking into account the loss of <span class="hlt">solar</span> <span class="hlt">wind</span> ions due to charge exchange. The calculations predict that for active comets, <span class="hlt">solar</span> <span class="hlt">wind</span> absorption due to charge exchange becomes important at a few thousand kilometers from the nucleus, and a surface separating the shocked <span class="hlt">solar</span> <span class="hlt">wind</span> from the cometary ionosphere develops in this region. These calculations are in reasonable agreement with the few observations available for the ionopause location at comets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E3124S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E3124S"><span>Transient flows of the <span class="hlt">solar</span> <span class="hlt">wind</span> associated with small-scale <span class="hlt">solar</span> activity in <span class="hlt">solar</span> minimum</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Slemzin, Vladimir; Veselovsky, Igor; Kuzin, Sergey; Gburek, Szymon; Ulyanov, Artyom; Kirichenko, Alexey; Shugay, Yulia; Goryaev, Farid</p> <p></p> <p>The data obtained by the modern high sensitive EUV-XUV telescopes and photometers such as CORONAS-Photon/TESIS and SPHINX, STEREO/EUVI, PROBA2/SWAP, SDO/AIA provide good possibilities for studying small-scale <span class="hlt">solar</span> activity (SSA), which is supposed to play an important role in heating of the corona and producing transient flows of the <span class="hlt">solar</span> <span class="hlt">wind</span>. During the recent unusually weak <span class="hlt">solar</span> minimum, a large number of SSA events, such as week <span class="hlt">solar</span> flares, small CMEs and CME-like flows were observed and recorded in the databases of flares (STEREO, SWAP, SPHINX) and CMEs (LASCO, CACTUS). On the other hand, the <span class="hlt">solar</span> <span class="hlt">wind</span> data obtained in this period by ACE, <span class="hlt">Wind</span>, STEREO contain signatures of transient ICME-like structures which have shorter duration (<10h), weaker magnetic field strength (<10 nT) and lower proton temperature than usual ICMEs. To verify the assumption that ICME-like transients may be associated with the SSA events we investigated the number of weak flares of C-class and lower detected by SPHINX in 2009 and STEREO/EUVI in 2010. The flares were classified on temperature and emission measure using the diagnostic means of SPHINX and Hinode/EIS and were confronted with the parameters of the <span class="hlt">solar</span> <span class="hlt">wind</span> (velocity, density, ion composition and temperature, magnetic field, pitch angle distribution of the suprathermal electrons). The outflows of plasma associated with the flares were identified by their coronal signatures - CMEs (only in few cases) and dimmings. It was found that the mean parameters of the <span class="hlt">solar</span> <span class="hlt">wind</span> projected to the source surface for the times of the studied flares were typical for the ICME-like transients. The results support the suggestion that weak flares can be indicators of sources of transient plasma flows contributing to the slow <span class="hlt">solar</span> <span class="hlt">wind</span> at <span class="hlt">solar</span> minimum, although these flows may be too weak to be considered as separate CMEs and ICMEs. The research leading to these results has received funding from the European Union’s Seventh Programme</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19790030552&hterms=three+field+view&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dthree%2Bfield%2Bof%2Bview','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19790030552&hterms=three+field+view&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dthree%2Bfield%2Bof%2Bview"><span>A view of <span class="hlt">solar</span> magnetic fields, the <span class="hlt">solar</span> corona, and the <span class="hlt">solar</span> <span class="hlt">wind</span> in three dimensions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Svalgaard, L.; Wilcox, J. M.</p> <p>1978-01-01</p> <p>In the last few years it has been recognized that the <span class="hlt">solar</span> corona and the <span class="hlt">solar</span> <span class="hlt">wind</span> are three-dimensional. The deviations from spherical or even cylindrical symmetry are first-order effects, which are important for a basic description and physical understanding of the coronal expansion. Models of coronal magnetic fields are considered along with the characteristics of large-scale <span class="hlt">solar</span> structure, the interplanetary magnetic field, coronal holes, geomagnetic activity, cosmic rays, and polar fields of the sun. It is pointed out that the present understanding of coronal and interplanetary morphology is based on data acquired during the descending part and the minimum of the considered sunspot cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890005692','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890005692"><span>Analysis of ISEE-3/ICE <span class="hlt">solar</span> <span class="hlt">wind</span> data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Coplan, Michael A.</p> <p>1989-01-01</p> <p>Under the grant that ended November 11, 1988 work was accomplished in a number of areas, as follows: (1) Analysis of <span class="hlt">solar</span> <span class="hlt">wind</span> data; (2) Analysis of Giacobini/Zinner encounter data; (3) Investigation of <span class="hlt">solar</span> <span class="hlt">wind</span> and magnetospheric electron velocity distributions; and (4) Experimental investigation of the electronic structure of clusters. Reprints and preprints of publications resulting from this work are included in the appendices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820024368','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820024368"><span>Calculation of <span class="hlt">solar</span> <span class="hlt">wind</span> flows about terrestrial planets</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stahara, S. S.; Spreiter, J. R.</p> <p>1982-01-01</p> <p>A computational model was developed for the determination of the plasma and magnetic field properties of the global interaction of the <span class="hlt">solar</span> <span class="hlt">wind</span> with terrestrial planetary magneto/ionospheres. The theoretical method is based on an established single fluid, steady, dissipationless, magnetohydrodynamic continuum model, and is appropriate for the calculation of supersonic, super Alfvenic <span class="hlt">solar</span> <span class="hlt">wind</span> flow past terrestrial planets. A summary is provided of the important research results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JGRA..118...45B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JGRA..118...45B"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> forcing at Mercury: WSA-ENLIL model results</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baker, Daniel N.; Poh, Gangkai; Odstrcil, Dusan; Arge, C. Nick; Benna, Mehdi; Johnson, Catherine L.; Korth, Haje; Gershman, Daniel J.; Ho, George C.; McClintock, William E.; Cassidy, Timothy A.; Merkel, Aimee; Raines, Jim M.; Schriver, David; Slavin, James A.; Solomon, Sean C.; TráVníčEk, Pavel M.; Winslow, Reka M.; Zurbuchen, Thomas H.</p> <p>2013-01-01</p> <p>Analysis and interpretation of observations from the MESSENGER spacecraft in orbit about Mercury require knowledge of <span class="hlt">solar</span> <span class="hlt">wind</span> "forcing" parameters. We have utilized the Wang-Sheeley-Arge (WSA)-ENLIL <span class="hlt">solar</span> <span class="hlt">wind</span> modeling tool in order to calculate the values of interplanetary magnetic field (IMF) strength (B), <span class="hlt">solar</span> <span class="hlt">wind</span> velocity (V) and density (n), ram pressure (~nV2), cross-magnetosphere electric field (V × B), Alfvén Mach number (MA), and other derived quantities of relevance for <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere interactions. We have compared upstream MESSENGER IMF and <span class="hlt">solar</span> <span class="hlt">wind</span> measurements to see how well the ENLIL model results compare. Such parameters as <span class="hlt">solar</span> <span class="hlt">wind</span> dynamic pressure are key for determining the Mercury magnetopause standoff distance, for example. We also use the relatively high-time-resolution B-field data from MESSENGER to estimate the strength of the product of the <span class="hlt">solar</span> <span class="hlt">wind</span> speed and southward IMF strength (Bs) at Mercury. This product VBs is the electric field that drives many magnetospheric dynamical processes and can be compared with the occurrence of energetic particle bursts within the Mercury magnetosphere. This quantity also serves as input to the global magnetohydrodynamic and kinetic magnetosphere models that are being used to explore magnetospheric and exospheric processes at Mercury. Moreover, this modeling can help assess near-real-time magnetospheric behavior for MESSENGER or other mission analysis and/or ground-based observational campaigns. We demonstrate that this <span class="hlt">solar</span> <span class="hlt">wind</span> forcing tool is a crucial step toward bringing heliospheric science expertise to bear on planetary exploration programs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170002772&hterms=Winds&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DWinds','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170002772&hterms=Winds&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DWinds"><span>On Electron-Scale Whistler Turbulence in the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Narita, Y.; Nakamura, R.; Baumjohann, W.; Glassmeier, K.-H.; Motschmann, U.; Giles, B.; Magnes, W.; Fischer, D.; Torbert, R. B.; Russell, C. T.</p> <p>2016-01-01</p> <p>For the first time, the dispersion relation for turbulence magnetic field fluctuations in the <span class="hlt">solar</span> <span class="hlt">wind</span> is determined directly on small scales of the order of the electron inertial length, using four-point magnetometer observations from the Magnetospheric Multiscale mission. The data are analyzed using the high-resolution adaptive wave telescope technique. Small-scale <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence is primarily composed of highly obliquely propagating waves, with dispersion consistent with that of the whistler mode.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750011027','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750011027"><span>Interplanetary stream magnetism: Kinematic effects. [<span class="hlt">solar</span> magnetic fields and <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burlaga, L. F.; Barouch, E.</p> <p>1974-01-01</p> <p>The particle density, and the magnetic field intensity and direction are calculated in corotating streams of the <span class="hlt">solar</span> <span class="hlt">wind</span>, assuming that the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity is constant and radial and that its azimuthal variations are not two rapid. The effects of the radial velocity profile in corotating streams on the magnetic fields were examined using kinematic approximation and a variety of field configurations on the inner boundary. Kinematic and dynamic effects are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991AcGSn..34..272Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991AcGSn..34..272Z"><span>System identification of geomagnetic disturbances initiated by the <span class="hlt">solar</span> <span class="hlt">wind</span>.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, Xiaoyan; Tschu, Kangkun</p> <p>1991-05-01</p> <p>On the basis of linear and time-invariant supposition, the geomagnetic disturbances initiated by the <span class="hlt">solar</span> <span class="hlt">wind</span> have been studied in terms of least square non-parametric identification method. The macro-external description of the response of the magnetosphere to the <span class="hlt">solar</span> <span class="hlt">wind</span> is given by the impulse response function. The predicted geomagnetic disturbances are compared with the observations; they are found to agree quite well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170002772&hterms=solar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsolar','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170002772&hterms=solar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsolar"><span>On Electron-Scale Whistler Turbulence in the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Narita, Y.; Nakamura, R.; Baumjohann, W.; Glassmeier, K.-H.; Motschmann, U.; Giles, B.; Magnes, W.; Fischer, D.; Torbert, R. B.; Russell, C. T.</p> <p>2016-01-01</p> <p>For the first time, the dispersion relation for turbulence magnetic field fluctuations in the <span class="hlt">solar</span> <span class="hlt">wind</span> is determined directly on small scales of the order of the electron inertial length, using four-point magnetometer observations from the Magnetospheric Multiscale mission. The data are analyzed using the high-resolution adaptive wave telescope technique. Small-scale <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence is primarily composed of highly obliquely propagating waves, with dispersion consistent with that of the whistler mode.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840065464&hterms=lithium+ions&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dlithium%2Bions','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840065464&hterms=lithium+ions&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dlithium%2Bions"><span>Collective capture of released lithium ions in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Winske, D.; Wu, C. S.; Li, Y. Y.; Zhou, G. C.</p> <p>1984-01-01</p> <p>The capture of newly ionized lithium ions in the <span class="hlt">solar</span> <span class="hlt">wind</span> by means of electromagnetic instabilities is investigated through linear analysis and computer simulation. Three instabilities, driven by a lithium velocity ring perpendicular to and drifting along the magnetic field, are considered. The capture time of the lithium by the <span class="hlt">solar</span> <span class="hlt">wind</span> is roughly 10 linear growth times, regardless of whether resonant or nonresonant modes dominate initially. Possible implications of the results for the Active Magnetosphere Particle Tracer Explorer (AMPTE) mission are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840005046','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840005046"><span>Mixed <span class="hlt">solar</span> <span class="hlt">wind</span> originating from coronal regions of different temperatures</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bochsler, P.</p> <p>1983-01-01</p> <p>Ionization states of elements in the <span class="hlt">solar</span> <span class="hlt">wind</span> are often used to determine thermal gradients in the lower corona. This method is based on the assumption, that in the beginning, <span class="hlt">solar</span> <span class="hlt">wind</span> material has a homogeneous temperature determining the original charge state of elements. Features in M/Q-spectra which might appear if the above assumption is violated are investigated and compared with observational evidence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.9271J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.9271J"><span>STEREO Observations of <span class="hlt">Solar</span> <span class="hlt">Wind</span> in 2007-2014</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jian, Lan; Luhmann, Janet; Russell, Christopher; Blanco-Cano, Xochitl; Kilpua, Emilia; Li, Yan</p> <p>2016-04-01</p> <p>Since the launch of twin STEREO spacecraft, we have been monitoring the <span class="hlt">solar</span> <span class="hlt">wind</span> and providing the Level 3 event lists of large-scale <span class="hlt">solar</span> <span class="hlt">wind</span> and particle events to public (http://www-ssc.igpp.ucla.edu/forms/stereo/stereo_level_3.html). The interplanetary coronal mass ejections (ICMEs), stream interaction regions (SIRs), interplanetary shocks, and <span class="hlt">solar</span> energetic particles (based on high energy telescope data) have been surveyed for 2007-2014 before STEREO A went to the superior <span class="hlt">solar</span> conjunction and STEREO B was lost in contact. In conjunction with our previous observations of same <span class="hlt">solar</span> <span class="hlt">wind</span> structures in 1995-2009 using <span class="hlt">Wind</span>/ACE data and the same identification criteria, we study the <span class="hlt">solar</span> cycle variations of these structures, especially compare the same phase of <span class="hlt">solar</span> cycles 23 and 24. Although the sunspot number at <span class="hlt">solar</span> maximum 24 is only 60% of the level at last <span class="hlt">solar</span> maximum, Gopalswamy et al. (2015a, b) found there were more halo CMEs in cycle 24 and the number of magnetic clouds did not decline either. We examine if the two vantage points of STEREO provide a consistent view with the above finding. In addition, because the twin STEREO spacecraft have experienced the full-range longitudinal separation of 0-360 degree, they have provided us numerous opportunities for multipoint observations. We will report the findings on the spatial scope of ICMEs including their driven shocks, and the stability of SIRs from the large event base.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..4310586V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..4310586V"><span>Transport of <span class="hlt">solar</span> <span class="hlt">wind</span> plasma onto the lunar nightside surface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vorburger, A.; Wurz, P.; Barabash, S.; Futaana, Y.; Wieser, M.; Bhardwaj, A.; Dhanya, M. B.; Asamura, K.</p> <p>2016-10-01</p> <p>We present first measurements of energetic neutral atoms that originate from <span class="hlt">solar</span> <span class="hlt">wind</span> plasma having interacted with the lunar nightside surface. We observe two distinct energetic neutral atom (ENA) distributions parallel to the terminator, the spectral shape, and the intensity of both of which indicate that the particles originate from the bulk <span class="hlt">solar</span> <span class="hlt">wind</span> flow. The first distribution modifies the dayside ENA flux to reach ˜6° into the nightside and is well explained by the kinetic temperature of the <span class="hlt">solar</span> <span class="hlt">wind</span> protons. The second distribution, which was not predicted, reaches from the terminator to up to 30° beyond the terminator, with a maximum at ˜102° in <span class="hlt">solar</span> zenith angle. As most likely wake transport processes for this second distribution we identify acceleration by the ambipolar electric field and by the negatively charged lunar nightside surface. In addition, our data provide the first observation indicative of a global <span class="hlt">solar</span> zenith angle dependence of positive dayside surface potentials.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110013339','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110013339"><span>The Character of the <span class="hlt">Solar</span> <span class="hlt">Wind</span>, Surface Interactions, and Water</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Farrell, William M.</p> <p>2011-01-01</p> <p>We discuss the key characteristics of the proton-rich <span class="hlt">solar</span> <span class="hlt">wind</span> and describe how it may interact with the lunar surface. We suggest that <span class="hlt">solar</span> <span class="hlt">wind</span> can be both a source and loss of water/OH related volatiles, and review models showing both possibilities. Energy from the Sun in the form of radiation and <span class="hlt">solar</span> <span class="hlt">wind</span> plasma are in constant interaction with the lunar surface. As such, there is a <span class="hlt">solar</span>-lunar energy connection, where <span class="hlt">solar</span> energy and matter are continually bombarding the lunar surface, acting at the largest scale to erode the surface at 0.2 Angstroms per year via ion sputtering [1]. Figure 1 illustrates this dynamically Sun-Moon system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730002067','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730002067"><span>Interplanetary shock waves and the structure of <span class="hlt">solar</span> <span class="hlt">wind</span> disturbances</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hundhausen, A. J.</p> <p>1972-01-01</p> <p>Observations and theoretical models of interplanetary shock waves are reviewed, with emphasis on the large-scale characteristics of the associated <span class="hlt">solar</span> <span class="hlt">wind</span> disturbances and on the relationship of these disturbances to <span class="hlt">solar</span> activity. The sum of observational knowledge indicates that shock waves propagate through the <span class="hlt">solar</span> <span class="hlt">wind</span> along a broad, roughly spherical front, ahead of plasma and magnetic field ejected from <span class="hlt">solar</span> flares. Typically, the shock front reaches 1 AU about two days after its flare origin, and is of intermediate strength. Not all large flares produce observable interplanetary shock waves; the best indicator of shock production appears to be the generation of both type 2 and type 4 radio bursts by a flare. Theoretical models of shock propagation in the <span class="hlt">solar</span> <span class="hlt">wind</span> can account for the typically observed shock strength, transit time, and shape.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/964607','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/964607"><span>Potential for Development of <span class="hlt">Solar</span> and <span class="hlt">Wind</span> Resource in Bhutan</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gilman, P.; Cowlin, S.; Heimiller, D.</p> <p>2009-09-01</p> <p>With support from the U.S. Agency for International Development (USAID), the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) produced maps and data of the <span class="hlt">wind</span> and <span class="hlt">solar</span> resources in Bhutan. The <span class="hlt">solar</span> resource data show that Bhutan has an adequate resource for flat-plate collectors, with annual average values of global horizontal <span class="hlt">solar</span> radiation ranging from 4.0 to 5.5 kWh/m2-day (4.0 to 5.5 peak sun hours per day). The information provided in this report may be of use to energy planners in Bhutan involved in developing energy policy or planning <span class="hlt">wind</span> and <span class="hlt">solar</span> projects, and to energy analysts around the world interested in gaining an understanding of Bhutan's <span class="hlt">wind</span> and <span class="hlt">solar</span> energy potential.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840024844','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840024844"><span><span class="hlt">Wind</span> loading on <span class="hlt">solar</span> concentrators: Some general considerations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Roschke, E. J.</p> <p>1984-01-01</p> <p>A survey was completed to examine the problems and complications arising from <span class="hlt">wind</span> loading on <span class="hlt">solar</span> concentrators. <span class="hlt">Wind</span> loading is site specific and has an important bearing on the design, cost, performance, operation and maintenance, safety, survival, and replacement of <span class="hlt">solar</span> collecting systems. Emphasis herein is on paraboloidal, two-axis tracking systems. Thermal receiver problems also are discussed. <span class="hlt">Wind</span> characteristics are discussed from a general point of view. Current methods for determining design <span class="hlt">wind</span> speed are reviewed. Aerodynamic coefficients are defined and illustrative examples are presented. <span class="hlt">Wind</span> tunnel testing is discussed, and environmental <span class="hlt">wind</span> tunnels are reviewed. Recent results on heliostat arrays are reviewed as well. Aeroelasticity in relation to structural design is discussed briefly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1984STIN...8432915R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1984STIN...8432915R"><span><span class="hlt">Wind</span> loading on <span class="hlt">solar</span> concentrators: Some general considerations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roschke, E. J.</p> <p>1984-05-01</p> <p>A survey was completed to examine the problems and complications arising from <span class="hlt">wind</span> loading on <span class="hlt">solar</span> concentrators. <span class="hlt">Wind</span> loading is site specific and has an important bearing on the design, cost, performance, operation and maintenance, safety, survival, and replacement of <span class="hlt">solar</span> collecting systems. Emphasis herein is on paraboloidal, two-axis tracking systems. Thermal receiver problems also are discussed. <span class="hlt">Wind</span> characteristics are discussed from a general point of view. Current methods for determining design <span class="hlt">wind</span> speed are reviewed. Aerodynamic coefficients are defined and illustrative examples are presented. <span class="hlt">Wind</span> tunnel testing is discussed, and environmental <span class="hlt">wind</span> tunnels are reviewed. Recent results on heliostat arrays are reviewed as well. Aeroelasticity in relation to structural design is discussed briefly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020086296','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020086296"><span>Investigation of <span class="hlt">Solar</span> <span class="hlt">Wind</span> Correlations and <span class="hlt">Solar</span> <span class="hlt">Wind</span> Modifications Near Earth by Multi-Spacecraft Observations: IMP 8, <span class="hlt">WIND</span> and INTERBALL-1</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Paularena, Karolen I.; Richardson, John D.; Zastenker, Georgy N.</p> <p>2002-01-01</p> <p>The foundation of this Project is use of the opportunity available during the ISTP (International <span class="hlt">Solar</span>-Terrestrial Physics) era to compare <span class="hlt">solar</span> <span class="hlt">wind</span> measurements obtained simultaneously by three spacecraft - IMP 8, <span class="hlt">WIND</span> and INTERBALL-1 at wide-separated points. Using these data allows us to study three important topics: (1) the size and dynamics of near-Earth mid-scale (with dimension about 1-10 million km) and small-scale (with dimension about 10-100 thousand km) <span class="hlt">solar</span> <span class="hlt">wind</span> structures; (2) the reliability of the common assumption that <span class="hlt">solar</span> <span class="hlt">wind</span> conditions at the upstream Lagrangian (L1) point accurately predict the conditions affecting Earth's magnetosphere; (3) modification of the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma and magnetic field in the regions near the Earth magnetosphere, the foreshock and the magnetosheath. Our Project was dedicated to these problems. Our research has made substantial contributions to the field and has lead others to undertake similar work.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004A%26G....45d..38H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004A%26G....45d..38H"><span><span class="hlt">Solar</span> <span class="hlt">wind</span>: The <span class="hlt">solar</span> <span class="hlt">wind</span> and the Sun-Earth link</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Habbal, Shadia Rifia; Woo, Richard</p> <p>2004-08-01</p> <p>The <span class="hlt">solar</span> <span class="hlt">wind</span> fills the space between the Sun and its planets, shapes the planetary environments and the heliosphere, and comes to a screeching halt at the heliopause, the boundary with the interstellar medium. This tenuous medium is a fertile environment for exotic plasma processes, most of which are not fully understood. It also holds the intimate secrets of the mechanisms heating the corona that continue to elude us. As the only accessible space plasma laboratory, we must continue its exploration in search of the processes that impact the Earth's environment and govern the evolution of stars and their planetary systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110005629','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110005629"><span>Dissipation of Turbulence in the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Goldstein, Melvyn L.</p> <p>2010-01-01</p> <p>I will describe the first three-dimensional (3-D) dispersion relations and wavenumber spectra of magnetic turbulence in the <span class="hlt">solar</span> <span class="hlt">wind</span> at sub-proton scales. The analysis takes advantage of the short separations of the Cluster spacecraft (d/sim approx.200 km) to apply the {it k}-filtering technique to the frequency range where the transition to sub-proton scales occurs. The dispersion diagrams show unambiguously that the cascade is carried by highly oblique Kinetic Alfven Wave with \\omega\\leq 0.1\\omega_{ci} in the plasma rest frame down to k_\\perp\\rho_i \\sim 2. The wavenumber spectra in the direction perpendicular to the mean magnetic field consists of two ranges of scales separated by a breakpoint in the interval [0.4,1] k_\\perp \\rho_i. Above the breakpoint, the spectra follow the Kolmogorov scaling k_\\perp^{-1.7}, consistent with existing theoretical predictions. Below the breakpoint, the spectra steepen to \\sim k_\\perp^{-4.5}. We conjecture that the turbulence undergoes a {\\it transition-range}, where part of energy is dissipated into proton heating via Landau damping, and the remaining energy cascades down to electron scales where electron Landau damping may predominate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040000671&hterms=sorting&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dsorting','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040000671&hterms=sorting&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dsorting"><span>Interaction of Comets and the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wagner, William (Technical Monitor); Raymond, John C.</p> <p>2003-01-01</p> <p>We had originally planned to analyze UVCS observations of Comet Machholz, but we obtained higher quality observations of Comet Kudo-Fujikawa in January 2003 at its 0.19 AU perihelion. Besides a large and rapidly increasing water outgassing rate, we detected a bright tail in doubly ionized carbon. The amount of carbon was greater than could be accounted for by GO photodissociation, and we attribute the carbon to evaporation of organics from dust. A spectacular disconnection event was apparent in the C III tail, and it coincides within the uncertainties with the position of the heliospheric current sheet. A paper is in press in Science, and it will be the subject of a press release. We are also analyzing two sungrazing comets. Comet C/2001 C2 shows evidence for sub-fragments and for a very long lasting source of neutrals, which we tentatively identify as evaporation of pyroxene dust grains. Comet C/2002 S2 shows a sudden 2 magnitude drop in optical brightness and an equally sudden recovery. UVCS observations during that time show a steadily increasing outgassing rate. We have derived <span class="hlt">solar</span> <span class="hlt">wind</span> densities for both comets, but we are still sorting out the ambiguities involving the fragmentation and optical behavior. We are collaborating with Philippe Lamy on the LASCO measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040182379','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040182379"><span>Interaction of Comets and the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wagner, William (Technical Monitor); Raymond, John C.</p> <p>2004-01-01</p> <p>The analysis of Comet Kudo-Fujikawa at perihelion was published and picked up by Der Spiegel. Besides a large and rapidly increasing water outgassing rate, we detected a bright tail in doubly ionized carbon. The amount of carbon was greater than could be accounted for by CO photodissociation, and we attribute it to evaporation of organics from dust. A spectacular disconnection event was apparent in the C III tail, and it coincides within the uncertainties to the position of the heliospheric current sheet. The analysis of the sungrazing comet C2001 C2 is in press. It showed evidence for subfragments and for a very long lasting source of neutrals, which we identify as evaporation of pyroxene dust grains. Results were also presented at COSPAR. We are working on observations of another sungrazer, comet C2002 S2, which shows a sudden 2 magnitude drop in optical brightness and an equally sudden recovery. UVCS observations during that time show a steadily increasing outgassing rate. We have derived <span class="hlt">solar</span> <span class="hlt">wind</span> densities for both comets, but we are still sorting out the ambiguities involving the fragmentation and optical behavior.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040000671&hterms=Williams+Raymond&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D40%26Ntt%3DWilliams%252C%2BRaymond','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040000671&hterms=Williams+Raymond&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D40%26Ntt%3DWilliams%252C%2BRaymond"><span>Interaction of Comets and the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wagner, William (Technical Monitor); Raymond, John C.</p> <p>2003-01-01</p> <p>We had originally planned to analyze UVCS observations of Comet Machholz, but we obtained higher quality observations of Comet Kudo-Fujikawa in January 2003 at its 0.19 AU perihelion. Besides a large and rapidly increasing water outgassing rate, we detected a bright tail in doubly ionized carbon. The amount of carbon was greater than could be accounted for by GO photodissociation, and we attribute the carbon to evaporation of organics from dust. A spectacular disconnection event was apparent in the C III tail, and it coincides within the uncertainties with the position of the heliospheric current sheet. A paper is in press in Science, and it will be the subject of a press release. We are also analyzing two sungrazing comets. Comet C/2001 C2 shows evidence for sub-fragments and for a very long lasting source of neutrals, which we tentatively identify as evaporation of pyroxene dust grains. Comet C/2002 S2 shows a sudden 2 magnitude drop in optical brightness and an equally sudden recovery. UVCS observations during that time show a steadily increasing outgassing rate. We have derived <span class="hlt">solar</span> <span class="hlt">wind</span> densities for both comets, but we are still sorting out the ambiguities involving the fragmentation and optical behavior. We are collaborating with Philippe Lamy on the LASCO measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1918255P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1918255P"><span>Intermittent structures at ion scales in the turbulent <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Perrone, Denise; Alexandrova, Olga; Lion, Sonny; Roberts, Owen W.; Maksimovic, Milan; Escoubet, Philippe C.; Zouganelis, Yannis</p> <p>2017-04-01</p> <p>Understanding the physical mechanisms of dissipation, and the related heating, in turbulent collisionless plasmas (such as the <span class="hlt">solar</span> <span class="hlt">wind</span>) represents nowadays one of the key issues of plasma physics. Although the complex behavior of the <span class="hlt">solar</span> <span class="hlt">wind</span> has been matter of investigation of many years, some of the primary problems still remain a puzzle for the scientific community. Here, we study coherent structures responsible for <span class="hlt">solar</span> <span class="hlt">wind</span> intermittency around ion characteristic scales. We find that, in fast <span class="hlt">solar</span> <span class="hlt">wind</span>, intermittency is due to current sheets and Alfvén vortex-like structures. In slow <span class="hlt">solar</span> <span class="hlt">wind</span>, we observe as well compressive structures like magnetic solitons, holes and shocks. By using high-time resolution magnetic field data of multi-point measurements of Cluster spacecraft, we characterize the observed coherent structures in terms of topology and propagation speed. We show that all structures, both in fast and slow <span class="hlt">solar</span> <span class="hlt">wind</span>, are characterized by a strong wave-vector anisotropy in the perpendicular direction with respect to the local magnetic field and typical scales around ion characteristic scales. Moreover, some of them propagate in the plasma rest frame. Moreover, a further analysis on the ion velocity distribution shows a high variability; in particular, close to coherent structures the proton distribution function appears strongly deformed and far from the thermodynamic equilibrium. We discuss possible interpretation of the observed structures and their role in the heating process of the plasma.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1051165','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1051165"><span>Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study Phase 2: Preprint</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lew, D.; Brinkman, G.; Ibanez, E.; Hodge, B.-M.; King, J.</p> <p>2012-09-01</p> <p>The Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study (WWSIS) investigates the impacts of high penetrations of <span class="hlt">wind</span> and <span class="hlt">solar</span> power into the Western Interconnection of the United States. WWSIS2 builds on the Phase 1 study but with far greater refinement in the level of data inputs and production simulation. It considers the differences between <span class="hlt">wind</span> and <span class="hlt">solar</span> power on systems operations. It considers mitigation options to accommodate <span class="hlt">wind</span> and <span class="hlt">solar</span> when full costs of wear-and-tear and full impacts of emissions rates are taken into account. It determines wear-and-tear costs and emissions impacts. New data sets were created for WWSIS2, and WWSIS1 data sets were refined to improve realism of plant output and forecasts. Four scenarios were defined for WWSIS2 that examine the differences between <span class="hlt">wind</span> and <span class="hlt">solar</span> and penetration level. Transmission was built out to bring resources to load. Statistical analysis was conducted to investigate <span class="hlt">wind</span> and <span class="hlt">solar</span> impacts at timescales ranging from seasonal down to 5 minutes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110015175','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110015175"><span>Sputtering by the <span class="hlt">Solar</span> <span class="hlt">Wind</span>: Effects of Variable Composition</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Killen, R. M.; Arrell, W. M.; Sarantos, M.; Delory, G. T.</p> <p>2011-01-01</p> <p>It has long been recognized that <span class="hlt">solar</span> <span class="hlt">wind</span> bombardment onto exposed surfaces in the <span class="hlt">solar</span> system will produce an energetic component to the exospheres about those bodies. Laboratory experiments have shown that there is no increase in the sputtering yield caused by highly charged heavy ions for metallic and for semiconducting surfaces, but the sputter yield can be noticeably increased in the case of a good insulating surface. Recently measurements of the <span class="hlt">solar</span> <span class="hlt">wind</span> composition have become available. It is now known that the <span class="hlt">solar</span> <span class="hlt">wind</span> composition is highly dependent on the origin of the particular plasma. Using the measured composition of the slow <span class="hlt">wind</span>, fast <span class="hlt">wind</span>, <span class="hlt">solar</span> energetic particle (SEP) population, and coronal mass ejection (CME), broken down into its various components, we have estimated the total sputter yield for each type of <span class="hlt">solar</span> <span class="hlt">wind</span>. Whereas many previous calculations of sputtering were limited to the effects of proton bombardment. we show that the heavy ion component. especially the He++ component. can greatly enhance the total sputter yield during times when the heavy ion population is enhanced. We will discuss sputtering of both neutrals and ions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1712421S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1712421S"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> precipitation - a comparison between Mars and Venus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stenberg Wieser, Gabriella; Nilsson, Hans; Futaana, Yoshifumi; Holmström, Mats; Barabash, Stas</p> <p>2015-04-01</p> <p>Mars and Venus both have atmospheres but both lack a substantial intrinsic magnetic field. Hence, their interaction with the <span class="hlt">solar</span> <span class="hlt">wind</span> is similar. Due to currents set up in the ionospheres the interplanetary magnetic field embedded in the <span class="hlt">solar</span> <span class="hlt">wind</span> drapes around the planets forming induced magnetospheres. The plasma instrument packages ASPERA-3 and ASPERA-4 on the two spacecraft Mars Express and Venus Express are very similar and invite to a comparison between the two plasma environments. In this study we used the Ion Mass Analyser (IMA) on both spacecraft to investigate the <span class="hlt">solar</span> <span class="hlt">wind</span> precipitation onto the upper atmospheres. We focus on the differences between the two planets. We conclude that on Mars we regularly observe precipitating <span class="hlt">solar</span> <span class="hlt">wind</span> ions (H+ and He2+) inside the induced magnetosphere boundary (IMB). The precipitation is clearly guided by the <span class="hlt">solar</span> <span class="hlt">wind</span> convection electric field and He2+ and H+ are seen independently of each other. On Venus precipitation of He2+ is only observed close to the IMB and always together with H+. The precipitation events on Venus have no clear correlation with the <span class="hlt">solar</span> <span class="hlt">wind</span> electric field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4604519','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4604519"><span>Impacts of <span class="hlt">wind</span> stilling on <span class="hlt">solar</span> radiation variability in China</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lin, Changgui; Yang, Kun; Huang, Jianping; Tang, Wenjun; Qin, Jun; Niu, Xiaolei; Chen, Yingying; Chen, Deliang; Lu, Ning; Fu, Rong</p> <p>2015-01-01</p> <p><span class="hlt">Solar</span> dimming and <span class="hlt">wind</span> stilling (slowdown) are two outstanding climate changes occurred in China over the last four decades. The <span class="hlt">wind</span> stilling may have suppressed the dispersion of aerosols and amplified the impact of aerosol emission on <span class="hlt">solar</span> dimming. However, there is a lack of long-term aerosol monitoring and associated study in China to confirm this hypothesis. Here, long-term meteorological data at weather stations combined with short-term aerosol data were used to assess this hypothesis. It was found that surface <span class="hlt">solar</span> radiation (SSR) decreased considerably with <span class="hlt">wind</span> stilling in heavily polluted regions at a daily scale, indicating that <span class="hlt">wind</span> stilling can considerably amplify the aerosol extinction effect on SSR. A threshold value of 3.5 m/s for <span class="hlt">wind</span> speed is required to effectively reduce aerosols concentration. From this SSR dependence on <span class="hlt">wind</span> speed, we further derived proxies to quantify aerosol emission and <span class="hlt">wind</span> stilling amplification effects on SSR variations at a decadal scale. The results show that aerosol emission accounted for approximately 20% of the typical <span class="hlt">solar</span> dimming in China, which was amplified by approximately 20% by <span class="hlt">wind</span> stilling. PMID:26463748</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMSH11A1502A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMSH11A1502A"><span>Implications of the Deep Minimum for Slow <span class="hlt">Solar</span> <span class="hlt">Wind</span> Origin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Antiochos, S. K.; Mikic, Z.; Lionello, R.; Titov, V. S.; Linker, J. A.</p> <p>2009-12-01</p> <p>The origin of the slow <span class="hlt">solar</span> <span class="hlt">wind</span> has long been one of the most important problems in <span class="hlt">solar</span>/heliospheric physics. Two observational constraints make this problem especially challenging. First, the slow <span class="hlt">wind</span> has the composition of the closed-field corona, unlike the fast <span class="hlt">wind</span> that originates on open field lines. Second, the slow <span class="hlt">wind</span> has substantial angular extent, of order 30 degrees, which is much larger than the widths observed for streamer stalks or the widths expected theoretically for a dynamic heliospheric current sheet. We propose that the slow <span class="hlt">wind</span> originates from an intricate network of narrow (possibly singular) open-field corridors that emanate from the polar coronal hole regions. Using topological arguments, we show that these corridors must be ubiquitous in the <span class="hlt">solar</span> corona. The total <span class="hlt">solar</span> eclipse in August 2008, near the lowest point of the Deep Minimum, affords an ideal opportunity to test this theory by using the ultra-high resolution Predictive Science's (PSI) eclipse model for the corona and <span class="hlt">wind</span>. Analysis of the PSI eclipse model demonstrates that the extent and scales of the open-field corridors can account for both the angular width of the slow <span class="hlt">wind</span> and its closed-field composition. We discuss the implications of our slow <span class="hlt">wind</span> theory for the structure of the corona and heliosphere at the Deep Minimum and describe further observational and theoretical tests. This work has been supported by the NASA HTP, SR&T, and LWS programs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26463748','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26463748"><span>Impacts of <span class="hlt">wind</span> stilling on <span class="hlt">solar</span> radiation variability in China.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lin, Changgui; Yang, Kun; Huang, Jianping; Tang, Wenjun; Qin, Jun; Niu, Xiaolei; Chen, Yingying; Chen, Deliang; Lu, Ning; Fu, Rong</p> <p>2015-10-14</p> <p><span class="hlt">Solar</span> dimming and <span class="hlt">wind</span> stilling (slowdown) are two outstanding climate changes occurred in China over the last four decades. The <span class="hlt">wind</span> stilling may have suppressed the dispersion of aerosols and amplified the impact of aerosol emission on <span class="hlt">solar</span> dimming. However, there is a lack of long-term aerosol monitoring and associated study in China to confirm this hypothesis. Here, long-term meteorological data at weather stations combined with short-term aerosol data were used to assess this hypothesis. It was found that surface <span class="hlt">solar</span> radiation (SSR) decreased considerably with <span class="hlt">wind</span> stilling in heavily polluted regions at a daily scale, indicating that <span class="hlt">wind</span> stilling can considerably amplify the aerosol extinction effect on SSR. A threshold value of 3.5 m/s for <span class="hlt">wind</span> speed is required to effectively reduce aerosols concentration. From this SSR dependence on <span class="hlt">wind</span> speed, we further derived proxies to quantify aerosol emission and <span class="hlt">wind</span> stilling amplification effects on SSR variations at a decadal scale. The results show that aerosol emission accounted for approximately 20% of the typical <span class="hlt">solar</span> dimming in China, which was amplified by approximately 20% by <span class="hlt">wind</span> stilling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015TESS....110802K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015TESS....110802K"><span>Using the fingerprints of <span class="hlt">solar</span> magnetic reconnection to identify the elemental building blocks of the slow <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kepko, Larry; Viall, Nicholeen M.; Kasper, Justin; Lepri, Sue</p> <p>2015-04-01</p> <p>While the source of the fast <span class="hlt">solar</span> <span class="hlt">wind</span> is well understood to be linked to coronal holes, the source of the slow <span class="hlt">solar</span> <span class="hlt">wind</span> has remained elusive. Many previous studies of the slow <span class="hlt">solar</span> <span class="hlt">wind</span> have examined trends in the composition and charge states over long time scales and found strong relationships between the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity and these plasma parameters. These relationships have been used to constrain models of <span class="hlt">solar</span> <span class="hlt">wind</span> source and acceleration. In this study, we take advantage of high time resolution (12 min) measurements of <span class="hlt">solar</span> <span class="hlt">wind</span> composition and charge-state abundances recently reprocessed by the ACE <span class="hlt">Solar</span> <span class="hlt">Wind</span> Ion Composition Spectrometer (SWICS) science team to probe the timescales of <span class="hlt">solar</span> <span class="hlt">wind</span> variability at relatively small scales. We study an interval of slow <span class="hlt">solar</span> <span class="hlt">wind</span> containing quasi-periodic 90 minute structures and show that they are remnants of <span class="hlt">solar</span> magnetic reconnection. Each 90-minute parcel of slow <span class="hlt">solar</span> <span class="hlt">wind</span>, though the speed remains steady, exhibits the complete range of charge state and composition variations expected for the entire range of slow <span class="hlt">solar</span> <span class="hlt">wind</span>, which is repeated again in the next 90-minute interval. These observations show that previous statistical results break down on these shorter timescales, and impose new and important constraints on models of slow <span class="hlt">solar</span> <span class="hlt">wind</span> creation. We conclude by suggesting these structures were created through interchange magnetic reconnection and form elemental building blocks of the slow <span class="hlt">solar</span> <span class="hlt">wind</span>. We also discuss the necessity of decoupling separately the process(es) responsible for the release and acceleration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19790009952&hterms=history+Silver&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dhistory%2BSilver','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19790009952&hterms=history+Silver&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dhistory%2BSilver"><span>Prediction of <span class="hlt">solar</span> energetic particle event histories using real-time particle and <span class="hlt">solar</span> <span class="hlt">wind</span> measurements</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Roelof, E. C.; Gold, R. E.</p> <p>1978-01-01</p> <p>The comparatively well-ordered magnetic structure in the <span class="hlt">solar</span> corona during the decline of <span class="hlt">Solar</span> Cycle 20 revealed a characteristic dependence of <span class="hlt">solar</span> energetic particle injection upon heliographic longitude. When analyzed using <span class="hlt">solar</span> <span class="hlt">wind</span> mapping of the large scale interplanetary magnetic field line connection from the corona to the Earth, particle fluxes display an approximately exponential dependence on heliographic longitude. Since variations in the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity (and hence the coronal connection longitude) can severely distort the simple coronal injection profile, the use of real-time <span class="hlt">solar</span> <span class="hlt">wind</span> velocity measurements can be of great aid in predicting the decay of <span class="hlt">solar</span> particle events. Although such exponential injection profiles are commonplace during 1973-1975, they have also been identified earlier in <span class="hlt">Solar</span> Cycle 20, and hence this structure may be present during the rise and maximum of the cycle, but somewhat obscured by greater temporal variations in particle injection.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002cosp...34E2182G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002cosp...34E2182G"><span>From <span class="hlt">solar</span> <span class="hlt">wind</span> to cometary dust: Curation and microanalysis of sample return</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Graham, G.; Butterworth, A.; Bland, P.; Kearsley, A.; Burchell, M.; Grady, M.; Wright, I.; Pillinger, C.</p> <p></p> <p>The coming decade has the potential to deliver ground truth evidence for a number of important unanswered cosmochemical questions, with sample return missions capturing <span class="hlt">solar</span> <span class="hlt">wind</span> and particles of interstellar, cometary and asteroidal origin. The yield of information that these samples can offer is unquestionable yet some fundamental issues must be resolved before their imminent return. Two immediate problems are those of curation and small sample size, arising because all the missions will return only micrometre or smaller material (implanted or embedded into dedicated capture cells). Furthermore coincidental capture of interplanetary dust particles will occur on the exposed surfaces of the <span class="hlt">Genesis</span> spacecraft. So the first non-trivial task is to develop appropriate extraction techniques. We have applied a novel approach of using a laser ablation extraction system (developed for liberating implanted <span class="hlt">solar</span> <span class="hlt">wind</span> oxygen from the <span class="hlt">Genesis</span> mission collectors) to slice the aerogel containing embedded particles from a light-gas-gun shot. For the intact materials returned by Stardust and Muses-C there are numerous sophisticated microanalysis techniques now available to routinely obtain chemical data on the nanometre scale. Yet many may damage vulnerable volatile-rich materials, or produce surface contamination if employed at too early a stage. Therefore initial assessment of the most appropriate analytical protocols for each grain is essential. Preliminary studies suggest that Raman microscopy and a new X- ray source technology have the potential to be powerful tools in the preliminary characterisation of captured grains. As the countdown for return continues there are many more challenges that await and must be resolved, not least the microanalysis techniques are often at the cutting edge of technological development requiring a commitment to continued development and support.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021284&hterms=solar+energy+you&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsolar%2Benergy%2Byou','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021284&hterms=solar+energy+you&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsolar%2Benergy%2Byou"><span>Electron energy transport in the <span class="hlt">solar</span> <span class="hlt">wind</span>: Ulysses observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Scime, Earl; Gary, S. Peter; Phillips, J. L.; Corniileau-Wehrlin, N.; Solomon, J.</p> <p>1995-01-01</p> <p>The electron heat flux in the <span class="hlt">solar</span> <span class="hlt">wind</span> has been measured by the Ulysses <span class="hlt">solar</span> <span class="hlt">wind</span> plasma experiment in the ecliptic from 1 to 5 AU and out of the ecliptic during the recently completed pass over the <span class="hlt">solar</span> south pole and the ongoing pass over the <span class="hlt">solar</span> north pole. Although the electron heat flux contains only a fraction of the kinetic energy of the <span class="hlt">solar</span> <span class="hlt">wind</span>. the available energy is sufficient to account for the non-adiabatic expansion of the <span class="hlt">solar</span> <span class="hlt">wind</span> electrons. The Ulysses measurements indicate that the electron heat flux is actively dissipated in the <span class="hlt">solar</span> <span class="hlt">wind</span>. The exact mechanism or mechanisms is unknown. but a model based on the whistler heat flux instability predicts radial gradients for the electron heat flux in good agreement with the data. We will present measurements of the correlation between wave activity measured by the unified radio and plasma experiment (URAP) and the electron heat flux throughout the Ulysses mission. The goal is to determine if whistler waves are a good candidate for the observed electron heat flux dissipation. The latitudinal gradients of the electron heat flux. wave activity. and electron pressure will be discussed in light of the changes in the magnetic field geometry from equator to poles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950063967&hterms=current+sheet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dcurrent%2Bsheet','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950063967&hterms=current+sheet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dcurrent%2Bsheet"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> eddies and the heliospheric current sheet</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Suess, S. T.; Mccomas, D. J.; Bame, S. J.; Goldstein, B. E.</p> <p>1995-01-01</p> <p>Ulysses has collected data between 1 and 5 AU during, and just following <span class="hlt">solar</span> maximum, when the heliospheric current sheet (HCS) can be thought of as reaching its maximum tilt and being subject to the maximum amount of turbulence in the <span class="hlt">solar</span> <span class="hlt">wind</span>. The Ulysses <span class="hlt">solar</span> <span class="hlt">wind</span> plasma instrument measures the vector velocity and can be used to estimate the flow speed and direction in turbulent 'eddies' in the <span class="hlt">solar</span> <span class="hlt">wind</span> that are a fraction of an astronomical unit in size and last (have either a turnover or dynamical interaction time of) several hours to more than a day. Here, in a simple exercise, these <span class="hlt">solar</span> <span class="hlt">wind</span> eddies at the HCS are characterized using Ulysses data. This character is then used to define a model flow field with eddies that is imposed on an ideal HCS to estimate how the HCS will be deformed by the flow. This model inherently results in the complexity of the HCS increasing with heliocentric distance, but the result is a measure of the degree to which the observed change in complexity is a measure of the importance of <span class="hlt">solar</span> <span class="hlt">wind</span> flows in deforming the HCS. By comparison with randomly selected intervals not located on the HCS, it appears that eddies on the HCS are similar to those elsewhere at this time during the <span class="hlt">solar</span> cycle, as is the resultant deformation of the interplanetary magnetic field (IMF). The IMF deformation is analogous to what is often termed the 'random walk' of interplanetary magnetic field lines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E.207B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E.207B"><span>Chandrayaan-1 results on the <span class="hlt">solar</span> <span class="hlt">wind</span> ion - regolith interaction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barabash, Stas</p> <p></p> <p>Recently several missions (Kaguya, Chandrayaan-1, IBEX) revealed for the first time the complexity of the <span class="hlt">solar</span> <span class="hlt">wind</span> ions interaction with the lunar regolith. In this review we focus on the observations performed by the Chandrayaan-1 mission at the Moon but similar interaction processes take place on all airless bodies covered by regolith. Contrary to early assumptions the <span class="hlt">solar</span> <span class="hlt">wind</span> ions are not fully absorbed by the regolith but experience strong (10-20% of the impinging flux) backscattering. Only hydrogen was firmly identified. Helium for the helium enriched <span class="hlt">solar</span> <span class="hlt">wind</span> was detected only tentatively. The charge - state of the backscattered particles is mainly neutral. The fraction of H (+) varies strongly with the impinging <span class="hlt">solar</span> <span class="hlt">wind</span> velocity and constitutes 0.01 - 10% of the total backscattered flux. No H (-) ions were detected. The spectrum of the backscattered hydrogen is best-fitted by a Maxwellian distribution with a temperature of 40 - 160 eV linearly proportional to the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity. The spectrum of the backscattered protons is also Maxwellian although shifted to a velocity some what smaller than the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity. The scattering function of the neutrals is close to isotropic at large impinging angles (small <span class="hlt">solar</span> zenith angles) and becomes backward peaked at shallow impinging angles. The scattering function and energy spectra of the backscatters indicate that the <span class="hlt">solar</span> <span class="hlt">wind</span> protons experience multiple collisions with surfaces of individual grain when traveling in the inter-grain space. Why the reflection efficiency is so high in this case is a puzzle. The <span class="hlt">solar</span> <span class="hlt">wind</span> also causes sputtering of elements composing the regolith minerals. Only sputtered oxygen was identified although at levels lower than expected. Chandrayaan-1 results on the <span class="hlt">solar</span> <span class="hlt">wind</span> ion - regolith interaction still remain to be explained. The orbital measurements should be complemented by measurements from landers revealing the “ground true”. Further studies of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080022945','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080022945"><span>On the Relationship Between <span class="hlt">Solar</span> <span class="hlt">Wind</span> Speed, Geomagnetic Activity, and the <span class="hlt">Solar</span> Cycle Using Annual Values</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, Robert M.; Hathaway, David H.</p> <p>2008-01-01</p> <p>The aa index can be decomposed into two separate components: the leading sporadic component due to <span class="hlt">solar</span> activity as measured by sunspot number and the residual or recurrent component due to interplanetary disturbances, such as coronal holes. For the interval 1964-2006, a highly statistically important correlation (r = 0.749) is found between annual averages of the aa index and the <span class="hlt">solar</span> <span class="hlt">wind</span> speed (especially between the residual component of aa and the <span class="hlt">solar</span> <span class="hlt">wind</span> speed, r = 0.865). Because cyclic averages of aa (and the residual component) have trended upward during cycles 11-23, cyclic averages of <span class="hlt">solar</span> <span class="hlt">wind</span> speed are inferred to have also trended upward.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17790539','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17790539"><span><span class="hlt">Solar</span> flare acceleration of <span class="hlt">solar</span> <span class="hlt">wind</span>: influence of active region magnetic field.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lundstedt, H; Wilcox, J M; Scherrer, P H</p> <p>1981-06-26</p> <p>The direction of the photospheric magnetic field at the site of a <span class="hlt">solar</span> flare is a good predictor of whether the flare will accelerate <span class="hlt">solar</span> <span class="hlt">wind</span> plasma. If the field has a southward component, high-speed <span class="hlt">solar</span> <span class="hlt">wind</span> plasma is usually observed near the earth about 4 days later. If the field has a northward component, such high-speed <span class="hlt">solar</span> <span class="hlt">wind</span> is almost never observed. Southward-field flares may then be expected to have much larger terrestrial effects than northward flares.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.3347T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.3347T"><span><span class="hlt">Solar</span> cycle dependence of the distribution of <span class="hlt">solar</span> <span class="hlt">wind</span> in-situ plasma parameters, and how this drives <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere coupling parameters.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tindale, Elizabeth; Chapman, Sandra</p> <p>2017-04-01</p> <p>Climate is the statistical distribution of observed weather and we thus expect the climate of space weather to vary with the <span class="hlt">solar</span> cycle of activity. The 11-year <span class="hlt">solar</span> cycle is irregular, with each cycle exhibiting a unique duration and peak activity. The distinct activity of each cycle is then coupled from the Sun to the Earth's magnetosphere via the <span class="hlt">solar</span> <span class="hlt">wind</span>, leading to long-term trends in the statistics of space weather. Here, we introduce the data quantile-quantile (DQQ) plot as a model-independent method for tracing <span class="hlt">solar</span> cycle changes in the likelihood of observing a given energy flow in the <span class="hlt">solar</span> <span class="hlt">wind</span>. We apply the method to 1-minute resolution <span class="hlt">Wind</span> data spanning the minima and maxima of cycles 23 and 24 [1]. We consider in-situ <span class="hlt">solar</span> <span class="hlt">wind</span> plasma parameters in fast and slow <span class="hlt">solar</span> <span class="hlt">wind</span> such as the magnetic energy density and the Poynting flux and how these influence commonly used <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere coupling functions such as Akasofu's ɛ parameter. The core of the plasma parameter distributions retains a log-normal functional form simply varying in amplitude with the <span class="hlt">solar</span> cycles, in agreement with previous work [e.g. 2] and suggestive of a multiplicative underlying physical process consistent with turbulence. The DQQ method also identifies the threshold energy flux at which <span class="hlt">solar</span> <span class="hlt">wind</span> plasma parameters depart from the lognormal regime; this 'extremal' component exhibits its own dependence on the <span class="hlt">solar</span> cycle which is distinct between fast and slow <span class="hlt">wind</span>. How the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma parameter distributions vary, and how this variation is reflected in that of the <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere coupling functions, is different between fast and slow <span class="hlt">solar</span> <span class="hlt">wind</span>. We can use this approach to compare different <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere coupling parameters to determine which, and under what conditions, are most sensitive to these <span class="hlt">solar</span> cycle <span class="hlt">solar</span> <span class="hlt">wind</span> changes. [1] Tindale, E., and S.C. Chapman (2016), Geophys. Res. Lett., 43(11), doi: 10.1002/2016GL068920. [2] Burlaga</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28139769','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28139769"><span>Global <span class="hlt">solar</span> <span class="hlt">wind</span> variations over the last four centuries.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Owens, M J; Lockwood, M; Riley, P</p> <p>2017-01-31</p> <p>The most recent "grand minimum" of <span class="hlt">solar</span> activity, the Maunder minimum (MM, 1650-1710), is of great interest both for understanding the <span class="hlt">solar</span> dynamo and providing insight into possible future heliospheric conditions. Here, we use nearly 30 years of output from a data-constrained magnetohydrodynamic model of the <span class="hlt">solar</span> corona to calibrate heliospheric reconstructions based solely on sunspot observations. Using these empirical relations, we produce the first quantitative estimate of global <span class="hlt">solar</span> <span class="hlt">wind</span> variations over the last 400 years. Relative to the modern era, the MM shows a factor 2 reduction in near-Earth heliospheric magnetic field strength and <span class="hlt">solar</span> <span class="hlt">wind</span> speed, and up to a factor 4 increase in <span class="hlt">solar</span> <span class="hlt">wind</span> Mach number. Thus <span class="hlt">solar</span> <span class="hlt">wind</span> energy input into the Earth's magnetosphere was reduced, resulting in a more Jupiter-like system, in agreement with the dearth of auroral reports from the time. The global heliosphere was both smaller and more symmetric under MM conditions, which has implications for the interpretation of cosmogenic radionuclide data and resulting total <span class="hlt">solar</span> irradiance estimates during grand minima.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5282500','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5282500"><span>Global <span class="hlt">solar</span> <span class="hlt">wind</span> variations over the last four centuries</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Owens, M. J.; Lockwood, M.; Riley, P.</p> <p>2017-01-01</p> <p>The most recent “grand minimum” of <span class="hlt">solar</span> activity, the Maunder minimum (MM, 1650–1710), is of great interest both for understanding the <span class="hlt">solar</span> dynamo and providing insight into possible future heliospheric conditions. Here, we use nearly 30 years of output from a data-constrained magnetohydrodynamic model of the <span class="hlt">solar</span> corona to calibrate heliospheric reconstructions based solely on sunspot observations. Using these empirical relations, we produce the first quantitative estimate of global <span class="hlt">solar</span> <span class="hlt">wind</span> variations over the last 400 years. Relative to the modern era, the MM shows a factor 2 reduction in near-Earth heliospheric magnetic field strength and <span class="hlt">solar</span> <span class="hlt">wind</span> speed, and up to a factor 4 increase in <span class="hlt">solar</span> <span class="hlt">wind</span> Mach number. Thus <span class="hlt">solar</span> <span class="hlt">wind</span> energy input into the Earth’s magnetosphere was reduced, resulting in a more Jupiter-like system, in agreement with the dearth of auroral reports from the time. The global heliosphere was both smaller and more symmetric under MM conditions, which has implications for the interpretation of cosmogenic radionuclide data and resulting total <span class="hlt">solar</span> irradiance estimates during grand minima. PMID:28139769</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NatSR...741548O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NatSR...741548O"><span>Global <span class="hlt">solar</span> <span class="hlt">wind</span> variations over the last four centuries</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Owens, M. J.; Lockwood, M.; Riley, P.</p> <p>2017-01-01</p> <p>The most recent “grand minimum” of <span class="hlt">solar</span> activity, the Maunder minimum (MM, 1650–1710), is of great interest both for understanding the <span class="hlt">solar</span> dynamo and providing insight into possible future heliospheric conditions. Here, we use nearly 30 years of output from a data-constrained magnetohydrodynamic model of the <span class="hlt">solar</span> corona to calibrate heliospheric reconstructions based solely on sunspot observations. Using these empirical relations, we produce the first quantitative estimate of global <span class="hlt">solar</span> <span class="hlt">wind</span> variations over the last 400 years. Relative to the modern era, the MM shows a factor 2 reduction in near-Earth heliospheric magnetic field strength and <span class="hlt">solar</span> <span class="hlt">wind</span> speed, and up to a factor 4 increase in <span class="hlt">solar</span> <span class="hlt">wind</span> Mach number. Thus <span class="hlt">solar</span> <span class="hlt">wind</span> energy input into the Earth’s magnetosphere was reduced, resulting in a more Jupiter-like system, in agreement with the dearth of auroral reports from the time. The global heliosphere was both smaller and more symmetric under MM conditions, which has implications for the interpretation of cosmogenic radionuclide data and resulting total <span class="hlt">solar</span> irradiance estimates during grand minima.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ApJ...731L..18M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ApJ...731L..18M"><span><span class="hlt">Solar</span> X-ray Jets, Type-II Spicules, Granule-size Emerging Bipoles, and the <span class="hlt">Genesis</span> of the Heliosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moore, Ronald L.; Sterling, Alphonse C.; Cirtain, Jonathan W.; Falconer, David A.</p> <p>2011-04-01</p> <p>From Hinode observations of <span class="hlt">solar</span> X-ray jets, Type-II spicules, and granule-size emerging bipolar magnetic fields in quiet regions and coronal holes, we advocate a scenario for powering coronal heating and the <span class="hlt">solar</span> <span class="hlt">wind</span>. In this scenario, Type-II spicules and Alfvén waves are generated by the granule-size emerging bipoles (EBs) in the manner of the generation of X-ray jets by larger magnetic bipoles. From observations and this scenario, we estimate that Type-II spicules and their co-generated Alfvén waves carry into the corona an area-average flux of mechanical energy of ~7 × 105 erg cm-2 s-1. This is enough to power the corona and <span class="hlt">solar</span> <span class="hlt">wind</span> in quiet regions and coronal holes, and therefore indicates that the granule-size EBs are the main engines that generate and sustain the entire heliosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSH13B2256R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSH13B2256R"><span>Comparing <span class="hlt">Solar</span> <span class="hlt">Wind</span> Velocity Measurements Derived from Sun-grazing Comet Lovejoy (C/2011 W3) with <span class="hlt">Solar</span> <span class="hlt">Wind</span> Models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ramanjooloo, Y.; Jones, G. H.; Coates, A. J.; Owens, M. J.; Battams, K.</p> <p>2012-12-01</p> <p>Comets' plasma (type I) tails have been studied as natural probes of the <span class="hlt">solar</span> <span class="hlt">wind</span> since the mid-20th century. Local <span class="hlt">solar</span> <span class="hlt">wind</span> conditions directly control the morphology and dynamics of a comet's plasma tail. During ideal observing geometries, the orientation and structure of the plasma tail can reveal large-scale and small-scale variations in the local <span class="hlt">solar</span> <span class="hlt">wind</span> structure. We present <span class="hlt">solar</span> <span class="hlt">wind</span> velocity measurements derived from multiple observing locations of comet Lovejoy (C/2011 W3) from the 14th - 19th December 2011 using recent images from the SECCHI and LASCO heliospheric imagers and coronagraphs aboard STEREO A and B, and SOHO. Overlapping observation sessions from the three spacecraft provided the perfect opportunity to use comet Lovejoy as a diagnostic tool to understand <span class="hlt">solar</span> <span class="hlt">wind</span> variability close to the Sun. Our unique analysis technique [submitted] allows us to determine the latitudinal variations of the <span class="hlt">solar</span> <span class="hlt">wind</span>, heliospheric current sheet sector boundaries and the boundaries of transient features as comet Lovejoy probes the Sun's atmosphere. We plan to compare our observations to results of suitable simulations of plasma conditions in the corona and inner heliosphere during the time of Lovejoy's perihelion passage.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015TESS....140902M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015TESS....140902M"><span>Plasma Properties of Pseudostreamers and Their <span class="hlt">Solar</span> <span class="hlt">Wind</span> Streams</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miralles, Mari Paz; Allen, Lorraine A.</p> <p>2015-04-01</p> <p>We study pseudostreamers (i.e., open-field extensions of plasma from unipolar footpoints in the corona; distinct from classical helmet streamers that have opposite-polarity footpoints) that are believed to be sources of slow to intermediate speed <span class="hlt">wind</span> streams. We make use of multi-spacecraft and ground-based observations that extend from the <span class="hlt">solar</span> corona to the <span class="hlt">solar</span> <span class="hlt">wind</span> at 1 AU. We compare the physical properties of selected pseudostreamers and helmet streamers to characterize how the differences in magnetic topology affect the plasma properties of the coronal structures and their <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21371703','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21371703"><span>Velocity Distributions and Proton Beam Production in the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pierrard, Viviane; Voitenko, Yuriy</p> <p>2010-03-25</p> <p>Helios, Ulysses, and <span class="hlt">Wind</span> spacecraft have observed the velocity distribution functions (VDFs) of <span class="hlt">solar</span> <span class="hlt">wind</span> particles deviating significantly from Maxwellians. We review recent models using different approximations and mechanisms that determine various observed characteristics of the VDFs for the electrons, protons and minor ions. A new generation mechanism is proposed for super-Alfvenic proton beams and tails that are often observed in the fast <span class="hlt">solar</span> <span class="hlt">wind</span>. The mechanism is based on the proton trapping and acceleration by kinetic Alfven waves (KAWs), which carry a field-aligned potential well propagating with super-Alfven velocities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SoPh..291.3777L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SoPh..291.3777L"><span>A Possible Cause of the Diminished <span class="hlt">Solar</span> <span class="hlt">Wind</span> During the <span class="hlt">Solar</span> Cycle 23 - 24 Minimum</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liou, Kan; Wu, Chin-Chun</p> <p>2016-12-01</p> <p>Interplanetary magnetic field and <span class="hlt">solar</span> <span class="hlt">wind</span> plasma density observed at 1 AU during <span class="hlt">Solar</span> Cycle 23 - 24 (SC-23/24) minimum were significantly smaller than those during its previous <span class="hlt">solar</span> cycle (SC-22/23) minimum. Because the Earth's orbit is embedded in the slow <span class="hlt">wind</span> during <span class="hlt">solar</span> minimum, changes in the geometry and/or content of the slow <span class="hlt">wind</span> region (SWR) can have a direct influence on the <span class="hlt">solar</span> <span class="hlt">wind</span> parameters near the Earth. In this study, we analyze <span class="hlt">solar</span> <span class="hlt">wind</span> plasma and magnetic field data of hourly values acquired by Ulysses. It is found that the <span class="hlt">solar</span> <span class="hlt">wind</span>, when averaging over the first (1995.6 - 1995.8) and third (2006.9 - 2008.2) Ulysses' perihelion ({˜} 1.4 AU) crossings, was about the same speed, but significantly less dense ({˜} 34 %) and cooler ({˜} 20 %), and the total magnetic field was {˜} 30 % weaker during the third compared to the first crossing. It is also found that the SWR was {˜} 50 % wider in the third ({˜} 68.5^deg; in heliographic latitude) than in the first ({˜} 44.8°) <span class="hlt">solar</span> orbit. The observed latitudinal increase in the SWR is sufficient to explain the excessive decline in the near-Earth <span class="hlt">solar</span> <span class="hlt">wind</span> density during the recent <span class="hlt">solar</span> minimum without speculating that the total <span class="hlt">solar</span> output may have been decreasing. The observed SWR inflation is also consistent with a cooler <span class="hlt">solar</span> <span class="hlt">wind</span> in the SC-23/24 than in the SC-22/23 minimum. Furthermore, the ratio of the high-to-low latitude photospheric magnetic field (or equatorward magnetic pressure force), as observed by the Mountain Wilson Observatory, is smaller during the third than the first Ulysses' perihelion orbit. These findings suggest that the smaller equatorward magnetic pressure at the Sun may have led to the latitudinally-wider SRW observed by Ulysses in SC-23/24 minimum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18764383','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18764383"><span>Eigenmode structure in <span class="hlt">solar-wind</span> Langmuir waves.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ergun, R E; Malaspina, D M; Cairns, Iver H; Goldman, M V; Newman, D L; Robinson, P A; Eriksson, S; Bougeret, J L; Briand, C; Bale, S D; Cattell, C A; Kellogg, P J; Kaiser, M L</p> <p>2008-08-01</p> <p>We show that observed spatial- and frequency-domain signatures of intense <span class="hlt">solar-wind</span> Langmuir waves can be described as eigenmodes trapped in a parabolic density well. Measured <span class="hlt">solar-wind</span> electric field spectra and waveforms are compared with 1D linear solutions and, in many cases, can be represented by 1-3 low-order eigenstates. To our knowledge, this report is the first observational confirmation of Langmuir eigenmodes in space. These results suggest that linear eigenmodes may be the starting point of the nonlinear evolution, critical for producing <span class="hlt">solar</span> type II and type III radio bursts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22304144','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22304144"><span>Scale-free texture of the fast <span class="hlt">solar</span> <span class="hlt">wind</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hnat, B; Chapman, S C; Gogoberidze, G; Wicks, R T</p> <p>2011-12-01</p> <p>The higher-order statistics of magnetic field magnitude fluctuations in the fast quiet <span class="hlt">solar</span> <span class="hlt">wind</span> are quantified systematically, scale by scale. We find a single global non-Gaussian scale-free behavior from minutes to over 5 h. This spans the signature of an inertial range of magnetohydrodynamic turbulence and a ~1/f range in magnetic field components. This global scaling in field magnitude fluctuations is an intrinsic component of the underlying texture of the <span class="hlt">solar</span> <span class="hlt">wind</span> and puts a strong constraint on any theory of <span class="hlt">solar</span> corona and the heliosphere. Intriguingly, the magnetic field and velocity components show scale-dependent dynamic alignment outside of the inertial range.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080022193&hterms=INTERFACE+INTERACTION&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DINTERFACE%2BINTERACTION','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080022193&hterms=INTERFACE+INTERACTION&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DINTERFACE%2BINTERACTION"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Stream Interaction Regions without Sector Boundaries</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Neugebauer, M.; Liewer, P. C.; Goldstein, B. E.; Zhou., X.; Steinberg, J. T.</p> <p>2004-01-01</p> <p>During periods of high <span class="hlt">solar</span> activity when there are many sources of <span class="hlt">solar</span> <span class="hlt">wind</span> on the <span class="hlt">solar</span> disk, a spacecraft occasionally encounters consecutive <span class="hlt">solar</span> <span class="hlt">wind</span> streams with the same magnetic polarity. The low-speed <span class="hlt">wind</span> in the region of interaction between the two streams exhibits many of the same features as, but has some differences from, the low-speed <span class="hlt">wind</span> that includes crossings of the heliospheric current sheet (HCS) where the direction of the heliospheric magnetic field reverses. The non-HCS slow <span class="hlt">wind</span> exhibits many of the same small-scale structures usually associated with the slow <span class="hlt">wind</span> around the HCS; these include discontinuous stream interfaces and other discontinuities, magnetic holes, and low-entropy structures. These entropy holes do not appear to have the same origin as the plasma sheets observed near the HCS, however. The helium abundances and heavy ion charge states in the non-HCS regions are not significantly different from those in HCS-associated regions. Some of the dynamical properties of the non-HCS regions differ from those found near the HCS; the regions between leading and trailing stream interfaces have a shorter duration or scale size, greater minimum speed, and lower peak and average densities. No correlation could be found between the non-HCS slow <span class="hlt">wind</span> and visible coronal streamers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22342072','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22342072"><span>The Yaglom law in the expanding <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gogoberidze, G.; Perri, S.; Carbone, V.</p> <p>2013-06-01</p> <p>We study the Yaglom law, which relates the mixed third-order structure function to the average dissipation rate of turbulence, in a uniformly expanding <span class="hlt">solar</span> <span class="hlt">wind</span> by using the two-scale expansion model of magnetohydrodynamic (MHD) turbulence. We show that due to the expansion of the <span class="hlt">solar</span> <span class="hlt">wind</span>, two new terms appear in the Yaglom law. The first term is related to the decay of the turbulent energy by nonlinear interactions, whereas the second term is related to the non-zero cross-correlation of the Elsässer fields. Using magnetic field and plasma data from <span class="hlt">WIND</span> and Helios 2 spacecrafts, we show that at lower frequencies in the inertial range of MHD turbulence the new terms become comparable to Yaglom's third-order mixed moment, and therefore they cannot be neglected in the evaluation of the energy cascade rate in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSH53A2268M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSH53A2268M"><span>Coronal Streamers and Their Associated <span class="hlt">Solar</span> <span class="hlt">Wind</span> Streams</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miralles, M. P.; Landi, E.; Cranmer, S. R.; Cohen, O.; Raymond, J. C.</p> <p>2012-12-01</p> <p>We use the EUV spectrometers aboard SOHO and Hinode and white-light coronagraphs to characterize the physical properties of coronal streamers during Earth/Ulysses quadrature configurations for the previous two <span class="hlt">solar</span> minimum periods. In addition, comparisons between coronal observations and in situ measurements of <span class="hlt">solar</span> <span class="hlt">wind</span> plasma properties are being used to further characterize the origins of slow <span class="hlt">wind</span> streams. In order to investigate slow <span class="hlt">solar</span> <span class="hlt">wind</span> heating and acceleration, we also compare with predictions from three-dimensional MHD models. We aim to use the empirical measurements to distinguish between different proposed physical processes for slow <span class="hlt">wind</span> acceleration (e.g., waves/turbulence versus reconnection). This work is supported by NASA grant NNX10AQ58G to the Smithsonian Astrophysical Observatory.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/582279','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/582279"><span>Shear flow induced wave couplings in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Poedts, S.; Rogava, A.D. |; Mahajan, S.M. |</p> <p>1998-01-01</p> <p>A sheared background flow in a plasma induces coupling between different MHD wave modes, resulting in their mutual transformations with corresponding energy redistributing between the modes. In this way, the energy can be transfered from one wave mode to the other, but energy can also be added to or extracted from the background flow. In the present paper it is investigated whether the wave coupling and energy transfer mechanisms can operate under <span class="hlt">solar</span> <span class="hlt">wind</span> conditions. It is shown that this is indeed the case. Hence, the long-period waves observed in the <span class="hlt">solar</span> <span class="hlt">wind</span> at r > 0.3 AU might be generated by much faster periodic oscillations in the photosphere of the Sun. Other possible consequences for observable beat phenomena in the <span class="hlt">wind</span> and the acceleration of the <span class="hlt">solar</span> <span class="hlt">wind</span> particles are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSH53A..05D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSH53A..05D"><span>Imaging the Top of the <span class="hlt">Solar</span> Corona and the Young <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>DeForest, C. E.; Matthaeus, W. H.; Viall, N. M.; Cranmer, S. R.</p> <p>2016-12-01</p> <p>We present the first direct visual evidence of the quasi-stationary breakup of <span class="hlt">solar</span> coronal structure and the rise of turbulence in the young <span class="hlt">solar</span> <span class="hlt">wind</span>, directly in the future flight path of <span class="hlt">Solar</span> Probe. Although the corona and, more recently, the <span class="hlt">solar</span> <span class="hlt">wind</span> have both been observed directly with Thomson scattered light, the transition from the corona to the <span class="hlt">solar</span> <span class="hlt">wind</span> has remained a mystery. The corona itself is highly structured by the magnetic field and the outflowing <span class="hlt">solar</span> <span class="hlt">wind</span>, giving rise to radial "striae" - which comprise the familiar streamers, pseudostreamers, and rays. These striae are not visible in wide-field heliospheric images, nor are they clearly delineated with in-situ measurements of the <span class="hlt">solar</span> <span class="hlt">wind</span>. Using careful photometric analysis of the images from STEREO/HI-1, we have, for the first time, directly observed the breakup of radial coronal structure and the rise of nearly-isotropic turbulent structure in the outflowing slow <span class="hlt">solar</span> <span class="hlt">wind</span> plasma between 10° (40 Rs) and 20° (80 Rs) from the Sun. These observations are important not only for their direct science value, but for predicting and understanding the conditions expected near SPP as it flies through - and beyond - this final frontier of the heliosphere, the outer limits of the <span class="hlt">solar</span> corona.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/419263','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/419263"><span>Ulysses <span class="hlt">solar</span> <span class="hlt">wind</span> plasma observations at high latitudes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Riley, P.; Bame, S.J.; Barraclough, B.L.</p> <p>1996-10-01</p> <p>Ulysses reached its peak northerly heliolatitude of 80.2{degrees}N on July 31, 1995, and now is moving towards aphelion at 5.41 AU which it will reach in May, 1998. We summarize measurements from the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma experiment, SWOOPS, emphasizing northern hemispheric observations but also providing southern and equatorial results for comparison. The <span class="hlt">solar</span> <span class="hlt">wind</span> momentum flux during Ulysses` fast pole-to- pole transit at <span class="hlt">solar</span> minimum was significantly higher over the poles than at near-equatorial latitudes, suggesting a non-circular cross section for the heliosphere. Furthermore, modest asymmetries in the <span class="hlt">wind</span> speed, density, and mass flux were observed between the two hemispheres during the fast latitude scan. The <span class="hlt">solar</span> <span class="hlt">wind</span> was faster and less dense in the north than in the south. These asymmetries persist in the most recent high- and mid-latitude data but are less pronounced. As of July 1, 1996 the northern fast <span class="hlt">solar</span> <span class="hlt">wind</span> has lacked any strong stream interactions or shocks and, although a comprehensive search has not yet been made, no CMEs have yet been identified during this interval. On the other hand, Alfv{acute e}nic, compressional, and pressure balanced features are abundant at high latitudes. The most recent data, at 4 AU and 32{degrees}N, has begun to show the effects of <span class="hlt">solar</span> rotation modulated features in the form of recurrent compressed regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021297&hterms=interferometer+distance&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dinterferometer%2Bdistance','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021297&hterms=interferometer+distance&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dinterferometer%2Bdistance"><span>Radio interferometer measurements of turbulence in the inner <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Spangler, S. R.; Sakurai, T.; Coles, William A.; Grall, R. R.; Harmon, J. K.</p> <p>1995-01-01</p> <p>Measurements can be made of Very Long Baseline Interferometer (VLBI) phase scintillations due to plasma turbulence in the <span class="hlt">solar</span> corona and <span class="hlt">solar</span> <span class="hlt">wind</span>. These measurements provide information on the spectrum and intensity of density fluctuations with scale sizes of a few hundred to several thousand kilometers. If we model the spatial power spectrum of the density fluctuations as P(sub delta n)(q) = C(sup 2)(sub N) q(sup -alpha), where q is the spatial wavenumber, these observations yield both alpha and the path-integrated value of C(sup 2)(sub N). The recently completed Very Long Baseline Array (VLBA) is capable of making such measurements over the heliocentric distance range from a few <span class="hlt">solar</span> radii to 60 <span class="hlt">solar</span> radii and beyond. This permits the determination with the same technique and instrument of the radial evolution of turbulent characteristics, as well as their dependence on <span class="hlt">solar</span> <span class="hlt">wind</span> transients, sector structure, etc. In this paper we present measurements of 13 sources observed at a wide range of <span class="hlt">solar</span> elongations, and at different times. These observations show that the coefficient C(sup 2(sub N), depends on heliocentric distance as approximately C(sup 2)(sub N) varies as (R/<span class="hlt">Solar</span> Radius)(sup -3.7). The radio derived power spectral characteristics are in agreement with in situ measurements by the Helios spacecraft for regions of slow <span class="hlt">solar</span> <span class="hlt">wind</span>, but fast <span class="hlt">solar</span> <span class="hlt">wind</span> does not have large enough density fluctuations to account for the magnitude of the observed scintillations. The observed radial dependence is consistent with a WKB-type evolution of the turbulence with heliocentric distance. Our data also show indication of turbulence enhancement associated with <span class="hlt">solar</span> <span class="hlt">wind</span> transients.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021392&hterms=sulfur+properties&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsulfur%2Bproperties','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021392&hterms=sulfur+properties&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsulfur%2Bproperties"><span>SWICS/Ulysses and MASS/<span class="hlt">wind</span> observations of <span class="hlt">solar</span> <span class="hlt">wind</span> sulfur charge states</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cohen, C. M. S.; Galvin, A. B.; Hamilton, D. C.; Gloeckler, G.; Geiss, J.; Bochsler, P.</p> <p>1995-01-01</p> <p>As Ulysses journeys from the southern to the northern <span class="hlt">solar</span> pole, the newly launched <span class="hlt">Wind</span> spacecraft is monitoring the <span class="hlt">solar</span> <span class="hlt">wind</span> near 1 AU, slightly upstream of the Earth. Different <span class="hlt">solar</span> <span class="hlt">wind</span> structures pass over both spacecraft as coronal holes and other features rotate in and out of view. Ulysses and <span class="hlt">Wind</span> are presently on opposing sides of the sun allowing us to monitor these streams for extended periods of time. Composition measurements made by instruments on both spacecraft provide information concerning the evolution and properties of these structures. We have combined data from the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Ion Composition Spectrometer (SWICS) on Ulysses and the high mass resolution spectrometer (MASS) on <span class="hlt">Wind</span> to determine the charge state distribution of sulfur in the <span class="hlt">solar</span> <span class="hlt">wind</span>. Both instruments employ electrostatic deflection with time-of-flight measurement. The high mass resolution of the MASS instrument (M/Delta-M approximately 100) allows sulfur to be isolated easily while the stepping energy/charge selection provides charge state information. SWICS measurements allow the unique identification of heavy ions by their mass and mass/charge with resolutions of M/Delta-M approximately 3 and M/q/Delta(M/q) approximately 20. The two instruments complement each other nicely in that MASS has the greater mass resolution while SWICS has the better mass/charge resolution and better statistics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSH54B..05R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSH54B..05R"><span>Continuing the Search for Natural <span class="hlt">Solar</span> <span class="hlt">Wind</span> States</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roberts, D. A.; Sipes, T.; Karimabadi, H.</p> <p>2015-12-01</p> <p>The need to classify <span class="hlt">solar</span> <span class="hlt">wind</span> states is partially the practical one of knowing what <span class="hlt">winds</span> will strongly affect the Earth, but it is also to help in understanding the origin of the <span class="hlt">winds</span>. In terms of the latter classification, of interest here, there is general agreement that "ejecta" represent a separate class from ordinary <span class="hlt">winds</span>, although the details of which parcels qualify as ejecta are still subject to considerable disagreement. It has become clear that the distinction between "slow" and "fast" <span class="hlt">wind</span> is at best misleading, and slow <span class="hlt">wind</span> sometimes displays temperature anisotropies, fluctuation spectra, and the like that are characteristic of the typical fast <span class="hlt">wind</span>. Recent work has focused on distinguishing "coronal hole <span class="hlt">wind</span>" from "streamer belt" and "strahl confusion zone" (heliospheric current sheet) <span class="hlt">winds</span>. The hope is to discern which <span class="hlt">wind</span> comes from coronal holes versus the boundaries of holes versus near active regions or other sources. The present work extends a simple method of clustering in the parameter space of a selected set of variables to see if "natural" states of <span class="hlt">wind</span> arise. This method (primarily "K-means" but we are also trying others) has proven capable of distinguishing states very similar to those in recent categorizations, especially when the variables of cross-helicity and residual energy are added to the parameter list, but we also find new, persistent, categories. The present work will look in more detail at the derived states and at different times in the <span class="hlt">solar</span> cycle. One suggestion in the research so far is that shock-like structures are fundamental in the mix; these have largely been ignored in recent work in <span class="hlt">solar</span> <span class="hlt">wind</span> heating.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSM34A..01H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSM34A..01H"><span>Kinetic Interactions Between the <span class="hlt">Solar</span> <span class="hlt">Wind</span> and Lunar Magnetic Fields</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Halekas, J. S.; Poppe, A. R.; Fatemi, S.; Turner, D. L.; Holmstrom, M.</p> <p>2016-12-01</p> <p>Despite their relatively weak strength, small scale, and incoherence, lunar magnetic anomalies can affect the incoming <span class="hlt">solar</span> <span class="hlt">wind</span> flow. The plasma interaction with lunar magnetic fields drives significant compressions of the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma and magnetic field, deflections of the incoming flow, and a host of plasma waves ranging from the ULF to the electrostatic range. Recent work suggests that the large-scale features of the <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetic anomaly interactions may be driven by ion-ion instabilities excited by reflected ions, raising the possibility that they are analogous to ion foreshock phenomena. Indeed, despite their small scale, many of the phenomena observed near lunar magnetic anomalies appear to have analogues in the foreshock regions of terrestrial planets. We discuss the charged particle distributions, fields, and waves observed near lunar magnetic anomalies, and place them in a context with the foreshocks of the Earth, Mars, and other <span class="hlt">solar</span> system objects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021277&hterms=Bern&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DBern','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021277&hterms=Bern&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DBern"><span>Elemental composition in the slow <span class="hlt">solar</span> <span class="hlt">wind</span> measured with the MASS instrument on <span class="hlt">WIND</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bochsler, P.; Gonin, M.; Sheldon, R. B.; Zurbuchen, Th.; Gloeckler, G.; Galvin, A. B.; Hovestadt, D.</p> <p>1995-01-01</p> <p>The MASS instrument on <span class="hlt">WIND</span> contains the first isochronous time-offlight spectrometer to be flown in the <span class="hlt">solar</span> <span class="hlt">wind</span>. The first spectra obtained with this instrument has demonstrated its capability to measure the abundances of several high-and low-FIP elements in the <span class="hlt">solar</span> <span class="hlt">wind</span>. The derivation of these abundances requires a careful calibration of the charge exchange efficiencies of the relevant ions in carbon foils. These efficiencies and the corresponding instrument functions have been determined in extensive calibration campaigns at different institutions. We present first and preliminary results obtained in slow <span class="hlt">solar</span> <span class="hlt">wind</span> streams and we compare these results with those obtained from previous investigations of <span class="hlt">solar</span> <span class="hlt">wind</span> abundances and of coronal abundances as derived from <span class="hlt">Solar</span> Energetic Particles. Recent models of the FIP related fractionation effect predict a depletion of a factor of typically 4 to 5 for high-FIP elements (He, N, O, Ne, Ar, etc.) relative to low-FIP elements (Mg, Fe, Si, etc.). We also compare our results with the detailed predictions of the different models and we discuss the resulting evidence to validate or to invalidate different physical scenarios explaining the feeding and the acceleration of slow stream <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMSH44B..03K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMSH44B..03K"><span>Collecting Samples of Coronal and <span class="hlt">Solar</span> <span class="hlt">Wind</span> Plasma with <span class="hlt">Solar</span> Probe Plus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kasper, J. C.; Solar Wind Electrons Alphas; Protons (Sweap) Team</p> <p>2011-12-01</p> <p>The primary science objective of the NASA <span class="hlt">Solar</span> Probe Plus mission is to determine the structure and dynamics of the Sun's coronal magnetic field and to understand how the corona and <span class="hlt">solar</span> <span class="hlt">wind</span> are heated and accelerated and how energetic particles are produced and evolve. To accomplish this, the spacecraft carries a broad payload of in situ and remote sensing instruments and uses a sequence of Venus gravitational assists to dive within 8.5 <span class="hlt">solar</span> radii of the surface of the Sun, making it the first spacecraft to enter the sub-Alfvénic <span class="hlt">solar</span> corona. This talk will focus on measurements of the thermal ions and electrons that constitute the bulk of the <span class="hlt">solar</span> corona and <span class="hlt">solar</span> <span class="hlt">wind</span>, covering open questions related to the structure, heating, and acceleration of the <span class="hlt">solar</span> corona and <span class="hlt">solar</span> <span class="hlt">wind</span>. The <span class="hlt">Solar</span> <span class="hlt">Wind</span> Electrons Alphas and Protons (SWEAP) Investigation on <span class="hlt">Solar</span> Probe Plus will be presented, including a description of how measurements from electrostatic analyzers behind the heat shield and a Sun-viewing Faraday Cup are combined to ensure continuous and comprehensive sampling of the corona and <span class="hlt">wind</span> throughout each encounter. Opportunities for coordinated observations with other spacecraft and ground-based observatories will be presented, along with a discussion of possible contributions from the theory and modeling communities, and from existing observations, as we prepare for this historic mission.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EPSC....9..528B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EPSC....9..528B"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> interaction with Venus and impact on its atmosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barabash, S.; Futaana, Y.; Wieser, G. S.; Luhmann, J.</p> <p>2014-04-01</p> <p>We present a review of the <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with Venus and how the interaction affects the Venusian atmosphere. The Venus Express observations for more than 8 years (2005-present) and quantitatively new simulation codes substantially advanced physical understanding of the plasma processes in the near-Venus space since the Pioneer Venus Orbiter (PVO) mission (1978-1992). The near-Venus space can be divided into several plasma domains: the magnetotail with the plasmasheet, induced magnetosphere, and magnetosheath. The bow shock separates the undisturbed <span class="hlt">solar</span> <span class="hlt">wind</span> from the Venus-affected environment. We review the shapes and positions of the boundaries enveloping the main domains and discuss how they are formed by the current systems and pressure balance. In particular, we discuss the morphology and dynamics of the near-Venus magnetotail that was not accessible by PVO. Using the unique Venus Express measurements we discuss the ion acceleration processes and their links to the ionosphere. The focus is given to the Venus' atmosphere erosion associated with the <span class="hlt">solar</span> <span class="hlt">wind</span> interaction, both through the energy (ion acceleration) and momentum (atmospheric sputtering) transfer. We review the measurements of the escape rates, their variability with the upstream <span class="hlt">solar</span> <span class="hlt">wind</span> conditions and the <span class="hlt">solar</span> cycle. We emphasize the measurements duirng extreme <span class="hlt">solar</span> <span class="hlt">wind</span> conditions as an analogue with nominal conditions for the young Sun. The modeling efforts in this area are also reviewed as they provide a quantitatively approach to understand the impact of the <span class="hlt">solar</span> <span class="hlt">wind</span> interaction on the atmospheric evolution. Finally, we compare Venus with other planets of the terrestrial planet group, the Earth and Mars. The Earth, a twin planet of the similar size, is magnetized. Mars, an unmagnetized planet like Venus, possesses by far weaker gravitation to hold its atmospheric gasses. This comparative magnetosphere approach based on the natural <span class="hlt">solar</span> system laboratory of experiments gives</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120000864','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120000864"><span>Cleaning <span class="hlt">Genesis</span> Mission Payload for Flight with Ultra-Pure Water and Assembly in ISO Class 4 Environment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Allton, Judith H.</p> <p>2012-01-01</p> <p><span class="hlt">Genesis</span> mission to capture and return to Earth <span class="hlt">solar</span> <span class="hlt">wind</span> samples had very stringent contamination control requirements in order to distinguish the <span class="hlt">solar</span> atoms from terrestrial ones. <span class="hlt">Genesis</span> mission goals were to measure <span class="hlt">solar</span> composition for most of the periodic table, so great care was taken to avoid particulate contamination. Since the number 1 and 2 science goals were to determine the oxygen and nitrogen isotopic composition, organic contamination was minimized by tightly controlling offgassing. The total amount of <span class="hlt">solar</span> material captured in two years is about 400 micrograms spread across one sq m. The contamination limit requirement for each of C, N, and O was <1015 atoms/sq cm. For carbon, this is equivalent to 10 ng/cm2. Extreme vigilance was used in pre-paring <span class="hlt">Genesis</span> collectors and cleaning hardware for flight. Surface contamination on polished silicon wafers, measured in <span class="hlt">Genesis</span> laboratory is approximately 10 ng/sq cm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SSRv..210..227C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SSRv..210..227C"><span>Minimal Magnetic States of the Sun and the <span class="hlt">Solar</span> <span class="hlt">Wind</span>: Implications for the Origin of the Slow <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cliver, E. W.; von Steiger, R.</p> <p>2017-09-01</p> <p>During the last decade it has been proposed that both the Sun and the <span class="hlt">solar</span> <span class="hlt">wind</span> have minimum magnetic states, lowest order levels of magnetism that underlie the 11-yr cycle as well as longer-term variability. Here we review the literature on basal magnetic states at the Sun and in the heliosphere and draw a connection between the two based on the recent deep 2008-2009 minimum between cycles 23 and 24. In particular, we consider the implications of the low <span class="hlt">solar</span> activity during the recent minimum for the origin of the slow <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1912916A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1912916A"><span><span class="hlt">Winds</span> of winter: How <span class="hlt">solar</span> <span class="hlt">wind</span> driven particle precipitation can affect northern winters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Asikainen, Timo; Maliniemi, Ville; Mursula, Kalevi</p> <p>2017-04-01</p> <p><span class="hlt">Solar</span> <span class="hlt">wind</span> drives the variability in the near Earth space. Coupling of <span class="hlt">solar</span> <span class="hlt">wind</span> and the magnetosphere feeds energetic particles into the inner magnetosphere through reconnection in the magnetotail. During the declining phase of the <span class="hlt">solar</span> cycle long-lived high-speed <span class="hlt">solar</span> <span class="hlt">wind</span> streams are more commonly observed at Earth's orbit. These accelerate particles to higher energies and in the process lead to enhanced particle precipitation into the atmosphere. Electrons from tens to hundreds of keV precipitate down to the mesosphere and upper stratosphere, where they can create nitrogen and hydrogen oxides. During winter, nitrogen oxides have enhanced lifetime in the polar night. They can descend down to the mid-stratosphere and destroy ozone, which leads to cooling of the high-latitude stratosphere. This enhances the meridional temperature gradient and westerly <span class="hlt">winds</span> under the thermal-<span class="hlt">wind</span> balance, thus accelerating the polar vortex. This mechanism is successfully modeled by chemistry-climate models. Dynamical changes in the stratosphere can descend down to the troposphere. During strong polar vortex, the northern annular mode (NAM) is anomalously positive. Positive NAM encloses the cold arctic air into the polar region and enhances the westerly <span class="hlt">winds</span> at mid-latitudes. Enhancement of westerlies bring warm and moist air from Atlantic to the Northern Eurasia causing positive temperature anomalies. At the same time negative temperature anomalies are observed in the Northern Canada and Greenland. Our recent observations show that the positive relation between precipitating electron fluxes/geomagnetic activity and NAM exists during winter. Positive NAM pattern is observed during the declining phase of the <span class="hlt">solar</span> cycle at least since the late 19th century. We also find that the quasi-biennial oscillation (QBO) of equatorial <span class="hlt">winds</span> strongly modulate this relation at high latitudes. These results give additional evidence that not only <span class="hlt">solar</span> electromagnetic radiation but also the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140011749','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140011749"><span>Cellulose Acetate Replica Cleaning Study of <span class="hlt">Genesis</span> Non-Flight Sample 3CZ00327</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kuhlman, K. R.; Schmeling, M.; Gonzalez, C. P.; Allton, J. H.; Burnett, D. S.</p> <p>2014-01-01</p> <p>The <span class="hlt">Genesis</span> mission collected <span class="hlt">solar</span> <span class="hlt">wind</span> and brought it back to Earth in order to provide precise knowledge of <span class="hlt">solar</span> isotopic and elemental compositions. The ions in the <span class="hlt">solar</span> <span class="hlt">wind</span> were stopped in the collectors at depths on the order of 10 to a few hundred nanometers. This shallow implantation layer is critical for scientific analysis of the composition of the <span class="hlt">solar</span> <span class="hlt">wind</span> and must be preserved throughout sample handling, cleaning, processing, distribution, preparation and analysis. We are working interactively with the community of scientists analyzing <span class="hlt">Genesis</span> samples, using our unique laboratory facilities -- and, where needed, our unique cleaning techniques -- to significantly enhance the science return from the <span class="hlt">Genesis</span> mission. This work is motivated by the need to understand the submicron contamination on the collectors in the <span class="hlt">Genesis</span> payload as recovered from the crash site in the Utah desert, and -- perhaps more importantly -- how to remove it. That is, we are evaluating the effectiveness of the wet-chemical "cleaning" steps used by various investigators, to enable them to design improved methods of stripping terrestrial contamination from surfaces while still leaving the <span class="hlt">solar-wind</span> signal intact.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19770051832&hterms=tritium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dtritium','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19770051832&hterms=tritium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dtritium"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> H-3 and C-14 abundances and <span class="hlt">solar</span> surface processes. [in lunar soil</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fireman, E. L.; Defelice, J.; Damico, J.</p> <p>1976-01-01</p> <p>Tritium is measured as a function of depth in a Surveyor 3 sample. The upper limit for <span class="hlt">solar-wind</span>-implanted tritium gives an H-3/H-1 limit for the <span class="hlt">solar</span> <span class="hlt">wind</span> of 10 to the -11th power. The temperature-release patterns of C-14 from lunar soils are measured. The C-14 release pattern from surface soils differs from a trench-bottom soil and gives positive evidence for the presence of C-14 in the <span class="hlt">solar</span> <span class="hlt">wind</span> with a C-14/H-1 ratio of approximately 6 by 10 to the -11th power. This C-14 content fixes a minimal magnitude for nuclear processes on the <span class="hlt">solar</span> surface averaged over the past 10,000 yr. The H-3 and C-14 contents combine to require that either the mixing rate above the photosphere be rapid or that the H-3 produced by nuclear reactions be destroyed by secondary nuclear reactions before escaping in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930049627&hterms=technologie&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dtechnologie','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930049627&hterms=technologie&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dtechnologie"><span>Ions with low charges in the <span class="hlt">solar</span> <span class="hlt">wind</span> as measured by SWICS on board Ulysses. [<span class="hlt">Solar</span> <span class="hlt">Wind</span> Ion Composition Spectrometer</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Geiss, J.; Ogilvie, K. W.; Von Steiger, R.; Mall, U.; Gloeckler, G.; Galvin, A. B.; Ipavich, F.; Wilken, B.; Gliem, F.</p> <p>1992-01-01</p> <p>We present new data on rare ions in the <span class="hlt">solar</span> <span class="hlt">wind</span>. Using the Ulysses-SWICS instrument with its very low background we have searched for low-charge ions during a 6-d period of low-speed <span class="hlt">solar</span> <span class="hlt">wind</span> and established sensitive upper limits for many species. In the <span class="hlt">solar</span> <span class="hlt">wind</span>, we found He(1+)/He(2+) of less than 5 x 10 exp -4. This result and the charge state distributions of heavier elements indicate that all components of the investigated ion population went through a regular coronal expansion and experienced the typical electron temperatures of 1 to 2 million Kelvin. We argue that the virtual absence of low-charge ions demonstrates a very low level of nonsolar contamination in the source region of the <span class="hlt">solar</span> <span class="hlt">wind</span> sample we studied. Since this sample showed the FlP effect typical for low-speed <span class="hlt">solar</span> <span class="hlt">wind</span>, i.e., an enhancement in the abundances of elements with low first ionization potential, we conclude that this enhancement was caused by an ion-atom separation mechanism operating near the <span class="hlt">solar</span> surface and not by foreign material in the corona.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SoPh..291.2441K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SoPh..291.2441K"><span>Sources of the Slow <span class="hlt">Solar</span> <span class="hlt">Wind</span> During the <span class="hlt">Solar</span> Cycle 23/24 Minimum</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kilpua, E. K. J.; Madjarska, M. S.; Karna, N.; Wiegelmann, T.; Farrugia, C.; Yu, W.; Andreeova, K.</p> <p>2016-10-01</p> <p>We investigate the characteristics and the sources of the slow ({<} 450 km s^{-1}) <span class="hlt">solar</span> <span class="hlt">wind</span> during the four years (2006 - 2009) of low <span class="hlt">solar</span> activity between <span class="hlt">Solar</span> Cycles 23 and 24. We used a comprehensive set of in-situ observations in the near-Earth <span class="hlt">solar</span> <span class="hlt">wind</span> ( <span class="hlt">Wind</span> and ACE) and removed the periods when large-scale interplanetary coronal mass ejections were present. The investigated period features significant variations in the global coronal structure, including the frequent presence of low-latitude active regions in 2006 - 2007, long-lived low- and mid-latitude coronal holes in 2006 - mid-2008 and mostly the quiet Sun in 2009. We examined Carrington rotation averages of selected <span class="hlt">solar</span> plasma, charge state, and compositional parameters and distributions of these parameters related to the quiet Sun, active region Sun, and the coronal hole Sun. While some of the investigated parameters ( e.g. speed, the C+6/C+4 and He/H ratios) show clear variations over our study period and with <span class="hlt">solar</span> <span class="hlt">wind</span> source type, some (Fe/O) exhibit very little changes. Our results highlight the difficulty of distinguishing between the slow <span class="hlt">solar</span> <span class="hlt">wind</span> sources based on the inspection of <span class="hlt">solar</span> <span class="hlt">wind</span> conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMSH11B1664L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMSH11B1664L"><span>STEREO SWEA Observations of <span class="hlt">Solar</span> <span class="hlt">Wind</span> Halo Electron Anomalous Heat Fluxes and their Organization by <span class="hlt">Solar</span> <span class="hlt">Wind</span> Structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luhmann, J. G.; Ellenburg, M. A.; Lee, C. O.; Schroeder, P. C.; Opitz, A.; Penou, E.; Lavraud, B.; Sauvaud, J. A.; Jian, L.; Russell, C. T.; Simunac, K. D.; Galvin, A. B.</p> <p>2010-12-01</p> <p>STEREO SWEA (<span class="hlt">Solar</span> <span class="hlt">Wind</span> Electron Analyzer) provides the opportunity to observe <span class="hlt">solar</span> <span class="hlt">wind</span> halo electron heat fluxes and strahl over 4pi steradians at locations free of Earth bow shock contamination. We have analyzed these measurements together with the magnetic field and plasma parameters to determine their organization with <span class="hlt">solar</span> <span class="hlt">wind</span> stream structure during the period between early 2007 and late 2009. This period is characterized by a very low level of <span class="hlt">solar</span> activity and thus presents an opportunity to diagnose the anomalous features, determining their location and character. This includes heat fluxes that appear to be traveling back toward the Sun, possibly indicating folded interplanetary field lines, interplanetary field loops which may be part of ICMEs, or sources of suprathermal electrons at shocks beyond 1 AU. Our results give a broad view of the issues related to using heat fluxes to interpret interplanetary field topology, even with the benefit of 4pi observations and two spacecraft.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18063784','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18063784"><span>Chromospheric alfvenic waves strong enough to power the <span class="hlt">solar</span> <span class="hlt">wind</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>De Pontieu, B; McIntosh, S W; Carlsson, M; Hansteen, V H; Tarbell, T D; Schrijver, C J; Title, A M; Shine, R A; Tsuneta, S; Katsukawa, Y; Ichimoto, K; Suematsu, Y; Shimizu, T; Nagata, S</p> <p>2007-12-07</p> <p>Alfvén waves have been invoked as a possible mechanism for the heating of the Sun's outer atmosphere, or corona, to millions of degrees and for the acceleration of the <span class="hlt">solar</span> <span class="hlt">wind</span> to hundreds of kilometers per second. However, Alfvén waves of sufficient strength have not been unambiguously observed in the <span class="hlt">solar</span> atmosphere. We used images of high temporal and spatial resolution obtained with the <span class="hlt">Solar</span> Optical Telescope onboard the Japanese Hinode satellite to reveal that the chromosphere, the region sandwiched between the <span class="hlt">solar</span> surface and the corona, is permeated by Alfvén waves with strong amplitudes on the order of 10 to 25 kilometers per second and periods of 100 to 500 seconds. Estimates of the energy flux carried by these waves and comparisons with advanced radiative magnetohydrodynamic simulations indicate that such Alfvén waves are energetic enough to accelerate the <span class="hlt">solar</span> <span class="hlt">wind</span> and possibly to heat the quiet corona.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1913260S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1913260S"><span>On the properties of energy transfer in <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sorriso-Valvo, Luca; Marino, Raffaele; Chen, Christopher H. K.; Wicks, Robert; Nigro, Giuseppina</p> <p>2017-04-01</p> <p>Spacecraft observations have shown that the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma is heated during its expansion in the heliosphere. The necessary energy is made available at small scales by a turbulent cascade, although the nature of the heating processes is still debated. Because of the intermittent nature of turbulence, the small-scale energy is inhomogeneously distributed in space, resulting for example in the formation of highly localized current sheets and eddies. In order to understand the small-scale plasma processes occurring in the <span class="hlt">solar</span> <span class="hlt">wind</span>, the global and local properties of such energy distribution must be known. Here we study such properties using a proxy derived from the Von Karman-Howart relation for magnetohydrodynamics. The statistical properties of the energy transfer rate in the fluid range of scales are studied in detail using <span class="hlt">WIND</span> spacecraft plasma and magnetic field measurements and discussed in the framework of the multifractal turbulent cascade. Dependence of the energy dissipation proxy on the <span class="hlt">solar</span> <span class="hlt">wind</span> conditions (speed, type, <span class="hlt">solar</span> activity...) is analysed, and its evolution during <span class="hlt">solar</span> <span class="hlt">wind</span> expansion in the heliosphere is described using Helios II and Ulysses measurements. A comparison with other proxies, such as the PVI, is performed. Finally, the local singularity properties of the energy dissipation proxy are conditionally compared to the corresponding particle velocity distributions. This allows the identification of specific plasma features occurring near turbulent dissipation events, and could be used as enhanced mode trigger in future space missions.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21567559','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21567559"><span><span class="hlt">SOLAR</span> <span class="hlt">WIND</span> MODELING WITH TURBULENCE TRANSPORT AND HEATING</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Usmanov, Arcadi V.; Goldstein, Melvyn L.; Matthaeus, William H.; Breech, Benjamin A.</p> <p>2011-02-01</p> <p>We have developed an axisymmetric steady-state <span class="hlt">solar</span> <span class="hlt">wind</span> model that describes properties of the large-scale <span class="hlt">solar</span> <span class="hlt">wind</span>, interplanetary magnetic field, and turbulence throughout the heliosphere from 0.3 AU to 100 AU. The model is based on numerical solutions of large-scale Reynolds-averaged magnetohydrodynamic equations coupled with a set of small-scale transport equations for the turbulence energy, normalized cross helicity, and correlation scale. The combined set of time-dependent equations is solved in the frame of reference corotating with the Sun using a time-relaxation method. We use the model to study the self-consistent interaction between the large-scale <span class="hlt">solar</span> <span class="hlt">wind</span> and smaller-scale turbulence and the role of the turbulence in the large-scale structure and temperature distribution in the <span class="hlt">solar</span> <span class="hlt">wind</span>. To illuminate the roles of the turbulent cascade and the pickup protons in heating the <span class="hlt">solar</span> <span class="hlt">wind</span> depending on the heliocentric distance, we compare the model results with and without turbulence/pickup protons. The variations of plasma temperature in the outer heliosphere are compared with Ulysses and Voyager 2 observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SoSyR..51..165O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SoSyR..51..165O"><span>On the history of the <span class="hlt">solar</span> <span class="hlt">wind</span> discovery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Obridko, V. N.; Vaisberg, O. L.</p> <p>2017-03-01</p> <p>The discovery of the <span class="hlt">solar</span> <span class="hlt">wind</span> has been an outstanding achievement in heliophysics and space physics. The <span class="hlt">solar</span> <span class="hlt">wind</span> plays a crucial role in the processes taking place in the <span class="hlt">Solar</span> System. In recent decades, it has been recognized as the main factor that controls the terrestrial effects of space weather. The <span class="hlt">solar</span> <span class="hlt">wind</span> is an unusual plasma laboratory of giant scale with a fantastic diversity of parameters and operating modes, and devoid of influence from the walls of laboratory plasma systems. It is also the only kind of stellar <span class="hlt">wind</span> accessible for direct study. The history of this discovery is quite dramatic. Like many remarkable discoveries, it had several predecessors. However, the honor of a discovery usually belongs to a scientist who was able to more fully explain the phenomenon. Such a man is deservedly considered the US theorist Eugene Parker, who discovered the <span class="hlt">solar</span> <span class="hlt">wind</span>, as we know it today, almost "with the point of his pen". In 2017, we will celebrate the 90th anniversary birthday of Eugene Parker.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25628139','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25628139"><span>Direct evidence for kinetic effects associated with <span class="hlt">solar</span> <span class="hlt">wind</span> reconnection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xu, Xiaojun; Wang, Yi; Wei, Fengsi; Feng, Xueshang; Deng, Xiaohua; Ma, Yonghui; Zhou, Meng; Pang, Ye; Wong, Hon-Cheng</p> <p>2015-01-28</p> <p>Kinetic effects resulting from the two-fluid physics play a crucial role in the fast collisionless reconnection, which is a process to explosively release massive energy stored in magnetic fields in space and astrophysical plasmas. In-situ observations in the Earth's magnetosphere provide solid consistence with theoretical models on the point that kinetic effects are required in the collisionless reconnection. However, all the observations associated with <span class="hlt">solar</span> <span class="hlt">wind</span> reconnection have been analyzed in the context of magnetohydrodynamics (MHD) although a lot of <span class="hlt">solar</span> <span class="hlt">wind</span> reconnection exhausts have been reported. Because of the absence of kinetic effects and substantial heating, whether the reconnections are still ongoing when they are detected in the <span class="hlt">solar</span> <span class="hlt">wind</span> remains unknown. Here, by dual-spacecraft observations, we report a <span class="hlt">solar</span> <span class="hlt">wind</span> reconnection with clear Hall magnetic fields. Its corresponding Alfvenic electron outflow jet, derived from the decouple between ions and electrons, is identified, showing direct evidence for kinetic effects that dominate the collisionless reconnection. The turbulence associated with the exhaust is a kind of background <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence, implying that the reconnection generated turbulence has not much developed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.9629O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.9629O"><span>Magnetospheric and Ionospheric Response to <span class="hlt">Solar</span> <span class="hlt">Wind</span> Variability at Mars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Opgenoorth, H. J.; Andrews, D.; Edberg, N.; Lester, M.; Williams, A.; Fraenz, M.; Witasse, O.; Duru, F.; Morgan, D.</p> <p>2012-04-01</p> <p>At planets with induced magnetospheres the coupling between the ionosphere, the small draped magnetosphere and the <span class="hlt">solar</span> <span class="hlt">wind</span> is very direct in comparison to Earth. On the other hand it is more complicated as the weak induced magnetosphere itself is created by and in its shape and strength dynamically depending on the prevailing <span class="hlt">Solar</span> <span class="hlt">wind</span> conditions. In early 2010 Mars was located behind Earth in the <span class="hlt">Solar</span> <span class="hlt">wind</span>. In this study we utilized coordinated data from multiple near-Earth spacecraft (Stereo, ACE) to evaluate what kind of <span class="hlt">Solar</span> <span class="hlt">wind</span> disturbances have passed by Earth and might hit Mars consecutively (and when). We use plasma data from the ESA Mars- Express mission (mainly from the ASPERA particle instrument and the MARSIS topside ionospheric sounder) to investigate, for a number of isolated events in March and April 2010, how the induced magnetosphere at Mars develops and decays in response to <span class="hlt">Solar</span> <span class="hlt">wind</span> variability in the magnetic field, density and velocity, and what kind of ionospheric dynamics are produced in association with such events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM44A..02L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM44A..02L"><span>The Importance of Suprathermal Electrons in the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>LE CHAT, G.; Meyer-Vernet, N.; Pantellini, F. G. E.; Issautier, K.; Moncuquet, M.</p> <p>2014-12-01</p> <p>Non-Gaussian distributions are ubiquitous in systems having long-range interactions, from real-world networks to astrophysical plasmas. The corona and <span class="hlt">solar</span> <span class="hlt">wind</span> are no exception. In this review, we concentrate on the corona and <span class="hlt">solar</span> <span class="hlt">wind</span> electrons, whose suprathermal tail governs heat transport and plays a crucial role in the temperature structure and <span class="hlt">wind</span> production, as first suggested thirty years ago by Olbert and confirmed by a large number of subsequent studies. These non-thermal electrons have been measured in both the corona and <span class="hlt">solar</span> <span class="hlt">wind</span>, and are a direct consequence of the fast increase with speed of the Coulomb free-path, compared to the pressure scale-height. This situation has four important consequences: (1) the fluid description, on which the vast majority of <span class="hlt">solar</span> <span class="hlt">wind</span> models are based is inadequate; (2) the heat flux is NOT given by the classical Spitzer-Härm expression in the corona and <span class="hlt">solar</span> <span class="hlt">wind</span>; (3) for most non-thermal distributions (except the convenient and fashionable Kappa distribution), the fraction of supra-thermal electrons increases with altitude in the corona because of velocity filtration; for example, with a sum of Maxwellians, the hotter the population, the larger the increase with altitude of its fractional contribution; (4) ad-hoc heat addition - assumed in most models, is not necessarily required to produce the observed variation in temperature and the <span class="hlt">wind</span> acceleration. We will shortly review the observed electron velocity distributions together with the theoretical expectations, the major role of the electric field and the consequences on the heat flux, the temperature structure and the <span class="hlt">wind</span> acceleration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1913763P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1913763P"><span>New stratagies for modelling and forecasting the background <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pinto, Rui; Rouillard, Alexis; Brun, Sacha</p> <p>2017-04-01</p> <p>The large-scale <span class="hlt">solar</span> <span class="hlt">wind</span> speed distribution varies in time in response to the cyclic variations of the strength and geometry of the magnetic field of the corona. Semi-empirical predictive laws (such as in the widely-used WSA law) parametrise the asymptotic <span class="hlt">solar</span> <span class="hlt">wind</span> speed via simple parameters describing the geometry of the coronal magnetic field. In practice, such scaling laws require ad-hoc corrections and empirical fits to in-situ spacecraft data, and a predictive law based solely on physical principles is still missing. I will discuss improvements to this kind of laws based on the analysis of very large samples of <span class="hlt">wind</span> acceleration profiles in open flux-tubes (both from MHD simulations and potential-field extrapolations), and show that flux-tube expansion effectively control the locations of the slow and fast <span class="hlt">wind</span> flows (as in WSA), but that the actual asymptotic <span class="hlt">wind</span> speeds attained - specially those of the slow <span class="hlt">wind</span> - are also dependent on field-line inclination. I will furthermore present a new <span class="hlt">solar</span> <span class="hlt">wind</span> model - MULTI-VP - which takes a coronal magnetic field map as input (past data or forecast), and computes a collection of <span class="hlt">solar</span> <span class="hlt">wind</span> profiles (1 to 30 Rsun) spanning a region of interest of the <span class="hlt">solar</span> atmosphere (up to a full synoptic map) at any instant desired in quasi-real time, while keeping a good description the plasma heating and cooling mechanisms. MULTI-VP provides full sets of inner boundary conditions for heliospheric propagation models (such as ENLIL; see https://stormsweb.irap.omp.eu/doku.php?id=windmaptable), bypassing the need to rely on semi-empirical approaches. I will fully discuss the predictive capabilities of the model (synthetic imagery and in-situ time series) and its suitability to real-time space-weather applications. This is work is supported by the FP7 project #606692 (HELCATS).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1215020','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1215020"><span>Role of Concentrating <span class="hlt">Solar</span> Power in Integrating <span class="hlt">Solar</span> and <span class="hlt">Wind</span> Energy: Preprint</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Denholm, P.; Mehos, M.</p> <p>2015-06-03</p> <p>As <span class="hlt">wind</span> and <span class="hlt">solar</span> photovoltaics (PV) increase in penetration it is increasingly important to examine enabling technologies that can help integrate these resources at large scale. Concentrating <span class="hlt">solar</span> power (CSP) when deployed with thermal energy storage (TES) can provide multiple services that can help integrate variable generation (VG) resources such as <span class="hlt">wind</span> and PV. CSP with TES can provide firm, highly flexible capacity, reducing minimum generation constraints which limit penetration and results in curtailment. By acting as an enabling technology, CSP can complement PV and <span class="hlt">wind</span>, substantially increasing their penetration in locations with adequate <span class="hlt">solar</span> resource.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006ilws.conf..140B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006ilws.conf..140B"><span>Planetary X-rays: Relationship with <span class="hlt">solar</span> X-rays and <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bhardwaj, A.</p> <p></p> <p>Recently X-ray flares are observed from the low-latitude disk of giant planets Jupiter and Saturn in the energy range of 0.2-2 keV. These flares are found to occur in tandem with the occurrence of <span class="hlt">solar</span> X-ray flare, when light travel time delay is accounted. These studies suggest that disk of outer planets Jupiter and Saturn acts as "diffuse mirror" for <span class="hlt">solar</span> X-rays and that X-rays from these planets can be used to study flaring on the hemisphere of the Sun that in invisible to near-Earth space weather satellites. Also by proper modeling of the observed planetary X-rays the <span class="hlt">solar</span> soft X-ray flux can be derived. X-ray flares are also observed on the Mars. On the other hand, X-rays from comets are produced mainly in charge exchange interaction between highly ionized heavy <span class="hlt">solar</span> <span class="hlt">wind</span> ions and cometary neutrals. Thus cometary X-rays provide a diagnostics of the <span class="hlt">solar</span> <span class="hlt">wind</span> properties. X-rays from Martian exosphere is also dominantly produced via charge exchange interaction between Martian corona and <span class="hlt">solar</span> <span class="hlt">wind</span>, providing proxy for <span class="hlt">solar</span> <span class="hlt">wind</span>. This paper provides a brief overview on the X-rays from some of the planets and comets and their connection with <span class="hlt">solar</span> X-rays and <span class="hlt">solar</span> <span class="hlt">wind</span>, and how planetary X-rays can be used to study the Sun.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070003746','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070003746"><span>Decontamination of <span class="hlt">Genesis</span> Array Materials by UV Ozone Cleaning</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Calaway, Michael J.; Burnett, D. S.; Rodriquez, M. C.; Sestak, S.; Allton, J. H.; Stansbery, E. K.</p> <p>2007-01-01</p> <p>Shortly after the NASA <span class="hlt">Genesis</span> Mission sample return capsule returned to earth on September 8, 2004, the science team discovered that all nine ultra-pure semiconductor materials were contaminated with a thin molecular organic film approximately 0 to 100 angstroms thick. The organic contaminate layer, possibly a silicone, situated on the surface of the materials is speculated to have formed by condensation of organic matter from spacecraft off-gassing at the Lagrange 1 halo orbit during times of <span class="hlt">solar</span> exposure. While the valuable <span class="hlt">solar</span> <span class="hlt">wind</span> atoms are safely secured directly below this organic contamination and/or native oxide layer in approximately the first 1000 angstroms of the ultra-pure material substrate, some analytical techniques that precisely measure <span class="hlt">solar</span> <span class="hlt">wind</span> elemental abundances require the removal of this organic contaminate. In 2005, <span class="hlt">Genesis</span> science team laboratories began to develop various methods for removing the organic thin film without removing the precious material substrate that contained the <span class="hlt">solar</span> <span class="hlt">wind</span> atoms. Stephen Sestak and colleagues at Open University first experimented with ultraviolet radiation ozone (UV/O3) cleaning of several non-flight and flown <span class="hlt">Genesis</span> silicon wafer fragments under a pure flowing oxygen environment. The UV/O3 technique was able to successfully remove organic contamination without etching into the bulk material substrate. At NASA Johnson Space Center <span class="hlt">Genesis</span> Curation Laboratory, we have installed an UV/O3 cleaning devise in an ambient air environment to further experimentally test the removal of the organic contamination on <span class="hlt">Genesis</span> wafer materials. Preliminary results from XPS analysis show that the UV/O3 cleaning instrument is a good non-destructive method for removing carbon contamination from flown <span class="hlt">Genesis</span> array samples. However, spectroscopic ellipsometry results show little change in the thickness of the surface film. All experiments to date have shown UV/O3 cleaning method to be the best non-destructive method</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJ...832...66E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJ...832...66E"><span>Long-term Trends in the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Proton Measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Elliott, Heather A.; McComas, David J.; DeForest, Craig E.</p> <p>2016-11-01</p> <p>We examine the long-term time evolution (1965-2015) of the relationships between <span class="hlt">solar</span> <span class="hlt">wind</span> proton temperature (T p) and speed (V p) and between the proton density (n p) and speed using OMNI <span class="hlt">solar</span> <span class="hlt">wind</span> observations taken near Earth. We find a long-term decrease in the proton temperature-speed (T p-V p) slope that lasted from 1972 to 2010, but has been trending upward since 2010. Since the <span class="hlt">solar</span> <span class="hlt">wind</span> proton density-speed (n p-V p) relationship is not linear like the T p-V p relationship, we perform power-law fits for n p-V p. The exponent (steepness in the n p-V p relationship) is correlated with the <span class="hlt">solar</span> cycle. This exponent has a stronger correlation with current sheet tilt angle than with sunspot number because the sunspot number maxima vary considerably from cycle to cycle and the tilt angle maxima do not. To understand this finding, we examined the average n p for different speed ranges, and found that for the slow <span class="hlt">wind</span> n p is highly correlated with the sunspot number, with a lag of approximately four years. The fast <span class="hlt">wind</span> n p variation was less, but in phase with the cycle. This phase difference may contribute to the n p-V p exponent correlation with the <span class="hlt">solar</span> cycle. These long-term trends are important since empirical formulas based on fits to T p and V p data are commonly used to identify interplanetary coronal mass ejections, but these formulas do not include any time dependence. Changes in the <span class="hlt">solar</span> <span class="hlt">wind</span> density over a <span class="hlt">solar</span> cycle will create corresponding changes in the near-Earth space environment and the overall extent of the heliosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17677760','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17677760"><span>Self-similar signature of the active <span class="hlt">solar</span> corona within the inertial range of <span class="hlt">solar-wind</span> turbulence.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kiyani, K; Chapman, S C; Hnat, B; Nicol, R M</p> <p>2007-05-25</p> <p>We quantify the scaling of magnetic energy density in the inertial range of <span class="hlt">solar-wind</span> turbulence seen in situ at 1 AU with respect to <span class="hlt">solar</span> activity. At <span class="hlt">solar</span> maximum, when the coronal magnetic field is dynamic and topologically complex, we find self-similar scaling in the <span class="hlt">solar</span> <span class="hlt">wind</span>, whereas at <span class="hlt">solar</span> minimum, when the coronal fields are more ordered, we find multifractality. This quantifies the <span class="hlt">solar-wind</span> signature that is of direct coronal origin and distinguishes it from that of local MHD turbulence, with quantitative implications for coronal heating of the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PhDT.......144G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PhDT.......144G"><span>A hybrid reconfigurable <span class="hlt">solar</span> and <span class="hlt">wind</span> energy system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gadkari, Sagar A.</p> <p></p> <p>We study the feasibility of a novel hybrid <span class="hlt">solar-wind</span> hybrid system that shares most of its infrastructure and components. During periods of clear sunny days the system will generate electricity from the sun using a parabolic concentrator. The concentrator is formed by individual mirror elements and focuses the light onto high intensity vertical multi-junction (VMJ) cells. During periods of high <span class="hlt">wind</span> speeds and at night, the same concentrator setup will be reconfigured to channel the <span class="hlt">wind</span> into a <span class="hlt">wind</span> turbine which will be used to harness <span class="hlt">wind</span> energy. In this study we report on the feasibility of this type of <span class="hlt">solar/wind</span> hybrid energy system. The key mechanisms; optics, cooling mechanism of VMJ cells and air flow through the system were investigated using simulation tools. The results from these simulations, along with a simple economic analysis giving the levelized cost of energy for such a system are presented. An iterative method of design refinement based on the simulation results was used to work towards a prototype design. The levelized cost of the system achieved in the economic analysis shows the system to be a good alternative for a grid isolated site and could be used as a standalone system in regions of lower demand. The new approach to <span class="hlt">solar</span> <span class="hlt">wind</span> hybrid system reported herein will pave way for newer generation of hybrid systems that share common infrastructure in addition to the storage and distribution of energy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950056914&hterms=Search+term&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DSearch%2Bterm','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950056914&hterms=Search+term&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DSearch%2Bterm"><span>Long term periodicity in <span class="hlt">solar</span> <span class="hlt">wind</span> velocity during the last three <span class="hlt">solar</span> cycles</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gazis, P. R.; Richardson, J. D.; Paularena, K. I.</p> <p>1995-01-01</p> <p><span class="hlt">Solar</span> <span class="hlt">wind</span> measurements from the Pioneer 10, Pioneer 11, Voyager 2, IMP 8, and Pioneer Venus Orbiter (PVO) spacecraft were examined to search for long-term periodicities during the last three <span class="hlt">solar</span> cycles. For the time of the last <span class="hlt">solar</span> maximum, these measurements confirm the existence of the periodic 1.3-year enhancements in <span class="hlt">solar</span> <span class="hlt">wind</span> velocity reported by Richardson et al. (1994). For most of the preceding two <span class="hlt">solar</span> cycles, long-term velocity enhancements occurred that were similar in structure but lacked the 1.3-year periodicity. It appears that long-term enhancements in <span class="hlt">solar</span> <span class="hlt">wind</span> velocity, with durations on the order of a few months to a year, are a common feature throughout the heliosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20366193','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20366193"><span>Generalized similarity in finite range <span class="hlt">solar</span> <span class="hlt">wind</span> magnetohydrodynamic turbulence.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chapman, S C; Nicol, R M</p> <p>2009-12-11</p> <p>Extended or generalized similarity is a ubiquitous but not well understood feature of turbulence that is realized over a finite range of scales. The ULYSSES spacecraft <span class="hlt">solar</span> polar passes at <span class="hlt">solar</span> minimum provide in situ observations of evolving anisotropic magnetohydrodynamic turbulence in the <span class="hlt">solar</span> <span class="hlt">wind</span> under ideal conditions of fast quiet flow. We find a single generalized scaling function characterizes this finite range turbulence and is insensitive to plasma conditions. The recent unusually inactive <span class="hlt">solar</span> minimum--with turbulent fluctuations down by a factor of approximately 2 in power--provides a test of this invariance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21370889','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21370889"><span>Generalized Similarity in Finite Range <span class="hlt">Solar</span> <span class="hlt">Wind</span> Magnetohydrodynamic Turbulence</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chapman, S. C.; Nicol, R. M.</p> <p>2009-12-11</p> <p>Extended or generalized similarity is a ubiquitous but not well understood feature of turbulence that is realized over a finite range of scales. The ULYSSES spacecraft <span class="hlt">solar</span> polar passes at <span class="hlt">solar</span> minimum provide in situ observations of evolving anisotropic magnetohydrodynamic turbulence in the <span class="hlt">solar</span> <span class="hlt">wind</span> under ideal conditions of fast quiet flow. We find a single generalized scaling function characterizes this finite range turbulence and is insensitive to plasma conditions. The recent unusually inactive <span class="hlt">solar</span> minimum - with turbulent fluctuations down by a factor of approx2 in power - provides a test of this invariance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA467056','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA467056"><span><span class="hlt">Solar</span> Radio Burst and <span class="hlt">Solar</span> <span class="hlt">Wind</span> Associations With Inferred Near-Relativistic Electron Injections</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2007-02-10</p> <p>in the <span class="hlt">solar</span> corona and their injection into space has been a or CME times to inferred electron injection times were not con- subject of recent...CONTRACT NUMBER <span class="hlt">Solar</span> Radio Burst and <span class="hlt">Solar</span> <span class="hlt">Wind</span> Associations with Inferred Near-Relativistic Electron Injections 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...Astrophysical Journal, Vol 656, pp 567-576, Feb 10, 2007. 14. ABSTRACT The <span class="hlt">solar</span> injections of near-relativistic (NR) electron events observed at I AU appear</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/574652','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/574652"><span>He abundance variations in the <span class="hlt">solar</span> <span class="hlt">wind</span>: Observations from Ulysses</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Barraclough, B.L.; Feldman, W.C.; Gosling, J.T.; McComas, D.J.; Phillips, J.L.; Goldstein, B.E.</p> <p>1996-07-01</p> <p>The Ulysses mission is providing the first opportunity to observe variations in <span class="hlt">solar</span> <span class="hlt">wind</span> plasma parameters at heliographic latitudes far removed from the ecliptic plane. We present here an overview of the <span class="hlt">solar</span> <span class="hlt">wind</span> speed and the variability in helium abundance, [He], for the entire mission to date, data on [He] in six high-latitude coronal mass ejections (CMEs), and a superposed epoch analysis of [He] variations at the seven heliospheric current sheet (HCS) crossings made during the rapid-latitude-scan portion of the mission. The differences in the variability of the <span class="hlt">solar</span> <span class="hlt">wind</span> speed and [He] in high-latitude and equatorial regions are quite striking. <span class="hlt">Solar</span> <span class="hlt">wind</span> speed is generally low but highly variable near the <span class="hlt">solar</span> equator, while at higher latitudes the average speed is quite high (average speed around 760 km/s) with little variability. [He] can vary over nearly two decades at low <span class="hlt">solar</span> latitudes, while at high latitudes it varies only slightly around an average value of {approximately}4.3{percent}. In contrast to the high [He] that is often associated with CMEs observed near the ecliptic, none of the six high-speed CMEs encountered at high southern heliographic latitudes showed any significant variation in helium content from average values. Reasons for this difference between high and low latitude CME observations are not yet understood. A superposed epoch analysis of the [He] during all seven HCS crossings made as Ulysses passed from the southern to northern <span class="hlt">solar</span> hemisphere shows the expected [He] minimum near the crossing and a broad ({plus_minus}3day) period of low [He] around the crossing time. We briefly discuss how our <span class="hlt">solar</span> <span class="hlt">wind</span> [He] observations may provide an accurate measure of the helium composition for all regions of the sun lying above the helium ionization zone. {copyright} {ital 1996 American Institute of Physics.}</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996AIPC..382...92L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996AIPC..382...92L"><span><span class="hlt">Solar</span> identification of <span class="hlt">solar-wind</span> disturbances observed at Ulysses</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lemen, J. R.; Acton, L. W.; Alexander, D.; Galvin, A. B.; Harvey, K. L.; Hoeksema, J. T.; Zhao, X.; Hudson, H. S.</p> <p>1996-07-01</p> <p>The Ulysses polar passages are producing a unique set of observations of <span class="hlt">solar-wind</span> disturbances at high heliographic latitudes. In this paper we use the Yohkoh soft X-ray telescope (SXT) to locate some of these events, as defined by the Ulysses/SWICS data, in the <span class="hlt">solar</span> corona. Of 8 events, we identify two with flares, three with front-side large arcade events, two with far-side events, and one was not seen in the Ulysses data. The arcade events generally resemble long-duration flares seen in active regions, but are larger, slower, and cooler. We present Yohkoh images of each of these events. In the large arcade events (see Alexander et al., 1996, for a detailed look at one of them) the magnetic morphology at the location of the Yohkoh arcade is generally consistent with the development of a large system of loops. Some of the identifications are ambiguous, and we summarize the reasons for this. From the SWICS data we have obtained ionization temperatures for several events, and find that they have no obvious pattern in relation to the X-ray temperatures; this may be expected on the basis that the interplanetary plasma cloud is physically distinct from the plasma trapped in the corona. Soft X-ray observations of the <span class="hlt">solar</span> corona show occasional occurrences of large-scale brightenings in the form of arcades of loops. Such structures have been known since Skylab (e.g., Sturrock, 1980), and have a clear relationship with coronal mass ejections (e.g., Kahler, 1977). We now may study this phenomenon statistically with the much more comprehensive Yohkoh observations; with Yohkoh movies we can also begin to extend our knowledge to the three-dimensional development of the structures. At the same time Ulysses has sampled the latitude dependence of the interplanetary effects. With this paper we introduce this subject and provide a preliminary listing of events from the passage of Ulysses through high heliographic latitudes. The starting point of the present survey is a list</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMSH11B1620K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMSH11B1620K"><span>The <span class="hlt">Solar</span> <span class="hlt">Wind</span> Electrons Alphas and Protons (SWEAP) Investigation for <span class="hlt">Solar</span> Probe Plus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kasper, J. C.; SWEAP Investigation Team</p> <p>2010-12-01</p> <p>The NASA <span class="hlt">Solar</span> Probe Plus mission will be humanity’s first direct visit to the atmosphere of our Sun. The spacecraft will close to within nine <span class="hlt">solar</span> radii (about four million miles) of the <span class="hlt">solar</span> surface in order to observe the heating of the corona and the acceleration of the <span class="hlt">solar</span> <span class="hlt">wind</span> first hand. A key requirement for <span class="hlt">Solar</span> Probe Plus is the ability to make continuous, accurate, and fast measurements of the electrons and ionized helium (alpha-particles) and hydrogen (protons) that constitute the bulk of the <span class="hlt">solar</span> <span class="hlt">wind</span>. The <span class="hlt">Solar</span> <span class="hlt">Wind</span> Electrons Alphas and Protons (SWEAP) Investigation is a two-instrument suite that provides these observations. The purpose of this talk is to describe the science motivation for SWEAP, the instrument designs, and the expected data products. SWEAP consists of the <span class="hlt">Solar</span> Probe Cup (SPC) and the <span class="hlt">Solar</span> Probe Analyzers (SPAN). SWEAP measurements enable discovery and understanding of <span class="hlt">solar</span> <span class="hlt">wind</span> acceleration and formation, coronal and <span class="hlt">solar</span> <span class="hlt">wind</span> heating, high-energy particle acceleration, and the interaction between <span class="hlt">solar</span> <span class="hlt">wind</span> and the dust environment of the inner heliosphere. SPC is a Faraday Cup (FC) that looks at the Sun and measures ion and electron fluxes and flow angles as a function of energy. SPAN consists of an ion and electron electrostatic analyzer (ESA) on the ram side of SPP (SPAN-A) and an electron ESA on the anti-ram side (SPAN-B). SPAN-A and -B are rotated 90 degrees relative to one another so their broad FOV combine like the seams on a baseball to view the entire sky except for the region obscured by the heat shield. SWEAP data products include ion and electron velocity distribution functions with high energy and angular resolution at 0.5-16 Hz and flow angles and fluxes at 128 Hz. Continuous buffering provides triggered burst observations during shocks, reconnection events, and other transient structures with no changes to the instrument operating mode.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22348569','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22348569"><span>Weakest <span class="hlt">solar</span> <span class="hlt">wind</span> of the space age and the current 'MINI' <span class="hlt">solar</span> maximum</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>McComas, D. J.; Angold, N.; Elliott, H. A.; Livadiotis, G.; Schwadron, N. A.; Smith, C. W.; Skoug, R. M.</p> <p>2013-12-10</p> <p>The last <span class="hlt">solar</span> minimum, which extended into 2009, was especially deep and prolonged. Since then, sunspot activity has gone through a very small peak while the heliospheric current sheet achieved large tilt angles similar to prior <span class="hlt">solar</span> maxima. The <span class="hlt">solar</span> <span class="hlt">wind</span> fluid properties and interplanetary magnetic field (IMF) have declined through the prolonged <span class="hlt">solar</span> minimum and continued to be low through the current mini <span class="hlt">solar</span> maximum. Compared to values typically observed from the mid-1970s through the mid-1990s, the following proton parameters are lower on average from 2009 through day 79 of 2013: <span class="hlt">solar</span> <span class="hlt">wind</span> speed and beta (∼11%), temperature (∼40%), thermal pressure (∼55%), mass flux (∼34%), momentum flux or dynamic pressure (∼41%), energy flux (∼48%), IMF magnitude (∼31%), and radial component of the IMF (∼38%). These results have important implications for the <span class="hlt">solar</span> <span class="hlt">wind</span>'s interaction with planetary magnetospheres and the heliosphere's interaction with the local interstellar medium, with the proton dynamic pressure remaining near the lowest values observed in the space age: ∼1.4 nPa, compared to ∼2.4 nPa typically observed from the mid-1970s through the mid-1990s. The combination of lower magnetic flux emergence from the Sun (carried out in the <span class="hlt">solar</span> <span class="hlt">wind</span> as the IMF) and associated low power in the <span class="hlt">solar</span> <span class="hlt">wind</span> points to the causal relationship between them. Our results indicate that the low <span class="hlt">solar</span> <span class="hlt">wind</span> output is driven by an internal trend in the Sun that is longer than the ∼11 yr <span class="hlt">solar</span> cycle, and they suggest that this current weak <span class="hlt">solar</span> maximum is driven by the same trend.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040082015','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040082015"><span>XMM-Newton Observations of <span class="hlt">Solar</span> <span class="hlt">Wind</span> Charge Exchange Emission</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Snowden, S. L.; Collier, M. R.; Kuntz, K. D.</p> <p>2004-01-01</p> <p>We present an XMM-Newton spectrum of diffuse X-ray emission from within the <span class="hlt">solar</span> system. The spectrum is dominated by O VII and O VIII lines at 0.57 keV and 0.65 keV, O VIII (and possibly Fe XVII) lines at approximately 0.8 keV, Ne IX lines at approximately 0.92 keV, and Mg XI lines at approximately 1.35 keV. This spectrum is consistent with what is expected from charge exchange emission between the highly ionized <span class="hlt">solar</span> <span class="hlt">wind</span> and either interstellar neutrals in the heliosphere or material from Earth's exosphere. The emission is clearly seen as a low-energy ( E less than 1.5 keV) spectral enhancement in one of a series of observations of the Hubble Deep Field North. The X-ray enhancement is concurrent with an enhancement in the <span class="hlt">solar</span> <span class="hlt">wind</span> measured by the ACE satellite. The <span class="hlt">solar</span> <span class="hlt">wind</span> enhancement reaches a flux level an order of magnitude more intense than typical fluxes at 1 AU, and has ion ratios with significantly enhanced higher ionization states. Whereas observations of the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma made at a single point reflect only local conditions which may only be representative of <span class="hlt">solar</span> <span class="hlt">wind</span> properties with spatial scales ranging from less than half of an Earth radii (approximately 10 s) to 100 Earth radii, X-ray observations of <span class="hlt">solar</span> <span class="hlt">wind</span> charge exchange are remote sensing measurements which may provide observations which are significantly more global in character. Besides being of interest in its own right for studies of the <span class="hlt">solar</span> system, this emission can have significant consequences for observations of more cosmological objects. It can provide emission lines at zero redshift which are of particular interest (e.g., O VII and O VIII) in studies of diffuse thermal emission, and which can therefore act as contamination in objects which cover the entire detector field of view. We propose the use of <span class="hlt">solar</span> <span class="hlt">wind</span> monitoring data, such as from the ACE and <span class="hlt">Wind</span> spacecraft, as a diagnostic to screen for such possibilities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMSA33B1640E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMSA33B1640E"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> and Global Electron Hemispheric Power in <span class="hlt">Solar</span> Minimum Intervals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Emery, B. A.; Richardson, I. G.; Evans, D. S.; Rich, F. J.; Wilson, G.</p> <p>2008-12-01</p> <p>We assess the periodicities of the hourly and daily <span class="hlt">solar</span> <span class="hlt">wind</span> velocity (Vsw) and average global electron auroral hemispheric power (Hpeg) with Lomb-Scargle (L-S) and Fast Fourier Transforms (FFTs) using three Carrington Rotations (CRs) to a year or more of data in two different <span class="hlt">solar</span> minimum periods. The first Whole Sun Month (WSM) interval (96223-96252) was during the last <span class="hlt">solar</span> minimum where the <span class="hlt">solar</span> magnetic field relaxed into a dipole. A strong 'semiannual' periodicity in Vsw maximizing in equinoxes was found, which enhanced the equinoctial maxima found in Hpeg (and Kp) due to the preferred <span class="hlt">solar</span> <span class="hlt">wind</span> and magnetospheric reconnection during equinoxes. In the present <span class="hlt">solar</span> minimum, the <span class="hlt">solar</span> magnetic field has considerable quadrupole components during the Whole Heliospheric Interval (WHI, 08080-08107). Hpeg exhibits <span class="hlt">solar</span> rotational periodicities similar to those for Vsw using both L-S and FFT analyses, where the 9- day periodicity is particularly strong in the present <span class="hlt">solar</span> minimum period. The 9-day periodicity in the WHI CR was caused by three periods of slow-speed <span class="hlt">solar</span> <span class="hlt">wind</span> from near the ecliptic plane as seen in the sign of IMF Bx. Periodicities are examined in Vsw since 1972, and in Hpeg since 1978 to assess <span class="hlt">solar</span> cycle variations. Periodicities longer than 100 days are not as strong or as well correlated between Vsw and Hpeg compared to the shorter <span class="hlt">solar</span> rotational periodicities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRA..122.6240H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRA..122.6240H"><span>Distribution and <span class="hlt">solar</span> <span class="hlt">wind</span> control of compressional <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetic anomaly interactions observed at the Moon by ARTEMIS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Halekas, J. S.; Poppe, A. R.; Lue, C.; Farrell, W. M.; McFadden, J. P.</p> <p>2017-06-01</p> <p>A statistical investigation of 5 years of observations from the two-probe Acceleration, Reconnection, Turbulence, and Electrodynamics of Moon's Interaction with the Sun (ARTEMIS) mission reveals that strong compressional interactions occur infrequently at high altitudes near the ecliptic but can form in a wide range of <span class="hlt">solar</span> <span class="hlt">wind</span> conditions and can occur up to two lunar radii downstream from the lunar limb. The compressional events, some of which may represent small-scale collisionless shocks ("limb shocks"), occur in both steady and variable interplanetary magnetic field (IMF) conditions, with those forming in steady IMF well organized by the location of lunar remanent crustal magnetization. The events observed by ARTEMIS have similarities to ion foreshock phenomena, and those observed in variable IMF conditions may result from either local lunar interactions or distant terrestrial foreshock interactions. Observed velocity deflections associated with compressional events are always outward from the lunar wake, regardless of location and <span class="hlt">solar</span> <span class="hlt">wind</span> conditions. However, events for which the observed velocity deflection is parallel to the upstream motional electric field form in distinctly different <span class="hlt">solar</span> <span class="hlt">wind</span> conditions and locations than events with antiparallel deflections. Consideration of the momentum transfer between incoming and reflected <span class="hlt">solar</span> <span class="hlt">wind</span> populations helps explain the observed characteristics of the different groups of events.<abstract type="synopsis"><title type="main">Plain Language SummaryWe survey the environment around the Moon to determine when and where strong amplifications in the charged particle density and magnetic field strength occur. These structures may be some of the smallest shock waves in the <span class="hlt">solar</span> system, and learning about their formation informs us about the interaction of charged particles with small-scale magnetic fields throughout the <span class="hlt">solar</span> system and beyond. We find that these compressions occur in an extended region</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19720035477&hterms=feature+discrete&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dfeature%2Bdiscrete','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720035477&hterms=feature+discrete&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dfeature%2Bdiscrete"><span>Theory of discrete wave packets in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wu, C. S.</p> <p>1972-01-01</p> <p>Discrete wave packets were observed by Ogo 5 and earlier satellites. These waves were believed to be in the whistler mode. Since their group velocities were found to be smaller than the <span class="hlt">solar-wind</span> speed, these waves could not have been generated in the bow shock and could not have propagated upstream later. The present theory discusses a mechanism similar to that of the echo phenomenon in plasma physics discovered in recent years. The present theory enables us to explain (a) why the wave packets were associated with the bow shock, (b) why the wave packets were characterized by coherent oscillations, and (c) why the wave packets had group velocities smaller than the <span class="hlt">solar</span> <span class="hlt">wind</span> and yet could still occur in the <span class="hlt">solar</span> <span class="hlt">wind</span>. In short, our theory is able to interpret all the essential features deduced from the observational data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMSH11B1668K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMSH11B1668K"><span>Non-polar Coronal Holes and <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Karachik, N.; Pevtsov, A. A.</p> <p>2010-12-01</p> <p>We investigate properties of non-polar coronal holes (CHs) and their correlation with fast <span class="hlt">solar</span> <span class="hlt">wind</span> at 1 AU. Using EIT/SOHO observations taken from 1998-2008 in 195A and 284A wavelength bands, we identify boundaries of coronal holes, and compute their area, total brightness of corona integrated over the CH, as well as the area and total brightness of pixels inside the CH associated with coronal bright points (CBPs). We investigate the effect of each parameter on <span class="hlt">solar</span> <span class="hlt">wind</span> speed, the mutual dependency of the parameters, and their changes with the sunspot activity. Our findings suggest that the reconnection events associated with coronal bright points situated in CHs do not play a major role in acceleration of the fast <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19720035478&hterms=magnetism&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dmagnetism','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720035478&hterms=magnetism&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dmagnetism"><span>Lunar fossil magnetism and perturbations of the <span class="hlt">solar</span> <span class="hlt">wind</span>.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sonett, C. P.; Mihalov, J. D.</p> <p>1972-01-01</p> <p>Perturbations of the <span class="hlt">solar</span> <span class="hlt">wind</span> downstream of the moon and lying outside of the rarefaction wave that defines the diamagnetic cavity are used to define possible source regions comprised of intrinsically magnetized areas of the moon. A map of the moon is constructed showing that a model in which the sources are exposed to the grazing <span class="hlt">solar</span> <span class="hlt">wind</span> during the lunation yields a selenographically invariant set of regions strongly favoring the lunar highlands over the maria. An alternative model with the source due to electromagnetic induction is explored. The ages of the field sources should be consistent with those based on the basalt ages and possibly far older if the sources are connected with the formation of the highland rocks themselves. The perturbations are tentatively identified as weak shock waves, and a Mach angle in accord with nominal values for the <span class="hlt">solar</span> <span class="hlt">wind</span> is found.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22364020','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22364020"><span>PROTON KINETIC EFFECTS IN VLASOV AND <span class="hlt">SOLAR</span> <span class="hlt">WIND</span> TURBULENCE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Servidio, S.; Valentini, F.; Perrone, D.; Veltri, P.; Osman, K. T.; Chapman, S.; Califano, F.; Matthaeus, W. H.</p> <p>2014-02-01</p> <p>Kinetic plasma processes are investigated in the framework of <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence, employing hybrid Vlasov-Maxwell (HVM) simulations. Statistical analysis of spacecraft observation data relates proton temperature anisotropy T /T {sub ∥} and parallel plasma beta β{sub ∥}, where subscripts refer to the ambient magnetic field direction. Here, this relationship is recovered using an ensemble of HVM simulations. By varying plasma parameters, such as plasma beta and fluctuation level, the simulations explore distinct regions of the parameter space given by T /T {sub ∥} and β{sub ∥}, similar to <span class="hlt">solar</span> <span class="hlt">wind</span> sub-datasets. Moreover, both simulation and <span class="hlt">solar</span> <span class="hlt">wind</span> data suggest that temperature anisotropy is not only associated with magnetic intermittent events, but also with gradient-type structures in the flow and in the density. This connection between non-Maxwellian kinetic effects and various types of intermittency may be a key point for understanding the complex nature of plasma turbulence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19810042382&hterms=history+theory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dhistory%2Btheory','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19810042382&hterms=history+theory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dhistory%2Btheory"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> flow past Venus - Theory and comparisons</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Spreiter, J. R.; Stahara, S. S.</p> <p>1980-01-01</p> <p>Advanced computational procedures are applied to an improved model of <span class="hlt">solar</span> <span class="hlt">wind</span> flow past Venus to calculate the locations of the ionopause and bow wave and the properties of the flowing ionosheath plasma in the intervening region. The theoretical method is based on a single-fluid, steady, dissipationless, magneto-hydrodynamic continuum model and is appropriate for the calculation of axisymmetric supersonic, super-Alfvenic <span class="hlt">solar</span> <span class="hlt">wind</span> flow past a nonmagnetic planet possessing a sufficiently dense ionosphere to stand off the flowing plasma above the subsolar point and elsewhere. Determination of time histories of plasma and magnetic field properties along an arbitrary spacecraft trajectory and provision for an arbitrary oncoming direction of the interplanetary <span class="hlt">solar</span> <span class="hlt">wind</span> have been incorporated in the model. An outline is provided of the underlying theory and computational procedures, and sample comparisons of the results are presented with observations from the Pioneer Venus orbiter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19658869','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19658869"><span>Electrostatic short-scale termination of <span class="hlt">solar-wind</span> turbulence.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Valentini, Francesco; Veltri, Pierluigi</p> <p>2009-06-05</p> <p>Recent hybrid Vlasov simulations [F. Valentini, Phys. Rev. Lett. 101, 025006 (2008)10.1103/PhysRevLett.101.025006] have shown that the short-scale termination of <span class="hlt">solar-wind</span> turbulence is characterized by the occurrence of longitudinal electrostatic fluctuations. Beside the ion-acoustic branch, in agreement with <span class="hlt">solar-wind</span> observations, a novel branch of acoustic-like waves, with phase velocity close to the ion thermal speed, has been recovered in the simulations. In this Letter, we show that these waves turn out to be Bernstein-Greene-Kruskal-like solutions of the hybrid Vlasov-Maxwell equations, driven by kinetic effects of resonant particle trapping. We also discuss the development of the <span class="hlt">solar-wind</span> turbulent spectra across the ion inertial length and especially stress the fact that turbulence privileges acoustic paths to develop towards short wavelengths.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021422&hterms=solar+wind+power&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsolar%2Bwind%2Bpower','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021422&hterms=solar+wind+power&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsolar%2Bwind%2Bpower"><span>Dominant 2D magnetic turbulence in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bieber, John W.; Wanner, Wolfgang; Matthaeus, William H.</p> <p>1995-01-01</p> <p>There have been recent suggestions that <span class="hlt">solar</span> <span class="hlt">wind</span> magnetic turbulence may be a composite of slab geometry (wavevector aligned with the mean magnetic field) and 2D geometry (wavevectors perpendicular to the mean field). We report results of two new tests of this hypothesis using Helios measurements of inertial ranged magnetic spectra in the <span class="hlt">solar</span> <span class="hlt">wind</span>. The first test is based upon a characteristic difference between perpendicular and parallel reduced power spectra which is expected for the 2D component but not for the slab component. The second test examines the dependence of power spectrum density upon the magnetic field angle (i.e., the angle between the mean magnetic field and the radial direction), a relationship which is expected to be in opposite directions for the slab and 2D components. Both tests support the presence of a dominant (approximately 85 percent by energy) 2D component in <span class="hlt">solar</span> <span class="hlt">wind</span> magnetic turbulence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021389&hterms=Properties+Helium&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DProperties%2BHelium','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021389&hterms=Properties+Helium&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DProperties%2BHelium"><span>Dynamic properties of helium ions in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zurbuchen, Th.; Bochsler, P.; von Steiger, R.</p> <p>1995-01-01</p> <p>We characterize the dynamic properties of He ions of the <span class="hlt">solar</span> <span class="hlt">wind</span>. Because of the non-negligible abundance and the significant fraction of momentum flux inherent in helium ions, this species has an influence on the state of turbulence. Especially, we analyze the helium dynamic properties of different <span class="hlt">solar</span> <span class="hlt">wind</span> types. After a discussion of the influence of measurement errors on the statistical analysis of He bulk velocities, we investigate the structure function dependency on the <span class="hlt">solar</span> <span class="hlt">wind</span> state. We find a self-similar sealing in the range of minutes to days with characteristic structure function slopes deviating from the canonical Kolmogorov values. For comparison with previous studies, we also analyze H structure functions of the same time periods and discuss differences of coinciding He and H structure functions in the framework of the concept of intermittency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17774231','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17774231"><span>Ulysses <span class="hlt">solar</span> <span class="hlt">wind</span> plasma observations at high southerly latitudes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Phillips, J L; Bame, S J; Feldman, W C; Gosling, J T; Hammond, C M; McComas, D J; Goldstein, B E; Neugebauer, M; Scime, E E; Suess, S T</p> <p>1995-05-19</p> <p><span class="hlt">Solar</span> <span class="hlt">wind</span> plasma observations made by the Ulysses spacecraft through -80.2 degrees <span class="hlt">solar</span> latitude and continuing equatorward to -40.1 degrees are summarized. Recurrent high-speed streams and corotating interaction regions dominated at middle latitudes. The speed of the <span class="hlt">solar</span> <span class="hlt">wind</span> was typically 700 to 800 kilometers per second poleward of -35 degrees . Corotating reverse shocks persisted farther south than did forward shocks because of the tilt of the heliomagnetic streamer belt. Sporadic coronal mass ejections were seen as far south as -60.5 degrees . Proton temperature was higher and the electron strahl was broader at higher latitudes. The high-latitude <span class="hlt">wind</span> contained compressional, pressure-balanced, and Alfvénic structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19720035478&hterms=Magnetism&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DMagnetism','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720035478&hterms=Magnetism&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DMagnetism"><span>Lunar fossil magnetism and perturbations of the <span class="hlt">solar</span> <span class="hlt">wind</span>.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sonett, C. P.; Mihalov, J. D.</p> <p>1972-01-01</p> <p>Perturbations of the <span class="hlt">solar</span> <span class="hlt">wind</span> downstream of the moon and lying outside of the rarefaction wave that defines the diamagnetic cavity are used to define possible source regions comprised of intrinsically magnetized areas of the moon. A map of the moon is constructed showing that a model in which the sources are exposed to the grazing <span class="hlt">solar</span> <span class="hlt">wind</span> during the lunation yields a selenographically invariant set of regions strongly favoring the lunar highlands over the maria. An alternative model with the source due to electromagnetic induction is explored. The ages of the field sources should be consistent with those based on the basalt ages and possibly far older if the sources are connected with the formation of the highland rocks themselves. The perturbations are tentatively identified as weak shock waves, and a Mach angle in accord with nominal values for the <span class="hlt">solar</span> <span class="hlt">wind</span> is found.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23004953','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23004953"><span>Intermittency and local heating in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Osman, K T; Matthaeus, W H; Wan, M; Rappazzo, A F</p> <p>2012-06-29</p> <p>Evidence for nonuniform heating in the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma near current sheets dynamically generated by magnetohydrodynamic (MHD) turbulence is obtained using measurements from the ACE spacecraft. These coherent structures only constitute 19% of the data, but contribute 50% of the total plasma internal energy. Intermittent heating manifests as elevations in proton temperature near current sheets, resulting in regional heating and temperature enhancements extending over several hours. The number density of non-Gaussian structures is found to be proportional to the mean proton temperature and <span class="hlt">solar</span> <span class="hlt">wind</span> speed. These results suggest magnetofluid turbulence drives intermittent dissipation through a hierarchy of coherent structures, which collectively could be a significant source of coronal and <span class="hlt">solar</span> <span class="hlt">wind</span> heating.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19810055592&hterms=store+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dstore%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19810055592&hterms=store+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dstore%2Benergy"><span>Energy coupling between the <span class="hlt">solar</span> <span class="hlt">wind</span> and the magnetosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Akasofu, S.-I.</p> <p>1981-01-01</p> <p>A description is given of the path leading to the first approximation expression for the <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere energy coupling function (epsilon), which correlates well with the total energy consumption rate (U sub T) of the magnetosphere. It is shown that epsilon is the primary factor controlling the time development of magnetospheric substorms and storms. The finding of this particular expression epsilon indicates how the <span class="hlt">solar</span> <span class="hlt">wind</span> couples its energy to the magnetosphere; the <span class="hlt">solar</span> <span class="hlt">wind</span> and the magnetosphere make up a dynamo. In fact, the power generated by the dynamo can be identified as epsilon through the use of a dimensional analysis. In addition, the finding of epsilon suggests that the magnetosphere is closer to a directly driven system than to an unloading system which stores the generated energy before converting it to substorm and storm energies. The finding of epsilon and its implications is considered to have significantly advanced and improved the understanding of magnetospheric processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995sowi.conf...73Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995sowi.conf...73Z"><span>Dynamic properties of helium ions in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zurbuchen, Th.; Bochsler, P.; von Steiger, R.</p> <p>1995-06-01</p> <p>We characterize the dynamic properties of He ions of the <span class="hlt">solar</span> <span class="hlt">wind</span>. Because of the non-negligible abundance and the significant fraction of momentum flux inherent in helium ions, this species has an influence on the state of turbulence. Especially, we analyze the helium dynamic properties of different <span class="hlt">solar</span> <span class="hlt">wind</span> types. After a discussion of the influence of measurement errors on the statistical analysis of He bulk velocities, we investigate the structure function dependency on the <span class="hlt">solar</span> <span class="hlt">wind</span> state. We find a self-similar sealing in the range of minutes to days with characteristic structure function slopes deviating from the canonical Kolmogorov values. For comparison with previous studies, we also analyze H structure functions of the same time periods and discuss differences of coinciding He and H structure functions in the framework of the concept of intermittency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19760033224&hterms=decay+methane&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Ddecay%2Bmethane','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19760033224&hterms=decay+methane&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Ddecay%2Bmethane"><span><span class="hlt">Solar-wind</span> interactions - Nature and composition of lunar atmosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mukherjee, N. R.</p> <p>1975-01-01</p> <p>The nature and composition of the lunar atmosphere are examined on the basis of <span class="hlt">solar-wind</span> interactions, and the nature of the species in the trapped-gas layer is discussed using results of theoretical and experimental investigations. It is shown that the moon has a highly tenuous atmosphere consisting of various species derived from five sources: <span class="hlt">solar-wind</span> interaction products, cosmic-ray interaction products, effects of meteoritic impacts, planetary degassing, and radioactive-decay products. Atmospheric concentrations are determined for those species derived from <span class="hlt">solar-wind</span> protons, alpha particles, and oxygen ions. Carbon chemistry is briefly discussed, and difficulties encountered in attempts to determine quantitatively the concentrations of molecular oxygen, atomic oxygen, carbon monoxide, carbon dioxide, and methane are noted. The calculated concentrations are shown to be in good agreement with observations by the Apollo 17 lunar-surface mass spectrometer and orbital UV spectrometer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021350&hterms=acceleration+physics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dacceleration%2Bphysics','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021350&hterms=acceleration+physics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dacceleration%2Bphysics"><span>Features of <span class="hlt">solar</span> <span class="hlt">wind</span> acceleration according to radio occultation data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Efimov, A. I.</p> <p>1995-01-01</p> <p>In addressing one of the fundamental problems in <span class="hlt">solar</span> physics establishing the mechanism(s) responsible for the <span class="hlt">solar</span> <span class="hlt">wind</span> acceleration and the corona heating - it is essential to have a reliable knowledge of the heliocentric radial dependence of the <span class="hlt">solar</span> <span class="hlt">wind</span> properties. Adequate data are available for small <span class="hlt">solar</span> distances R less than 4 R(<span class="hlt">solar</span> mass) from coronal white light and EUV observations and at distances R greater than 60 R(<span class="hlt">solar</span> mass) from in situ measurements. One of the few methods available to fill in the gap between these boundaries is the radio scintillation technique. Taking the example of the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity, the most reliable such measurements are obtained when phase fluctuation observations of scattered radio waves, which are not susceptible to saturation effects, are recorded at two or more widely-spaced ground stations. Two extensive observation campaigns of this type were carried out with the Venus-orbiting satellites Venera 10 in 1976 and Venera 15/16 in 1984. The observations were performed over the course of three months near superior conjunction at <span class="hlt">solar</span> offset distances R approximately 6-80 R(<span class="hlt">solar</span> mass). The main results from the subsequent analysis of these data are: (1) velocities vary between 250 and 380 km s(exp -1) for R greater than 20 R(<span class="hlt">solar</span> mass), agreeing with similar measurements using natural sources (IPS); (2) velocities derived from two-station phase fluctuation observations varv between 70 and 120 km s(exp -1) for R less than 12 R(<span class="hlt">solar</span> mass), i.e. values substantially lower than those derived from conventional IPS data; and (3) it is suggested that the different velocity profiles derived from the two data sets at small R may be due to the effects of magnetosonic and Alfvenic waves on radio wave scattering. Further analysis of additional radio sounding data should help resolve the apparent discrepancy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSH22B..06E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSH22B..06E"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Observations from 10 to 30 AU Measured With The New Horizons <span class="hlt">Solar</span> <span class="hlt">Wind</span> Around Pluto (SWAP) Instrument</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Elliott, H. A.; McComas, D. J.; Valek, P. W.; Nicolaou, G.; Bagenal, F.; Delamere, P. A.; Livadiotis, G.</p> <p>2014-12-01</p> <p>Beginning in 2012 the New Horizons mission to Pluto began collecting <span class="hlt">solar</span> <span class="hlt">wind</span> observations during the spacecraft hibernation greatly increasing the <span class="hlt">solar</span> <span class="hlt">wind</span> coverage. We have extensively analyzed both the laboratory and flight calibration measurements for the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Around Pluto (SWAP) instrument to produce a data set of <span class="hlt">solar</span> <span class="hlt">wind</span> observations at times when the New Horizons spacecraft is spinning. This full data set spans from 10 to 30 AU, and the improved coverage portion spans from 20- 30 AU. Coincidently, in 2012 and 2013 the ACE, STEREO A, and STEREO B were well separated in longitude. We compare the New Horizons speeds with propagated 1 AU speed measurements, and find many of the largest scale structures persist beyond 20 AU. The New Horizons <span class="hlt">solar</span> <span class="hlt">wind</span> coverage between 20 and 30 AU is now extensive enough to examine the temperature-speed relationship and compare that to the relationship found in the inner heliosphere and to that in the Voyager 2 observations. Upon initial examination we also find a temperature-speed relationship that persists in the 20-30 AU distance range.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22519953','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22519953"><span>THE NEW HORIZONS <span class="h