Science.gov

Sample records for genesis solar wind

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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).

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

    NASA Astrophysics Data System (ADS)

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

    2009-03-01

    The cleaning efficiency of the Genesis Ultra-pure Water Megasonic Wafer Spin Cleaner will be presented. Results show the effectiveness of the new cleaner removing particle contamination from Genesis silicon wafers implanted with solar wind.

  9. 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

  10. 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.

  11. 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

    ...-000; EG13-63-000; EG13-64-000; FC13-13-000] Genesis Solar, LLC; NRG Delta LLC; Mountain View Solar, LLC; Pheasant Run Wind, LLC; Pheasant Run Wind II, LLC; Tuscola Wind II, LLC; Mountain Wind Power, LLC; Mountain Wind Power II, LLC; Summerhaven Wind, LP; Notice of Effectiveness of Exempt Wholesale Generator...

  12. 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.

  13. 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.

  14. 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.

  15. 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.

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

    DOE PAGESBeta

    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; et al

    2015-10-01

    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

  17. Noble gas composition of the solar wind as collected by the Genesis mission

    NASA Astrophysics Data System (ADS)

    Heber, Veronika S.; Wieler, Rainer; Baur, Heinrich; Olinger, Chad; Friedmann, Tom A.; Burnett, Donald S.

    2009-12-01

    We present the elemental and isotopic composition of noble gases in the bulk solar wind collected by the NASA Genesis sample return mission. He, Ne, and Ar were analyzed in diamond-like carbon on a silicon substrate (DOS) and 84,86Kr and 129,132Xe in silicon targets by UV laser ablation noble gas mass spectrometry. Solar wind noble gases are quantitatively retained in DOS and with exception of He also in Si as shown by a stepwise heating experiment on a flown DOS target and analyses on other bulk solar wind collector materials. Solar wind data presented here are absolutely calibrated and the error of the standard gas composition is included in stated uncertainties. The isotopic composition of the light noble gases in the bulk solar wind is as follows: 3He/ 4He: (4.64 ± 0.09) × 10 -4, 20Ne/ 22Ne: 13.78 ± 0.03, 21Ne/ 22Ne: 0.0329 ± 0.0001, 36Ar/ 38Ar 5.47 ± 0.01. The elemental composition is: 4He/ 20Ne: 656 ± 5, and 20Ne/ 36Ar 42.1 ± 0.3. Genesis provided the first Kr and Xe data on the contemporary bulk solar wind. The preliminary isotope and elemental composition is: 86Kr/ 84Kr: 0.302 ± 0.003, 129Xe/ 132Xe: 1.05 ± 0.02, 36Ar/ 84Kr 2390 ± 150, and 84Kr/ 132Xe 9.5 ± 1.0. The 3He/ 4He and the 4He/ 20Ne ratios in the Genesis DOS target are the highest solar wind values measured in exposed natural and artificial targets. The isotopic composition of the other noble gases and the Kr/Xe ratio obtained in this work agree with data from lunar samples containing "young" (˜100 Ma) solar wind, indicating that solar wind composition has not changed within at least the last 100 Ma. Genesis could provide in many cases more precise data on solar wind composition than any previous experiment. Because of the controlled exposure conditions, Genesis data are also less prone to unrecognized systematic errors than, e.g., lunar sample analyses. The solar wind is the most authentic sample of the solar composition of noble gases, however, the derivation of solar noble gas

  18. Isotopic Mass Fractionation of Solar Wind: Evidence from Fast and Slow Solar Wind Collected by the Genesis mission

    NASA Astrophysics Data System (ADS)

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

    2012-11-01

    NASA's Genesis space mission returned samples of solar wind collected over ~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‰ for He, 4.2 ± 0.5‰ amu-1 for Ne and 2.6 ± 0.5‰ amu-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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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. PMID:21700869

  5. 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.

  6. 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.

  7. 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).

  8. 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.

  9. 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].

  10. 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

    2015-10-01

    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.

  11. THE GENESIS SOLAR WIND CONCENTRATOR TARGET: MASS FRACTIONATION CHARACTERISED BY NE ISOTOPES

    SciTech Connect

    WIENS, ROGER C.; OLINGER, C.; HEBER, V.S.; REISENFELD, D.B.; BURNETT, D.S.; ALLTON, J.H.; BAUR, H.; WIECHERT, U.; WIELER, R.

    2007-01-02

    The concentrator on Genesis provides samples of increased fluences of solar wind ions for precise determination of the oxygen isotopic composition of the solar wind. The concentration process caused mass fractionation as function of the radial target position. They measured the fractionation using Ne released by UV laser ablation along two arms of the gold cross from the concentrator target to compare measured Ne with modeled Ne. The latter is based on simulations using actual conditions of the solar wind during Genesis operation. Measured Ne abundances and isotopic composition of both arms agree within uncertainties indicating a radial symmetric concentration process. Ne data reveal a maximum concentration factor of {approx} 30% at the target center and a target-wide fractionation of Ne isotopes of 3.8%/amu with monotonously decreasing {sup 20}Ne/{sup 22}Ne ratios towards the center. The experimentally determined data, in particular the isotopic fractionation, differ from the modeled data. They discuss potential reasons and propose future attempts to overcome these disagreements.

  12. The oxygen isotopic composition of captured solar wind: first results from the Genesis mission

    NASA Astrophysics Data System (ADS)

    McKeegan, K. D.; Coath, C. D.; Heber, V.; Jarzebinski, G.; Kallio, A.; Kunihiro, T.; Mao, P. H.; Burnett, D.

    2008-12-01

    Oxygen is the major constituent of rocky planets and the third most abundant element comprising the Sun, yet the solar oxygen isotopic composition has remained essentially unknown. One reason is that the usual appeal to primitive meteorites does not work because oxygen is isotopically distinct in all different classes of meteorites. The cause of this premier "isotopic anomaly" (first discovered in 1973) has been variously ascribed to nucleosynthetic input, e.g. from a nearby supernova, or to exotic isotope-selective chemistry in the solar nebula, e.g. based on molecular symmetry or UV photolysis. Knowledge of the average starting composition of the solar system, which is preserved in the Sun, would provide a baseline from which one could interpret the oxygen isotopic compositions of planetary materials. To this end, NASA flew the Genesis Mission to capture samples of the solar wind (SW) in ultra-pure target materials and return them to Earth for laboratory analysis. At UCLA, we have designed and constructed a hybrid secondary ion and accelerator mass spectrometer (SIMS/AMS), called the "MegaSIMS", specifically to tackle the unique analytical challenges posed by the Genesis samples: dilute elemental concentrations, limited sample material, and close proximity of likely surface contamination to the implanted solar wind ions. Three years after the crash- landing of the sample return capsule in the Utah desert, we have succeeded in making oxygen isotopic measurements on SW captured in a SiC target from the Genesis SW concentrator. Our preliminary data indicate that the Sun is enriched in 16O by at least 5% relative to Earth and meteorites. Implications for planetary science will be discussed.

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. 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].

  18. 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.

  19. 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.

  20. 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

  1. Solar composition from the Genesis Discovery Mission.

    PubMed

    Burnett, D S; Team, Genesis Science

    2011-11-29

    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

  2. Solar composition from the Genesis Discovery Mission.

    PubMed

    Burnett, D S; Team, Genesis Science

    2011-11-29

    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.

  3. 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.

  4. 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.

  5. 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.

  6. Solar Wind Neon Isotopic Analyses by UV Laser Ablation on the Genesis Concentrator Gold Cross for Calibration of Oxygen Isotope Data

    NASA Astrophysics Data System (ADS)

    Heber, V. S.; Wiens, R. C.; Burnett, D. S.; Baur, H.; Wiechert, U. H.; Wieler, R.

    2005-12-01

    To determine the oxygen isotopic composition of the present day solar wind, a proxy for the solar nebula, is one of the key goals of the Genesis solar wind (SW) collection mission. In order to increase analytical precision on measured O isotopes, ions of incoming SW in the mass range to 28 amu were accelerated and focussed onto the target by an electrostatic mirror. The concentration factor is about 20. However, these processes are expected to fractionate the isotopic composition of SW ions, with fractionation varying as a function of target radius. We will directly measure the instrumental fractionation factors by analysing Ne isotopes with high precision and spatial resolution along the radius on the electroplated Au cross that framed the concentrator targets. Ne isotopes are most suitable to investigate fractionation because of i) it is an abundant element in the Sun, ii) its isotopic composition in SW is well understood, and iii) Ne is hardly influenced by terrestrial contamination. We will analyse Ne isotopes by UV laser ablation (248 nm) of small areas (0.1 x 0.1 mm) using a very sensitive noble gas mass spectrometer equipped with a molecular drag pump conveying the gas almost quantitatively into the ion source. The target precision of O isotopic composition is about 0.1% (2-sigma). Therefore, the most important issue for us is to achieve a similar high precision of the Ne isotope data allowing to determine the trend of instrumental fractionation along the target radius, which is computed to be in total about 2%. Currently, we obtain a reproducibility of <0.2% using standard calibration gas containing similar Ne amounts as expected. Blank analyses of the ultra-clean electroplated Au target result in absolutely negligible amounts of Ne. At the meeting we will present first Ne results of the first arm analysed of the Au cross.

  7. 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.

  8. 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.

  9. 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.

  10. Lunar and Planetary Science XXXV: Genesis Mission

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The titles in this section include: 1) The Genesis Mission Solar Wind Collection: Solar-Wind Statistics over the Period of Collection; 2) Artificial Implantation of Noble Gases on Genesis Targets; 3) Depth Sensitive Sampling of Implanted Species in Genesis Collectors Using UV Laser Ablation and SIMS; 4) A High Energy Secondary Ion Mass Spectrometer for the Analysis of Captured Solar Wind; 5) Genesis Preliminary Examination Plans; 6) Genesis Sample Material Subdividing Plans.

  11. 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.

  12. The Solar Wind

    NASA Technical Reports Server (NTRS)

    Goldstein, B. E.

    1998-01-01

    The first evidence of the solar wind was provided through observations of comet tail deflections by L. Biermann in 1951. A cometary ion tail is oriented along the difference between the cometary and solar wind velocities, whereas the dust tail is in the antisunward direction; the ion tail directions demonstrated the existence of an outflow of ionized gas from the Sun (the solar wind) and allowed estimates of solar wind speed. Spacecraft observations have now established that at 1 AU the solar wind has a typical ion number density of about 7 /cc and is composed by number of about 95% protons and 5% Helium, with other minor ions also present. The solar wind as observed at 1 AU in the ecliptic has speeds typically in the range 300-700 km/ s. At such speeds ions travel from the Sun to 1 AU in from 2.5 to 6 days. The impact of the solar wind on planets with magnetic fields (Earth, Jupiter, Saturn, Uranus, Neptune) causes phenomena such as magnetospheres, aurorae, and geomagnetic storms, whereas at objects lacking magnetospheres (Mars, Venus, comets), atmospheric neutrals undergo charge exchange and are picked up by the solar wind flow. The solar wind also shields the Earth from low energy cosmic rays, and is responsible for the existence of the anomalous component of the cosmic rays a low energy component that is created locally rather than in the galaxy. Presented here is a brief introduction to the solar wind and a description of some current topics of research. Solar wind properties vary a great deal due to the changing magnetic structure on the Sun.

  13. 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

    ... Plan was published in the Federal Register on April 9, 2010 (75 FR 18204). Comments on the Draft RMP... 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...

  14. 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.

  15. Solar wind composition

    NASA Technical Reports Server (NTRS)

    Ogilvie, K. W.; Coplan, M. A.

    1995-01-01

    Advances in instrumentation have resulted in the determination of the average abundances of He, C, N, O, Ne, Mg, Si, S, and Fe in the solar wind to approximately 10%. Comparisons with solar energetic particle (SEP) abundances and galactic cosmic ray abundances have revealed many similarities, especially when compared with solar photospheric abundances. It is now well established that fractionation in the corona results in an overabundance (with respect to the photosphere) of elements with first ionization potentials less than 10 eV. These observations have in turn led to the development of fractionation models that are reasonably successful in reproducing the first ionization (FIP) effect. Under some circumstances it has been possible to relate solar wind observations to particular source regions in the corona. The magnetic topologies of the source regions appear to have a strong influence on the fractionation of elements. Comparisons with spectroscopic data are particularly useful in classifying the different topologies. Ions produced from interstellar neutral atoms are also found in the solar wind. These ions are picked up by the solar wind after ionization by solar radiation or charge exchange and can be identified by their velocity in the solar wind. The pick-up ions provide most of the pressure in the interplanetary medium at large distances. Interstellar abundances can be derived from the observed fluxes of solar wind pick-up ions.

  16. Solar wind travel time

    NASA Astrophysics Data System (ADS)

    Russell, C. T.

    A useful rule of thumb in solar terrestrial studies is that the solar wind travels 4 Earth radii (RE) per minute. Long-term studies of solar wind velocity [e.g., Luhmann et al., 1993; 1994] show that the median velocity is about 420 km/s, corresponding to 3.96 RE min-1. The quartiles are about 370 km/s and 495 km/s, corresponding to 3.48 Re min-1 and 4.66 Re min-1 respectively. This number helps estimate the delays expected when observing a discontinuity at a solar wind monitor; one example is ISEE-3 when it was at the forward libration point (about 60 min). It is also helpful for estimating how much time passes before the dayside magnetosphere is compressed as denser solar wind flows by (about 2.5 min).

  17. Solar Wind Complexity

    NASA Astrophysics Data System (ADS)

    Iliopoulos, A.; Pavlos, G.; Karakatsanis, L.; Xenakis, M.; Pavlos, E.

    2013-09-01

    In this study results concerning the nonlinear analysis of the ion flux solar wind time series of three shock phenomena, occurred during 24 October 2011, 09 September 2011 and 26 September 2011 correspondingly, as well as the non-extensive statistical theory of Tsallis are presented. In particular, the triplet of Tsallis, as well as the correlation dimension and the Lyapunov exponent spectrum were estimated for the solar wind time series. Also the multifractal scaling exponent spectrum , the generalized Renyi dimension spectrum and the spectrum of the structure function exponents were estimated experimentally and theoretically using the entropy principle included in Tsallis non-extensive statistical theory. Our analysis showed clearly the following: a) a phase transition process in the solar wind dynamics from high dimensional non-Gaussian self-organized critical (SOC) state to a low dimensional also non-Gaussian chaotic state, b) strong intermittent solar wind turbulence and anomalous (multifractal) diffusion solar wind process, c) faithful agreement of Tsallis non-equilibrium statistical theory with the experimental estimations, d) non-Gaussian probability distribution function , ii) and , iii) for the solar wind index and its underlying non-equilibrium solar dynamics.

  18. 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.

  19. Elemental composition variations in the solar wind: Comparisons between Ulysses and ACE within different solar wind regimes

    NASA Astrophysics Data System (ADS)

    Pilleri, P.; Reisenfeld, D. B.; Wiens, R. C.

    2013-12-01

    The elemental composition of the solar wind is likely established at the base of the corona, a conclusion based on the observed dependence of solar wind abundances on the first ionization potential (FIP) of the elements. Although the plasma conditions within the ecliptic solar wind are highly variable, the elemental composition is less so, and is an indicator of the nature of the solar source. In particular, coronal hole (CH, fast) solar wind tends to have less of a FIP enhancement of the low -FIP elements (e.g., Fe, Mg, Si) than interstream (IS, slow) solar wind. The elemental composition of coronal mass ejections (CMEs) is more variable, but tends to be similar to IS composition. The question we address here is how much does the average composition of the different solar wind regimes vary over the course of the solar cycle and between solar cycles. For the most recent solar cycle, which included the unusually deep and prolonged solar minimum (2006 - 2010) Lepri et al. (2013) have shown measurable drifts in the elemental composition within solar wind regimes using data from the Advanced Composition Explorer (ACE) Solar Wind Ion Composition Spectrometer (SWICS). In contrast, von Steiger and Zurbuchen (2011) have shown using Ulysses SWIC data that the composition of the very fast polar coronal hole flow has remained constant. Here, we extend the Lepri et al. ecliptic analysis to include data from Ulysses, which allows us to expand the analysis to the previous solar cycle (1990 - 2001), as well as check consistency with their recent solar cycle results. (Note that although Ulysses was nominally a polar mission, it spent considerable time at low latitudes as well.) A major driver for this investigation is the Genesis Mission solar wind sample analysis. Namely, was the solar wind sampled by Genesis between late 2001 and early 2004 typical of the solar wind over longer time scales, and hence a representative sample of the long-term solar wind, or was it somehow unique

  20. 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.

  1. Application of grazing incidence x-ray fluorescence technique to discriminate and quantify implanted solar wind

    SciTech Connect

    Kitts, K.; Choi, Y.; Eng, P. J.; Ghose, S. K.; Sutton, S. R.; Rout, B.

    2009-03-15

    NASA launched the Genesis return mission to obtain pristine solar wind samples in order to better understand solar wind mechanics, solar physics, and solar system evolution. Unfortunately, the probe crash-landed shattering the collector plates necessitating the application of a grazing incidence x-ray fluorescence technique. This nondestructive methodology differentiates the terrestrial contamination from the low concentration implanted solar wind. Using this technique, the elemental depth distribution is obtained resulting in the determination of absolute solar wind elemental abundance. We describe this application and present the solar wind Fe concentration determination as an example.

  2. 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...

  3. Solar wind composition experiment

    NASA Technical Reports Server (NTRS)

    Geiss, J.; Buehler, F.; Cerutti, H.; Eberhardt, P.; Filleux, C.

    1972-01-01

    The Apollo 16 SWC experiment is a continuation of the earlier experiments; however, an essential change was introduced in the solar wind particle collection technique. Platinum surfaces were incorporated in the collector foil, and use was made of a layer technique for distinguishing particles of different energies and different directions of arrival. The improvements and the expanded scope of the Apollo 16 experiment, relative to the earlier SWC experiments, can be summarized as follows: elimination of possible residual dust contamination by treating the platinum foil sections with dilute hydrofluoric acid before analysis; increased accuracy of solar wind argon abundance; determination of solar wind albedo; and search for helium in the energy range above approximately 40 KeV/nucleon.

  4. Genesis: Sorting Out the Pieces

    NASA Astrophysics Data System (ADS)

    McNamara, K. M.; Westphal, A. J.; Butterworth, A. L.; Burnett, D. S.

    2005-03-01

    Due to failed parachutes during Genesis recovery, significant collector damage and fragment mixing occurred. We discuss generating the detailed information of material, solar wind regime collected, and condition of collector.

  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. Corona and solar wind

    NASA Astrophysics Data System (ADS)

    Withbroe, G. L.

    1986-04-01

    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.

  7. 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.

  8. 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.

  9. Solar wind and magnetosphere interactions

    NASA Technical Reports Server (NTRS)

    Russell, C. T.; Allen, J. H.; Cauffman, D. P.; Feynman, J.; Greenstadt, E. W.; Holzer, R. E.; Kaye, S. M.; Slavin, J. A.; Manka, R. H.; Rostoker, G.

    1979-01-01

    The relationship between the magnetosphere and the solar wind is addressed. It is noted that this interface determines how much of the solar plasma and field energy is transferred to the Earth's environment, and that this coupling not only varies in time, responding to major solar disturbances, but also to small changes in solar wind conditions and interplanetary field directions. It is recommended that the conditions of the solar wind and interplanetary medium be continuously monitored, as well as the state of the magnetosphere. Other recommendations include further study of the geomagnetic tail, tests of Pc 3,4 magnetic pulsations as diagnostics of the solar wind, and tests of kilometric radiation as a remote monitor of the auroral electrojet.

  10. 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.

  11. Solar wind composition. Progress report

    SciTech Connect

    Ogilvie, K.W.; Coplan, M.A.

    1995-01-01

    Advances in instrumentation have resulted in the determination of the average abundances of He, C, N, O, Ne, Mg, Si, S, and Fe in the solar wind to approximately 10%. Comparisons with solar energetic particle (SEP) abundances and galactic cosmic ray abundances have revealed many similarities, especially when compared with solar photospheric abundances. It is now well established that fractionation in the corona results in an overabundance (with respect to the photosphere) of elements with first ionization potentials less than 10 eV. These observations have in turn led to the development of fractionation models that are reasonably successful in reproducing the first ionization (FIP) effect. Under some circumstances it has been possible to relate solar wind observations to particular source regions in the corona. The magnetic topologies of the source regions appear to have a strong influence on the fractionation of elements. Comparisons with spectroscopic data are particularly useful in classifying the different topologies. Ions produced from interstellar neutral atoms are also found in the solar wind. These ions are picked up by the solar wind after ionization by solar radiation or charge exchange and can be identified by their velocity in the solar wind. The pick-up ions provide most of the pressure in the interplanetary medium at large distances. Interstellar abundances can be derived from the observed fluxes of solar wind pick-up ions.

  12. 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..., LLC, Avalon Wind 2, LLC, Catalina Solar, LLC, Catalina Solar 2, LLC, Pacific Wind Lessee, LLC,...

  13. 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

  14. 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.

  15. 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.

  16. 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 motivate…

  17. 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...

  18. 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.

  19. 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.

  20. Mars and the Solar Wind

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This artist's rendition depicts the response of the solar wind to the obstacle - the planet Mars - in it's path. A supersonic 'solar wind' consisting of electrically charged particles (ions and electrons) streams off the Sun into space. It is slowed to subsonic speeds in the vicinity of Mars at a parabolic surface called a 'bow shock' upstream of the planet. Here, the magnetic field fluctuates wildly and the flow of the solar wind becomes chaotic. Part of the orbital trajectory of the Mars Global Surveyor is indicated, with MGS approaching the planet just prior to over-flight of the pole.

    The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO. JPL is an operating division of California Institute of Technology (Caltech).

  1. 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.

  2. 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.

  3. 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.

  4. Latitudinal dependence of solar wind speed

    NASA Technical Reports Server (NTRS)

    Fry, C. D.; Akasofu, S.-I.

    1987-01-01

    The data of King (1979, 1983) and of Hoeksema et al. (1982, 1983) are used to investigate the solar-cycle evolution of solar wind bulk speed as a function of source magnetic field strength. The effects of solar transient events are removed. The data suggest that the latitudinal gradient in background solar wind speed is steepest at solar minimum and broadest at solar maximum. The lowest and highest background speeds are found to remain fairly constant throughout the solar cycle. A function developed for the background solar wind speed is inserted into the improved kinematic code of Hakamada and Akasofu (1982), and solar wind speed and IMF are simulated for two periods in the solar cycle. The observed parameters for specific coronal hole passage are well reproduced by the analysis.

  5. Improvement of background solar wind predictions

    NASA Astrophysics Data System (ADS)

    Dálya, Zsuzsanna; Opitz, Andrea

    2016-04-01

    In order to estimate the solar wind properties at any heliospheric positions propagation tools use solar measurements as input data. The ballistic method extrapolates in-situ solar wind observations to the target position. This works well for undisturbed solar wind, while solar wind disturbances such as Corotating Interaction Regions (CIRs) and Coronal Mass Ejections (CMEs) need more consideration. We are working on dedicated ICME lists to clean these signatures from the input data in order to improve our prediction accuracy. These ICME lists are created from several heliospheric spacecraft measurements: ACE, WIND, STEREO, SOHO, MEX and VEX. As a result, we are able to filter out these events from the time series. Our corrected predictions contribute to the investigation of the quiet solar wind and space weather studies.

  6. Wind loading on solar collectors

    SciTech Connect

    Bhaduri, S.; Murphy, L.M.

    1985-06-01

    The present design methodology for the determination of wind loading on the various solar collectors has been 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, have been 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, have been 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.

  7. Observations of solar-wind helium

    NASA Technical Reports Server (NTRS)

    Neugebauer, M.

    1981-01-01

    It is pointed out that the concentration of helium in the solar wind relative to hydrogen fluctuates wildly. Under certain circumstances, the helium to hydrogen abundance ratio is strongly enhanced over probable solar values; at other times, the amount of helium in the solar wind is immeasurably small. In spite of the fact that helium is heavier than hydrogen, solar-wind helium often leaves the solar gravitational field with a higher velocity than does the hydrogen. It is thought that the mechanisms responsible for helium behavior may contain clues to unanswered questions concerning the acceleration and energy exchange processes of the entire solar wind. A brief review is given of the principal features and theories of the solar wind as a whole. In addition, measurement techniques are discussed. Emphasis throughout is on the experimental data concerning the dynamics of solar-wind helium. On the basis of coronal temperatures, it is shown that helium in the solar wind is almost always doubly ionized. It is also shown that the average abundance of helium ions in the solar wind is usually in the range of 3 to 6% by number.

  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. MHD Waves in the Solar Wind

    NASA Astrophysics Data System (ADS)

    Ofman, L.

    2016-02-01

    This chapter focuses on reviewing several observational aspects of magnetohydrodynamic (MHD) waves in the solar wind, in particular on Alfvén waves, Alfvénic turbulent spectrum, and their role in heating and accelerating the solar wind. It also reviews computational models that incorporate Alfvén waves as the driving source of the wind in the lower corona (coronal holes) and in the inner heliosphere, with emphasis on multi-dimensional models. Evidence for MHD waves in the solar wind is obtained from interplanetary scintillation (IPS) observations using Earth-based radio telescope observations of distant (galactic) radio sources. The solar wind electron density variability in the line of sight affects the received radio signal. The propagating fluctuations and their correlations are used to estimate the solar wind velocity and the wave amplitude in the parallel and the perpendicular directions in line of sight.

  10. 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.

  11. Strahl variations with the Solar Wind properties

    NASA Astrophysics Data System (ADS)

    Nieves-Chinchilla, T.; F.-Viñas, A.; Goldstein, M. L.; Gurgiolo, C.

    2009-04-01

    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 the strahl component in the ambient solar wind since the launch of Cluster. The excursion of Cluster into the solar wind provides the opportunity to analyze this component of the electron velocity distribution function in a wide range of solar wind velocities and densities. The moment density and fluid velocity have been computed by spherical harmonic spectral model method. The analysis shows a correlation of the strahl density with the solar wind velocity and the time variation of the strahl density with solar cycle. This result agrees with the postulate that coronal holes are the source of this population. These preliminary results have been extended to include half solar cycle data (e.g., from 2001) to provide continuous results from solar maximum to minimum.

  12. 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.

  13. Observational constraints on solar wind acceleration mechanisms

    NASA Technical Reports Server (NTRS)

    Neugebauer, M.

    1983-01-01

    A complete theoretical understanding of the acceleration of the solar wind must account for at least three types of solar wind flow: high-speed streams associated with coronal holes, low-speed boundary layer flows associated with sector boundaries, and both high- and low-speed flows associated with impulsive ejections from the Sun. The properties of each type of flow are summarized.

  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. Solar- and wind-powered irrigation systems

    NASA Astrophysics Data System (ADS)

    Enochian, R. V.

    1982-02-01

    Five different direct solar and wind energy systems are technically feasible for powering irrigation pumps. However, with projected rates of fossil fuel costs, only two may produce significant unsubsidied energy for irrigation pumping before the turn of the century. These are photovoltaic systems with nonconcentrating collectors (providing that projected costs of manufacturing solar cells prove correct); and wind systems, especially in remote areas where adequate wind is available.

  18. 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.

  19. 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.

  20. 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].

  1. 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.

  2. Global network of slow solar wind

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

    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.

  3. The Spectrum of Solar Wind Superhalo Electrons

    NASA Astrophysics Data System (ADS)

    Wang, L.; Yang, L.; Tu, C. Y.; He, J.; Yoon, P. H.; Wimmer-Schweingruber, R. F.; Salem, C. S.; Bale, S. D.

    2015-12-01

    The WIND/3DP measurements show that solar wind superhalo electrons are continuously present at energies above 2 keV in the interplanetary medium (IPM), even in absence of any significant solar and interplanetary activity (e.g., solar flares, shocks, etc.). The observed omnidirectional differential flux of quiet-time superhalo electrons generally fits to a power-law spectrum, J~E-β, with an average index β of ~2.4. Thus, superhalo electrons appear to be one of the most common electron acceleration phenomena in the heliosphere. The superhalo power-law spectrum shows no obvious correlation with sunspot number and solar wind core populations. If they are formed by acceleration through the IPM, then solar wind halo/strahl electrons can provide seed electrons for such acceleration. Finally, we will also present the correlation between the power-law spectrum of superhalo electrons and the kappa distribution of halo/strahl electrons.

  4. Solar winds along curved magnetic field lines

    NASA Astrophysics Data System (ADS)

    Li, B.; Xia, L. D.; Chen, Y.

    2011-05-01

    Context. Both remote-sensing measurements using the interplanetary scintillation (IPS) technique and in-situ measurements by the Ulysses spacecraft show a bimodal structure for the solar wind at solar minimum conditions. At present it still remains to address why the fast wind is fast and the slow wind is slow. While a robust empirical correlation exists between the coronal expansion rate fc of the flow tubes and the speeds v measured in situ, a more detailed data analysis suggests that v depends on more than just fc. Aims. We examine whether the non-radial shape of field lines, which naturally accompanies any non-radial expansion, could be an additional geometrical factor. Methods. We solved the transport equations incorporating the heating from turbulent Alfvén waves for an electron-proton solar wind along curved field lines given by an analytical magnetic field model, which is representative of a solar minimum corona. Results. The field line shape is found to influence the solar wind parameters substantially, reducing the asymptotic speed by up to ~130 km s-1 or by ~28% in relative terms, compared with the case where the field line curvature is neglected. This effect was interpreted in the general framework of energy addition in the solar wind: compared to the straight case, the field line curvature enhances the effective energy deposition to the subsonic flow, which results in a higher proton flux and a lower terminal proton speed. Conclusions. Our computations suggest that the field line curvature could be a geometrical factor which, in addition to the tube expansion, substantially influences the solar wind speed. Furthermore, although the field line curvature is unlikely to affect the polar fast solar wind at solar minima, it does help make the wind at low latitudes slow, which in turn helps better reproduce the Ulysses measurements.

  5. 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.

  6. Solar wind interaction with planets --Abstract only

    NASA Astrophysics Data System (ADS)

    Michel, F. C.

    1994-06-01

    The solar system displays a wide variety of solar wind interactions with the planets and satellites. The 'classic' interaction with the Earth's magnetoscope is just one special case which even now leaves important questions unanswered. We will touch on (1) the Earth's magnetospheric interaction and then go on to what are probably representative limiting cases. (2) the interaction with an unmagnetized object having no atmosphere (the Moon), (3) the interaction with unmagnetized objects having atmospheres (Mars and Venus), and (4) the interaction with bodies having so much plasma in their magnetospheres that they would probably generate winds of their own if not confined by the solar wind (Jupiter).

  7. Magnetic ropes in the solar wind

    SciTech Connect

    Ruzmaikin, A.; Shukurov, A.; Sokolov, D. IZMIRAN, Troitsk Moscow State Univ. )

    1992-10-01

    The generation of magnetic fluctuations by MHD turbulence in the solar wind is discussed. An estimate of the effective magnetic Reynolds number in the solar wind based on a width of the inertial range of the turbulence is proposed. Dynamo activity is predicted to lead to generation of magnetic ropes whose length is of the order of the energy range scale, 2.5 x 10 exp 11 cm, and whose thickness can be as low as 5 x 10 exp 8 cm. Experimental detection of the ropes would require determination of two-point and higher correlation functions for the magnetic fluctuations in the solar wind. 21 refs.

  8. 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.

  9. 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

  10. Source regions of solar wind disappearance events

    NASA Astrophysics Data System (ADS)

    Janardhan, P.; Fujiki, K.; Sawant, H. S.; Kojima, M.; Hakamada, K.; Krishnan, R.

    2008-03-01

    During the period 1999-2002 there have been three instances, in May 1999, March 2002, and May 2002, respectively, when the solar wind densities at 1 AU dropped to abnormally low values (<0.1 cm-3) for extended periods of time (12-24 h). These long-lasting low-density anomalies observed at 1 AU are referred to as "solar wind disappearance events" and in this paper, we locate the solar sources of the two disappearance events in March and May 2002 and show that like the well-studied disappearance event of 11 May 1999, these events too originate in active region complexes located at central meridian and are characterized by highly nonradial solar wind outflows. We also show that during disappearance events, the interplanetary magnetic field is stable and unipolar and the associated solar wind outflows have extended Alfvén radii. Using the fact that solar wind flows from active regions have higher ratios of O7+/O6+ than wind from coronal holes, we try to pinpoint the solar sources of these very unusual and rare events and show that they represent the dynamic evolution of either active region open fields or small coronal hole boundaries embedded in or near large active region complexes located at or close to central meridian.

  11. Acceleration and heating of the solar wind

    NASA Technical Reports Server (NTRS)

    Barnes, A.

    1978-01-01

    Some of the competing theories of solar wind acceleration and heating are reviewed, and the observations that are required to distinguish among them are discussed. In most cases what is required is measurement of plasma velocity and temperature and magnetic field, as near the sun as possible and certainly inside 20 solar radii; another critical aspect of this question is determining whether a turbulent envelope exists in this inner region, and if so, defining its properties. Plasma and magnetic observations from the proposed Solar Probe mission would thus yield a quantum jump in our understanding of the dynamics of the solar wind.

  12. 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.

  13. 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.

  14. Ceres interaction with the solar wind

    NASA Astrophysics Data System (ADS)

    Holmstrom, Mats; Lindkvist, Jesper

    2016-10-01

    The solar wind interaction with Ceres is studied for a high water vapor release from its surface using a hybrid model including photoionization. We use a water vapor production rate thought to be due to subsurface sublimation, corresponding to a detection on 6 March 2013 by the Herschel Space Observatory. We present the general morphology of the plasma interactions, both close to Ceres and on a larger scale. Mass-loading of water ions causes a magnetic pile-up region in-front of Ceres, where the solar wind deflects and slows down. The large body makes an obstacle to the solar wind and creates an asymmetric wake downstream. On a global scale, Ceres has a comet-like interaction with the solar wind with observable perturbations far downstream of the body.

  15. 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.

  16. 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.

  17. 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.

  18. Solar Wind Interaction With the Lunar Environment

    NASA Astrophysics Data System (ADS)

    Halekas, J. S.

    2005-12-01

    The Earth's Moon, lacking a substantial atmosphere or global magnetic field, presents one of the simpler obstacles to solar wind flow in our solar system. Despite this apparent simplicity, a rich array of interesting plasma physics occurs in the lunar environment. To first order, the Moon is completely unshielded from solar wind plasma and solar photons, and direct incidence of solar wind plasma can lead to implantation of volatiles and ion sputtering and pickup. The solar wind is blocked by the lunar obstacle, resulting in a plasma void on the night side. A potential drop across the wake boundary is generated as solar wind electrons attempt to refill the wake cavity, resulting in a tenuous high-temperature electron population and anisotropic ion beams in the wake. A system of diamagnetic currents is formed on the boundary surface, enhancing the magnetic field in the wake and reducing the field around it. Meanwhile, waves are generated by the unstable particle distributions generated by this interaction. On the day side, photon-driven positive charging of the lunar surface occurs. On the night side, on the other hand, charging is controlled by the tenuous wake plasma, and is generally electron-driven and negative. When the Moon traverses the Earth's magnetotail and is exposed to low-density plasma in the tail lobes and high-temperature plasma in the plasmasheet, extreme surface charging of up to hundreds of V positive and several keV negative can occur. Lunar surface charging may affect ion sputtering and likely results in significant dust transport. The presence of remanent crustal magnetism causes significant perturbations to this picture. Some crustal fields are large enough to stand off the solar wind (possibly affecting solar wind volatile implantation), and we observe large shock-like magnetic enhancements upstream from the largest crustal sources. The occurence of these "limb shocks" depends on solar wind parameters, suggesting that the crustal sources are

  19. Quiet-time Solar Wind Superhalo Electrons

    NASA Astrophysics Data System (ADS)

    Wang, L.; Yang, L.; Tu, C. Y.; He, J.; Wimmer-Schweingruber, R. F.; Li, G.; Salem, C. S.; Bale, S. D.

    2015-12-01

    Superhalo electrons carry important information on the electron acceleration in the solar wind. Using the STEREO/STE electron measurements at ~2-20 keV and WIND/3DP measurements at ~20-200 keV, we find that solar wind superhalo electrons are present in the interplanetary medium (IPM) even in absence of any significant solar and interplanetary activity. The observed superhalo electrons generally have a nearly isotropic angular distribution and a power-law energy spectrum, J~E-β. The spectral index β ranges from ~1.5 to ~3.7, with an average of ~2.4. Both the superhalo power-law spectrum and anisotropy show no obvious correlation with sunspot number, solar flares, solar wind core population, etc. These superhalo electrons may form a quiet-time energetic electron background/reservoir in the IPM. They may originate from nonthermal processes related to the acceleration of solar wind, followed by scattering into isotropic angular distributions in the IPM. Another possibility is that superhalo electrons could be formed mainly due to acceleration by wave-particle interactions through the IPM.

  20. New Horizons Solar Wind Around Pluto Solar Wind (SWAP) Measurements from 5 to 23 AU

    NASA Astrophysics Data System (ADS)

    Elliott, H. A.; McComas, D. J.; Delamere, P. A.

    2012-12-01

    This year the Solar Wind Around Pluto (SWAP) instrument on the New Horizons (NH) spacecraft collected 79 days of solar wind measurements during hibernation, about 30 days of data during annual checkout operations, and has begun recording another 168 days of data in hibernation which will be played back next year. The currently available NH-SWAP solar wind observations now span from about 5.1 to 23.4 AU. We examine how the peak solar wind speed in the New Horizons measurements vary with distance, report on progress toward automating the fitting of the SWAP solar wind count rate distributions, and take an initial look at the solar wind temperature-speed relationship beyond 11 AU. Since most of the SWAP solar wind observations were collected while spinning, and ions from the entire field-of-view (10 by 276 degrees) are focused onto one pair of coincidence Channel Electron Multiplier, we need to evaluate the effect of spinning on the measured rates. By comparing the 3-axis stabilized, to the rolling and spinning measurements, we strive to assess spin variations in the observed SWAP count rates and develop techniques to account for them. To test our analysis, we fit simulated count rate distributions to quantify how well our technique recovers the input solar wind conditions.

  1. 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

  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. Cleaning Study of Genesis Sample 60487

    NASA Technical Reports Server (NTRS)

    Kuhlman, Kim R.; Rodriquez, M. C.; Gonzalez, C. P.; Allton, J. H.; Burnett, D. S.

    2013-01-01

    The Genesis mission collected solar wind and brought it back to Earth in order to provide precise knowledge of solar isotopic and elemental compositions. The ions in the solar wind 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 solar wind and must be preserved throughout sample handling, cleaning, processing, distribution, preparation and analysis. Particles of Genesis 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 solar wind. We have conducted a correlative microscopic study of the efficacy of cleaning Genesis 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

  4. Observed Properties of the Solar Wind

    NASA Astrophysics Data System (ADS)

    Neugebauer, Marcia

    2008-11-01

    The earliest measurements of the solar wind fully supported Gene Parker's theory. The wind was persistent and nearly radial, its speed was hundreds of km/s, the density was as predicted, and, on average, the interplanetary magnetic field was consistent with an Archimedian spiral. The fastest wind, with speed >700 km/s, traced back to Bartel's unipolar M regions rather than to the hotter active regions, and the highest densities could be explained by compression where the fast wind plowed into the slower wind in its path. But, even in the early data, there were mysteries, some of which are not yet completely resolved. Understanding the alpha particles has been a challenge. Their abundance is highly variable, in the fast wind their temperature is generally > 4 times the proton temperature, and, despite their greater mass, they flow away from the Sun faster than the protons. To complicate the picture further, the protons, alphas, and electrons all have complex, anisotropic distribution functions, often with double peaks. The expanding wind cools more slowly than adiabatically, suggesting a zoo of wave-particle interactions probably responsible for marginal stabilities of the particle distributions. The study of interplanetary waves and turbulence is an active field of research. Recent decades have also seen the study of ions heavier than alphas, including particles in the wind that did not originate at the Sun. Fifty years after Parker's landmark paper, solar-wind physics is still an active area of research.

  5. 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.

  6. The oxygen isotopic composition of the Sun inferred from captured solar wind.

    PubMed

    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

    2011-06-24

    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 solar system composition. We measured the oxygen isotopic composition of solar wind captured and returned to Earth by NASA's Genesis mission. Our results demonstrate that the Sun is highly enriched in (16)O relative to the Earth, Moon, Mars, and bulk meteorites. Because the solar photosphere preserves the average isotopic composition of the solar system for elements heavier than lithium, we conclude that essentially all rocky materials in the inner solar 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. PMID:21700868

  7. Evidence for solar wind modulation of lightning

    NASA Astrophysics Data System (ADS)

    Scott, C. J.; Harrison, R. G.; Owens, M. J.; Lockwood, M.; Barnard, L.

    2014-05-01

    The response of lightning rates over Europe to arrival of high speed solar wind streams at Earth is investigated using a superposed epoch analysis. Fast solar wind stream arrival is determined from modulation of the solar wind V y component, measured by the Advanced Composition Explorer spacecraft. Lightning rate changes around these event times are determined from the very low frequency arrival time difference (ATD) system of the UK Met Office. Arrival of high speed streams at Earth is found to be preceded by a decrease in total solar irradiance and an increase in sunspot number and Mg II emissions. These are consistent with the high speed stream’s source being co-located with an active region appearing on the Eastern solar limb and rotating at the 27 d period of the Sun. Arrival of the high speed stream at Earth also coincides with a small (˜1%) but rapid decrease in galactic cosmic ray flux, a moderate (˜6%) increase in lower energy solar energetic protons (SEPs), and a substantial, statistically significant increase in lightning rates. These changes persist for around 40 d in all three quantities. The lightning rate increase is corroborated by an increase in the total number of thunder days observed by UK Met stations, again persisting for around 40 d after the arrival of a high speed solar wind stream. This result appears to contradict earlier studies that found an anti-correlation between sunspot number and thunder days over solar cycle timescales. The increase in lightning rates and thunder days that we observe coincides with an increased flux of SEPs which, while not being detected at ground level, nevertheless penetrate the atmosphere to tropospheric altitudes. This effect could be further amplified by an increase in mean lightning stroke intensity that brings more strokes above the detection threshold of the ATD system. In order to remove any potential seasonal bias the analysis was repeated for daily solar wind triggers occurring during the summer

  8. Algebra and statistics of the solar wind

    NASA Astrophysics Data System (ADS)

    Veselovsky, I. S.; Dmitriev, A. V.; Suvorova, A. V.

    2010-04-01

    Statistical studies of properties of the solar wind and interplanetary magnetic field, based on an extended database for the period 1963-2007 including four solar cycles, show that the Gaussian approximation well suites for some parameters as the probability distribution of their numerical values, while for others the lognormal law is preferred. This paper gives an interpretation of these results as associated with predominance of linear or nonlinear processes in composition and interaction of various disturbances and irregularities propagating and originating in the interior of the Sun and its atmosphere, including the solar corona and the solar wind running away from it. Summation of independent random components of disturbances leads, according to the central limit theorem of the probability theory, to the normal (Gaussian) distributions of quantities proper, while their multiplication leads to the normal distributions of logarithms. Thus, one can discuss the algebra of events and associate observed statistical distinctions with one or another process of formation of irregularities in the solar wind. Among them there are impossible events (having null probability) and reliable events (occurring with 100% probability). For better understanding of the relationship between algebra and statistics of events in the solar wind further investigations are necessary.

  9. Solar wind ion composition and charge states

    SciTech Connect

    Vonsteiger, R.

    1995-06-01

    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. The authors 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, the authors 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, the authors 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.

  10. Latitudinal properties of the solar wind from studies of ionic comet tails. [statistical analysis of solar wind speed variations

    NASA Technical Reports Server (NTRS)

    Brandt, J. C.

    1976-01-01

    A statistical analysis is presented of the orientations of ionic comet tails in the solar wind. The analysis indicates that the radial solar wind speed is not necessarily higher near the solar poles than near the equator. The results refer to a long-term, global flow pattern and do not refer to short-term variations of solar wind speed.

  11. 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.

  12. Solar wind controlled pulsations: A review

    SciTech Connect

    Odera, T.J.

    1986-02-01

    Studies of the solar wind controlled Pc 3, 4 pulsations by early and recent researchers are highlighted. The review focuses on the recent observations, which cover the time during the International Magnetospheric Study (IMS). Results from early and recent observations agree on one point, that is, that the Pc 3, 4 pulsations are influenced by three main solar wind parameters, namely, the solar wind velocity V/sub 5w/, the IMF orientation theta/sub x/B, and magnitude B. The results can be interpreted, preferably, in terms of an external origin for Pc 3, 4 pulsations. This implies, essentially, the signal model, which means that the pulsations originate in the upstream waves (in the interplanetary medium) and are transported by convection to the magnetopause, where they couple to oscillations of the magnetospheric field lines.

  13. 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.

  14. Solar wind-magnetosphere energy input functions

    SciTech Connect

    Bargatze, L.F.; McPherron, R.L.; Baker, D.N.

    1985-01-01

    A new formula for the solar wind-magnetosphere energy input parameter, P/sub i/, is sought by applying the constraints imposed by dimensional analysis. Applying these constraints yields a general equation for P/sub i/ which is equal to rho V/sup 3/l/sub CF//sup 2/F(M/sub A/,theta) where, rho V/sup 3/ is the solar wind kinetic energy density and l/sub CF//sup 2/ is the scale size of the magnetosphere's effective energy ''collection'' region. The function F which depends on M/sub A/, the Alfven Mach number, and on theta, the interplanetary magnetic field clock angle is included in the general equation for P/sub i/ in order to model the magnetohydrodynamic processes which are responsible for solar wind-magnetosphere energy transfer. By assuming the form of the function F, it is possible to further constrain the formula for P/sub i/. This is accomplished by using solar wind data, geomagnetic activity indices, and simple statistical methods. It is found that P/sub i/ is proportional to (rho V/sup 2/)/sup 1/6/VBG(theta) where, rho V/sup 2/ is the solar wind dynamic pressure and VBG(theta) is a rectified version of the solar wind motional electric field. Furthermore, it is found that G(theta), the gating function which modulates the energy input to the magnetosphere, is well represented by a ''leaky'' rectifier function such as sin/sup 4/(theta/2). This function allows for enhanced energy input when the interplanetary magnetic field is oriented southward. This function also allows for some energy input when the interplanetary magnetic field is oriented northward. 9 refs., 4 figs.

  15. Geomagnetic activity: Dependence on solar wind parameters

    NASA Technical Reports Server (NTRS)

    Svalgaard, L.

    1977-01-01

    Current ideas about the interaction between the solar wind and the earth's magnetosphere are reviewed. The solar wind dynamic pressure as well as the influx of interplanetary magnetic field lines are both important for the generation of geomagnetic activity. The influence of the geometry of the situation as well as the variability of the interplanetary magnetic field are both found to be important factors. Semi-annual and universal time variations are discussed as well as the 22-year cycle in geomagnetic activity. All three are found to be explainable by the varying geometry of the interaction. Long term changes in geomagnetic activity are examined.

  16. Solar wind interaction with Pluto's escaping atmosphere

    NASA Astrophysics Data System (ADS)

    Bagenal, F.

    2015-12-01

    NASA's New Horizons spacecraft carries two instruments, SWAP and PEPSSI, that measure low and high energy particles respectively. These particle instruments have been measuring the conditions in the solar wind for most of the trajectory from Earth to Pluto. The Venetia Burney Student Dust Counter measured impacts from micron-sixed dust particles. These particle instruments also made observations during the flyby of Pluto on July 14, 2015. We report on New Horizons measurements of the interaction of the solar wind interaction with Pluto's extended atmosphere and discuss comparisons with theoretical expectations.

  17. Workshop on Solar Activity, Solar Wind, Terrestrial Effects, and Solar Acceleration

    NASA Technical Reports Server (NTRS)

    1992-01-01

    A summary of the proceedings from the workshop are presented. The areas covered were solar activity, solar wind, terrestrial effects, and solar acceleration. Specific topics addressed include: (1) solar cycle manifestations, both large and small scale, as well as long-term and short-term changes, including transients such as flares; (2) sources of solar wind, 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 solar wind and transient energetic particle emissions; and (4) origin and propagation of solar cosmic rays as related to solar activity and terrestrial effects, and solar wind coronal-hole relationships and dynamics.

  18. Comet Halley and the solar wind

    SciTech Connect

    Sagdeev, R.Z.; Galeev, A.A.

    1987-03-01

    A qualitative model is presented for the formation and phenomena of a cometary tail. A comet encounters outward moving solar magnetic field lines. Gas and dust from the comet expand outward for several million kilometers and encounter and are stripped into ions by the solar wind. The particles become entwined in the broken solar field lines and spiral away from the sun, beyond the comet, at velocities of 400-500 km/sec, forming a plasma tail. Interplanetary magnetic field perturbations which result were, e.g., detected by the ICE spacecraft 28 million km from Comet Halley. Interactions among the comet bow shock, the solar wind, the IMF lines, and the outward flowing cometary material produce turbulence such as that observed in the tail of Comet Giacobini-Zinner.

  19. Adiabatic cooling of solar wind electrons

    NASA Technical Reports Server (NTRS)

    Sandbaek, Ornulf; Leer, Egil

    1992-01-01

    In thermally driven winds emanating from regions in the solar corona with base electron densities of n0 not less than 10 exp 8/cu cm, a substantial fraction of the heat conductive flux from the base is transfered into flow energy by the pressure gradient force. The adiabatic cooling of the electrons causes the electron temperature profile to fall off more rapidly than in heat conduction dominated flows. Alfven waves of solar origin, accelerating the basically thermally driven solar wind, lead to an increased mass flux and enhanced adiabatic cooling. The reduction in electron temperature may be significant also in the subsonic region of the flow and lead to a moderate increase of solar wind mass flux with increasing Alfven wave amplitude. In the solar wind model presented here the Alfven wave energy flux per unit mass is larger than that in models where the temperature in the subsonic flow is not reduced by the wave, and consequently the asymptotic flow speed is higher.

  20. Diagnostics of the Solar Wind Plasma

    NASA Astrophysics Data System (ADS)

    Issautier, K.

    The solar wind is a fully ionized plasma, coming from the outer atmosphere of the Sun, the so-called solar corona, which expands as a supersonic flow into the interplanetary medium [55]. The first observations indicating that the Sun might be emitting a wind 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 “solar corpuscular radiation” of the Sun. In 1958, E.N. Parker explained theoretically this “particle radiation” using a simple fluid model [55], showing that the solar atmosphere is not in hydrostatic equilibrium but must expand into the interplanetary medium as a wind. The existence of this solar wind 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).

  1. Implications of solar wind measurements for solar models and composition

    NASA Astrophysics Data System (ADS)

    Serenelli, Aldo; Scott, Pat; Villante, Francesco L.; Vincent, Aaron C.; Asplund, Martin; Basu, Sarbani; Grevesse, Nicolas; Peña-Garay, Carlos

    2016-08-01

    We critically examine recent claims of a high solar metallicity by von Steiger & Zurbuchen (2016, vSZ16) based on in situ measurements of the solar wind, rather than the standard spectroscopically-inferred abundances (Asplund et al. 2009, AGSS09). We test the claim by Vagnozzi et al. (2016) that a composition based on the solar wind enables one to construct a standard solar model in agreement with helioseismological observations and thus solve the decades-old solar 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 fare 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 solar interior, identifying the first ionisation potential effect in the outer solar atmosphere and wind as the likely culprit.

  2. Implications of solar wind measurements for solar models and composition

    NASA Astrophysics Data System (ADS)

    Serenelli, Aldo; Scott, Pat; Villante, Francesco L.; Vincent, Aaron C.; Asplund, Martin; Basu, Sarbani; Grevesse, Nicolas; Peña-Garay, Carlos

    2016-11-01

    We critically examine recent claims of a high solar metallicity by von Steiger & Zurbuchen (2016, vSZ16) based on in situ measurements of the solar wind, 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 solar wind enables one to construct a standard solar model in agreement with helioseismological observations and thus solve the decades-old solar 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 solar interior, identifying the first ionization potential effect in the outer solar atmosphere and wind as the likely culprit.

  3. Wind/solar resource in Texas

    SciTech Connect

    Nelson, V.; Starcher, K.; Gaines, H.

    1997-12-31

    Data are being collected at 17 sites to delineate a baseline for the wind and solar resource across Texas. Wind data are being collected at 10, 25, and 40 m (in some cases at 50 m) to determine wind 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 wind 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 wind potential.

  4. 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.

    2016-06-01

    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. However, the following questions remain open: What are the source regions and their contributions to the SSW? What is the role of the magnetic topology in the corona for the origin, acceleration and energy deposition of the SSW? What are the possible acceleration and heating mechanisms for the SSW? The aim of this review is to present insights on the SSW origin and formation gathered from the discussions at the International Space Science Institute (ISSI) by the Team entitled "Slow solar wind sources and acceleration mechanisms in the corona" held in Bern (Switzerland) in March 2014 and 2015.

  5. Magnetic Influences on the Solar Wind

    NASA Astrophysics Data System (ADS)

    Woolsey, Lauren

    2016-05-01

    The steady, supersonic outflow from the Sun we call the solar wind was first posited in the 1950s and initial theories rightly linked the acceleration of the wind to the existence of the million-degree solar corona. Still today, the wind acceleration mechanisms and the coronal heating processes remain unsolved challenges in solar physics. In this work, I seek to answer a portion of the mystery by focusing on a particular acceleration process: Alfven waves launched by the motion of magnetic field footpoints in the photosphere. The entire corona is threaded with magnetic loops and flux tubes that open up into the heliosphere. I have sought a better understanding of the role these magnetic fields play in determining solar wind properties in open flux tubes. After an introduction of relevant material, I discuss my parameter study of magnetic field profiles and the statistical understanding we can draw from the resulting steady-state wind. In the chapter following, I describe how I extended this work to consider time dependence in the turbulent heating by Alfven waves in three dimensional simulations. The bursty nature of this heating led to a natural next step that expands my work to include not only the theoretical, but also a project to analyze observations of small network jets in the chromosphere and transition region, and the underlying photospheric magnetic field that forms thresholds in jet production. In summary, this work takes a broad look at the extent to which Alfven-wave-driven turbulent heating can explain measured solar wind properties and other observed phenomena.

  6. Coronal Plumes in the Fast Solar Wind

    NASA Technical Reports Server (NTRS)

    Velli, Marco; Lionello, Roberto; Linker, Jon A.; Mikic, Zoran

    2011-01-01

    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 solar wind 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 solar wind 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 solar wind, may be easily explained by slightly different heat deposition profiles in different plumes. Statistical pressure balance in the fast wind 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 Solar Orbiter and Solar Probe Plus, should therefore definitely be able to identify plume remnants in the solar wind.

  7. Apollo 11 solar wind composition experiment: first results.

    PubMed

    Bühler, F; Eberhardt, P; Geiss, J; Meister, J; Signer, P

    1969-12-19

    The helium-4 solar wind flux during the Apollo 11 lunar surface excursion was (6.3 +/- 1.2) x 10(6) atoms per square centimeter per second. The solar wind direction and energy are essentially not perturbed by the moon. Evidence for a lunar solar wind albedo was found.

  8. Status of Genesis Mo-Pt Foils

    NASA Technical Reports Server (NTRS)

    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.

    2005-01-01

    A total of 8,000 sq cm of Mo-coated Pt foils were exposed to solar wind for 884 days by the Genesis mission. Solar wind 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 solar wind. The expected flux of these nuclides in the solar wind 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.

  9. Energy Primer: Solar, Water, Wind, and Biofuels.

    ERIC Educational Resources Information Center

    Portola Inst., Inc., Menlo Park, CA.

    This is a comprehensive, fairly technical book about renewable forms of energy--solar, water, wind, 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…

  10. Identifying Wind and Solar Ramping Events: Preprint

    SciTech Connect

    Florita, A.; Hodge, B. M.; Orwig, K.

    2013-01-01

    Wind and solar 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 wind and solar power forecasting; however, its relative utility is also uncertain. Within the variability of solar and wind 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 wind and solar 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.

  11. THOR Cold Solar Wind (CSW) instrument

    NASA Astrophysics Data System (ADS)

    Lavraud, Benoit; De Keyser, Johan; Amoros, Carine; Neef, Eddy; Anciaux, Michel; Andre, Nicolas; Baruah, Rituparna; Berkenbosch, Sophie; Bonnewijn, Sabrina; Cara, Antoine; Echim, Marius; Fedorov, Andrei; Genot, Vincent; Licciardi, Lucas; Louarn, Philippe; Maes, Jeroen; Maggiolo, Romain; Mathon, Romain; Ranvier, Sylvain; Wong, King-Wah

    2016-04-01

    Turbulence Heating ObserveR (THOR) is the first mission ever flown in space dedicated to the study of plasma turbulence. We present the Cold Solar Wind (CSW) instrument that is being designed for THOR. CSW will measure the full three dimensional distribution functions of solar wind protons and alphas with unprecedented accuracies. It will measure solar wind proton distributions in 150 ms with energy resolution of 5-7% and angular resolution of 3°. 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) and an Application-Specific Integrated Circuit (ASIC) for charge amplification. 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 solar wind turbulence.

  12. Electrodynamic sailing - Beating into the solar wind.

    NASA Technical Reports Server (NTRS)

    Sonett, C. P.; Fahleson, U.; Alfven, H.

    1972-01-01

    The recent suggestion by Alfven (1972) of a novel means of spacecraft propulsion based upon energy extraction from the electromagnetic field of the solar wind is critically reviewed. In response to this review, the original suggestion is somewhat amplified and clarified by its author.

  13. Magnetohydrodynamic turbulence in the solar wind

    NASA Technical Reports Server (NTRS)

    Matthaeus, W. H.; Goldstein, M. L.

    1983-01-01

    Recent work in describing the solar wind as an MHD turbulent fluid has shown that the magnetic fluctuations are adequately described as time stationary and to some extent as spatially homogeneous. Spectra of the three rugged invariants of incompressible MHD are the principal quantities used to characterize the velocity and magnetic field fluctuations. Unresolved issues concerning the existence of actively developing turbulence are discussed.

  14. The energy balance of the solar wind

    NASA Technical Reports Server (NTRS)

    Hollweg, J. V.

    1981-01-01

    The effects of modifying some of the 'classical' assumptions underlying many of the solar wind models constructed over the past 20 years are examined in an effort to obtain both a better fit with the observations and a deeper understanding of the relevant physical processes.

  15. Combined Solar and Wind Energy Systems

    NASA Astrophysics Data System (ADS)

    Tripanagnostopoulos, Y.; Souliotis, M.; Makris, Th.

    2010-01-01

    In this paper we present the new concept of combined solar and wind energy systems for buildings applications. Photovoltaics (PV) and small wind turbines (WTs) can be install on buildings, in case of sufficient wind 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 solar 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 solar part depends on the sunshine time and the output of the wind turbine part depends on the wind 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.

  16. Material Interactions with Solar Wind Ion Environments

    NASA Technical Reports Server (NTRS)

    Minow, Joseph I.; McWilliams, Brett

    2006-01-01

    Solar wind 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 solar wind velocity from 300 km/s to 1000 km/sec with extremes of a few 10 s keV during periods of extremely high solar wind 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 solar sail propulsion systems for use in a variety of locations in the inner solar system from 0.5 to 1 AU. In addition, there is interest in designing spacecraft for solar 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 solar UV photons which can compromise mission requirements. This paper will evaluate the relative contributions of sputtering and blister formation to material degradation in solar wind environments over a range of radial distances from the Sun to demonstrate where solar wind environments become important for materials selection. We will first review the physics and results from laboratory measurements of light ion sputtering

  17. The origin of the solar wind

    NASA Technical Reports Server (NTRS)

    Axford, W. I.; McKenzie, J. F.

    1995-01-01

    The high speed solar wind, 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 wind, with its associated coronal holes, forms the basic mode of solar wind flow. In contrast, the low speed wind 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 solar wind 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 solar wind 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 wind. 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

  18. Electric solar wind sail mass budget model

    NASA Astrophysics Data System (ADS)

    Janhunen, P.; Quarta, A. A.; Mengali, G.

    2013-02-01

    The electric solar wind sail (E-sail) is a new type of propellantless propulsion system for Solar System transportation, which uses the natural solar wind to produce spacecraft propulsion. The E-sail consists of thin centrifugally stretched tethers that are kept charged by an onboard electron gun and, as such, experience Coulomb drag through the high-speed solar wind plasma stream. This paper discusses a mass breakdown and a performance model for an E-sail spacecraft that hosts a mission-specific payload of prescribed mass. In particular, the model is able to estimate the total spacecraft mass and its propulsive acceleration as a function of various design parameters such as the number of tethers and their length. A number of subsystem masses are calculated assuming existing or near-term E-sail technology. In light of the obtained performance estimates, an E-sail represents a promising propulsion system for a variety of transportation needs in the Solar System.

  19. Noncompressive density enhancements in the solar wind

    NASA Technical Reports Server (NTRS)

    Gosling, J. T.; Asbridge, J. R.; Bame, S. J.; Feldman, W. C.; Hildner, E.

    1977-01-01

    When the bulk flow speed is nearly constant or falling, high densities are sometimes observed in the solar wind. These densities do not appear to be generated in interplanetary space. It is noted that the magnetic field is not enhanced within these events, and that the proton and/or electron temperatures are low, varying in opposition to the density. About 1/3 of these density events contains interplanetary magnetic field reversals, some of which are noisy and do not qualify as sector boundaries. It is estimated that the average event contains approximately 10 to the 16th g of material and 2.6 x 10 to the 31st ergs, so that aggregated events, when they are common, make a negligible contribution to the total mass and energy budget of the solar wind at 1 AU. It is suggested that there may be an association between density enhancements and solar coronal mass ejection events.

  20. Imaging the origins of solar wind variability

    NASA Astrophysics Data System (ADS)

    DeForest, C.; Howard, T. A.

    2012-12-01

    STEREO/SECCHI permits near-continuous imaging of of solar plasma packets as they form and propagate from the low, middle, and high corona into the heliosphere. The plasma packets in the solar wind "should" be visible as they leave the Sun. So why are they hard to view? Partly because it is difficult to identify the relevant phenomena against the changing, bright background of the corona itself. We will show recently produced movies from the COR and HI instruments in the STEREO/SECCHI suite, using new motion-filtering and background subtraction techniques that highlight variable features over the fixed and slowly-evolving streamer belt. These data reveal several potential sources of the solar wind variability, including packets of departing coronal material, signs of turbulent instabilities that may break up some streamers, and possible turbulent mixing in the low heliosphere. We will present initial results and discuss the course of future work.

  1. Numerical simulations to study solar wind turbulence

    SciTech Connect

    Sharma, R. P.; Sharma, Nidhi; Kumar, Sanjay; Kumar, Sachin; Singh, H. D.

    2011-02-15

    Numerical simulation of coupled equations of kinetic Alfven wave (KAW) and ion acoustic wave is presented in the solar wind. 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 solar 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 solar wind.

  2. Martian ionosphere response to solar wind variability during solar minimum

    NASA Astrophysics Data System (ADS)

    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

    2016-04-01

    Solar cycle variations in solar radiation create notable density changes in the Martian ionosphere. In addition to this long-term variability, there are numerous short-term and non-recurrent solar events that hit Mars which need to be considered, such as Interplanetary Coronal Mass Ejections (ICMEs), Co-Rotation Interaction Regions (CIRs), solar flares, or solar wind 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 solar activity in 2008 and 2009. This work shows the long-term solar 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 solar 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 solar 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 solar wind data are provided by ACE and STEREO-B and supported by simulations using the WSA-ENLIL Model. The solar wind conditions lead to the formation of a CIR centred on the interface of the fast and the slow solar wind streams. Mars' system reacted to

  3. Small Particulate Contamination Survey Of Genesis Flight Sample 61423

    NASA Technical Reports Server (NTRS)

    Kuhlman, K. R.; Schmeling, M.; Gonzalez, C. P.; Allums, K. K.; Allton, J. H.; Burnett, D. S.

    2016-01-01

    The Genesis mission collected solar wind and brought it back to Earth in order to provide precise knowledge of solar isotopic and elemental compositions. The ions in the solar wind 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 solar wind and must be preserved throughout sample handling, cleaning, processing, distribution, preparation and analysis. We continue to work with the community of scientists analyzing Genesis samples using our unique laboratory facilities -- and, where needed, our unique cleaning techniques -- to significantly enhance the science return from the Genesis mission. This work is motivated by the need to understand the submicron contamination on the collectors in the Genesis 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 solar-wind signal intact.

  4. Wind and IMP 8 Solar Wind, Magnetosheath and Shock Data

    NASA Technical Reports Server (NTRS)

    2004-01-01

    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 solar wind data with flags indicating whether each data point is in the solar wind, 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 Wind 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/wind/sheath These are the two products promised in the work statement and they have been completed in full.

  5. Solar Wind Ablation of Terrestrial Planet Atmospheres

    NASA Technical Reports Server (NTRS)

    Moore, Thomas Earle; Fok, Mei-Ching H.; Delcourt, Dominique C.

    2009-01-01

    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 wind 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 wind ablation of volatile materials from the system- Planets or smaller bodies that harbor intrinsic magnetic fields develop an apparent shield against direct stellar wind 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 solar wind 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 wind 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 wind. Bodies with little sensible atmosphere may still produce an exosphere of sputtered matter when exposed to direct solar wind impact. Bodies with a magnetosphere and internal sources of plasma interact more strongly with the stellar wind owing to the magnetic linkage between the two created by reconnection.

  6. On Solar-Wind Electron Heating at Large Solar Distances

    NASA Astrophysics Data System (ADS)

    Chashei, Igor V.; Fahr, Hans J.

    2014-04-01

    We study the temperature of electrons advected with the solar wind to large solar distances far beyond 1 AU. Almost nothing is known about the thermodynamics of these electrons from in-situ plasma observations at these distances, and usually it is tacitly assumed that electrons, due to adiabatic behaviour and vanishing heat conduction, rapidly cool off to very low temperatures at larger distances. In this article we show, however, that electrons on their way to large distances undergo non-adiabatic interactions with travelling shocks and solar-wind bulk-velocity jumps and thereby are appreciably heated. Examining this heating process on an average statistical basis, we find that solar-wind electrons first cool down to a temperature minimum, which depending on the occurrence frequency of bulk velocity jumps is located between 3 and 6 AU, but beyond this the lowest electron temperature again starts to increase with increasing solar distance, finally achieving temperatures of about 7×104 K to 7×105 K at the location of the termination shock. Hence these electrons are unexpectedly shown to play an important dynamical role in structuring this shock and in determining the downstream plasma properties.

  7. Elemental building blocks of the slow solar wind

    NASA Astrophysics Data System (ADS)

    Kepko, L.; Viall, N. M.; Lepri, S. T.

    2014-12-01

    While the source of the fast solar wind is well understood to be linked to coronal holes, the source of the slow solar wind has remained elusive. A distinguishing characteristic of the slow solar wind is the high variability of the plasma parameters, such as magnetic field, velocity, density, composition, and charge state. Many previous studies of the slow solar wind have examined trends in the composition and charge states over long time scales and using data with comparatively low temporal resolution. In this study, we take advantage of high time resolution (12 min) measurements of the charge-state abundances recently reprocessed by the ACE SWICS science team to probe the timescales of solar wind variability of coherent structures at relatively small scales (<2000 Mm, or ~ 90 minutes at slow wind speeds). We use an interval of slow solar wind containing quasi pressure-balanced, periodic number density structures previously studied by Kepko et al and shown to be important in solar wind-magnetospheric coupling. The combination of high temporal resolution composition measurements and the clearly identified boundaries of the periodic structures allows us to probe the elemental slow solar wind flux tubes/structures. We use this train of 2000Mm periodic density structures as tracers of solar wind origin and/or acceleration. We find that each 2000 Mm parcel of slow solar wind, though its speed is steady, exhibits the complete range of charge state and composition variations expected for the entire range of slow solar wind, in a repeated sequence. Each parcel cycles through three states: 1) 'normal' slow wind, 2) compositionally slow wind with very high density, and 3) compositionally fast but typical slow solar wind density. We conclude by suggesting these structures form elemental building blocks of the slow solar wind, and discuss whether it is necessary to decouple separately the process(es) responsible for the release and acceleration.

  8. Magnetosheath influence on solar wind - magnetosphere coupling

    NASA Astrophysics Data System (ADS)

    Pulkkinen, Tuija; Kilpua, Emilia; Dimmock, Andrew; Myllys, Minna; Osmane, Adnane; Nykyri, Katariina; Lakka, Antti

    2016-07-01

    We have shown that the solar wind - 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 solar wind 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 solar wind - 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 solar minimum in 2008-2010, comparing the results with steady but stronger drivers during magnetic cloud events.

  9. Pluto's solar wind interaction: Collisional effects

    NASA Astrophysics Data System (ADS)

    Cravens, T. E.; Strobel, D. F.

    2015-01-01

    Exospheric neutral atoms and molecules (primarily N2, with trace amounts of CH4 and CO according to our current understanding of Pluto's atmosphere) escape from Pluto and travel into interplanetary space for millions of kilometers. Eventually, the neutrals are ionized by solar EUV photons and/or by collisions with solar wind electrons. The mass-loading associated with this ion pick-up is thought to produce a comet-like interaction of the solar wind with Pluto. Within a few thousand kilometers of Pluto the solar wind interaction should lead to a magnetic field pile-up and draping, as it does around other "non-magnetic" bodies such as Venus and comets. The structure of plasma regions and boundaries will be greatly affected by large gyroradii effects and the extensive exosphere. Energetic plasma should disappear from the flow within radial distances of a few thousand kilometers due to charge exchange collisions. An ionosphere should be present close to Pluto with a composition that is determined both by the primary ion production and ion-neutral chemistry. One question discussed in the paper is whether or not the ionosphere has a Venus-like sharply defined ionopause boundary or a diamagnetic cavity such as that found around comet Halley. Simple physical estimates of plasma processes and structures in the collision-dominated region are made in this paper and predictions are made for the New Horizons mission.

  10. Magnetic latitude effects in the solar wind

    NASA Technical Reports Server (NTRS)

    Winge, C. R., Jr.; Coleman, P. J., Jr.

    1972-01-01

    The Weber-Davis model of the solar wind is generalized to include the effects of latitude. The principal assumptions of high electrical conductivity, rotational symmetry, the polytropic relation between pressure and density, and a flow-alined field in a system rotating with the sun, are retained. An approximate solution to the resulting equations for spherical boundary conditions at the base of the corona indicates a small component of latitudinal flow toward the solar poles at large distances from the sun as result of latitudinal magnetic forces.

  11. Suprathermal Solar Wind Electrons and Langmuir Turbulence

    NASA Astrophysics Data System (ADS)

    Kim, Sunjung; Yoon, Peter H.; Choe, G. S.; moon, Y.-J.

    2016-09-01

    The steady-state model recently put forth for the solar wind electron velocity distribution function during quiet time conditions, was originally composed of three population electrons (core, halo, and superhalo) with the core remaining nonresonant with any plasma waves while the halo and superhalo separately maintained steady-state resonance with whistler- and Langmuir-frequency range fluctuations, respectively. However, a recent paper demonstrates that whistler-range fluctuations in fact have no significant contribution. The present paper represents a consummation of the model in that a self-consistent model of the suprathermal electron population, which encompasses both the halo and the superhalo, is constructed solely on the basis of the Langmuir fluctuation spectrum. Numerical solutions to steady-state particle and wave kinetic equations are obtained on the basis of an initial trial electron distribution and Langmuir wave spectrum. Such a finding offers a self-consistent explanation for the observed steady-state electron distribution in the solar wind.

  12. Deimos: an obstacle to the solar wind.

    PubMed

    Sauer, K; Dubinin, E; Baumgärtel, K; Bogdanov, A

    1995-08-25

    Two isolated solar wind 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 solar wind 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.

  13. Latitudinal Variation of Solar Wind Velocity

    NASA Astrophysics Data System (ADS)

    Ananthakrishnan, S.; Balasubramanian, V.; Janardhan, P.

    1995-04-01

    Single station solar wind velocity measurements using the Ooty Radio Telescope (ORT) in India (operating at 327 MHz) are reported for the period August 1992 to August 1993. Interplanetary scintillation (IPS) observations on a large number of compact radio sources covering a latitudinal range of ±80° were used to derive solar wind velocities using the method of fitting a power law model to the observed IPS spectra. The data shows a velocity versus heliographic latitude pattern which is similar to that reported by Rickett and Coles (1991) for the 1981 1982 period. However, the average of the measured equatorial velocities are higher, being about 470 km s-1 compared to their value of 400 km s-1. The distribution of electron density variations (ΔN e ) between 50R⊙ and 90R⊙ was also determined and it was found that ΔN e was about 30% less at the poles as compared to the equator.

  14. The solar wind and magnetospheric dynamics

    NASA Technical Reports Server (NTRS)

    Russell, C. T.

    1974-01-01

    The dynamic processes involved in the interaction between the solar wind 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 solar wind-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.

  15. Anisotropy in solar wind plasma turbulence.

    PubMed

    Oughton, S; Matthaeus, W H; Wan, M; Osman, K T

    2015-05-13

    A review of spectral anisotropy and variance anisotropy for solar wind 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 solar wind parameters.

  16. Solar wind thermally induced magnetic fluctuations.

    PubMed

    Navarro, R E; Moya, P S; Muñoz, V; Araneda, J A; F-Viñas, A; Valdivia, J A

    2014-06-20

    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 solar wind, 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 solar wind.

  17. Solar-wind interaction with planetary ionospheres

    NASA Technical Reports Server (NTRS)

    Cloutier, P. A.

    1976-01-01

    Planetary encounters by numerous spacecraft have furnished information concerning the solar wind 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 solar wind 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.

  18. Turbulence and waves in the solar wind

    SciTech Connect

    Roberts, D.A.; Goldstein, M.L. )

    1991-01-01

    Studies of turbulence and waves in the solar wind 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.

  19. Magnetic pumping of the solar wind

    NASA Astrophysics Data System (ADS)

    Egedal, Jan; Lichko, Emily; Daughton, William

    2015-11-01

    The transport of matter and radiation in the solar wind and terrestrial magnetosphere is a complicated problem involving competing processes of charged particles interacting with electric and magnetic fields. Given the rapid expansion of the solar wind, it would be expected that superthermal electrons originating in the corona would cool rapidly as a function of distance to the Sun. However, this is not observed, and various models have been proposed as candidates for heating the solar wind. In the compressional pumping mechanism explored by Fisk and Gloeckler particles are accelerated by random compressions by the interplanetary wave turbulence. This theory explores diffusion due to spatial non-uniformities and provides a mechanism for redistributing particle. For investigation of a related but different heating mechanism, magnetic pumping, in our work we include diffusion of anisotropic features that develops in velocity space. The mechanism allows energy to be transferred to the particles directly from the turbulence. Guided by kinetic simulations a theory is derived for magnetic pumping. At the heart of this work is a generalization of the Parker Equation to capture the role of the pressure anisotropy during the pumping process. Supported by NASA grant NNX15AJ73G.

  20. The MAVEN Solar Wind Electron Analyzer

    NASA Astrophysics Data System (ADS)

    Mitchell, D. L.; Mazelle, C.; Sauvaud, J.-A.; Thocaven, J.-J.; Rouzaud, J.; Fedorov, A.; Rouger, P.; Toublanc, D.; Taylor, E.; Gordon, D.; Robinson, M.; Heavner, S.; Turin, P.; Diaz-Aguado, M.; Curtis, D. W.; Lin, R. P.; Jakosky, B. M.

    2016-04-01

    The MAVEN Solar Wind Electron Analyzer (SWEA) is a symmetric hemispheric electrostatic analyzer with deflectors that is designed to measure the energy and angular distributions of 3-4600-eV electrons in the Mars environment. This energy range is important for impact ionization of planetary atmospheric species, and encompasses the solar wind core and halo populations, shock-energized electrons, auroral electrons, and ionospheric primary photoelectrons. The instrument is mounted at the end of a 1.5-meter boom to provide a clear field of view that spans nearly 80 % of the sky with ˜20° resolution. With an energy resolution of 17 % (Δ E/E), SWEA readily distinguishes electrons of solar wind and ionospheric origin. Combined with a 2-second measurement cadence and on-board real-time pitch angle mapping, SWEA determines magnetic topology with high (˜8-km) spatial resolution, so that local measurements of the plasma and magnetic field can be placed into global context.

  1. Quasi-steady solar wind dynamics

    NASA Technical Reports Server (NTRS)

    Pizzo, V. J.

    1983-01-01

    Progress in understanding the large scale dynamics of quasisteady, corotating solar wind structure was reviewed. The nature of the solar wind 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 solar wind 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.

  2. Magnetospheric feedbacks in solar wind energy transfer

    NASA Astrophysics Data System (ADS)

    Palmroth, Minna; Pulkkinen, Tuija I.; Anekallu, Chandrasekhar R.; Honkonen, Ilja; Koskinen, Hannu E. J.; Lucek, Elizabeth A.; Dandouras, Iannis

    2010-05-01

    The solar wind kinetic energy, fueling all dynamical processes within the near-Earth space, is extracted by a dynamo process at the magnetopause converting kinetic energy into magnetic energy. We investigate the magnetopause energy transfer both in small and large scales; using Cluster observations as well as a three-dimensional global magnetohydrodynamic (MHD) simulation GUMICS-4. In the simulation, the spatial distribution of the energy transfer exhibits a dependence on the interplanetary magnetic field (IMF) orientation, which is shown to agree with observational local estimates from Cluster spacecraft recordings. In both sythetic runs with artificial solar wind input as well as in reproductions of the observed solar wind we observe a "hysteresis" effect, where the magnetopause energy input stays enhanced longer than the traditional energy transfer proxies (e.g., epsilon) indicate. Specifically we focus in the simulation of a substorm sequence on Feb 18, 2004, during which an exceptional agreement between the simulation results and spacecraft recordings was observed on several orbits within the near-Earth space. In this event, we again observe the hysteresis effect and investigate the processes causing it at the magnetopause. We argue that since GUMICS-4 reproduces the observed signatures of the substorm sequence in question, the simulation results represent physical processes within the magnetosphere. We conclude that as the simulation energy input exhibits delays already at the magnetopause, the delays in the classical substorm loading - unloading cycle may be interpreted in a new light.

  3. Solar Wind Charge Exchange During Geomagnetic Storms

    NASA Technical Reports Server (NTRS)

    Robertson, Ina P.; Cravens, Thomas E.; Sibeck, David G.; Collier, Michael R.; Kuntz, K. D.

    2012-01-01

    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 solar wind-magnetosphere interaction during the peak of this geomagnetic storm. Robertson et aL then modeled the expected 50ft 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 July 14, 2000 (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.

  4. Western Wind and Solar Integration Study (Fact Sheet)

    SciTech Connect

    Not Available

    2012-09-01

    Initiated in 2007 to examine the operational impact of up to 35% penetration of wind, photovoltaic (PV), and concentrating solar power (CSP) energy on the electric power system, the Western Wind and Solar Integration Study (WWSIS) is one of the largest regional wind and solar integration studies to date. The goal is to understand the effects of variability and uncertainty of wind, PV, and CSP on the grid. In the Western Wind and Solar Integration Study Phase 1, solar 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 Wind and Solar Integration Study Phase 2 to include high penetrations of solar - not only CSP and rooftop PV but also utility-scale PV plants.

  5. Solar wind effects on atmosphere evolution at Venus and Mars

    NASA Technical Reports Server (NTRS)

    Luhmann, Janet G.; Bauer, S. J.

    1992-01-01

    The weak intrinsic magnetism of Venus and Mars leaves these planets subject to some unique atmospheric loss processes. This paper reviews the ways in which material seems to be removed by the solar wind interaction, including atmospheric ion pickup by the solar wind, bulk removal and outflow of ionospheric plasma, and atmospheric sputtering by pickup ions. The factors in the planets' and sun's histories, such as planetary magnetism, solar luminosity, and past solar wind properties, that must ultimately be folded into considerations of the effects of the solar wind interaction on atmosphere evolution are discussed.

  6. Solar-wind control of the extent of planetary ionospheres

    NASA Technical Reports Server (NTRS)

    Bauer, S. J.

    1976-01-01

    In our solar 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 solar wind, whereas the ionosphere of Venus, at least, interacts directly with the solar wind. However, the solar wind interaction with the planetary environment, in both cases, affects the behavior of their ionospheres. The role the solar wind interaction plays in limiting the extent of the ionospheres of both magnetic and nonmagnetic planets is discussed.

  7. Electron energy flux in the solar wind.

    NASA Technical Reports Server (NTRS)

    Ogilvie, K. W.; Scudder, J. D.; Sugiura, M.

    1971-01-01

    Description of studies of electrons between 10 eV and 9.9 keV in the solar wind. 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 solar 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 solar-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 solar-wind theories.

  8. Cosmic ray modulation by solar wind disturbances

    NASA Astrophysics Data System (ADS)

    Dumbović, M.; Vršnak, B.; Čalogović, J.; Karlica, M.

    2011-07-01

    Aims: We perform a systematic statistical study of the relationship between characteristics of solar wind disturbances, caused by interplanetary coronal mass ejections and corotating interaction regions, and properties of Forbush decreases (FDs). Since the mechanism of FDs is still being researched, this analysis should provide a firm empirical basis for physical interpretations of the FD phenomenon. Methods: The analysis is based on the ground-based neutron monitor data and the solar wind data recorded by the Advanced Composition Explorer, where the disturbances were identified as increases in proton speed, magnetic field, and magnetic field fluctuations. We focus on the relative timing of FDs, as well as on the correlations between various FD and solar wind parameters, paying special attention to the statistical significance of the results. Results: It was found that the onset, the minimum, and the end of FDs are delayed after the onset, the maximum, and the end of the magnetic field enhancement. The t-test shows that at the 95% significance level the average lags have to be longer than 3, 7, and 26 h, respectively. FD magnitude (| FD|) is correlated with the magnetic field strength (B), magnetic field fluctuations (δB), and speed (v), as well as with combined parameters, BtB, Bv, vtB, and BvtB, where tB is the duration of the magnetic field disturbance. In the |FD|(B) dependence, a "branching" effect was observed, i.e., two different trends exist. The analysis of the FD duration and recovery period reveals a correlation with the duration of the magnetic field enhancement. The strongest correlations are obtained for the dependence on combined solar wind parameters of the product of the FD duration and magnitude, implying that combined parameters are in fact true variables themselves, rather than just a product of variables. Conclusions: From the time lags we estimate that "the penetration depth" in the disturbance, at which FD onset becomes recognizable, is on

  9. Solar Wind Boron in Ilmenite Grains from Lunar Soil 71501

    NASA Astrophysics Data System (ADS)

    Fujiya, W.; Bochsler, P.; Wieler, R.; Hoppe, P.; Ott, U.

    2016-08-01

    We measured abundances of solar wind boron implanted into ilmenite grains from lunar soil 71501. The inferred B/Ar ratio of the solar wind is ~3 x 10^-3, which is a factor of ~15 higher than the solar photospheric ratio.

  10. Solar Wind Nine: Proceedings of the Ninth International Solar Wind Conference. Proceedings

    SciTech Connect

    Habbal, S.R.; Esser, R.; Hollweg, J.V.; Isenberg, P.A.

    1999-06-01

    These proceedings represent papers presented at the 9th Solar Wind International Conference, held in Nantucket, Massachusetts, USA, in October, 1998. The Conference was attended by 235 scientists from 25 countries. The aim of the Conference was to integrate theory, modeling, in situ measurements, and remote sensing observations of the solar wind. The Conference succeeded in accomplishing that, as is evident from the papers presented. The topics discussed included coronal plasma and streamers, small scale magnetic structure, dynamics of large scale structure, coronal mass ejection, waves and turbulence, the outer heliosphere, magnetohydrodynamics radio tracking, bursts and shock waves, and galactic cosmic rays. At the beginning of the Conference, a historical overview was presented by E. N. Parker, the predictor of solar wind forty years ago. There were 188 papers presented at the conference, out of which 15 have been abstracted for the Energy,Science and Technology database.(AIP)

  11. Dust in the Solar Wind

    NASA Astrophysics Data System (ADS)

    Kramer, Emily; Bauer, James; Mainzer, Amy; Grav, Tommy; Nugent, Carolyn; Sonnett, Sarah; Stevenson, Rachel

    2015-08-01

    As some of the most pristine objects in the Solar System, comets present an excellent opportunity to understand the mechanics and chemistry of the planetary formation era. By studying a large number of comets in different dynamical classes, we can better understand their ensemble properties.NEOWISE is the planetary-funded mission that uses data from the Wide-field Infrared Survey Explorer (WISE) spacecraft to detect and characterize moving objects. The WISE mission surveyed the sky in four infrared wavelength bands (3.4, 4.6, 12 and 22-microns) between January 2010 and February 2011, during which time over 160 comets were detected. Since the restart of the mission as NEOWISE in December 2013, over 60 additional comets have been observed in the shorter two wavelength channels. In both phases of the mission, a mix of both long-period comets and short-period comets were detected. Over half of the comets in the prime mission displayed a significant dust tail in the 12 and 22-micron (thermal emission) bands, showing a wide range of activity levels and dust morphology. In both the prime and restarted phases of the mission, extended dust structures were also detected for many of the comets in the 3.4 and 4.6-micron bands. For the comets that displayed a significant dust tail, we have estimated the sizes and ages of the particles using dynamical models based on the Finson-Probstein method. We will present updated modeling results, comparing the different comet populations.

  12. Topological Origins of the Slow Solar Wind

    NASA Technical Reports Server (NTRS)

    Antiochos, Spiro

    2008-01-01

    Although the slow solar wind 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 wind 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 wind 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 wind 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 wind are discussed, and observational tests of the mode

  13. Coronal Holes and Solar Wind High-Speed Streams: I. Forecasting the Solar Wind Parameters

    NASA Astrophysics Data System (ADS)

    Vršnak, Bojan; Temmer, Manuela; Veronig, Astrid M.

    2007-02-01

    We analyze the relationship between the coronal hole (CH) area/position and physical characteristics of the associated corotating high-speed stream (HSS) in the solar wind 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 solar wind characteristics are found, which allows us to forecast the solar wind 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 solar wind 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 solar wind 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 solar wind characteristics.

  14. Variations of the solar wind and solar cycle in the last 300 years

    NASA Technical Reports Server (NTRS)

    Feynman, J.; Silverman, S.

    1980-01-01

    The past history of the solar wind and solar cycle, inferred from records of geomagnetics and aurora, is examined. Records show that the solar wind 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 solar wind and hence the Sun changes on a time scale long compared to a solar cycle and short compared to the Maunder minimum. The inclusion of a study on the solar wind and solar cycle variations for the SCADM mission is discussed.

  15. Interpretation of Solar Wind Ion Composition Measurements from Ulysses

    NASA Technical Reports Server (NTRS)

    Esser, Ruth

    1998-01-01

    The ion compositions measured in situ in the solar wind 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 solar wind 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 solar wind. The ion charge states in the solar wind 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 solar wind and calculating the ion fractions predicted for different solar wind conditions, constraints on the electron temperature and ion flow speeds can be placed if the electron density is measured using polarization brightness measurements.

  16. Variations of Strahl Properties With Fast and Slow Solar Wind

    NASA Astrophysics Data System (ADS)

    Nieves-Chinchilla, T.; Viñas, A. F.; Goldstein, M. L.; Gurgiolo, C.

    2008-12-01

    The interplanetary solar wind 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 solar wind. 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 solar wind during high and slow speed solar wind. The moment density and fluid velocity have been computed by a semi-numerical integration method. The variations of solar wind density and drift velocity with the general bulk solar wind speed could provide some insight into the source, origin, and evolution of the strahl.

  17. Influence of solar wind variability on geomagnetic activity

    NASA Technical Reports Server (NTRS)

    Garrett, H. B.; Dessler, A. J.; Hill, T. W.

    1974-01-01

    A statistical study of solar wind data from the Explorer 33 satellite shows that interplanetary magnetic field irregularities are enhanced in the interaction region where a fast solar wind stream overtakes a slower solar wind stream. Comparison with geomagnetic AE and ap indexes further shows that these interplanetary irregularities enhance the level of geomagnetic disturbances. Thus while substorm occurrence is highly correlated with the dawn-dusk component of the solar wind electric field, the amplitude of the substorms is an increasing function of the variance in the interplanetary field. This result can be interpreted as a capacitative effect of the magnetopause that allows a time-varying solar wind electric field to penetrate the magnetosphere more effectively than a static solar wind electric field.

  18. Radial evolution of the energy density of solar wind fluctuations

    NASA Technical Reports Server (NTRS)

    Zank, G. P.; Matthaeus, W. H.; Smith, C. W.

    1995-01-01

    On the basis of transport theories appropriate to a radially expanding solar wind, we describe new results for the radial evolution of the energy density in solar wind 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 solar wind heating, cosmic ray diffusion and interstellar pick-up ions will also be addressed.

  19. Morphology of Pseudostreamers and Solar Wind Properties

    NASA Astrophysics Data System (ADS)

    Panasenco, Olga; Velli, Marco

    2016-05-01

    The solar dynamo and photospheric convection lead to three main types of structures extending from the solar surface into the corona - active regions, solar 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 solar wind properties. 1D numerical analysis of PSs shows that the properties of the solar wind from around PSs depend on the presence/absence of filament channels, number of channels and chirality at the PS base low in the corona.

  20. Morphology of Pseudostreamers and Solar Wind Properties

    NASA Astrophysics Data System (ADS)

    Panasenco, Olga; Velli, Marco

    2016-05-01

    The solar dynamo and photospheric convection lead to three main types of structures extending from the solar surface into the corona – active regions, solar 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 solar wind properties. 1D numerical analysis of PSs shows that the properties of the solar wind from around PSs depend on the presence/absence of filament channels, number of channels and chirality at the PS base low in the corona.

  1. Solar wind influence on Jupiter's magnetosphere and aurora

    NASA Astrophysics Data System (ADS)

    Vogt, Marissa; Gyalay, Szilard; Withers, Paul

    2016-04-01

    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-solar wind 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 solar wind is generally expected to have only a small influence on Jupiter's magnetosphere and aurora, 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. We will report on the results of a comprehensive, quantitative study of the influence of the solar wind on various magnetospheric data sets measured by the Galileo mission from 1996 to 2003. 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. 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 solar wind conditions or that the solar wind modulates the quasi-periodicity seen in the magnetic field dipolarizations and flow bursts.

  2. The very slow solar wind: Properties, origin and variability

    NASA Astrophysics Data System (ADS)

    Sanchez-Diaz, Eduardo; Rouillard, Alexis P.; Lavraud, Benoit; Segura, Kevin; Tao, Chihiro; Pinto, Rui; Sheeley, N. R.; Plotnikov, Illya

    2016-04-01

    Solar wind slower than 300 km/s, hereafter termed very slow solar wind (VSSW), is seldom observed at 1 AU. It was, however, commonly measured inside 0.7 AU by the two Helios spacecraft, particularly during solar maximum. Magnetohydrodynamic (MHD) modeling reveals that the disappearance of VSSW at 1 AU is the result of its interaction with faster solar wind. The acceleration and compression of the VSSW contributes to the observed highly variable structure of the slow solar wind at 1 AU. The VSSW usually contains the heliospheric plasma sheet and current sheet. It has higher density and lower temperature than the regular slow solar wind, extending the known scaling laws below 300 km/s. Its helium abundance increases with solar activity even more significantly than the slow solar wind. Contrary to faster solar winds, the helium ions in the VSSW are slower than the dominant protons. Combining a Potential Field Source Surface (PFSS) model with ballistic back tracing, we study the source region of the VSSW. We show that the proton density flux for the VSSW is much higher than for the faster winds, particularly at solar maximum.

  3. Pluto's interaction with the solar wind

    NASA Astrophysics Data System (ADS)

    McComas, D. J.; Elliott, H. A.; Weidner, S.; Valek, P.; Zirnstein, E. J.; Bagenal, F.; Delamere, P. A.; Ebert, R. W.; Funsten, H. O.; Horanyi, M.; McNutt, R. L.; Moser, C.; Schwadron, N. A.; Strobel, D. F.; Young, L. A.; Ennico, K.; Olkin, C. B.; Stern, S. A.; Weaver, H. A.

    2016-05-01

    This study provides the first observations of Plutogenic ions and their unique interaction with the solar wind. We find ~20% solar wind slowing that maps to a point only ~4.5 RP upstream of Pluto and a bow shock most likely produced by comet-like mass loading. The Pluto obstacle is a region of dense heavy ions bounded by a "Plutopause" where the solar wind is largely excluded and which extends back >100 RP into a heavy ion tail. The upstream standoff distance is at only ~2.5 RP. The heavy ion tail contains considerable structure, may still be partially threaded by the interplanetary magnetic field (IMF), and is surrounded by a light ion sheath. The heavy ions (presumably CH4+) have average speed, density, and temperature of ~90 km s-1, ~0.009 cm-3, and ~7 × 105 K, with significant variability, slightly increasing speed/temperature with distance, and are N-S asymmetric. Density and temperature are roughly anticorrelated yielding a pressure ~2 × 10-2 pPa, roughly in balance with the interstellar pickup ions at ~33 AU. We set an upper bound of <30 nT surface field at Pluto and argue that the obstacle is largely produced by atmospheric thermal pressure like Venus and Mars; we also show that the loss rate down the tail (~5 × 1023 s-1) is only ~1% of the expected total CH4 loss rate from Pluto. Finally, we observe a burst of heavy ions upstream from the bow shock as they are becoming picked up and tentatively identify an IMF outward sector at the time of the NH flyby.

  4. Spectroscopic measurements of solar wind generation

    NASA Technical Reports Server (NTRS)

    Kohl, J. L.; Withbroe, G. L.; Zapata, C. A.; Noci, G.

    1983-01-01

    Spectroscopically observable quantities are described which are sensitive to the primary plasma parameters of the solar wind'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.

  5. Solar wind turbulence as a driver of geomagnetic activity

    NASA Astrophysics Data System (ADS)

    Ikechukwu Ugwu, Ernest Benjamin; Nneka Okeke, Francisca; Ugonabo, Obiageli Josephine

    2016-07-01

    We carried out simultaneous analyses of interplanetary and geomagnetic datasets for the period of (solar Maunder) least (2009) and maximum (2002) solar activity to determine the nature of solar wind turbulence on geomagnetic activity using AE, ASY-D, and ASY-H indices. We determined the role played by Alfvénic fluctuations in the solar wind so as to find out the nature of the turbulence. Our analyses showed that solar wind turbulence play a role in geomagnetic processes at high latitudes during periods of low and high solaractivity but does not have any effect at mid-low latitudes.

  6. A numerical study of transient, thermally-conductive solar wind

    NASA Technical Reports Server (NTRS)

    Han, S. M.; Wu, S. T.; Dryer, M.

    1987-01-01

    A numerical analysis of transient solar wind starting at the solar 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 solar wind. Higher thermal conduction results in higher solar wind speed, higher temperature, but lower plasma density at 1 AU. Higher base temperature at the solar 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.

  7. Magnetic Influences on the Solar Wind

    NASA Astrophysics Data System (ADS)

    Woolsey, Lauren N.

    2016-01-01

    The Sun is our closest star, and even with the ability to resolve fine structure, there are several large mysteries that remain unsolved. One of these unanswered questions is how the supersonic outflow from the Sun, the solar wind, is generated and accelerated. In this dissertation, I have investigated the role of Alfvén waves in heating the corona and accelerating the wind. I focus on modeling of flux tubes that are open to the heliosphere, i.e. bundles of magnetic field that stretch beyond a few solar radii into the heliosphere. In these flux tubes, Alfvén waves are launched by the shaking of the footpoints from the convective motions of granulation on the solar photosphere. I present results of modeling efforts in one dimension that investigate how this process changes for a variety of different magnetic field structures over a solar cycle and three-dimensional modeling of time-dependent processes that unlock a connection between pico- and nanoflare-scale events and the turbulent heating generated by counter-propagating Alfvén waves. In addition to computational modeling, I also present efforts to find magnetic thresholds in observations of small-scale network jets seen with the Interface Region Imaging Spectrograph (IRIS). These jets were first discovered by IRIS due to their short lifetimes (10s of seconds) and small size (widths of 100s of kilometers). The findings for this project suggest that the modeled Alfvén-wave-driven turbulence is consistent with these network jets.

  8. Latitudinal Dependence of Coronal Hole-Associated Fast Solar Wind

    NASA Astrophysics Data System (ADS)

    Zhao, L.; Landi, E.

    2014-05-01

    The fast solar wind 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 winds have not been well studied, nor have the differences in their evolution over the solar cycles. Ulysses' 19 years of observations from 1990 to 2009, combined with ACE observations from 1998 to the present, provide us with measurements of solar wind properties that span two entire solar cycles, which allow us to study the in-situ properties and evolution of the coronal hole-associated solar wind at different latitudes. In this work, we focus on the PCH and ECH solar winds during the minima between solar 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 wind and ECH wind, with a special focus on their differences during the recent two solar minima. We also include the slow and hot, streamer-associated (ST) wind as a reference in the comparison. The comparison of PCH and ECH wind shows that: 1) the in-situ properties of ECH and PCH winds are significantly different during the two solar minima, and 2) the two types of coronal hole-associated solar wind respond differently to changes in solar activity strength from cycle 23 to cycle 24.

  9. Ulysses Composition, Plasma and Magnetic Field Observations of High Speed Solar wind Streams

    NASA Technical Reports Server (NTRS)

    Smith, E. J.

    1997-01-01

    During 1992-3 as the Ulysses spacecraft passed in and out of the southern high speed solar wind stream, the Solar Wind Ion Spectrometer, SWICS made continuous composition and temperature measurements of all major solar wind ions.

  10. Magnetic pumping of the solar wind

    NASA Astrophysics Data System (ADS)

    Egedal, Jan; Lichko, Emily; Daughton, William

    2014-10-01

    The transport of matter and radiation in the solar wind and terrestrial magnetosphere is a complicated problem involving competing processes of charged particles interacting with electric and magnetic fields. Given the rapid expansion of the solarwind, it would be expected that superthermal electrons originating in the corona would cool rapidly as a function of distance to the Sun. However, this is not observed, and various models have been proposed as plausible candidates for heating the solar wind as it super-sonically streams away from the sun. In the compressional pumping mechanism explored by Fisk & Gloeckler particles are accelerated by random compressions by the interplanetary wave turbulence. This theory explores diffusion due to spatial non-uniformities and provides a mechanism for redistributing particle. For investigation of a related but different heating mechanism, magnetic pumping, in our work we include diffusion of anisotropic features that develops in velocity space. The mechanism allows energy to be transferred to the particles directly from the turbulence. The efficiency of the process is explored using kinetic simulations. Moved to poster by APS.

  11. Anisotropy in solar wind plasma turbulence.

    PubMed

    Oughton, S; Matthaeus, W H; Wan, M; Osman, K T

    2015-05-13

    A review of spectral anisotropy and variance anisotropy for solar wind 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 solar wind parameters. PMID:25848082

  12. Electric conductivity of plasma in solar wind

    NASA Technical Reports Server (NTRS)

    Chertkov, A. D.

    1995-01-01

    One of the most important parameters in MHD description of the solar wind is the electric conductivity of plasma. There exist now two quite different approaches to the evaluation of this parameter. In the first one a value of conductivity taken from the most elaborated current theory of plasma should be used in calculations. The second one deals with the empirical, phenomenological value of conductivity. E.g.: configuration of interplanetary magnetic field, stretched by the expanding corona, depends on the magnitude of electrical conductivity of plasma in the solar wind. Knowing the main empirical features of the field configuration, one may estimate the apparent phenomenological value of resistance. The estimations show that the electrical conductivity should be approximately 10(exp 13) times smaller than that calculated by Spitzer. It must be noted that the empirical value should be treated with caution. Due to the method of its obtaining it may be used only for 'large-scale' description of slow processes like coronal expansion. It cannot be valid for 'quick' processes, changing the state of plasma, like collisions with obstacles, e.g., planets and vehicles. The second approach is well known in large-scale planetary hydrodynamics, stemming from the ideas of phenomenological thermodynamics. It could formulate real problems which should be solved by modern plasma physics, oriented to be adequate for complicated processes in space.

  13. Variance Anisotropy of Solar Wind fluctuations

    NASA Astrophysics Data System (ADS)

    Oughton, S.; Matthaeus, W. H.; Wan, M.; Osman, K.

    2013-12-01

    Solar wind observations at MHD scales indicate that the energy associated with velocity and magnetic field fluctuations transverse to the mean magnetic field is typically much larger than that associated with parallel fluctuations [eg, 1]. This is often referred to as variance anisotropy. Various explanations for it have been suggested, including that the fluctuations are predominantly shear Alfven waves [1] and that turbulent dynamics leads to such states [eg, 2]. Here we investigate the origin and strength of such variance anisotropies, using spectral method simulations of the compressible (polytropic) 3D MHD equations. We report on results from runs with initial conditions that are either (i) broadband turbulence or (ii) fluctuations polarized in the same sense as shear Alfven waves. The dependence of the variance anisotropy on the plasma beta and Mach number is examined [3], along with the timescale for any variance anisotropy to develop. Implications for solar wind fluctuations will be discussed. References: [1] Belcher, J. W. and Davis Jr., L. (1971), J. Geophys. Res., 76, 3534. [2] Matthaeus, W. H., Ghosh, S., Oughton, S. and Roberts, D. A. (1996), J. Geophys. Res., 101, 7619. [3] Smith, C. W., B. J. Vasquez and K. Hamilton (2006), J. Geophys. Res., 111, A09111.

  14. Anisotropy in solar wind plasma turbulence

    PubMed Central

    Oughton, S.; Matthaeus, W. H.; Wan, M.; Osman, K. T.

    2015-01-01

    A review of spectral anisotropy and variance anisotropy for solar wind 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 solar wind parameters. PMID:25848082

  15. The solar wind effect on cosmic rays and solar activity

    NASA Technical Reports Server (NTRS)

    Fujimoto, K.; Kojima, H.; Murakami, K.

    1985-01-01

    The relation of cosmic ray intensity to solar wind 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 solar activity.

  16. The structure of the solar wind in the inner heliosphere

    NASA Astrophysics Data System (ADS)

    Lee, Christina On-Yee

    2010-12-01

    This dissertation is devoted to expanding our understanding of the solar wind structure in the inner heliosphere and variations therein with solar activity. Using spacecraft observations and numerical models, the origins of the large-scale structures and long-term trends of the solar wind 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 solar wind density, velocity, interplanetary magnetic field, and particles, together with models based on solar magnetic field data, to generate time series of these properties that span one solar rotation (˜27 days). From these time series, I assemble and obtain the synoptic overviews of the solar wind properties. The resulting synoptic overviews show that the solar wind around Mercury, Venus, Earth, and Mars is a complex co-rotating structure with recurring features and occasional transients. During quiet solar 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 solar rotations. Within the sector boundaries are the slow and fast speed solar wind 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 solar period. The existence of these recurring features depends on how long-lived are their source regions. In the last decade, 3D numerical solar wind 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

  17. Genesis Sample Material Subdividing Plans

    NASA Technical Reports Server (NTRS)

    McNamara, K. M.; Stansbery, E. K.

    2004-01-01

    Subdivision of Genesis collectors is necessary to maximize the science return of the mission and retain a representative subset of the collection to archive for the future. The ability to verify important scientific results and resolve experiment anomalies through experiment replication and independent experimental techniques requires a method for subdividing individual sample collectors so that equivalent samples are made available. In addition, subdividing the Genesis collectors is required to accommodate the size limitations of many analytical systems. Samples allocated for analysis are likely to be small sections of individual collectors. Subdivision of returned Genesis solar wind samples must be performed in a manner having minimum impact on the accuracy and interpretation of analytical information obtained from these samples. It is also necessary that we ensure that consequences of any processing are well understood and documented. half of the collectors are actually thin coatings on silicon and sapphire substrates. Most of these are merely physically deposited coatings with limited adhesion and hardness, complicating the handling of these collectors. Finally, the concentrator targets, which are to be evaluated to address the highest priority goals of the mission, represent all of these difficulties and require cutting to greater precision as a result of the extremely limited quantities available.

  18. The solar wind in the third dimension

    SciTech Connect

    Neugebauer, M.

    1996-07-20

    For many years, solar-wind 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 solar corona to estimate the properties of the high-latitude solar wind. 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 solar wind 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

  19. Correlations between solar wind parameters and auroral kilometric radiation intensity

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.; Dangelo, N.

    1981-01-01

    The relationship between solar wind 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 solar wind data from the composite Solar Wind Plasma Data Set, most of which was supplied by the IMP-8 spacecraft. Correlations are made between smoothed daily averages of solar wind ion density, bulk flow speed, total IMF strength, electric field, solar wind speed in the southward direction, solar wind speed multiplied by total IMF strength, the substorm parameter epsilon and the Kp index. The greatest correlation is found between solar wind 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 solar wind.

  20. Solar and wind energy utilization in broiler production

    SciTech Connect

    Brinsfield, R.B.; Yaramanoglu, M.; Wheaton, F.

    1984-01-01

    Available solar and wind energy and both the electrical and thermal energy demand of a typical broiler facility were mathematically modeled based on 10 years of weather data for Salisbury, Maryland. The available energy was then compared with the broiler facility demands as a means of sizing solar and wind energy collection equipment to meet the demands.

  1. Comparative Study of MHD Modeling of the Background Solar Wind

    NASA Astrophysics Data System (ADS)

    Gressl, C.; Veronig, A. M.; Temmer, M.; Odstrčil, D.; Linker, J. A.; Mikić, Z.; Riley, P.

    2014-05-01

    Knowledge about the background solar wind plays a crucial role in the framework of space-weather forecasting. In-situ measurements of the background solar wind are only available for a few points in the heliosphere where spacecraft are located, therefore we have to rely on heliospheric models to derive the distribution of solar-wind parameters in interplanetary space. We test the performance of different solar-wind models, namely Magnetohydrodynamic Algorithm outside a Sphere/ENLIL (MAS/ENLIL), Wang-Sheeley-Arge/ENLIL (WSA/ENLIL), and MAS/MAS, by comparing model results with in-situ measurements from spacecraft located at 1 AU distance to the Sun (ACE, Wind). To exclude the influence of interplanetary coronal mass ejections (ICMEs), we chose the year 2007 as a time period with low solar activity for our comparison. We found that the general structure of the background solar wind is well reproduced by all models. The best model results were obtained for the parameter solar-wind speed. However, the predicted arrival times of high-speed solar-wind streams have typical uncertainties of the order of about one day. Comparison of model runs with synoptic magnetic maps from different observatories revealed that the choice of the synoptic map significantly affects the model performance.

  2. Solar and Wind Technologies for Hydrogen Production Report to Congress

    SciTech Connect

    None, None

    2005-12-01

    DOE's Solar and Wind Technologies for Hydrogen Production Report to Congress summarizes the technology roadmaps for solar- and wind-based hydrogen production. Published in December 2005, it fulfills the requirement under section 812 of the Energy Policy Act of 2005.

  3. Western Wind and Solar Integration Study Phase 3: Technical Overview

    SciTech Connect

    2015-11-01

    Technical fact sheet outlining the key findings of Phase 3 of the Western Wind and Solar 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 wind and solar power.

  4. Three-fluid solar wind model with Alfven waves

    NASA Technical Reports Server (NTRS)

    Esser, Ruth; Habbal, Shadia R.; Hu, You Q.

    1995-01-01

    We present a study of a three-fluid solar wind 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 solar wind as a function of heat input, Alfven wave energy input, and alpha particle abundance.

  5. Turbulence in the solar wind: Kinetic effects

    NASA Technical Reports Server (NTRS)

    Goldstein, M. L.

    1995-01-01

    Although a casual look at the fluctuating magnetic and velocity fields in the solar wind 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 solar wind 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 solar radio bursts.

  6. Alfvénic fluctuations in ``newborn'' polar solar wind

    NASA Astrophysics Data System (ADS)

    Bavassano, B.; Pietropaolo, E.; Bruno, R.

    2005-06-01

    The 3-D structure of the solar wind is strongly dependent upon the Sun's activity cycle. At low solar activity a bimodal structure is dominant, with a fast and uniform flow at the high latitudes, and slow and variable flows at low latitudes. Around solar maximum, in sharp contrast, variable flows are observed at all latitudes. This last kind of pattern, however, is a relatively short-lived feature, and quite soon after solar maximum the polar wind tends to regain its role. The plasma parameter distributions for these newborn polar flows appear very similar to those typically observed in polar wind at low solar activity. The point addressed here is about polar wind fluctuations. As is well known, the low-solar-activity polar wind is characterized by a strong flow of Alfvénic fluctuations. Does this hold for the new polar flows too? An answer to this question is given here through a comparative statistical analysis on parameters such as total energy, cross helicity, and residual energy, that are of general use to describe the Alfvénic character of fluctuations. Our results indicate that the main features of the Alfvénic fluctuations observed in low-solar-activity polar wind have been quickly recovered in the new polar flows developed shortly after solar maximum. Keywords. Interplanetary physics (MHD waves and turbulence; Sources of the solar wind) Space plasma physics (Turbulence)

  7. The Western Wind and Solar Integration Study Phase 2

    SciTech Connect

    Lew, D.; Brinkman, G.; Ibanez, E.; Hodge, B. M.; Hummon, M.; Florita, A.; Heaney, M.

    2013-09-01

    The electric grid is a highly complex, interconnected machine, and changing one part of the grid can have consequences elsewhere. Adding wind and solar 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 Wind and Solar Integration Study (WWSIS-2) evaluated these costs and emissions and simulated grid operations for a year to investigate the detailed impact of wind and solar on the fossil-fueled fleet. This built on Phase 1, one of the largest wind and solar integration studies ever conducted, which examined operational impacts of high wind and solar penetrations in the West.

  8. The Western Wind and Solar Integration Study Phase 2

    SciTech Connect

    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.

    2013-09-01

    The electric grid is a highly complex, interconnected machine, and changing one part of the grid can have consequences elsewhere. Adding wind and solar 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 Wind and Solar Integration Study (WWSIS-2) evaluated these costs and emissions and simulated grid operations for a year to investigate the detailed impact of wind and solar on the fossil-fueled fleet. This built on Phase 1, one of the largest wind and solar integration studies ever conducted, which examined operational impacts of high wind and solar penetrations in the West(GE Energy 2010).

  9. INTERPRETING MAGNETIC VARIANCE ANISOTROPY MEASUREMENTS IN THE SOLAR WIND

    SciTech Connect

    TenBarge, J. M.; Klein, K. G.; Howes, G. G.; Podesta, J. J.

    2012-07-10

    The magnetic variance anisotropy (A{sub m}) of the solar wind has been used widely as a method to identify the nature of solar wind 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 solar wind 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 solar wind measurements. In both cases, linear theory compares well and suggests that the solar wind for the interval studied is dominantly Alfvenic in the inertial and dissipation ranges to scales of k{rho}{sub i} {approx_equal} 5.

  10. Solar wind iron charge states preceding a driver plasma

    NASA Technical Reports Server (NTRS)

    Galvin, A. B.; Ipavich, F. M.; Gloeckler, G.; Hovestadt, D.; Tsurutani, B. T.

    1987-01-01

    Iron and silicon/sulfur charge state and velocity measurements and iron density measurements in the shocked solar wind which preceded the flare-related driver plasma observed on September 29, 1978 by ISEE 3 are reported. Given the assumption that the driver plasma is magnetically isolated from the ambient solar wind, the contact surface separating these two plasma regimes is expected to form an distinct boundary in the charge state composition. Instead, an apparent transition in the ionization state of the shocked solar wind from ambient solar wind values to those typical of the driver plasma is observed. This result may reflect X-ray ionization of the solar wind plasma near the flare site.

  11. Magnetohydrodynamic modeling of the solar wind in the outer heliosphere

    SciTech Connect

    Usmanov, A. V.; Goldstein, M. L.; Matthaeus, W. H.

    2012-05-21

    We present initial results from a solar wind model that accounts for transport of turbulence and treats pickup protons as a separate fluid. The model is based on a numerical solution of the coupled set of mean-field Reynolds-averaged solar wind equations and small-scale turbulence transport equations in the region from 0.3-100 AU. The pickup protons are assumed to be comoving with the solar wind flow and described by separate mass and energy equations. The equations include the terms for energy transfer from pickup protons to solar wind protons and for the plasma heating by turbulent dissipation. The momentum equation contains a term that describes the loss of momentumby the solar wind flow due to the charge exchangewith the interstellar neutral hydrogen.

  12. Geomagnetic responses to the solar wind and the solar activity

    NASA Technical Reports Server (NTRS)

    Svalgaard, L.

    1975-01-01

    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 solar wind 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 solar wind 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.

  13. Abundance variations in the solar wind

    NASA Astrophysics Data System (ADS)

    von Steiger, R.; Schweingruber, R. F. Wimmer; Geiss, J.; Gloeckler, G.

    1995-07-01

    The solar wind (SW) allows us to probe the solar material in situ, particularly its composition, without the need to fly a spacecraft to inhospitably small heliocentric distances. However, it turns out that this plasma source is biased with respect to the photosphere. Elements with a low first ionization potential (FIP) are overabundant by a factor of 3-5 relative to high-FIP elements in the slow SW, but only by a factor of 1.5-2 in the fast streams emanating from coronal holes. It is thus important to have a good understanding of this FIP fractionation effect, which operates between the photosphere and the corona. Such a theory may improve on our understanding of the solar atmosphere and SW acceleration. We present SW measurements, concentrating on results of the SWICS mass spectrometer on Ulysses, which is currently sampling the SW on a highly inclined orbit. IN 1992/93, Ulysses was traversing a recurrent high-speed stream once per solar rotation, alternating with slow SW, providing a unique opportunity to compare these two SW types. We find a strongly positive correlation for low- to high-FIP element ratios (such as Mg/O) with coronal temperature, which in turn is anticorrelated with the SW speed. The correlation of these three parameters -- one chromospheric, one coronal, and one from the SW -- points at a common cause for their variations, and provides a challenge to theorists to model these three domains in an unified approach. Further, abundance variations found in the SW from coronal streamers and in coronal mass ejections are presented and discussed. Finally, we address the question of abundance variations within the fast streams, looking for abundance gradients with heliographic latitude.

  14. Development of three-dimensional magnetohydrodynamic model for solar corona and solar wind simulation

    NASA Astrophysics Data System (ADS)

    Yuan, Xingqiu; Trichtchenko, Larisa; Boteler, David

    Propagation of coronal mass ejections from solar surface to the Earth magnetosphere is strongly influenced by the conditions in solar corona and ambient solar wind. Thus, reliable simulation of the background solar wind is the primary task toward the development of numerical model for the transient events. In this paper we introduce a new numerical model which has been specifically designed for numerical study of the solar corona and ambient solar wind. This model is based on our recently developed three-dimensional Spherical Coordinate Adaptive Magneto-Hydro-Dynamic (MHD) code (SCA-MHD-3D) [Yuan et al., 2009]. Modifications has been done to include the observed magnetic field at the photosphere as inner boundary conditions. The energy source term together with reduced plasma gamma are used in the nonlinear MHD equations in order to simulate the solar wind acceleration from subsonic speed at solar surface to supersonic speed at the inter-heliosphere region, and the absorbing boundary conditions are used at the solar surface. This model has been applied to simulate the background solar wind condition for several different solar rotations, and comparison between the observation and model output have shown that it reproduces many features of solar wind, including open and closed magnetic fields, fast and slow solar wind speed, sector boundaries, etc.

  15. Solar energetic particle events in different types of solar wind

    SciTech Connect

    Kahler, S. W.; Vourlidas, A.

    2014-08-10

    We examine statistically some properties of 96 20 MeV gradual solar energetic proton (SEP) events as a function of three different types of solar wind (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 solar activity.

  16. Solar Coronal Plumes and the Fast Solar Wind

    NASA Astrophysics Data System (ADS)

    Dwivedi, Bhola N.; Wilhelm, Klaus

    2015-03-01

    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 Solar Wind (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 Solar Ultraviolet Measurements of Emitted Radiation (SUMER) aboard the Solar 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.

  17. Solar Energetic Particle Events in Different Types of Solar Wind

    NASA Astrophysics Data System (ADS)

    Kahler, Stephen W.; Vourlidas, Angelos

    2014-06-01

    We examine statistically some properties of 96 20 MeV gradual solar energetic proton (SEP) events as a function of three different types of solar winds (SWs) as classified by Richardson and Cane (2012). Gradual SEP (E > 10 MeV) events are produced in shocks driven by fast (V > 900 km/s) and wide (W > 60 deg) coronal mass ejections (CMEs). We find no differences between transient and fast or slow SW streams for SEP 20-MeV 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 solar activity.

  18. Solar Energetic Particle Events in Different Types of Solar Wind

    NASA Astrophysics Data System (ADS)

    Kahler, S. W.; Vourlidas, A.

    2014-08-01

    We examine statistically some properties of 96 20 MeV gradual solar energetic proton (SEP) events as a function of three different types of solar wind (SW) as classified by Richardson and Cane. Gradual SEP (E > 10 MeV) events are produced in shocks driven by fast (V >~ 900 km s-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 solar activity.

  19. The solar wind - Advances in our knowledge through two solar cycles

    NASA Technical Reports Server (NTRS)

    Feynman, Joan

    1989-01-01

    As the Pioneer and Voyager spacecraft have moved outward they have gradually unfolded a view of distant regions of the heliosphere. Information on the solar wind velocity, density and temperature as a function of distance out to more than 40 AU has been gathered. Meanwhile the description of the solar wind has evolved. Long-standing questions on the sources of the wind causing geomagnetic activity were clarified by the discovery of coronal holes and coronal mass ejections. The propagation of the resultant solar wind disturbances through the heliosphere has been studied using both observations and models. Plasma physical processes have been studied. This review focuses on the development of the concepts that have been used to describe the solar wind in the three dimensional heliosphere over the last two solar cycles. Collisionless shocks, transient disturbances in space, disturbance propagation and the distant solar wind are discussed.

  20. Microstructures in the Polar Solar Wind: Ulysses

    NASA Technical Reports Server (NTRS)

    Tsuruyani, Bruce T.; Arballo, J. K.; Galvan, C.; Goldstein, B. E.; Lakhina, G. S.; Sakurai, R.; Smith, E. J.; Neugebauer, M.

    1999-01-01

    We find that small (10-200 rP) magnetic decreases comprise a dominant part of the polar solar wind 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.

  1. Innovations in Wind and Solar PV Financing

    SciTech Connect

    Cory, K.; Coughlin, J.; Jenkin, T.; Pater, J.; Swezey, B.

    2008-02-01

    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 wind and solar photovoltaic (PV) energy project financing in the electric power industry, and identifies both barriers to and opportunities for increased investment.

  2. Nonaxisymmetric anisotropy of solar wind turbulence.

    PubMed

    Turner, A J; Gogoberidze, G; Chapman, S C; Hnat, B; Müller, W-C

    2011-08-26

    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 solar wind 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.

  3. Bidirectional solar wind electron heat flux events

    NASA Technical Reports Server (NTRS)

    Gosling, J. T.; Baker, D. N.; Bame, S. J.; Feldman, W. C.; Zwickl, R. D.; Smith, E. J.

    1987-01-01

    ISEE 3 plasma and magnetic field data are used here to document the general characteristics of bidirectional electron heat flux events (BEHFEs). Significant field rotations often occur at the beginning and/or end of such events and, at times, the large-field rotations characteristic of 'magnetic clouds' are present. Approximately half of all BEHFEs are associated with and follow interplanetary shocks, while the other events have no obvious shock associations. When shock-associated, the delay from shock passage typically is about 13 hours, corresponding to a radial separation of about 0.16 AU. When independent of any shock association, BEHFEs typically are about 0.13 AU thick in the radial direction. It is suggested that BEHFEs are one of the more prominent signatures of coronal mass ejection events in the solar wind at 1 AU.

  4. Magnetic holes in the solar wind

    NASA Technical Reports Server (NTRS)

    Turner, J. M.; Burlaga, L. F.; Ness, N. F.; Lemaire, J. F.

    1977-01-01

    An analysis of high-resolution magnetic field measurements from the Goddard Space Flight Center magnetometer on Explorer 43 showed that low magnetic field intensities (less than 1 gamma) in the solar wind at 1 AU occur as distinct depressions, or 'holes', in otherwise nearly average conditions. These magnetic holes are new kinetic scale phenomena, having a characteristic dimension of the order of 20,000 km. They occurred at a rate of 1.5/d in the 18-day interval (March 18 to April 6, 1971) that was considered. Most magnetic holes are characterized by both a depression in /B/ and a change in the magnetic field direction, and some of these are possibly the result of magnetic merging. However, in other cases the direction, does not change; such holes are not due to merging but might be a diamagnetic effect due to localized plasma inhomogeneities.

  5. Suprathermal protons in the interplanetary solar wind

    NASA Technical Reports Server (NTRS)

    Goodrich, C. C.; Lazarus, A. J.

    1976-01-01

    Using the Mariner 5 solar wind plasma and magnetic field data, we present observations of field-aligned suprathermal proton velocity distributions having pronounced high-energy shoulders. These observations, similar to the interpenetrating stream observations of Feldman et al. (1974), are clear evidence that such proton distributions are interplanetary rather than bow shock associated phenomena. Large Alfven speed is found to be a requirement for the occurrence of suprathermal proton distribution; further, we find the proportion of particles in the shoulder to be limited by the magnitude of the Alfven speed. It is suggested that this last result could indicate that the proton thermal anisotropy is limited at times by wave-particle interactions

  6. Solar wind interaction with Jupiter's magnetosphere

    NASA Astrophysics Data System (ADS)

    Delamere, P. A.; Bagenal, F.

    2009-12-01

    We suggest that the solar wind interaction with Jupiter's magnetosphere is dominated by viscous processes at the magnetopause boundary rather than a coherent reconnection-driven Dungey cycle. In particular, we show that shear flow-driven instabilities (e.g. Kelvin-Helmholtz) on Jupiter's magnetopheric flank can account for observations of: 1) flux tubes substantially depleted of energetic particles in regions outside of the plasmasheet, 2) anti-sunward flow in the dawnside ionosphere, 3) an aurorally active polar cap, and 4) a long magnetotail extending ~4 AU downstream. A preliminary analysis of the Kelvin-Helmholtz instability (KHI) as a function of local time will be presented along with initial two-dimensional hybrid code simulations of KHI at Jupiter's magnetopause boundary.

  7. RELAXATION PROCESSES IN SOLAR WIND TURBULENCE

    SciTech Connect

    Servidio, S.; Carbone, V.; Gurgiolo, C.; Goldstein, M. L.

    2014-07-10

    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 solar wind. Such events have important consequences for the statistics of plasma turbulence.

  8. Stationarity of extreme bursts in the solar wind.

    PubMed

    Moloney, N R; Davidsen, J

    2014-05-01

    Recent results have suggested that the statistics of bursts in the solar wind vary with solar 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 solar wind ε parameter and similar observables are independent of the solar 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 solar flares and, thus, provides evidence in favor of a link between solar flares and extreme bursts in the solar wind. PMID:25353849

  9. Stationarity of extreme bursts in the solar wind.

    PubMed

    Moloney, N R; Davidsen, J

    2014-05-01

    Recent results have suggested that the statistics of bursts in the solar wind vary with solar 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 solar wind ε parameter and similar observables are independent of the solar 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 solar flares and, thus, provides evidence in favor of a link between solar flares and extreme bursts in the solar wind.

  10. Evolution of solar wind turbulence and intermittency over the solar cycle

    NASA Astrophysics Data System (ADS)

    Väisänen, Pauli; Virtanen, Ilpo; Echim, Marius; Munteanu, Costel; Mursula, Kalevi

    2016-04-01

    Solar wind 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 solar wind is subject of many studies of, e.g., intermittency, turbulence and other nonlinear space plasma phenomena. Turbulence is an important feature of the solar wind dynamics, e.g., for the energy transfer mechanisms and their scale invariance, the solar wind evolution, the structure of the heliospheric magnetic field (HMF), the particle energization and heating, and for phenomena related to solar wind interaction with the planetary plasma systems. Here we analyse high resolution measurements of the solar wind 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 solar wind and HMF measurements from the start of solar cycle 23 to the current declining phase of solar 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 solar wind 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 solar cycle.

  11. COMPOSITION OF THE SOLAR CORONA, SOLAR WIND, AND SOLAR ENERGETIC PARTICLES

    SciTech Connect

    Schmelz, J. T.; Reames, D. V.; Von Steiger, R.; Basu, S.

    2012-08-10

    Along with temperature and density, the elemental abundance is a basic parameter required by astronomers to understand and model any physical system. The abundances of the solar corona are known to differ from those of the solar photosphere via a mechanism related to the first ionization potential of the element, but the normalization of these values with respect to hydrogen is challenging. Here, we show that the values used by solar physicists for over a decade and currently referred to as the 'coronal abundances' do not agree with the data themselves. As a result, recent analysis and interpretation of solar data involving coronal abundances may need to be revised. We use observations from coronal spectroscopy, the solar wind, and solar energetic particles as well as the latest abundances of the solar photosphere to establish a new set of abundances that reflect our current understanding of the coronal plasma.

  12. Solar wind compressible structures at ion scales

    NASA Astrophysics Data System (ADS)

    Perrone, D.; Alexandrova, O.; Rocoto, V.; Pantellini, F. G. E.; Zaslavsky, A.; Maksimovic, M.; Issautier, K.; Mangeney, A.

    2014-12-01

    In the solar wind 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 solar wind can provide constraints on theoretical modeling of small scale turbulence and dissipation in collisionless magnetized plasmas.

  13. CONDITIONED ANALYSIS OF HIGH-LATITUDE SOLAR WIND INTERMITTENCY

    SciTech Connect

    D'Amicis, R.; Consolini, G.; Bavassano, B.; Bruno, R.

    2012-08-10

    The solar wind is a turbulent medium displaying intermittency. Its intermittent features have been widely documented and studied, showing how the intermittent character is different in fast and slow wind. In this paper, a statistical conditioned analysis of the solar wind intermittency for a period of high-latitude fast solar wind is presented. In particular, the intermittent features are investigated as a function of the Alfvenic degree of fluctuations at a given scale. The results show that the main contribution to solar wind intermittency is due to non-Alfvenic structures, while Alfvenic increments are found to be characterized by a smaller level of intermittency than the previous ones. Furthermore, the lifetime statistics of Alfvenic periods are discussed in terms of a multiscale texture of randomly oriented flux tubes.

  14. Comparison of Coronal Streamer Properties to Solar Wind Models For The Last Two Solar Cycle Minima

    NASA Astrophysics Data System (ADS)

    Miralles, Mari Paz; Landi, E.; Cranmer, S. R.; Raymond, J. C.; Cohen, O.; Oran, R.

    2013-07-01

    We characterize the physical properties of two coronal streamers during Earth/Ulysses quadrature configurations for the previous two solar minimum periods. Comparisons between coronal remote-sensing observations and in situ measurements of solar wind plasma properties are being used to characterize the origin of slow wind streams. In order to investigate slow solar wind heating and acceleration, we compare the measurements with predictions from MHD models. We aim to use the empirical measurements to distinguish between different proposed physical processes for the slow solar wind. This work is supported by NASA grant NNX10AQ58G to the Smithsonian Astrophysical Observatory.

  15. Wind and radiant solar energy for drying fruits and vegetables

    SciTech Connect

    Wagner, C.J. Jr.; Coleman, R.L.; Berry, R.E.

    1981-01-01

    The combination of wind with radiant solar energy for drying fruits and vegetables can help promote conservation of food and nonrenewable energy resources. Low-cost, small-scale solar dryers have been developed with the potential for developing larger dryers. These dryers depend on natural air convection to remove moisture. Designing the dryers to incorporate natural wind currents, providing forced air circulation, could increase drying rates. Preliminary studies to provide information for such designs included: (1) comparing drying tests with and without forced air circulation, (2) monitoring wind speeds on-site, and (3) testing wind collecting devices. Average wind speeds during solar periods were higher than air velocities from unassisted air convection in these small food dryers. Drying rates were increased by 6 to 11% when the natural convection dryer was provided with a small electric fan. Either of two wind collecting devices also could increase drying rates.

  16. Modeling solar wind with boundary conditions from interplanetary scintillations

    SciTech Connect

    Manoharan, P.; Kim, T.; Pogorelov, N. V.; Arge, C. N.

    2015-09-30

    Interplanetary scintillations make it possible to create three-dimensional, time- dependent distributions of the solar wind velocity. Combined with the magnetic field observations in the solar photosphere, they help perform solar wind 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 solar wind. 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 solar wind flow from 0.1 AU to 1 AU with the boundary conditions based on both Ooty and WSA data.

  17. Modeling solar wind with boundary conditions from interplanetary scintillations

    DOE PAGESBeta

    Manoharan, P.; Kim, T.; Pogorelov, N. V.; Arge, C. N.; Manoharan, P. K.

    2015-09-30

    Interplanetary scintillations make it possible to create three-dimensional, time- dependent distributions of the solar wind velocity. Combined with the magnetic field observations in the solar photosphere, they help perform solar wind 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 solar wind. 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 solar wind flow from 0.1 AUmore » to 1 AU with the boundary conditions based on both Ooty and WSA data.« less

  18. Validation of solar wind high-speed stream predictions

    NASA Astrophysics Data System (ADS)

    Reiss, Martin; Temmer, Manuela; Veronig, Astrid; Nikolic, Ljubomir; Schöngassner, Florian; Vennerstrøm, Susanne

    2016-04-01

    Solar wind high-speed streams emanating from coronal holes are frequently impinging on the Earth's magnetosphere causing recurrent, medium-level geomagnetic storm activity. As major contributors to space weather disturbances at times of low solar activity, prediction models of solar wind high-speed streams are becoming highly desirable. We present a verification analysis of two operational solar wind prediction models (empirical model, Wang-Sheeley-Arge like model) by comparing the model runs for the period 2011 to 2014 with in-situ plasma measurements from the ACE spacecraft located at 1 AU. We find that both prediction models achieve a similar accuracy but demonstrate the tendency to under-predict and over-predict events of solar wind high-speed streams, respectively. General advantages and disadvantages of both models are diagnosed and outlined.

  19. Cleaning Genesis Mission Payload for Flight with Ultra-Pure Water and Assembly in ISO Class 4 Environment

    NASA Technical Reports Server (NTRS)

    Allton, Judith H.

    2012-01-01

    Genesis mission to capture and return to Earth solar wind samples had very stringent contamination control requirements in order to distinguish the solar atoms from terrestrial ones. Genesis mission goals were to measure solar 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 solar 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 Genesis collectors and cleaning hardware for flight. Surface contamination on polished silicon wafers, measured in Genesis laboratory is approximately 10 ng/sq cm.

  20. Little or no solar wind enters Venus' atmosphere at solar minimum.

    PubMed

    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

    2007-11-29

    Venus has no significant internal magnetic field, which allows the solar wind 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 solar minimum. (Our current knowledge of the solar wind interaction with Venus is derived from measurements at solar maximum.) The bow shock is close to the planet, meaning that it is possible that some solar wind 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 solar activity conditions seems to be in the position that would be expected from a complete deflection by a magnetized ionosphere. Therefore little solar wind enters the Venus ionosphere even at solar minimum.

  1. SOLAR X-RAY JETS, TYPE-II SPICULES, GRANULE-SIZE EMERGING BIPOLES, AND THE GENESIS OF THE HELIOSPHERE

    SciTech Connect

    Moore, Ronald L.; Sterling, Alphonse C.; Cirtain, Jonathan W.; Falconer, David A.

    2011-04-10

    From Hinode observations of solar 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 solar wind. In this scenario, Type-II spicules and Alfven 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 Alfven waves carry into the corona an area-average flux of mechanical energy of {approx}7 x 10{sup 5} erg cm{sup -2} s{sup -1}. This is enough to power the corona and solar wind 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.

  2. The solar wind interaction with unmagnetized planets - A tutorial

    NASA Technical Reports Server (NTRS)

    Luhmann, J. G.

    1990-01-01

    The interaction of the solar wind with the Venus ionosphere induces currents which can substantially exclude the solar wind and IMF from the dayside ionosphere beneath the 'ionopause', where ionosphere thermal pressure equals incident solar wind 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.

  3. Solar Wind observations using the Mexican Array Radio Telescope (MEXART)

    NASA Astrophysics Data System (ADS)

    Romero-Hernandez, E.; Gonzalez-Esparza, A.; Villanueva, P.; Aguilar-Rodriguez, E.; Mejia-Ambriz, J. C.; Mexart

    2013-05-01

    The Mexican Array Radiotelescope (MEXART) is an instrument devoted to observations of radio sources to study large-scale structures in the solar wind employing the Interplanetary Scintillation (IPS) technique. We report recent IPS observations, from January to April of 2013, including an analysis of the scintillation index and the estimation of solar wind velocities for a set of radio sources. We track the first ICMEs registered by the MEXART. We are initiating a continuos operation for a complete monitoring of IPS radio sources that will complement solar wind studies based on in-situ observations.

  4. Charge-exchange born He(+) ions in the solar wind

    NASA Technical Reports Server (NTRS)

    Gruntman, Michael A.

    1992-01-01

    The effect of charge transfer between solar wind 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 solar wind 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 solar wind are presented, and the possibility of measuring this plasma component on deep space missions is discussed.

  5. MEASUREMENTS OF RAPID DENSITY FLUCTUATIONS IN THE SOLAR WIND

    SciTech Connect

    Malaspina, D. M.; Ergun, R. E.; Kellogg, P. J.; Bale, S. D.

    2010-03-01

    The power spectrum of density fluctuations in the solar wind 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 solar wind direction, indicating significant anisotropy in solar wind high-frequency density turbulence.

  6. The relationship between Saturn kilometric radiation and the solar wind

    NASA Technical Reports Server (NTRS)

    Desch, M. D.; Rucker, H. O.

    1983-01-01

    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 solar wind ram pressure variation. In all, thirteen solar wind 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 solar wind pressure changes at Saturn's dayside magnetopause.

  7. Charge-exchange born He(+) ions in the solar wind

    NASA Astrophysics Data System (ADS)

    Gruntman, Michael A.

    1992-07-01

    The effect of charge transfer between solar wind 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 solar wind 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 solar wind are presented, and the possibility of measuring this plasma component on deep space missions is discussed.

  8. Solar wind electron temperature and density measurements on the Solar Orbiter with thermal noise spectroscopy

    NASA Astrophysics Data System (ADS)

    Maksimovic, M.; Issautier, K.; Meyer-Vernet, N.; Perche, C.; Moncuquet, M.; Zouganelis, I.; Bale, S. D.; Vilmer, N.; Bougeret, J.-L.

    The measurement of the solar wind electron temperature in the unexplored region between 1 and 45 Rs is of prime importance for understanding the solar wind acceleration. Solar Orbiter's location, combined with the fact that the spacecraft will nearly co-rotate with the sun on some portions of its orbit, will furnish observations placing constraints on solar wind models. We discuss the implementation of the plasma thermal noise analysis for the Solar Orbiter, in order to get accurate measurements of the total electron density and electron temperature and to correct the spacecraft charging effects which affect the electron analyzers.

  9. Solar wind electron temperature and density measurements for the Solar Orbiter using the thermal noise spectroscopy

    NASA Astrophysics Data System (ADS)

    Maksimovic, M.; Issautier, K.; Moncuquet, M.; Meyer-Vernet, N.; Zouganelis, I.; Bale, S. D.; Vilmer, N.; Bougeret, J.-L.

    The measurement of the solar wind electron temperature radial profile in the unexplored region between 1 and 45 R_s is of prime importance for understanding the solar wind acceleration. Solar Orbiter's location, combined with its ability to observe the corona in co-rotation, will furnish strong observational constraints on solar wind models. We discuss the implementation of the plasma thermal noise analysis for the Solar Orbiter, in order (i) to get accurate measurements of the total electron density and core electron temperature and (ii) to allow direct determination of the spacecraft charging effects which affect the electron analyzers.

  10. Wind loading on solar concentrators: some general considerations

    SciTech Connect

    Roschke, E. J.

    1984-05-01

    A survey has been completed to examine the problems and complications arising from wind loading on solar concentrators. Wind loading is site specific and has an important bearing on the design, cost, performance, operation and maintenance, safety, survival, and replacement of solar collecting systems. Emphasis herein is on paraboloidal, two-axis tracking systems. Thermal receiver problems also are discussed. Wind characteristics are discussed from a general point of view; current methods for determining design wind speed are reviewed. Aerodynamic coefficients are defined and illustrative examples are presented. Wind tunnel testing is discussed, and environmental wind tunnels are reviewed; recent results on heliostat arrays are reviewed as well. Aeroelasticity in relation to structural design is discussed briefly. Wind loads, i.e., forces and moments, are proportional to the square of the mean wind velocity. Forces are proportional to the square of concentrator diameter, and moments are proportional to the cube of diameter. Thus, wind 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 wind loading are possible for a given paraboloidal concentrator configuration, provided that reliable and relevant wind conditions are specified. Such predictions will be useful to the design engineer and to the systems engineer as well. Information is lacking, however, on wind effects in field arrays of paraboloidal concentrators. Wind tunnel tests have been performed on model heliostat arrays, but there are important aerodynamic differences between heliostats and paraboloidal dishes.

  11. Cellulose Acetate Replica Cleaning Study of Genesis Non-Flight Sample 3CZ00327

    NASA Technical Reports Server (NTRS)

    Kuhlman, K. R.; Schmeling, M.; Gonzalez, C. P.; Allton, J. H.; Burnett, D. S.

    2014-01-01

    The Genesis mission collected solar wind and brought it back to Earth in order to provide precise knowledge of solar isotopic and elemental compositions. The ions in the solar wind 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 solar wind and must be preserved throughout sample handling, cleaning, processing, distribution, preparation and analysis. We are working interactively with the community of scientists analyzing Genesis samples, using our unique laboratory facilities -- and, where needed, our unique cleaning techniques -- to significantly enhance the science return from the Genesis mission. This work is motivated by the need to understand the submicron contamination on the collectors in the Genesis 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 solar-wind signal intact.

  12. Decontamination of Genesis Array Materials by UV Ozone Cleaning

    NASA Technical Reports Server (NTRS)

    Calaway, Michael J.; Burnett, D. S.; Rodriquez, M. C.; Sestak, S.; Allton, J. H.; Stansbery, E. K.

    2007-01-01

    Shortly after the NASA Genesis 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 solar exposure. While the valuable solar wind 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 solar wind elemental abundances require the removal of this organic contaminate. In 2005, Genesis science team laboratories began to develop various methods for removing the organic thin film without removing the precious material substrate that contained the solar wind atoms. Stephen Sestak and colleagues at Open University first experimented with ultraviolet radiation ozone (UV/O3) cleaning of several non-flight and flown Genesis 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 Genesis 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 Genesis 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 Genesis 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

  13. Solar wind proton flux extremes and their association with pseudostreamers

    NASA Astrophysics Data System (ADS)

    Zhao, Liang; Gibson, Sarah E.; Fisk, Lennard A.

    2013-06-01

    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 wind and extended to high heliomagnetic latitudes during the recent two solar minima. We examine the solar wind exclusive of ICMEs from Ulysses and ACE observations, to analyze the solar wind in-situ data exhibiting extremes in proton flux. We first find these extreme-proton-flux winds generally originate in latitudes middle-distant from the heliospheric current sheet (HCS), and they have relatively slower speed than the bulk of the solar wind. Then we map the in-situ ACE observations in Carrington rotation (CR) 1997 back to the solar surface by using the Potential-Field-Source-Surface (PFSS) model, in order to consider the coronal properties at the extreme-proton-flux wind sources. We find there is a clear association between these extreme-proton-flux solar wind and the mid-latitude coronal holes and "pseudostreamer" structures.

  14. Different magnetospheric modes: solar wind driving and coupling efficiency

    NASA Astrophysics Data System (ADS)

    Partamies, N.; Pulkkinen, T. I.; McPherron, R. L.; McWilliams, K.; Bryant, C. R.; Tanskanen, E.; Singer, H. J.; Reeves, G. D.; Thomsen, M. F.

    2009-11-01

    This study describes a systematic statistical comparison of isolated non-storm substorms, steady magnetospheric convection (SMC) intervals and sawtooth events. The number of events is approximately the same in each group and the data are taken from about the same years to avoid biasing by different solar cycle phase. The very same superposed epoch analysis is performed for each event group to show the characteristics of ground-based indices (AL, PCN, PC potential), particle injection at the geostationary orbit and the solar wind and IMF parameters. We show that the monthly occurrence of sawtooth events and isolated non-stormtime substorms closely follows maxima of the geomagnetic activity at (or close to) the equinoxes. The most strongly solar wind driven event type, sawtooth events, is the least efficient in coupling the solar wind energy to the auroral ionosphere, while SMC periods are associated with the highest coupling ratio (AL/EY). Furthermore, solar wind speed seems to play a key role in determining the type of activity in the magnetosphere. Slow solar wind is capable of maintaining steady convection. During fast solar wind streams the magnetosphere responds with loading-unloading cycles, represented by substorms during moderately active conditions and sawtooth events (or other storm-time activations) during geomagnetically active conditions.

  15. Solar wind-plasma interaction: The AMPTE solar wind plasma releases

    NASA Technical Reports Server (NTRS)

    1986-01-01

    In situ measurements during AMPTE solar wind 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 solar wind plasma and the expanding cloud plasma of the Li and artificial comet releases may have relevance to astrophysical situations as, for instance, encountered in solar flares, interstellar clouds, or during accretion of matter onto compact objects.

  16. Transient flows of the solar wind associated with small-scale solar activity in solar minimum

    NASA Astrophysics Data System (ADS)

    Slemzin, Vladimir; Veselovsky, Igor; Kuzin, Sergey; Gburek, Szymon; Ulyanov, Artyom; Kirichenko, Alexey; Shugay, Yulia; Goryaev, Farid

    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 solar activity (SSA), which is supposed to play an important role in heating of the corona and producing transient flows of the solar wind. During the recent unusually weak solar minimum, a large number of SSA events, such as week solar 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 solar wind data obtained in this period by ACE, Wind, 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 solar wind (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 solar wind 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 solar wind at solar 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

  17. Dst Prediction Based on Solar Wind Parameters

    NASA Astrophysics Data System (ADS)

    Park, Yoon-Kyung; Ahn, Byung-Ho

    2009-12-01

    We reevaluate the Burton equation (Burton et al. 1975) of predicting Dst index using high quality hourly solar wind data supplied by the ACE satellite for the period from 1998 to 2006. Sixty magnetic storms with monotonously decreasing main phase are selected. In order to determine the injection term (Q) and the decay time (tau) of the equation, we examine the relationships between Dst^ast and VB_s, Delta Dst^ast and VB_s, and Delta Dst^ast and Dst^ast during the magnetic storms. For this analysis, we take into account one hour of the propagation time from the ACE satellite to the magnetopause, and a half hour of the response time of the magnetosphere/ring current to the solar wind forcing. The injection term is found to be Q({nT}/h)=-3.56VB_s for VB_s>0.5mV/m and Q({nT}/h)=0 for VB_s leq0.5mV/m. The tau (hour) is estimated as 0.060 Dst^ast + 16.65 for Dst^ast>-175nT and 6.15 hours for Dst^ast leq -175nT. Based on these empirical relationships, we predict the 60 magnetic storms and find that the correlation coefficient between the observed and predicted Dst^ast is 0.88. To evaluate the performance of our prediction scheme, the 60 magnetic storms are predicted again using the models by Burton et al. (1975) and O'Brien & McPherron (2000a). The correlation coefficients thus obtained are 0.85, the same value for both of the two models. In this respect, our model is slightly improved over the other two models as far as the correlation coefficients is concerned. Particularly our model does a better job than the other two models in predicting intense magnetic storms (Dst^ast lesssim -200nT).

  18. He abundance variations in the solar wind: Observations from Ulysses

    SciTech Connect

    Barraclough, B.L.; Gosling, J.T.; Phillips, J.L.; McComas, D.J.; Feldman, W.C.; Goldstein, B.E.

    1995-09-01

    The Ulysses mission is providing the first opportunity to observe variations in solar wind plasma parameters at heliographic latitudes far removed from the ecliptic plane. We present an overview of the solar wind 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 solar wind speed and [He] in high latitude and equatorial regions are quite striking. Solar wind speed is generally low but highly variable near the solar equator, while at higher latitudes the average speed is quite high with little variability. [He] can vary over nearly two decades at low solar 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 solar hemisphere shows the expected [He] minimum near the crossing and a broad region of low [He] around the crossing time. We discuss how our solar wind [He] observations may provide an accurate measure of the helium composition for the entire convective zone of the Sun.

  19. A parametric study of the solar wind interaction with comets

    NASA Technical Reports Server (NTRS)

    Russell, C. T.; Le, G.; Luhmann, J. G.; Fedder, J. A.

    1991-01-01

    The Naval Research Laboratory's magnetohydrodynamic simulation code is used to simulate the solar wind interction with comet Halley for two different outgassing rates and several different solar wind states. The magnetic field is more strongly draped for fast solar wind conditions than slow. For higher mass loading rates, the tail becomes wider and contains more magnetic flux. The visual appearance of the comet differs for the case in which the interplanetary magnetic field lies in the plane of the sky from the case when it lies along the line of sight. The ion tail appears shorter in the latter case. Thus variation in the IMF direction can cause significant changes in the appearance of comets. The comet also creates a large momentum flux deficit in the solar wind with a narrow enhanced region within it corresponding to the ion tail.

  20. The visual appearance of comets under varying solar wind conditions

    NASA Technical Reports Server (NTRS)

    Russell, C. T.; Guan, L.; Luhmann, J. G.; Fedder, J. A.

    1989-01-01

    Three-dimensional MHD simulations have been performed for four different sets of solar wind conditions and cometary outgassing rates appropriate to the Halley encounters. Even though the simulations are single fluid calculations, it is possible to separate the solar wind and cometary ions using the divergenceless nature of the solar wind ions. The cometary ion density is then integrated along the line-of-sight from the observer through the comet to determine how the comet would look to a distant observer under these different conditions. In general, comet tails appear longer when the interplanetary magnetic field lies in the plane of the sky rather than along the line-of-sight. Also, the tail shrinks as the speed of the solar wind increases and/or the mass loading rate decreases.

  1. Saturn radio emission and the solar wind - Voyager-2 studies

    SciTech Connect

    Desch, M.D.; Rucker, H.O.

    1985-01-01

    Voyager 2 data from the Plasma Science experiment, the Magnetometer experiment and the Planetary Radio Astronomy experiment were used to analyze the relationship between parameters of the solar wind/interplanetary medium and the nonthermal Saturn radiation. Solar wind and interplanetary magnetic field properties were combined to form quantities known to be important in controlling terrestrial magnetospheric processes. The Voyager 2 data set used in this investigation consists of 237 days of Saturn preencounter measurements. However, due to the immersion of Saturn and the Voyager 2 spacecraft into the extended Jupiter magnetic tail, substantial periods of the time series were lacking solar wind data. To cope with this problem a superposed epoch method (CHREE analysis) was used. The results indicate the superiority of the quantities containing the solar wind density in stimulating the radio emission of Saturn - a result found earlier using Voyager 1 data - and the minor importance of quantities incorporating the interplanetary magnetic field. 10 references.

  2. Solar wind flow upstream of the coronal slow shock

    NASA Technical Reports Server (NTRS)

    Whang, Y. C.

    1986-01-01

    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 solar-wind 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 solar wind 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 solar wind 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 solar wind.

  3. Relationship between the sawtooth period and solar wind drivers

    NASA Astrophysics Data System (ADS)

    Cai, X.; Clauer, C. R.; Weimer, D. R.

    2009-12-01

    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 solar wind drivers or internal magnetospheric parameters, is unknown. In this presentation, we examine the relationship between the solar wind 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 solar wind 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 solar wind-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.

  4. Solar wind stream structure at large heliocentric distances Pioneer observations

    NASA Technical Reports Server (NTRS)

    Gazis, P. R.

    1987-01-01

    Time profiles and histograms of plasma data from Pioneers 10 and 11 are examined for the period between 1975 and 1983. During this time, Pioneer 10 traveled between a heliocentric distance of 8.7 and 30.4 AU. The velocity structure of the solar wind at these heliocentric distances is found to have one of two distinct forms: approximately 70 percent of the time the solar wind has a nearly flat velocity profile. Occasionally, this flat velocity profile is accompanied by quasi-periodic variations in density and in thermal speed consistent with the concept that the 'corotating interaction regions' which are produced by the interaction of high- and low-speed streams at intermediate heliocentric distances are replaced by 'pressure regions' in the outer heliosphere. The remaining 30 percent of the time the solar wind is marked by large (50-200 km/s) long-term (30-120 days) shifts in the average solar wind velocity.

  5. Charge exchange in solar wind-cometary interactions

    NASA Technical Reports Server (NTRS)

    Gombosi, T. I.; Horanyi, M.; Kecskemety, K.; Cravens, T. E.; Nagy, A. F.

    1983-01-01

    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 solar wind-cometary interaction is considered, taking into account the loss of solar wind ions due to charge exchange. The calculations predict that for active comets, solar wind absorption due to charge exchange becomes important at a few thousand kilometers from the nucleus, and a surface separating the shocked solar wind 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.

  6. Western Wind and Solar Integration Study Phase 2 (Fact Sheet)

    SciTech Connect

    Not Available

    2013-09-01

    This is one-page, two-sided fact sheet presents high-level summary results of the Western Wind and Solar Integration Study Phase 2, which examined operational impacts of high penetrations of variable renewable generation in the West.

  7. Magnetic fields of Mars and Venus - Solar wind interactions

    NASA Technical Reports Server (NTRS)

    Ness, N. F.

    1974-01-01

    Recent USSR studies of the magnetic field and solar wind flow in the vicinity of Mars and Venus confirm earlier U.S. reports of a bow shock wave developed as the solar wind 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 solar wind 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 solar wind 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.

  8. Electrodynamics of solar wind-magnetosphere-ionosphere interactions

    NASA Technical Reports Server (NTRS)

    Kan, Joseph R.; Akasofu, Syun-Ichi

    1989-01-01

    The paper presents a coherent picture of fundamental physical processes in three basic elements of the solar-wind/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 solar-wind/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 solar wind. Energy is transferred from the solar wind to the magnetosphere by a dynamo process, primarily on open field lines.

  9. Western Wind and Solar Integration Study: Phase 2 (Presentation)

    SciTech Connect

    Lew, D.; Brinkman, G.; Ibanez, E.; Lefton, S.; Kumar, N.; Venkataraman, S.; Jordan, G.

    2013-09-01

    This presentation summarizes the scope and results of the Western Wind and Solar Integration Study Phase 2, which examined operational impacts of high penetrations of variable renewable generation in the West.

  10. Lunar nitrogen - Evidence for secular change in the solar wind

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

    The lunar soil is an efficient trap for nitrogen in the solar wind. The concentration of nitrogen in lunar soils implies a flux of solar wind at least three times greater than that which is observed today. The implication is that the present-day flux is anomalously low. Soil samples from drill cores, and soil breccias excavated from buried levels of the regolith provide samples of ancient solar wind. From these samples it is apparent that the N-15/N-14 ratio in the solar wind has undergone a monotonic secular increase over the last 2.5 billion years, at a rate of about 15% per billion years. Nuclear reactions in the sun appear to be the most likely cause of the variation.

  11. On Electron-scale Whistler Turbulence in the Solar Wind

    NASA Astrophysics Data System (ADS)

    Narita, Y.; Nakamura, R.; Baumjohann, W.; Glassmeier, K.-H.; Motschmann, U.; Giles, B.; Magnes, W.; Fischer, D.; Torbert, R. B.; Russell, C. T.; Strangeway, R. J.; Burch, J. L.; Nariyuki, Y.; Saito, S.; Gary, S. P.

    2016-08-01

    For the first time, the dispersion relation for turbulence magnetic field fluctuations in the solar wind 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 solar wind turbulence is primarily composed of highly obliquely propagating waves, with dispersion consistent with that of the whistler mode.

  12. Sensing the solar-wind termination shock from Earth's orbit

    NASA Technical Reports Server (NTRS)

    Hsieh, K. C.; Shih, K. L.; Jokipii, J. R.; Gruntman, M. A.

    1992-01-01

    The solar-wind termination shock is inaccessible for repeated in situ investigation. We examine, therefore, the possibility of remote sensing the entire heliopause from Earth's orbit using the energetic neutral atoms (ENA) produced by charge exchange between energetic ions and the neutral atoms of the interstellar medium at and beyond the termination shock. We estimate the ENA fluxes at Earth's orbit coming from the thermalized solar-wind ions and the shock-accelerated anomalous cosmic rays (ACR) at the heliospheric boundary.

  13. Interplanetary stream magnetism: Kinematic effects. [solar magnetic fields and wind

    NASA Technical Reports Server (NTRS)

    Burlaga, L. F.; Barouch, E.

    1974-01-01

    The particle density, and the magnetic field intensity and direction are calculated in corotating streams of the solar wind, assuming that the solar wind 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.

  14. Comet-solar wind interaction - Dynamical length scales and models

    NASA Astrophysics Data System (ADS)

    Mendis, D. A.; Smith, E. J.; Tsurutani, B. T.; Slavin, J. A.; Jones, D. E.; Siscoe, G. L.

    1986-03-01

    ICE magnetometer measurements at Comet Giacobini-Zinner and model simulations of comet-solar wind interactions are analyzed. The magnetometer data reveal the existence of intense hydromagnetic turbulence, a draping of the magnetic field lines to form a magnetotail, a weak shock, and a magnetic barrier region in the magnetosphere. The global models of the comet-solar wind interaction are described. The observed data and models are compared and good correlation is displayed.

  15. Mixed solar wind originating from coronal regions of different temperatures

    NASA Technical Reports Server (NTRS)

    Bochsler, P.

    1983-01-01

    Ionization states of elements in the solar wind are often used to determine thermal gradients in the lower corona. This method is based on the assumption, that in the beginning, solar wind 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.

  16. Calculation of solar wind flows about terrestrial planets

    NASA Technical Reports Server (NTRS)

    Stahara, S. S.; Spreiter, J. R.

    1982-01-01

    A computational model was developed for the determination of the plasma and magnetic field properties of the global interaction of the solar wind 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 solar wind flow past terrestrial planets. A summary is provided of the important research results.

  17. STEREO Observations of Solar Wind in 2007-2014

    NASA Astrophysics Data System (ADS)

    Jian, Lan; Luhmann, Janet; Russell, Christopher; Blanco-Cano, Xochitl; Kilpua, Emilia; Li, Yan

    2016-04-01

    Since the launch of twin STEREO spacecraft, we have been monitoring the solar wind and providing the Level 3 event lists of large-scale solar wind 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 solar energetic particles (based on high energy telescope data) have been surveyed for 2007-2014 before STEREO A went to the superior solar conjunction and STEREO B was lost in contact. In conjunction with our previous observations of same solar wind structures in 1995-2009 using Wind/ACE data and the same identification criteria, we study the solar cycle variations of these structures, especially compare the same phase of solar cycles 23 and 24. Although the sunspot number at solar maximum 24 is only 60% of the level at last solar 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.

  18. Potential for Development of Solar and Wind Resource in Bhutan

    SciTech Connect

    Gilman, P.; Cowlin, S.; Heimiller, D.

    2009-09-01

    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 wind and solar resources in Bhutan. The solar resource data show that Bhutan has an adequate resource for flat-plate collectors, with annual average values of global horizontal solar 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 wind and solar projects, and to energy analysts around the world interested in gaining an understanding of Bhutan's wind and solar energy potential.

  19. Off-disk penetration of ancient solar wind

    SciTech Connect

    Sasaki, SHO )

    1991-05-01

    Following a suggestion by Wetherill (1981), an estimation is made of the capture of an ancient, intense solar wind by primordial dust. Because the mutual collision of planetesimals would generate additional dust grains in interplanetary space after the solar nebula's dissipation, the vertical distribution of the dust is taken into account. The solar wind penetrates the dust swarm through the less opaque off-disk portions, explaining both the trapping of a substantial quantity of solar wind species and the high abundances of solar-type noble gases in gas-rich meteorites and on Venus. The off-disk trap is efficient when the disk is opaque and its relative thickness does not diminish with increasing heliocentric distance. 34 refs.

  20. Interplanetary shock waves and the structure of solar wind disturbances

    NASA Technical Reports Server (NTRS)

    Hundhausen, A. J.

    1972-01-01

    Observations and theoretical models of interplanetary shock waves are reviewed, with emphasis on the large-scale characteristics of the associated solar wind disturbances and on the relationship of these disturbances to solar activity. The sum of observational knowledge indicates that shock waves propagate through the solar wind along a broad, roughly spherical front, ahead of plasma and magnetic field ejected from solar 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 solar wind can account for the typically observed shock strength, transit time, and shape.

  1. The dynamic character of the polar solar wind

    SciTech Connect

    Jackson, B. V.; Yu, H.-S.; Buffington, A.; Hick, P. P. E-mail: hsyu@ucsd.edu E-mail: pphick@ucsd.edu

    2014-09-20

    The Solar and Heliospheric Observatory (SOHO) Large Angle and Spectrometric Coronagraph C2 and Solar Terrestrial Relations Observatory (STEREO) COR2A coronagraph images, when analyzed using correlation tracking techniques, show a surprising result in places ordinarily thought of as 'quiet' solar wind above the poles in coronal hole regions. Instead of the static well-ordered flow and gradual acceleration normally expected, coronagraph images show outflow in polar coronal holes consisting of a mixture of intermittent slow and fast patches of material. We compare measurements of this highly variable solar wind from C2 and COR2A images and show that both coronagraphs measure essentially the same structures. Measurements of the mean velocity as a function of height of these structures are compared with mass flux determinations of the solar wind outflow in the large polar coronal hole regions and give similar results.

  2. The Character of the Solar Wind, Surface Interactions, and Water

    NASA Technical Reports Server (NTRS)

    Farrell, William M.

    2011-01-01

    We discuss the key characteristics of the proton-rich solar wind and describe how it may interact with the lunar surface. We suggest that solar wind 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 solar wind plasma are in constant interaction with the lunar surface. As such, there is a solar-lunar energy connection, where solar 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.

  3. Solar wind: The solar wind and the Sun-Earth link

    NASA Astrophysics Data System (ADS)

    Habbal, Shadia Rifia; Woo, Richard

    2004-08-01

    The solar wind 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.

  4. Wind loading on solar concentrators: Some general considerations

    NASA Technical Reports Server (NTRS)

    Roschke, E. J.

    1984-01-01

    A survey was completed to examine the problems and complications arising from wind loading on solar concentrators. Wind loading is site specific and has an important bearing on the design, cost, performance, operation and maintenance, safety, survival, and replacement of solar collecting systems. Emphasis herein is on paraboloidal, two-axis tracking systems. Thermal receiver problems also are discussed. Wind characteristics are discussed from a general point of view. Current methods for determining design wind speed are reviewed. Aerodynamic coefficients are defined and illustrative examples are presented. Wind tunnel testing is discussed, and environmental wind tunnels are reviewed. Recent results on heliostat arrays are reviewed as well. Aeroelasticity in relation to structural design is discussed briefly.

  5. Interaction of Comets and the Solar Wind

    NASA Technical Reports Server (NTRS)

    Wagner, William (Technical Monitor); Raymond, John C.

    2004-01-01

    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 solar wind densities for both comets, but we are still sorting out the ambiguities involving the fragmentation and optical behavior.

  6. Interaction of Comets and the Solar Wind

    NASA Technical Reports Server (NTRS)

    Wagner, William (Technical Monitor); Raymond, John C.

    2003-01-01

    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 solar wind 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.

  7. Dissipation of Turbulence in the Solar Wind

    NASA Technical Reports Server (NTRS)

    Goldstein, Melvyn L.

    2010-01-01

    I will describe the first three-dimensional (3-D) dispersion relations and wavenumber spectra of magnetic turbulence in the solar wind 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.

  8. On Solar Wind Origin and Acceleration: Measurements from ACE

    NASA Astrophysics Data System (ADS)

    Stakhiv, Mark; Lepri, Susan T.; Landi, Enrico; Tracy, Patrick; Zurbuchen, Thomas H.

    2016-10-01

    The origin and acceleration of the solar wind are still debated. In this paper, we search for signatures of the source region and acceleration mechanism of the solar wind in the plasma properties measured in situ by the Advanced Composition Explorer spacecraft. Using the elemental abundances as a proxy for the source region and the differential velocity and ion temperature ratios as a proxy for the acceleration mechanism, we are able to identify signatures pointing toward possible source regions and acceleration mechanisms. We find that the fast solar wind in the ecliptic plane is the same as that observed from the polar regions and is consistent with wave acceleration and coronal-hole origin. We also find that the slow wind is composed of two components: one similar to the fast solar wind (with slower velocity) and the other likely originating from closed magnetic loops. Both components of the slow solar wind show signatures of wave acceleration. From these findings, we draw a scenario that envisions two types of wind, with different source regions and release mechanisms, but the same wave acceleration mechanism.

  9. Solar wind precipitation - a comparison between Mars and Venus

    NASA Astrophysics Data System (ADS)

    Stenberg Wieser, Gabriella; Nilsson, Hans; Futaana, Yoshifumi; Holmström, Mats; Barabash, Stas

    2015-04-01

    Mars and Venus both have atmospheres but both lack a substantial intrinsic magnetic field. Hence, their interaction with the solar wind is similar. Due to currents set up in the ionospheres the interplanetary magnetic field embedded in the solar wind 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 solar wind precipitation onto the upper atmospheres. We focus on the differences between the two planets. We conclude that on Mars we regularly observe precipitating solar wind ions (H+ and He2+) inside the induced magnetosphere boundary (IMB). The precipitation is clearly guided by the solar wind 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 solar wind electric field.

  10. Properties of Suprathermal Ions in Solar Wind Compression Regions

    NASA Astrophysics Data System (ADS)

    Jensema, R. J.; Desai, M. I.; Broiles, T. W.; Mason, G. M.

    2014-12-01

    Corotating interaction regions (CIRs) or more generally solar wind compression regions are believed to draw their source material from persistent but highly dynamic population of suprathermal (ST) particles with energies from a few keV up to 100's of keV. Additionally, the suprathermal particle population is observed as an inverse power-law "tail" that smoothly connects to the thermal solar wind. Despite the prevalence of ST ions in interplanetary space, their origin is highly controversial primarily because many local and remote sources can contribute and cause large variations in tail properties such as intensity, density, spectral indices, and ion composition. Using solar wind, magnetic field, and suprathermal ion data (.02 -2 MeV/nuc) obtained by the Wind spacecraft, we perform a comprehensive study of the properties of ST ion populations associated with compression regions observed near Earth orbit from 1994 to 2014. This continuous, multi-year dataset has provided us with measurements over nearly two solar cycles (23 and 24) through differing solar wind and sunspot activity conditions. Our preliminary survey shows that the heavy ion spectral indices exhibit large variations on short (<1 year) and long (>1 year) timescales. We also investigate the relationships between the spectral indices, peak intensities, maximum energies, and various plasma properties such as compression ratios and solar wind speed changes, and use these statistical correlations to determine a set of new observational constraints for current acceleration models of suprathermal ions.

  11. Sputtering by the Solar Wind: Effects of Variable Composition

    NASA Technical Reports Server (NTRS)

    Killen, R. M.; Arrell, W. M.; Sarantos, M.; Delory, G. T.

    2011-01-01

    It has long been recognized that solar wind bombardment onto exposed surfaces in the solar 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 solar wind composition have become available. It is now known that the solar wind composition is highly dependent on the origin of the particular plasma. Using the measured composition of the slow wind, fast wind, solar 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 solar wind. 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.

  12. Modeling the Acceleration Process of Dust in the Solar Wind

    NASA Astrophysics Data System (ADS)

    Jia, Y. D.; Lai, H.; Russell, C. T.; Wei, H.

    2015-12-01

    In previous studies we have identified structures created by nano-dust in the solar wind, and we have observed the expected draping and diverting signatures of such structures using well-spaced multi-spacecraft observations. In this study, we reproduce such an interaction event with our multi-fluid MHD model, modeling the dust particles as a fluid. When the number density of dust particles is comparable to the solar wind ions, a significant draping in the IMF is created, with amplitude larger than the ambient fluctuations. We note that such a density is well above several nano dust particles per Debye sphere and a dusty fluid is appropriate for modeling the dust-solar wind interaction. We assume a spherical cloud of dust travelling with 90% solar wind speed. In addition to reproducing the IMF response to the nano-dust at the end-stage of dust acceleration, we model the entire process of such acceleration in the gravity field of the inner heliosphere. It takes hours for the smallest dust with 3000 amu per proton charge to reach the solar wind speed. We find the dust cloud stretched along the solar wind flow. Such stretching enhances the draping of IMF, compared to the spherical cloud we used in an earlier stage of this study. This model will be further used to examine magnetic perturbations at an earlier stage of dust cloud acceleration, and then determine the size, density, and total mass of dust cloud, as well as its creation and acceleration.

  13. Structure of magnetic field in the solar wind

    NASA Technical Reports Server (NTRS)

    Chertkov, A. D.

    1995-01-01

    This work is concerned with empirical data on magnetic field in the solar wind in frame of a concept of dissipative solar wind, developed in papers (Solar Wind 7 Conf., Pergamon Press, 1992, 165 and 1992 STEP/5th COSPAR Coll. Pergamon Press, 1994, 117; 235; 803). Interplanetary magnetic fields should be classified with respect to their origin. It is very important for all the theoretical problems from the necessity to specify correctly boundary and initial conditions: the magnetic field must be sewed with its source. One should select the field, connected directly with the Sun (stretched out from it), and the field of moving electric currents. It occured central in discussion about the velocity of Alfven waves, probably warming up the solar wind, relative to the Sun, the magnetic field and solar wind plasma. The selection problem corresponds to an inverse problem and obviously has no single solution. The dissipative model of the solar wind introduce the slipping and leakage of plasma relative to magnetic field. There are no 'interplanetary current sheets' in it. But temporal fluctuations from the filamentation of electric currents play the key role. As a whole, the new concept requires the re-interpretation of main objects in the interplanetary magnetic field.

  14. Western Wind and Solar Integration Study Phase 2: Preprint

    SciTech Connect

    Lew, D.; Brinkman, G.; Ibanez, E.; Hodge, B.-M.; King, J.

    2012-09-01

    The Western Wind and Solar Integration Study (WWSIS) investigates the impacts of high penetrations of wind and solar 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 wind and solar power on systems operations. It considers mitigation options to accommodate wind and solar 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 wind and solar and penetration level. Transmission was built out to bring resources to load. Statistical analysis was conducted to investigate wind and solar impacts at timescales ranging from seasonal down to 5 minutes.

  15. Investigation of Solar Wind Correlations and Solar Wind Modifications Near Earth by Multi-Spacecraft Observations: IMP 8, WIND and INTERBALL-1

    NASA Technical Reports Server (NTRS)

    Paularena, Karolen I.; Richardson, John D.; Zastenker, Georgy N.

    2002-01-01

    The foundation of this Project is use of the opportunity available during the ISTP (International Solar-Terrestrial Physics) era to compare solar wind measurements obtained simultaneously by three spacecraft - IMP 8, WIND 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) solar wind structures; (2) the reliability of the common assumption that solar wind conditions at the upstream Lagrangian (L1) point accurately predict the conditions affecting Earth's magnetosphere; (3) modification of the solar wind 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.

  16. Using the fingerprints of solar magnetic reconnection to identify the elemental building blocks of the slow solar wind

    NASA Astrophysics Data System (ADS)

    Kepko, Larry; Viall, Nicholeen M.; Kasper, Justin; Lepri, Sue

    2015-04-01

    While the source of the fast solar wind is well understood to be linked to coronal holes, the source of the slow solar wind has remained elusive. Many previous studies of the slow solar wind have examined trends in the composition and charge states over long time scales and found strong relationships between the solar wind velocity and these plasma parameters. These relationships have been used to constrain models of solar wind source and acceleration. In this study, we take advantage of high time resolution (12 min) measurements of solar wind composition and charge-state abundances recently reprocessed by the ACE Solar Wind Ion Composition Spectrometer (SWICS) science team to probe the timescales of solar wind variability at relatively small scales. We study an interval of slow solar wind containing quasi-periodic 90 minute structures and show that they are remnants of solar magnetic reconnection. Each 90-minute parcel of slow solar wind, though the speed remains steady, exhibits the complete range of charge state and composition variations expected for the entire range of slow solar wind, 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 solar wind creation. We conclude by suggesting these structures were created through interchange magnetic reconnection and form elemental building blocks of the slow solar wind. We also discuss the necessity of decoupling separately the process(es) responsible for the release and acceleration.

  17. Impacts of wind stilling on solar radiation variability in China.

    PubMed

    Lin, Changgui; Yang, Kun; Huang, Jianping; Tang, Wenjun; Qin, Jun; Niu, Xiaolei; Chen, Yingying; Chen, Deliang; Lu, Ning; Fu, Rong

    2015-01-01

    Solar dimming and wind stilling (slowdown) are two outstanding climate changes occurred in China over the last four decades. The wind stilling may have suppressed the dispersion of aerosols and amplified the impact of aerosol emission on solar 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 solar radiation (SSR) decreased considerably with wind stilling in heavily polluted regions at a daily scale, indicating that wind stilling can considerably amplify the aerosol extinction effect on SSR. A threshold value of 3.5 m/s for wind speed is required to effectively reduce aerosols concentration. From this SSR dependence on wind speed, we further derived proxies to quantify aerosol emission and wind stilling amplification effects on SSR variations at a decadal scale. The results show that aerosol emission accounted for approximately 20% of the typical solar dimming in China, which was amplified by approximately 20% by wind stilling. PMID:26463748

  18. Impacts of wind stilling on solar radiation variability in China.

    PubMed

    Lin, Changgui; Yang, Kun; Huang, Jianping; Tang, Wenjun; Qin, Jun; Niu, Xiaolei; Chen, Yingying; Chen, Deliang; Lu, Ning; Fu, Rong

    2015-01-01

    Solar dimming and wind stilling (slowdown) are two outstanding climate changes occurred in China over the last four decades. The wind stilling may have suppressed the dispersion of aerosols and amplified the impact of aerosol emission on solar 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 solar radiation (SSR) decreased considerably with wind stilling in heavily polluted regions at a daily scale, indicating that wind stilling can considerably amplify the aerosol extinction effect on SSR. A threshold value of 3.5 m/s for wind speed is required to effectively reduce aerosols concentration. From this SSR dependence on wind speed, we further derived proxies to quantify aerosol emission and wind stilling amplification effects on SSR variations at a decadal scale. The results show that aerosol emission accounted for approximately 20% of the typical solar dimming in China, which was amplified by approximately 20% by wind stilling.

  19. Impacts of wind stilling on solar radiation variability in China

    NASA Astrophysics Data System (ADS)

    Lin, Changgui; Yang, Kun; Huang, Jianping; Tang, Wenjun; Qin, Jun; Niu, Xiaolei; Chen, Yingying; Chen, Deliang; Lu, Ning; Fu, Rong

    2015-10-01

    Solar dimming and wind stilling (slowdown) are two outstanding climate changes occurred in China over the last four decades. The wind stilling may have suppressed the dispersion of aerosols and amplified the impact of aerosol emission on solar 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 solar radiation (SSR) decreased considerably with wind stilling in heavily polluted regions at a daily scale, indicating that wind stilling can considerably amplify the aerosol extinction effect on SSR. A threshold value of 3.5 m/s for wind speed is required to effectively reduce aerosols concentration. From this SSR dependence on wind speed, we further derived proxies to quantify aerosol emission and wind stilling amplification effects on SSR variations at a decadal scale. The results show that aerosol emission accounted for approximately 20% of the typical solar dimming in China, which was amplified by approximately 20% by wind stilling.

  20. On the Relationship Between Solar Wind Speed, Geomagnetic Activity, and the Solar Cycle Using Annual Values

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.; Hathaway, David H.

    2008-01-01

    The aa index can be decomposed into two separate components: the leading sporadic component due to solar 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 solar wind speed (especially between the residual component of aa and the solar wind speed, r = 0.865). Because cyclic averages of aa (and the residual component) have trended upward during cycles 11-23, cyclic averages of solar wind speed are inferred to have also trended upward.

  1. Electron energy transport in the solar wind: Ulysses observations

    NASA Technical Reports Server (NTRS)

    Scime, Earl; Gary, S. Peter; Phillips, J. L.; Corniileau-Wehrlin, N.; Solomon, J.

    1995-01-01

    The electron heat flux in the solar wind has been measured by the Ulysses solar wind plasma experiment in the ecliptic from 1 to 5 AU and out of the ecliptic during the recently completed pass over the solar south pole and the ongoing pass over the solar north pole. Although the electron heat flux contains only a fraction of the kinetic energy of the solar wind. the available energy is sufficient to account for the non-adiabatic expansion of the solar wind electrons. The Ulysses measurements indicate that the electron heat flux is actively dissipated in the solar wind. 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.

  2. Solar wind eddies and the heliospheric current sheet

    NASA Technical Reports Server (NTRS)

    Suess, S. T.; Mccomas, D. J.; Bame, S. J.; Goldstein, B. E.

    1995-01-01

    Ulysses has collected data between 1 and 5 AU during, and just following solar 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 solar wind. The Ulysses solar wind plasma instrument measures the vector velocity and can be used to estimate the flow speed and direction in turbulent 'eddies' in the solar wind 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 solar wind 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 solar wind 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 solar 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.

  3. Initial Subdivision of Genesis Early Science Polished Aluminum Collector

    NASA Technical Reports Server (NTRS)

    Allton, J. H.; Stansbery, E. K.; McNamara, K. M.; Meshik, A.; See, T. H.; Bastien, R.

    2005-01-01

    A large surface, about 245 square centimeters, of highly polished aluminum 6061 T6 alloy was attached to the science canister thermal panel for the purpose of collecting solar wind noble gases. The analysis of this collector will be part of the Genesis Early Science results. The pre-launch configuration of the collector is shown. The collector sustained some damage during the recovery impact in Utah, September 8, 2004.

  4. Element Abundances in the Sun and Solar Wind Along the Solar Cycle

    NASA Astrophysics Data System (ADS)

    Landi, Enrico

    2015-04-01

    Element abundances are a critical parameter in almost every aspect of solar physics, from regulating the energy flow and the structure of the solar interior, to shaping the energy losses of the solar atmosphere, ruling the radiative output of the UV, EUV and X-rays solar radiation which impacts the Earth's upper atmosphere, and determining the composition of the solar wind.In this work we study the evolution of the element abundances in the solar corona and in the solar wind from 1996 to date using data from SoHO, Hinode, Ulysses and ACE satellites, in order to determine their variability along the solar cycle, and the relationship between solar abundance variations in the solar wind and in its source regions in the solar atmosphere. We study all the most abundant elements, with a special emphasis on Ne and O. We discuss our results in light of the source region of the solar wind, and of the radiative output of the solar corona.

  5. Genesis: Sorting Out the Pieces

    NASA Technical Reports Server (NTRS)

    McNamara, K. M.; Westphal, Andrew; Butterworth, A. L.; Burnett, D. S.

    2005-01-01

    The Genesis mission returned to Earth on September 8, 2004, experiencing a non-nominal reentry. The parachutes which were supposed to slow and stabilize the capsule throughout the return failed to deploy, causing the capsule to impact the desert floor at a speed of nearly 200 MPH. The result is that instead of receiving 301 intact solar wind collectors, mission personnel recovered and documented more than 10,000 collector fragments. Most of the fragments were pieces of the collector arrays but were not recovered on their original array locations. These were classified by size (longest dimension), identity (sometimes a guess) and found location (when known). The work took more than one month in Utah, and details are discussed elsewhere[1] The samples were transferred to their permanent home at the Johnson Space Center on October 4, 2004.

  6. A Possible Cause of the Diminished Solar Wind During the Solar Cycle 23 - 24 Minimum

    NASA Astrophysics Data System (ADS)

    Liou, Kan; Wu, Chin-Chun

    2016-10-01

    Interplanetary magnetic field and solar wind plasma density observed at 1 AU during Solar Cycle 23 - 24 (SC-23/24) minimum were significantly smaller than those during its previous solar cycle (SC-22/23) minimum. Because the Earth's orbit is embedded in the slow wind during solar minimum, changes in the geometry and/or content of the slow wind region (SWR) can have a direct influence on the solar wind parameters near the Earth. In this study, we analyze solar wind plasma and magnetic field data of hourly values acquired by Ulysses. It is found that the solar wind, 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° in heliographic latitude) than in the first ( {˜} 44.8° solar orbit. The observed latitudinal increase in the SWR is sufficient to explain the excessive decline in the near-Earth solar wind density during the recent solar minimum without speculating that the total solar output may have been decreasing. The observed SWR inflation is also consistent with a cooler solar wind 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.

  7. Velocity Distributions and Proton Beam Production in the Solar Wind

    SciTech Connect

    Pierrard, Viviane; Voitenko, Yuriy

    2010-03-25

    Helios, Ulysses, and Wind spacecraft have observed the velocity distribution functions (VDFs) of solar wind 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 solar wind. 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.

  8. Some remarks on waves in the solar wind

    NASA Technical Reports Server (NTRS)

    Kellogg, Paul J.

    1995-01-01

    Waves are significant to the solar wind in two ways as modifiers of the particle distribution functions, and as diagnostics. In addition, the solar wind serves as an important laboratory for the study of plasma wave processes, as it is possible to make detailed measurements of phenomena which are too small to be easily measured by laboratory sized sensors. There are two areas where waves (we include discontinuities under this heading) must make important modifications of the distribution functions: in accelerating the alpha particles to higher speeds than the protons (Marsch et al.) and in accelerating the solar wind itself. A third area is possibly in maintaining the relative isotropy of the solar wind ion distribution in the solar wind rest frame. As the solar wind is nearly collisionless, the ions should conserve magnetic moment in rushing out from the sun, and therefore Tperp/B should be relatively constant, but it is obviously not. This has not received much attention. The waves, both electromagnetic and electrostatic, which are pan of the solar Type 111 burst phenomenon, have been extensively studied as examples of nonlinear plasma phenomena, and also used as remote sensors to trace the solar magnetic field. The observations made by Ulysses show that the field can be traced in this way out to perhaps a little more than an A.U., but then the electromagnetic pan of the type 111 burst fades out. Nevertheless, sometimes Langmuir waves appear at Ulysses at an appropriate extrapolated time. This seems to support the picture in which the electromagnetic waves at the fundamental plasma frequency are trapped in density fluctuations. Langmuir waves in the solar wind are usually in quasi-thermal equilibrium quasi because the solar wind itself is not isothermal. The Observatory of Paris group (Steinberg. Meyer-Vernet, Hoang) has exploited this with an experiment on WIND which is capable of providing density and temperature on a faster time scale than hitherto. Recently

  9. Hybrid Simulations of Solar Wind Interactions of Mars

    NASA Astrophysics Data System (ADS)

    Brecht, S. H.; Ledvina, S. A.

    2013-09-01

    In this paper the results of hybrid simulations of Mars will be presented. These simulations include the crustal magnetic fields and examine their role in the solar wind interaction with Mars. The focus is the ionospheric response to differing situations on the ionosphere as well as the ionospheric loss from Mars. A comparison between solar maximum conditions and solar minimum conditions will be presented. Further, the effect of different crustal magnetic field orientations will also be presented.

  10. Preferred solar wind emitting longitudes on the sun

    NASA Technical Reports Server (NTRS)

    Gosling, J. T.; Asbridge, J. R.; Bame, S. J.; Feldman, W. C.

    1977-01-01

    During the 11 1/2-year period from July 1964 through December 1975, high- and low-speed solar wind flows originated from preferred solar longitudes. The preferred longitude effect was most pronounced from 1970 onward but was also evident in the years preceding 1970. The most pronounced modulation in average solar wind speed with longitude (approximately 20%) was obtained when it was assumed that the synodic rotation period of the sun is 27.025 days. Some deep internal structure in the sun must ultimately be responsible for these long-lived longitudinal effects, which appear to rotate rigidly with the sun.

  11. Shear flow induced wave couplings in the solar wind

    SciTech Connect

    Poedts, S.; Rogava, A.D. |; Mahajan, S.M. |

    1998-01-01

    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 solar wind conditions. It is shown that this is indeed the case. Hence, the long-period waves observed in the solar wind 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 wind and the acceleration of the solar wind particles are also discussed.

  12. The interaction of active comets with the solar wind

    SciTech Connect

    Neugebauer, M. )

    1990-11-01

    The interaction of the solar wind with active comets is investigated based on observations of cometary plasma processes and studies of comets using telescopes and photographic plates. Data were also collected when a spacecraft flew through the tail of Comet Giacobini-Zinner in 1985 and five spacecraft encountered Comet Halley in 1986. The solar wind is considered to be supersonic (thermal Mach number 2-10) and to carry a magnetic field twisted into an Archimedean spiral by the rotation of the sun. Since the wind can change its properties during the time a spacecraft is inside the ionosphere or magnetosphere of the body being studied, it is difficult to separate spatial from temporal effects. Photoionization results in addition of plasma to the solar wind. Between the outer and inner edges of the cometosheath, the increasing rate of ion pickup causes the flow to slow down until it stagnates, while the plasma density and the magnetic field strength increase.

  13. Self-consistent Castaing Distribution of Solar Wind Turbulent Fluctuations

    NASA Astrophysics Data System (ADS)

    Sorriso-Valvo, L.; Marino, R.; Lijoi, L.; Perri, S.; Carbone, V.

    2015-07-01

    The intermittent behavior of solar wind turbulent fluctuations has often been investigated through the modeling of their probability distribution functions (PDFs). Among others, the Castaing model has successfully been used in the past. In this paper, the energy dissipation field of solar wind turbulence has been studied for fast, slow, and polar wind samples recorded by Helios 2 and Ulysses spacecraft. The statistical description of the dissipation rate has then been used to remove intermittency through conditioning of the PDFs. Based on such observation, a self-consistent, parameter-free Castaing model is presented. The self-consistent model is tested against experimental PDFs, showing good agreement and supporting the picture of a multifractal energy cascade at the origin of solar wind intermittency.

  14. Coronal Streamers and Their Associated Solar Wind Streams

    NASA Astrophysics Data System (ADS)

    Miralles, M. P.; Landi, E.; Cranmer, S. R.; Cohen, O.; Raymond, J. C.

    2012-12-01

    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 solar minimum periods. In addition, comparisons between coronal observations and in situ measurements of solar wind plasma properties are being used to further characterize the origins of slow wind streams. In order to investigate slow solar wind 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 wind acceleration (e.g., waves/turbulence versus reconnection). This work is supported by NASA grant NNX10AQ58G to the Smithsonian Astrophysical Observatory.

  15. Ulysses solar wind plasma observations at high latitudes

    SciTech Connect

    Riley, P.; Bame, S.J.; Barraclough, B.L.

    1996-10-01

    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 solar wind plasma experiment, SWOOPS, emphasizing northern hemispheric observations but also providing southern and equatorial results for comparison. The solar wind momentum flux during Ulysses` fast pole-to- pole transit at solar 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 wind speed, density, and mass flux were observed between the two hemispheres during the fast latitude scan. The solar wind 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 solar wind 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 solar rotation modulated features in the form of recurrent compressed regions.

  16. Improving solar wind modeling at Mercury: Incorporating transient solar phenomena into the WSA-ENLIL model

    NASA Astrophysics Data System (ADS)

    Dewey, R. M.; Baker, D. N.; Anderson, B. J.; Benna, M.; Johnson, C. L.; Korth, H.; Gershman, D. J.; Ho, G. C.; McClintock, W. E.; Odstrcil, D.; Philpott, L. C.; Raines, J. M.; Schriver, D.; Slavin, J. A.; Solomon, S. C.; Winslow, R. M.; Zurbuchen, T.

    2014-12-01

    Coronal mass ejections (CMEs) and other transient solar phenomena play important roles in magnetospheric and exospheric dynamics. Although a planet may only occasionally interact with the products of these events, such transient phenomena can result in departures from the background solar wind that often involve more than an order of magnitude greater ram pressure and interplanetary electric field applied to the magnetosphere. For Mercury, an order of magnitude greater ram pressure can push the magnetopause to the planet's surface, exposing the surface directly to the solar wind. In order to understand how the solar wind interacts with Mercury's magnetosphere and exosphere, previous studies have used the Wang-Sheeley-Arge (WSA)-ENLIL solar wind modeling tool to calculate basic and composite solar wind parameters, such as solar wind velocity (V) and Alfvén Mach number (MA) at Mercury's orbital location. This model forecasts only the background solar wind, however, and does not include these transient events. The Cone extension permits the inclusion of CMEs and other phenomena, and thus enables characterization of the effect of strong solar wind perturbations on the Mercury system. The Cone extension is predicated on the assumption of constant angular and radial velocities of ejecta to integrate them into the WSA-ENLIL coupled model. Comparisons of the model results with the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft observations indicate that the WSA-ENLIL-Cone model more accurately forecasts total solar wind conditions at Mercury and has greater predictive power for magnetospheric and exospheric processes than the WSA-ENLIL model alone.

  17. The Solar Wind Interaction with Pluto: Part 2

    NASA Astrophysics Data System (ADS)

    Elliott, H. A.; McComas, D. J.; Valek, P. W.; Weidner, S.; Bagenal, F.; Delamere, P. A.; Stern, A.; Weaver, H. A., Jr.; Young, L. A.; Ennico Smith, K.; Olkin, C.; McNutt, R. L., Jr.; Hill, M. E.; Nicolaou, G.

    2015-12-01

    On 14 July 2015 the New Horizons (NH) spacecraft flew past Pluto and the Solar Wind Around Pluto (SWAP) instrument recorded the its remarkable interaction with the impinging solar wind. The interaction is unique in the solar system, in some ways intermediate between the mass loading interactions of comets and ionospheric interactions of massive planets, and in other ways different from both of these more common extremes. Little mass loading was observed until quite close to Pluto and the solar wind was excluded from a region filled with heavy ions from Pluto's escaping atmosphere that extended well behind it. At the time this abstract was due, only small snippets of SWAP data had been telemetered to Earth, but by the AGU meeting, plasma data from the entire flyby with have been received and initially analyzed. This talk is given on behalf of the SWAP and NH teams.

  18. The Solar Wind Interaction with Pluto: Part 1

    NASA Astrophysics Data System (ADS)

    McComas, D. J.

    2015-12-01

    On 14 July 2015 the New Horizons (NH) spacecraft flew past Pluto and the Solar Wind Around Pluto (SWAP) instrument recorded its remarkable interaction with the impinging solar wind. The interaction is unique in the solar system, in some ways intermediate between the mass loading interactions of comets and ionospheric interactions of massive planets, and in other ways different from both of these more common extremes. Little mass loading was observed until quite close to Pluto and the solar wind was excluded from a region filled with heavy ions from Pluto's escaping atmosphere that extended well behind it. At the time this abstract was due, only small snippets of SWAP data had been telemetered to Earth, but by the AGU meeting, plasma data from the entire flyby will have been received and initially analyzed. This talk is given on behalf of the SWAP and NH teams.

  19. Continuing the Search for Natural Solar Wind States

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    The need to classify solar wind states is partially the practical one of knowing what winds will strongly affect the Earth, but it is also to help in understanding the origin of the winds. In terms of the latter classification, of interest here, there is general agreement that "ejecta" represent a separate class from ordinary winds, 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" wind is at best misleading, and slow wind sometimes displays temperature anisotropies, fluctuation spectra, and the like that are characteristic of the typical fast wind. Recent work has focused on distinguishing "coronal hole wind" from "streamer belt" and "strahl confusion zone" (heliospheric current sheet) winds. The hope is to discern which wind 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 wind 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 solar 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 solar wind heating.

  20. SOLAR WIND HEAVY IONS OVER SOLAR CYCLE 23: ACE/SWICS MEASUREMENTS

    SciTech Connect

    Lepri, S. T.; Landi, E.; Zurbuchen, T. H.

    2013-05-01

    Solar wind plasma and compositional properties reflect the physical properties of the corona and its evolution over time. Studies comparing the previous solar minimum with the most recent, unusual solar minimum indicate that significant environmental changes are occurring globally on the Sun. For example, the magnetic field decreased 30% between the last two solar minima, and the ionic charge states of O have been reported to change toward lower values in the fast wind. In this work, we systematically and comprehensively analyze the compositional changes of the solar wind during cycle 23 from 2000 to 2010 while the Sun moved from solar maximum to solar minimum. We find a systematic change of C, O, Si, and Fe ionic charge states toward lower ionization distributions. We also discuss long-term changes in elemental abundances and show that there is a {approx}50% decrease of heavy ion abundances (He, C, O, Si, and Fe) relative to H as the Sun went from solar maximum to solar minimum. During this time, the relative abundances in the slow wind remain organized by their first ionization potential. We discuss these results and their implications for models of the evolution of the solar atmosphere, and for the identification of the fast and slow wind themselves.

  1. Solar cosmic ray, solar wind, solar flare, and neutron albedo measurements, part C

    NASA Technical Reports Server (NTRS)

    Burnett, D.; Hohenberg, C.; Maurette, M.; Monnin, M.; Walker, R.; Wollum, D.

    1972-01-01

    All mineral detectors exposed on Apollo 16 had high surface track densities probably produced by a solar flare that occurred during the mission. The heavy ions followed a power law spectrum with exponent approximately 3 down to approximately 200 KeV/nucleon. The abundance of low-energy particle tracks observed in this flare may explain the high track densities observed in lunar dust grains. Pristine heavy-particle tracks in feldspar give long tracks. Shallow pits similar to those expected from extremely heavy solar wind ions were observed in about the expected number. Initial results give a low apparent value of neutron albedo relative to theory.

  2. Sources of the Slow Solar Wind During the Solar Cycle 23/24 Minimum

    NASA Astrophysics Data System (ADS)

    Kilpua, E. K. J.; Madjarska, M. S.; Karna, N.; Wiegelmann, T.; Farrugia, C.; Yu, W.; Andreeova, K.

    2016-10-01

    We investigate the characteristics and the sources of the slow ({<} 450 km s^{-1}) solar wind during the four years (2006 - 2009) of low solar activity between Solar Cycles 23 and 24. We used a comprehensive set of in-situ observations in the near-Earth solar wind ( Wind 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 solar 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 solar wind source type, some (Fe/O) exhibit very little changes. Our results highlight the difficulty of distinguishing between the slow solar wind sources based on the inspection of solar wind conditions.

  3. Sources of the Slow Solar Wind During the Solar Cycle 23/24 Minimum

    NASA Astrophysics Data System (ADS)

    Kilpua, E. K. J.; Madjarska, M. S.; Karna, N.; Wiegelmann, T.; Farrugia, C.; Yu, W.; Andreeova, K.

    2016-09-01

    We investigate the characteristics and the sources of the slow ( {<} 450 km s^{-1}) solar wind during the four years (2006 - 2009) of low solar activity between Solar Cycles 23 and 24. We used a comprehensive set of in-situ observations in the near-Earth solar wind (Wind 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 solar 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 solar wind source type, some (Fe/O) exhibit very little changes. Our results highlight the difficulty of distinguishing between the slow solar wind sources based on the inspection of solar wind conditions.

  4. Ions with low charges in the solar wind as measured by SWICS on board Ulysses. [Solar Wind Ion Composition Spectrometer

    NASA Technical Reports Server (NTRS)

    Geiss, J.; Ogilvie, K. W.; Von Steiger, R.; Mall, U.; Gloeckler, G.; Galvin, A. B.; Ipavich, F.; Wilken, B.; Gliem, F.

    1992-01-01

    We present new data on rare ions in the solar wind. 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 solar wind and established sensitive upper limits for many species. In the solar wind, 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 solar wind sample we studied. Since this sample showed the FlP effect typical for low-speed solar wind, 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 solar surface and not by foreign material in the corona.

  5. Chromospheric alfvenic waves strong enough to power the solar wind.

    PubMed

    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

    2007-12-01

    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 solar wind to hundreds of kilometers per second. However, Alfvén waves of sufficient strength have not been unambiguously observed in the solar atmosphere. We used images of high temporal and spatial resolution obtained with the Solar Optical Telescope onboard the Japanese Hinode satellite to reveal that the chromosphere, the region sandwiched between the solar 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 solar wind and possibly to heat the quiet corona. PMID:18063784

  6. Chromospheric alfvenic waves strong enough to power the solar wind.

    PubMed

    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

    2007-12-01

    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 solar wind to hundreds of kilometers per second. However, Alfvén waves of sufficient strength have not been unambiguously observed in the solar atmosphere. We used images of high temporal and spatial resolution obtained with the Solar Optical Telescope onboard the Japanese Hinode satellite to reveal that the chromosphere, the region sandwiched between the solar 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 solar wind and possibly to heat the quiet corona.

  7. Charge state composition in coronal hole and CME related solar wind: Latitudinal variations observed by Ulysses and WIND

    NASA Technical Reports Server (NTRS)

    Galvin, A. B.; Gloeckler, G.

    1997-01-01

    Iron charge states in recurrent coronal hole-associated solar wind flows are obtained in the ecliptic by WIND/SMS, while measurements of iron and silicon from the polar coronal holes are available from Ulysses/SWICS. Ulysses/SWICS also provides ion composition of coronal mass ejection (CME)-related solar wind. Both coronal hole-associated and CME-related solar wind charge charges show heliographic latitudinal variations.

  8. Solar Wind Magnetic Fluctuations and Electron Non-Thermal Temperature Anisotropy: Survey of Wind-SWE-VEIS Observations

    NASA Astrophysics Data System (ADS)

    Vinas, A. F.; Adrian, M. L.; Moya, P. S.; Wendel, D. E.

    2015-12-01

    The solar wind electron velocity distribution function (eVDF) exhibits a great variety of non-thermal features that deviate from thermal equilibrium. These deviations from thermal equilibrium provide a local source for electromagnetic fluctuation emissions, which among others include the electron whistler-cyclotron and firehose instabilities. We present a systematic analysis of Wind-SWE-VEIS observations of solar wind electron plasma and their associated Wind-MFI observed magnetic fluctuations. We show for the first time clear evidence that the temperature anisotropy threshold of the parallel electron anisotropic instability bounds solar wind electrons — when the full electron distribution and its moments are considered — during slow solar wind periods. Analysis shows that during slow solar wind periods, collisional effects are dominant. During fast solar wind periods, magnetic fluctuations and solar wind anisotropies are enhanced above the parallel whistler anisotropic threshold boundary and collisional effects are drastically reduced. Preliminary calculations further show that the oblique electron whistler mirror anisotropic instability bounds both the slow and fast solar wind. Regardless of solar wind speed, the solar wind electron thermal anisotropy appears globally bounded by the parallel electron firehose instability for anisotropies Te,perp / Te,parallel < 1. When considering collisional effects, our results indicate that collisions are rare in the solar wind, yet appear to play a necessary role in regulating the eVDFs. The results of our analysis are strikingly different from those for solar wind ions suggesting that the slow solar wind electron plasma is only marginally stable with respect to parallel propagating instabilities.

  9. Role of Concentrating Solar Power in Integrating Solar and Wind Energy: Preprint

    SciTech Connect

    Denholm, P.; Mehos, M.

    2015-06-03

    As wind and solar photovoltaics (PV) increase in penetration it is increasingly important to examine enabling technologies that can help integrate these resources at large scale. Concentrating solar power (CSP) when deployed with thermal energy storage (TES) can provide multiple services that can help integrate variable generation (VG) resources such as wind 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 wind, substantially increasing their penetration in locations with adequate solar resource.

  10. Direct evidence for kinetic effects associated with solar wind reconnection

    PubMed Central

    Xu, Xiaojun; Wang, Yi; Wei, Fengsi; Feng, Xueshang; Deng, Xiaohua; Ma, Yonghui; Zhou, Meng; Pang, Ye; Wong, Hon-Cheng

    2015-01-01

    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 solar wind reconnection have been analyzed in the context of magnetohydrodynamics (MHD) although a lot of solar wind 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 solar wind remains unknown. Here, by dual-spacecraft observations, we report a solar wind 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 solar wind turbulence, implying that the reconnection generated turbulence has not much developed. PMID:25628139

  11. Direct evidence for kinetic effects associated with solar wind reconnection.

    PubMed

    Xu, Xiaojun; Wang, Yi; Wei, Fengsi; Feng, Xueshang; Deng, Xiaohua; Ma, Yonghui; Zhou, Meng; Pang, Ye; Wong, Hon-Cheng

    2015-01-01

    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 solar wind reconnection have been analyzed in the context of magnetohydrodynamics (MHD) although a lot of solar wind 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 solar wind remains unknown. Here, by dual-spacecraft observations, we report a solar wind 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 solar wind turbulence, implying that the reconnection generated turbulence has not much developed. PMID:25628139

  12. Direct evidence for kinetic effects associated with solar wind reconnection.

    PubMed

    Xu, Xiaojun; Wang, Yi; Wei, Fengsi; Feng, Xueshang; Deng, Xiaohua; Ma, Yonghui; Zhou, Meng; Pang, Ye; Wong, Hon-Cheng

    2015-01-01

    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 solar wind reconnection have been analyzed in the context of magnetohydrodynamics (MHD) although a lot of solar wind 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 solar wind remains unknown. Here, by dual-spacecraft observations, we report a solar wind 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 solar wind turbulence, implying that the reconnection generated turbulence has not much developed.

  13. SOLAR WIND MODELING WITH TURBULENCE TRANSPORT AND HEATING

    SciTech Connect

    Usmanov, Arcadi V.; Goldstein, Melvyn L.; Matthaeus, William H.; Breech, Benjamin A.

    2011-02-01

    We have developed an axisymmetric steady-state solar wind model that describes properties of the large-scale solar wind, 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 solar wind and smaller-scale turbulence and the role of the turbulence in the large-scale structure and temperature distribution in the solar wind. To illuminate the roles of the turbulent cascade and the pickup protons in heating the solar wind 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.

  14. The Importance of Suprathermal Electrons in the Solar Wind

    NASA Astrophysics Data System (ADS)

    LE CHAT, G.; Meyer-Vernet, N.; Pantellini, F. G. E.; Issautier, K.; Moncuquet, M.

    2014-12-01

    Non-Gaussian distributions are ubiquitous in systems having long-range interactions, from real-world networks to astrophysical plasmas. The corona and solar wind are no exception. In this review, we concentrate on the corona and solar wind electrons, whose suprathermal tail governs heat transport and plays a crucial role in the temperature structure and wind 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 solar wind, 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 solar wind models are based is inadequate; (2) the heat flux is NOT given by the classical Spitzer-Härm expression in the corona and solar wind; (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 wind 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 wind acceleration.

  15. Solar wind and coronal rotation during an activity cycle

    NASA Astrophysics Data System (ADS)

    Pinto, Rui; Brun, Allan Sacha

    The properties of the solar wind flow are strongly affected by the time-varying strength and geometry of the global background magnetic field. The wind velocity and mass flux depend directly on the size and position of the wind sources at the surface, and on the geometry of the magnetic flux-tubes along which the wind flows. We address these problems by performing numerical simulations coupling a kinematic dynamo code (STELEM) evolve in a 2.5D axisymmetric coronal MHD code (DIP) covering an 11 yr activity cycle. The latitudinal distribution of the calculated wind velocities agrees with in-situ (ULYSSES, HELIO) and radio measurements (IPS). The transition from fast to slow wind flows can be explained in terms of the high overall flux-tube superradial expansion factors in the vicinities of coronal streamer boundaries. We found that the Alfvén radii and the global Sun's mass loss rate vary considerably throughout the cycle (by a factor 4.5 and 1.6, respectively), leading to strong temporal modulations of the global angular momentum flux and magnetic braking torque. The slowly varying magnetic topology introduces strong non-uniformities in the coronal rotation rate in the first few solar radii. Finally, we point out directions to assess the effects of surface transient phenomena on the global properties of the solar wind.

  16. Solar identification of solar-wind disturbances observed at Ulysses

    NASA Astrophysics Data System (ADS)

    Lemen, J. R.; Acton, L. W.; Alexander, D.; Galvin, A. B.; Harvey, K. L.; Hoeksema, J. T.; Zhao, X.; Hudson, H. S.

    1996-07-01

    The Ulysses polar passages are producing a unique set of observations of solar-wind 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 solar 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 solar 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

  17. Determining the Coronal Origins of the Solar Wind Using Remote Sensing and In Situ Observations

    NASA Astrophysics Data System (ADS)

    Miralles, Mari Paz

    2013-05-01

    We study the origin and evolution of the solar wind by characterizing the physical properties of the solar wind plasma with multi-spacecraft (Hinode, SDO, SOHO, STEREO, ACE, Ulysses, WIND) and ground-based (MLSO, MWO, NSO, WSO) observations. We discuss the results for the fast solar wind from polar and low-latitude coronal-hole wind streams and for the slow wind from coronal-streamer wind streams. We also compare the characteristics of these wind streams with results from the previous solar cycle. This work is supported by NASA grant NNX10AQ58G to the Smithsonian Astrophysical Observatory.

  18. Generalized similarity in finite range solar wind magnetohydrodynamic turbulence.

    PubMed

    Chapman, S C; Nicol, R M

    2009-12-11

    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 solar polar passes at solar minimum provide in situ observations of evolving anisotropic magnetohydrodynamic turbulence in the solar wind 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 solar minimum--with turbulent fluctuations down by a factor of approximately 2 in power--provides a test of this invariance. PMID:20366193

  19. Generalized similarity in finite range solar wind magnetohydrodynamic turbulence.

    PubMed

    Chapman, S C; Nicol, R M

    2009-12-11

    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 solar polar passes at solar minimum provide in situ observations of evolving anisotropic magnetohydrodynamic turbulence in the solar wind 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 solar minimum--with turbulent fluctuations down by a factor of approximately 2 in power--provides a test of this invariance.

  20. Generalized Similarity in Finite Range Solar Wind Magnetohydrodynamic Turbulence

    SciTech Connect

    Chapman, S. C.; Nicol, R. M.

    2009-12-11

    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 solar polar passes at solar minimum provide in situ observations of evolving anisotropic magnetohydrodynamic turbulence in the solar wind 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 solar minimum - with turbulent fluctuations down by a factor of approx2 in power - provides a test of this invariance.

  1. The Solar Wind Electrons Alphas and Protons (SWEAP) Investigation for Solar Probe Plus

    NASA Astrophysics Data System (ADS)

    Kasper, J. C.; SWEAP Investigation Team

    2010-12-01

    The NASA Solar Probe Plus mission will be humanity’s first direct visit to the atmosphere of our Sun. The spacecraft will close to within nine solar radii (about four million miles) of the solar surface in order to observe the heating of the corona and the acceleration of the solar wind first hand. A key requirement for Solar 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 solar wind. The Solar Wind 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 Solar Probe Cup (SPC) and the Solar Probe Analyzers (SPAN). SWEAP measurements enable discovery and understanding of solar wind acceleration and formation, coronal and solar wind heating, high-energy particle acceleration, and the interaction between solar wind 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.

  2. Weakest solar wind of the space age and the current 'MINI' solar maximum

    SciTech Connect

    McComas, D. J.; Angold, N.; Elliott, H. A.; Livadiotis, G.; Schwadron, N. A.; Smith, C. W.; Skoug, R. M.

    2013-12-10

    The last solar 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 solar maxima. The solar wind fluid properties and interplanetary magnetic field (IMF) have declined through the prolonged solar minimum and continued to be low through the current mini solar 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: solar wind 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 solar wind'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 solar wind as the IMF) and associated low power in the solar wind points to the causal relationship between them. Our results indicate that the low solar wind output is driven by an internal trend in the Sun that is longer than the ∼11 yr solar cycle, and they suggest that this current weak solar maximum is driven by the same trend.

  3. Weakest Solar Wind of the Space Age and the Current "Mini" Solar Maximum

    NASA Astrophysics Data System (ADS)

    McComas, D. J.; Angold, N.; Elliott, H. A.; Livadiotis, G.; Schwadron, N. A.; Skoug, R. M.; Smith, C. W.

    2013-12-01

    The last solar 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 solar maxima. The solar wind fluid properties and interplanetary magnetic field (IMF) have declined through the prolonged solar minimum and continued to be low through the current mini solar 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: solar wind 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 solar wind'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 solar wind as the IMF) and associated low power in the solar wind points to the causal relationship between them. Our results indicate that the low solar wind output is driven by an internal trend in the Sun that is longer than the ~11 yr solar cycle, and they suggest that this current weak solar maximum is driven by the same trend.

  4. He abundance variations in the solar wind: Observations from Ulysses

    SciTech Connect

    Barraclough, B.L.; Feldman, W.C.; Gosling, J.T.; McComas, D.J.; Phillips, J.L.; Goldstein, B.E.

    1996-07-01

    The Ulysses mission is providing the first opportunity to observe variations in solar wind plasma parameters at heliographic latitudes far removed from the ecliptic plane. We present here an overview of the solar wind 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 solar wind speed and [He] in high-latitude and equatorial regions are quite striking. Solar wind speed is generally low but highly variable near the solar 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 solar 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 solar 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 solar wind [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.}

  5. XMM-Newton Observations of Solar Wind Charge Exchange Emission

    NASA Technical Reports Server (NTRS)

    Snowden, S. L.; Collier, M. R.; Kuntz, K. D.

    2004-01-01

    We present an XMM-Newton spectrum of diffuse X-ray emission from within the solar 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 solar wind 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 solar wind measured by the ACE satellite. The solar wind 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 solar wind plasma made at a single point reflect only local conditions which may only be representative of solar wind properties with spatial scales ranging from less than half of an Earth radii (approximately 10 s) to 100 Earth radii, X-ray observations of solar wind 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 solar 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 solar wind monitoring data, such as from the ACE and Wind spacecraft, as a diagnostic to screen for such possibilities.

  6. Features of solar wind acceleration according to radio occultation data

    NASA Technical Reports Server (NTRS)

    Efimov, A. I.

    1995-01-01

    In addressing one of the fundamental problems in solar physics establishing the mechanism(s) responsible for the solar wind acceleration and the corona heating - it is essential to have a reliable knowledge of the heliocentric radial dependence of the solar wind properties. Adequate data are available for small solar distances R less than 4 R(solar mass) from coronal white light and EUV observations and at distances R greater than 60 R(solar 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 solar wind 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 solar offset distances R approximately 6-80 R(solar 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(solar 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(solar 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.

  7. Dynamic properties of helium ions in the solar wind

    NASA Technical Reports Server (NTRS)

    Zurbuchen, Th.; Bochsler, P.; von Steiger, R.

    1995-01-01

    We characterize the dynamic properties of He ions of the solar wind. 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 solar wind 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 solar wind 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.

  8. Energy coupling between the solar wind and the magnetosphere

    NASA Technical Reports Server (NTRS)

    Akasofu, S.-I.

    1981-01-01

    A description is given of the path leading to the first approximation expression for the solar wind-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 solar wind couples its energy to the magnetosphere; the solar wind 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.

  9. Solar wind flow past Venus - Theory and comparisons

    NASA Technical Reports Server (NTRS)

    Spreiter, J. R.; Stahara, S. S.

    1980-01-01

    Advanced computational procedures are applied to an improved model of solar wind 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 solar wind 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 solar wind 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.

  10. Lunar fossil magnetism and perturbations of the solar wind.

    NASA Technical Reports Server (NTRS)

    Sonett, C. P.; Mihalov, J. D.

    1972-01-01

    Perturbations of the solar wind 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 solar wind 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 solar wind is found.

  11. Effects of electrons on the solar wind proton temperature anisotropy

    SciTech Connect

    Michno, M. J.; Lazar, M.; Schlickeiser, R.; Yoon, P. H. E-mail: mlazar@tp4.rub.de E-mail: yoonp@umd.edu

    2014-01-20

    Among the kinetic microinstabilities, the firehose instability is one of the most efficient mechanisms to restrict the unlimited increase of temperature anisotropy in the direction of an ambient magnetic field as predicted by adiabatic expansion of collision-poor solar wind. Indeed, the solar wind proton temperature anisotropy detected near 1 AU shows that it is constrained by the marginal firehose condition. Of the two types of firehose instabilities, namely, parallel and oblique, the literature suggests that the solar wind data conform more closely to the marginal oblique firehose condition. In the present work, however, it is shown that the parallel firehose instability threshold is markedly influenced by the presence of anisotropic electrons, such that under some circumstances, the cumulative effects of both electron and proton anisotropies could describe the observation without considering the oblique firehose mode.

  12. Ulysses solar wind plasma observations at high southerly latitudes.

    PubMed

    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

    1995-05-19

    Solar wind plasma observations made by the Ulysses spacecraft through -80.2 degrees solar 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 solar wind 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 wind contained compressional, pressure-balanced, and Alfvénic structures.

  13. Solar Wind Observations from 10 to 30 AU Measured With The New Horizons Solar Wind Around Pluto (SWAP) Instrument

    NASA Astrophysics Data System (ADS)

    Elliott, H. A.; McComas, D. J.; Valek, P. W.; Nicolaou, G.; Bagenal, F.; Delamere, P. A.; Livadiotis, G.

    2014-12-01

    Beginning in 2012 the New Horizons mission to Pluto began collecting solar wind observations during the spacecraft hibernation greatly increasing the solar wind coverage. We have extensively analyzed both the laboratory and flight calibration measurements for the Solar Wind Around Pluto (SWAP) instrument to produce a data set of solar wind 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 solar wind 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.

  14. The New Horizons Solar Wind Around Pluto (SWAP) Observations of the Solar Wind from 11-33 au

    NASA Astrophysics Data System (ADS)

    Elliott, H. A.; McComas, D. J.; Valek, P.; Nicolaou, G.; Weidner, S.; Livadiotis, G.

    2016-04-01

    The Solar Wind Around Pluto (SWAP) instrument on National Aeronautics and Space Administration's New Horizons Pluto mission has collected solar wind observations en route from Earth to Pluto, and these observations continue beyond Pluto. Few missions have explored the solar wind in the outer heliosphere making this dataset a critical addition to the field. We created a forward model of SWAP count rates, which includes a comprehensive instrument response function based on laboratory and flight calibrations. By fitting the count rates with this model, the proton density (n), speed (V), and temperature (T) parameters are determined. Comparisons between SWAP parameters and both propagated 1 au observations and prior Voyager 2 observations indicate consistency in both the range and mean wind values. These comparisons as well as our additional findings confirm that small and midsized solar wind structures are worn down with increasing distance due to dynamic interaction of parcels of wind with different speed. For instance, the T-V relationship steepens, as the range in V is limited more than the range in T with distance. At times the T-V correlation clearly breaks down beyond 20 au, which may indicate wind currently expanding and cooling may have an elevated T reflecting prior heating and compression in the inner heliosphere. The power of wind parameters at shorter periodicities decreases with distance as the longer periodicities strengthen. The solar rotation periodicity is present in temperature beyond 20 au indicating the observed parcel temperature may reflect not only current heating or cooling, but also heating occurring closer to the Sun.

  15. The New Horizons Solar Wind Around Pluto (SWAP) Observations of the Solar Wind from 11–33 au

    NASA Astrophysics Data System (ADS)

    Elliott, H. A.; McComas, D. J.; Valek, P.; Nicolaou, G.; Weidner, S.; Livadiotis, G.

    2016-04-01

    The Solar Wind Around Pluto (SWAP) instrument on National Aeronautics and Space Administration's New Horizons Pluto mission has collected solar wind observations en route from Earth to Pluto, and these observations continue beyond Pluto. Few missions have explored the solar wind in the outer heliosphere making this dataset a critical addition to the field. We created a forward model of SWAP count rates, which includes a comprehensive instrument response function based on laboratory and flight calibrations. By fitting the count rates with this model, the proton density (n), speed (V), and temperature (T) parameters are determined. Comparisons between SWAP parameters and both propagated 1 au observations and prior Voyager 2 observations indicate consistency in both the range and mean wind values. These comparisons as well as our additional findings confirm that small and midsized solar wind structures are worn down with increasing distance due to dynamic interaction of parcels of wind with different speed. For instance, the T–V relationship steepens, as the range in V is limited more than the range in T with distance. At times the T–V correlation clearly breaks down beyond 20 au, which may indicate wind currently expanding and cooling may have an elevated T reflecting prior heating and compression in the inner heliosphere. The power of wind parameters at shorter periodicities decreases with distance as the longer periodicities strengthen. The solar rotation periodicity is present in temperature beyond 20 au indicating the observed parcel temperature may reflect not only current heating or cooling, but also heating occurring closer to the Sun.

  16. Agua Caliente Wind/Solar Project at Whitewater Ranch

    SciTech Connect

    Hooks, Todd; Stewart, Royce

    2014-12-16

    Agua Caliente Band of Cahuilla Indians (ACBCI) was awarded a grant by the Department of Energy (DOE) to study the feasibility of a wind and/or solar renewable energy project at the Whitewater Ranch (WWR) property of ACBCI. Red Mountain Energy Partners (RMEP) was engaged to conduct the study. The ACBCI tribal lands in the Coachella Valley have very rich renewable energy resources. The tribe has undertaken several studies to more fully understand the options available to them if they were to move forward with one or more renewable energy projects. With respect to the resources, the WWR property clearly has excellent wind and solar resources. The DOE National Renewable Energy Laboratory (NREL) has continued to upgrade and refine their library of resource maps. The newer, more precise maps quantify the resources as among the best in the world. The wind and solar technology available for deployment is also being improved. Both are reducing their costs to the point of being at or below the costs of fossil fuels. Technologies for energy storage and microgrids are also improving quickly and present additional ways to increase the wind and/or solar energy retained for later use with the network management flexibility to provide power to the appropriate locations when needed. As a result, renewable resources continue to gain more market share. The transitioning to renewables as the major resources for power will take some time as the conversion is complex and can have negative impacts if not managed well. While the economics for wind and solar systems continue to improve, the robustness of the WWR site was validated by the repeated queries of developers to place wind and/or solar there. The robust resources and improving technologies portends toward WWR land as a renewable energy site. The business case, however, is not so clear, especially when the potential investment portfolio for ACBCI has several very beneficial and profitable alternatives.

  17. Generation of a Solar Wind Ensemble for Space Weather Forecasting

    NASA Astrophysics Data System (ADS)

    Hassan, E.; Morley, S.; Steinberg, J. T.

    2015-12-01

    Knowing the upstream solar wind conditions is essential in forecasting the variations in the geomangetic field and the status of the Earth's ionosphere. Most data-driven simulations or data-assimilation codes, used for space weather forecasting, are based on the solar wind measurements at 1 AU, or more specifically at the first Lagrangian orbit (L1), such as observations from the Advanced Composition Explorer (ACE). However, L1 measurements may not represent the solar wind conditions just outside the magnetosphere. As a result, time-series measurements from L1 by themselves are not adequate to run simulations to derive probabilistic forecasts of the magnetosphere and ionosphere. To obtain confidence levels and uncertainty estimates, a solar wind ensemble data set is desirable. Therefore we used three years of measurements atACE advected using the flat delay method to the Interplanetary Monitoring Platform (IMP8) spacecraft location. Then, we compared both measurements to establish Kernel Density Estimation (KDE) functions for IMP8 measurements based on ACE measurements. In addition, we used a 4-categorization scheme to sort the incoming solar wind into ejecta, coronal-hole-origin, sector-reversal-regions, and streamer-belt-origin categories at both ACE and IMP8. We established the KDE functions for each category and compared with the uncategorized KDE functions. The location of the IMP8 spacecraft allows us to use these KDE functions to generate ensemble of solar wind data close to Earth's magnetopause. The ensemble can then be used to forecast the state of the geomagnetic field and the ionosphere.

  18. Strong interaction between Phobos and the solar wind

    NASA Astrophysics Data System (ADS)

    Futaana, Y.; Barabash, S.; Holmstrom, M.; Nilsson, H.; Lundin, R.

    2009-12-01

    During the Mars Express (MEX) closest approach to Phobos on July 23, 2008, the ASPERA-3/IMA (Ion Mass Analyser) sensor on board MEX carried out ion observations. The approach was in the upstream solar wind, and IMA detected unusual signatures of the proton fluxes close to Phobos apart from the commonly seen bow shock signatures. Because MEX has no magnetometer on board it is not possible to directly back trace the trajectories of the observed protons. Thus, it was not easy to confirm if those protons came from Phobos. However, after a careful analysis, we conclude that the origin of these protons is indeed Phobos. The reasons are: 1. The energy of the observed protons is slightly less than the solar wind proton energy, and the energy spectrum have a low-energy tail. The protons behave as backscattered solar wind protons which was reported by the Japanese Kaguya mission at the Moon. 2. We conducted test particle backtracing assuming that the protons originate from Phobos under various magnetic field conditions. A consistent solution for all independent observations was found. 3. We looked through all the IMA data observed in the undisturbed solar wind, and found that the strong signals were only observed during the Phobos flyby. These analyses indicate that Phobos is the most probable source of the observed protons during the flyby. Even though the generation mechanism is not fully understood, by taking Kaguya observation close to Moon as an analogy, the observed protons close to Phobos are most probably solar wind protons backscattered from Phobos. The process of backscattering of impinging keV particles has never been considered because most of the particles have been assumed to be absorbed at the very rough surface of the regolith. However, these investigations suggest that the backscattering of the solar wind protons are a general feature of the atmosphereless body covered by regolith, which would be applicable to Mercury, meteorite, and moons of giant planets.

  19. Turbulent Heating and Wave Pressure in Solar Wind Acceleration Modeling: New Insights to Empirical Forecasting of the Solar Wind

    NASA Astrophysics Data System (ADS)

    Woolsey, L. N.; Cranmer, S. R.

    2013-12-01

    The study of solar wind acceleration has made several important advances recently due to improvements in modeling techniques. Existing code and simulations test the competing theories for coronal heating, which include reconnection/loop-opening (RLO) models and wave/turbulence-driven (WTD) models. In order to compare and contrast the validity of these theories, we need flexible tools that predict the emergent solar wind properties from a wide range of coronal magnetic field structures such as coronal holes, pseudostreamers, and helmet streamers. ZEPHYR (Cranmer et al. 2007) is a one-dimensional magnetohydrodynamics code that includes Alfven wave generation and reflection and the resulting turbulent heating to accelerate solar wind in open flux tubes. We present the ZEPHYR output for a wide range of magnetic field geometries to show the effect of the magnetic field profiles on wind properties. We also investigate the competing acceleration mechanisms found in ZEPHYR to determine the relative importance of increased gas pressure from turbulent heating and the separate pressure source from the Alfven waves. To do so, we developed a code that will become publicly available for solar wind prediction. This code, TEMPEST, provides an outflow solution based on only one input: the magnetic field strength as a function of height above the photosphere. It uses correlations found in ZEPHYR between the magnetic field strength at the source surface and the temperature profile of the outflow solution to compute the wind speed profile based on the increased gas pressure from turbulent heating. With this initial solution, TEMPEST then adds in the Alfven wave pressure term to the modified Parker equation and iterates to find a stable solution for the wind speed. This code, therefore, can make predictions of the wind speeds that will be observed at 1 AU based on extrapolations from magnetogram data, providing a useful tool for empirical forecasting of the sol! ar wind.

  20. The turbulent cascade and proton heating in the solar wind during solar minimum

    SciTech Connect

    Coburn, Jesse T.; Smith, Charles W.; Vasquez, Bernard J.; Stawarz, Joshua E.; Forman, Miriam A.

    2013-06-13

    Solar wind measurements at 1 AU during the recent solar minimum and previous studies of solar maximum provide an opportunity to study the effects of the changing solar cycle on in situ heating. Our interest is to compare the levels of activity associated with turbulence and proton heating. Large-scale shears in the flow caused by transient activity are a source that drives turbulence that heats the solar wind, but as the solar cycle progresses the dynamics that drive the turbulence and heat the medium are likely to change. The application of third-moment theory to Advanced Composition Explorer (ACE) data gives the turbulent energy cascade rate which is not seen to vary with the solar cycle. Likewise, an empirical heating rate shows no significan changes in proton heating over the cycle.

  1. Source reliability in a combined wind-solar-hydro system

    NASA Astrophysics Data System (ADS)

    Traca de Almeida, A.; Martins, A.; Jesus, H.; Climaco, J.

    1983-06-01

    The results of an examination of the feasibility of using coupled wind-solar-hydro power generation systems to provide all of Portugal's electricity by the year 2000 are reported. Portugal used 15.6 TWh of electricity in 1981, of which hydro supplied 10 TWh. Demand is expected to reach 34 TWh in 2000 AD. The full development of hydropower resource would furnish 18 TWh and a storage capacity of 4.5 TWh. The installed hydro system could meet the peak demand of 6 GW, while solar cells and wind turbines must produce 16 TWh annually plus a reserve. The Growian wind turbine, 100 m tall, is considered for its 2.2 MW output. A coastal strip of wind turbines 150 x 20 km, with 1 km spacing between the machines, would be needed to produce 5.4 GW of power. Partially tracking solar cell arrays generating 9.4 GW of electricity would require an area of 100 sq km. Computer simulations of the annual rainfall, combined with projections of the variations in wind-solar output, demonstrates that a reserve margin of 1.20 will be necessary. The costs of installation of the renewable energy converters are estimated at about three times that currently necessary for obtaining the same capacity from fission power plants, although the situation may change due to import and technical considerations.

  2. Coherent structure and Intermittent Turbulence in the Solar Wind Plasma

    NASA Astrophysics Data System (ADS)

    Sondhiya, Deepak Kumar; Gwal, Ashok Kumar; Kasde, Satish Kumar

    2016-07-01

    We analyze the coherent structures and intermittent turbulence in the solar wind plasma using measurements from the Wind spacecraft. Previously established novel wavelet and higher order statistics are used in this work. We analyze the wavelet power spectrum of various solar wind plasma parameters. We construct a statistical significance level in the wavelet power spectrum to quantify the interference effects arising from filling missing data in the time series, allowing extraction of significant power from the measured data. We analyze each wavelet power spectra for transient coherency, and global periodicities resulting from the superposition of repeating coherent structures. Furthermore, these coherent structures are preferentially found in plasma unstable to the mirror and firehose instabilities. These results offer a new understanding of various processes in a turbulent regime. Finally, we discuss the implications of our results for current theories of solar wind generation and describe future work for determining the relationship between the coherent structures in our ionic composition data and the structure of the coronal magnetic field. Keywords: Wavelet Power Spectrum, Coherent structure and Solar wind plasma

  3. CORE ELECTRON HEATING IN SOLAR WIND RECONNECTION EXHAUSTS

    SciTech Connect

    Pulupa, M. P.; Salem, C.; Phan, T. D.; Bale, S. D.; Gosling, J. T.

    2014-08-10

    We present observational evidence of core electron heating in solar wind reconnection exhausts. We show two example events, one which shows clear heating of the core electrons within the exhaust, and one which demonstrates no heating. The event with heating occurred during a period of high inflow Alfvén speed (V {sub AL}), while the event with no heating had a low V {sub AL}. This agrees with the results of a recent study of magnetopause exhausts, and suggests that similar core electron heating can occur in both symmetric (solar wind) and asymmetric (magnetopause) exhausts.

  4. Mass fractionation of the lunar surface by solar wind sputtering

    NASA Technical Reports Server (NTRS)

    Switkowski, Z. E.; Haff, P. K.; Tombrello, T. A.; Burnett, D. S.

    1977-01-01

    An investigation is conducted concerning the mass-fractionation effects produced in connection with the bombardment of the moon by the solar wind. Most of the material ejected by sputtering escapes the moon's gravity, but some returning matter settles back onto the lunar surface. This material, which is somewhat richer in heavier atoms than the starting surface, is incorporated into the heavily radiation-damaged outer surfaces of grains. The investigation indicates that sputtering of the lunar surface by the solar wind will give rise to significant surface heavy atom enrichments if the grain surfaces are allowed to come into sputtering equilibrium.

  5. Distribution of solar wind implanted noble gases in lunar samples

    NASA Technical Reports Server (NTRS)

    Kiko, J.; Kirsten, T.

    1986-01-01

    The distribution of solar wind implanted noble gases in lunar samples depends on implantation energy, fluence, diffusion, radiation damage and erosion. It is known that at least the lighter rare gases are fractionated after implantation, but the redistribution processes, which mainly drive the losses, are not well understood. Some information about this one can get by looking at the concentration profiles of solar wind implanted He-4 measured by the Gas Ion Probe in single lunar grains. The observed profiles were divided in three groups. These groups are illustrated and briefly discussed.

  6. Solar wind control of magnetospheric pressure (CDAW 6)

    NASA Technical Reports Server (NTRS)

    Fairfield, D. H.

    1985-01-01

    The CDAW 6 data base is used to compare solar wind and magnetospheric pressures. The flaring angle of the tail magnetopause is determined by assuming that the component of solar wind pressure normal to the tail boundary is equal to the total pressure within the tail. Results indicate an increase in the tail flaring angle from 18 deg to 32 deg prior to the 1055 substorm onset and a decrease to 25 deg after the onset. This behavior supports the concept of tail energy storage before the substorm and subsequent release after the onset.

  7. The solar wind-magnetosphere-ionosphere current-voltage relationship

    NASA Technical Reports Server (NTRS)

    Fedder, J. A.; Lyon, J. G.

    1987-01-01

    The global current-voltage relationship for the solar wind-magnetosphere-ionosphere system (SW-M-I) is investigated, restricting the study to strong southward IMF. The dynamo presently identified is on open field lines, and it operates at close to short circuit and at a fraction of the available power output. Control of the dynamo by ionospheric conductivity is discussed. Implications of the simulation results, including the relationship between open and closed field dynamos, the effect of solar wind conditions, the control of reconnection on the bow, the size of the open field line region, and the effects of increased auroral conductivity, are discussed.

  8. Solar wind interaction with Pluto’s escaping atmosphere

    NASA Astrophysics Data System (ADS)

    Bagenal, Fran; Stern, S. A.; Weaver, H. A.; Young, L. A.; Ennico, K.; Olkin, C.; McComas, D. J.; McNutt, R. L.; Horanyi, M.; Elliott, H. A.; Hill, M. E.; Zernstein, E.; Kollman, P.; Krimigis, S. M.; Lisse, C. M.; Strobel, D. F.; SzalAy, J.; Piquette, M.

    2015-11-01

    NASA’s New Horizons spacecraft carries two instruments, SWAP and PEPSSI, that measure low and high energy particles respectively. These particle instruments have been measuring the conditions in the solar wind for most of the trajectory from Earth to Pluto. The Venetia Burney Student Dust Counter measured impacts from micron-sixed dust particles. These particle instruments also made observations during the flyby of Pluto on July 14, 2015. We report on New Horizons measurements of the interaction of the solar wind interaction with Pluto’s extended atmosphere and discuss comparisons with theoretical expectations.

  9. Electron energy transport in the solar wind: Ulysses observations

    SciTech Connect

    Scime, E.E.; Gary, S.P.; Phillips, J.L.; Balogh, A.; Lengyel-Frey, D.

    1996-07-01

    Previous analysis suggests that the whistler heat flux instability is responsible for the regulation of the electron heat flux of the solar wind. For an interval of quiescent solar wind during the in-ecliptic phase of the Ulysses mission, the plasma wave data in the whistler frequency regime are compared to the predictions of the whistler heat flux instability model. The data is well constrained by the predicted upper bound on the electron heat flux and a clear correlation between wave activity and electron heat flux dissipation is observed. {copyright} {ital 1996 American Institute of Physics.}

  10. Electron energy transport in the solar wind: Ulysses observations

    SciTech Connect

    Scime, Earl E.; Gary, S. Peter; Phillips, John L.; Balogh, Andre; Lengyel-Frey, Denise

    1996-07-20

    Previous analysis suggests that the whistler heat flux instability is responsible for the regulation of the electron heat flux of the solar wind. For an interval of quiescent solar wind during the in-ecliptic phase of the Ulysses mission, the plasma wave data in the whistler frequency regime are compared to the predictions of the whistler heat flux instability model. The data is well constrained by the predicted upper bound on the electron heat flux and a clear correlation between wave activity and electron heat flux dissipation is observed.

  11. Compressive turbulent cascade and heating in the solar wind

    SciTech Connect

    Marino, R.; Sorriso-Valvo, L.; Noullez, A.; Bruno, R.

    2010-03-25

    A turbulent energy cascade has been recently identified in high-latitude solar wind data samples by using a Yaglom-like relation. However, analogous scaling law, suitably modified to take into account compressible fluctuations, has been observed in a much more extended fraction of the same data set recorded by the Ulysses spacecraft. Thus, it seems that large scale density fluctuations, despite their low amplitude, play a major role in the basic scaling properties of turbulence. The compressive turbulent cascade, moreover, seems to be able to supply the energy needed to account for the local heating of the non-adiabatic solar wind.

  12. Transport and Modulation of Cosmic Rays in the Solar Wind

    NASA Astrophysics Data System (ADS)

    Bieber, John

    2004-11-01

    Understanding the mechanism by which energetic charged particles scatter and diffuse in collisionless plasma is an enduring fundamental problem of astrophysics. The study of this process in the solar wind provides vital opportunities for confronting theoretical models with direct observation. This talk will review recent advances in this field resulting from (1) an improved understanding of magnetic turbulence in the solar wind (especially relating to turbulence geometry), (2) the use of nonlinear methods in particle scattering theory, (3) increasingly realistic models of turbulence evolution and transport, and (4) detailed observations at far flung locations through the heliosphere (especially from Pioneer, Voyager, and Ulysses). Supported by NSF grant ATM-0000315.

  13. Interpretation of Solar Wind Composition Measurements from Ulysses

    NASA Technical Reports Server (NTRS)

    Esser, Ruth

    1999-01-01

    Ion charge states measured in situ in interplanetary space carry information on the properties of the solar wind plasma in the inner corona. This information is, however, not easy to extract from the in situ observations. The goal of the proposal was to determine solar wind models and coronal observations that are necessary tools for the interpretation of charge state observations. It has been shown that the interpretation of the in situ ion fractions are heavily dependent on the assumptions about conditions in the inner corona.

  14. Ion kinetic scale in the solar wind observed.

    PubMed

    Śafránková, Jana; Němeček, Zdeněk; Přech, Lubomír; Zastenker, Georgy N

    2013-01-11

    This Letter shows the first results from the solar wind monitor onboard the Spektr-R spacecraft which measures plasma moments with a time resolution of 31 ms. This high-time resolution allows us to make direct observations of solar wind turbulence below ion kinetic length scales. We present examples of the frequency spectra of the density, velocity, and thermal velocity. Our study reveals that although these parameters exhibit the same behavior at the magnetohydrodynamic scale, their spectra are remarkably different at the kinetic scale.

  15. Coronal Magnetic Field Topology and Source of Fast Solar Wind

    NASA Technical Reports Server (NTRS)

    Guhathakurta, M.; Sittler, E.; Fisher, R.; McComas, D.; Thompson, B.

    1999-01-01

    We have developed a steady state, 2D semi-empirical MHD model of the solar corona and the solar wind with many surprising results. This model for the first time shows, that the boundary between the fast and the slow solar wind as observed by Ulysses beyond 1 AU, is established in the low corona. The fastest wind observed by Ulysses (680-780 km/s) originates from the polar coronal holes at 70 -90 deg. latitude at the Sun. Rapidly diverging magnetic field geometry accounts for the fast wind reaching down to a latitude of +/- 30 deg. at the orbit of Earth. The gradual increase in the fast wind observed by Ulysses, with latitude, can be explained by an increasing field strength towards the poles, which causes Alfven wave energy flux to increase towards the poles. Empirically, there is a direct relationship between this gradual increase in wind speed and the expansion factor, f, computed at r greater than 20%. This relationship is inverse if f is computed very close to the Sun.

  16. The solar cycle variation of coronal mass ejections and the solar wind mass flux

    NASA Technical Reports Server (NTRS)

    Webb, David F.; Howard, Russell A.

    1994-01-01

    Coronal mass ejections (CMEs) are an important aspect of coronal physics and a potentially significant contributor to perturbations of the solar wind, such as its mass flux. Sufficient data on CMEs are now available to permit study of their longer-term occurrency patterns. Here we present the results of a study of CME occurrence rates over more than a complete 11-year solar sunspot cycle and a comparison of these rates with those of other activity related to CMEs and with the solar wind particle flux at 1 AU. The study includes an evaluation of correlations to the CME rates, which include instrument duty cycles, visibility functions, mass detection thresholds, and geometrical considerations. The main results are as follows: (1) The frequency of occurrence of CMEs tends to track the solar activity cycle in both amplitude and phase; (2) the CME rates from different instruments, when corrected for both duty cycles and visibility functions, are reasonably consistent; (3) considering only longer-term averages, no one class of solar activity is better correlated with CME rate than any other; (4) the ratio of the annualized CME to solar wind mass flux tends to track the solar cycle; and (5) near solar maximum, CMEs can provide a significant fraction (i.e., approximately equals 15%) of the average mass flux to the near-ecliptic solar wind.

  17. Advances in understanding the genesis and evolution solar energetic particle events over the last two solar cycles

    NASA Astrophysics Data System (ADS)

    Vainio, Rami

    2016-04-01

    I will review the observational and modeling efforts related to solar energetic particle (SEP) events over the 23rd and 24th solar cycles. I will concentrate on large SEP events related to coronal mass ejections (CMEs), but discuss observations related to the possible role of flares in the acceleration of particles in those events, as well. The possible roles of various acceleration and transport processes in understanding the characteristics of the events will be discussed. This work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 637324 (HESPERIA).

  18. A reexamination of two-fluid solar wind models

    NASA Technical Reports Server (NTRS)

    Nerney, S.; Barnes, A.

    1977-01-01

    The two-fluid solar-wind equations have been solved by a method which is approximately 50 times faster than any previously developed, through the use of asymptotic expansions which are self-consistently iterated upon to find a solution that passes through the critical point. The energy assumptions in two-fluid solar-wind models are reexamined, and the conclusions are as follows: (1) proton thermal conduction may not be neglected, (2) the Coulomb logarithm must be calculated as a function of radius, and (3) the electron and proton temperatures at the base need not be equal, even when the time scale for energy exchange between the species is an order of magnitude smaller than the expansion time at the base. It is possible to reproduce reasonable quiet-time solar-wind parameters at 1 AU, but only if the proton temperature is approximately twice the electron temperature at 1 solar radius. This may indicate that extended proton heating is important in the outer solar corona. Winds with velocities at 1 AU of 450 km/s are generated without nonthermal energy deposition but require high proton temperatures as well as very low densities at the base. Higher-velocity solutions are not possible in a spherically symmetric geometry for reasonable particle fluxes at 1 AU, and it is suggested that these higher-velocity states probably require additional heating, acceleration mechanisms, or nonradial flow.

  19. CHARACTERIZATION OF TRANSITIONS IN THE SOLAR WIND PARAMETERS

    SciTech Connect

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

    2010-02-20

    The distinction between fast and slow solar wind streams and the dynamically evolved interaction regions is reflected in the characteristic fluctuations of both the solar wind and the embedded magnetic field. High-resolution magnetic field data from the Ulysses spacecraft have been analyzed. The observations show rapid variations in the magnetic field components and in the magnetic field strength, suggesting a structured nature of the solar wind at small scales. The typical sizes of fluctuations cover a broad range. If translated to the solar surface, the scales span from the size of granules ({approx}10{sup 3} km) and supergranules ({approx}10{sup 4} km) on the Sun down to {approx}10{sup 2} km and less. The properties of the short time structures change in the different types of solar wind. While fluctuations in fast streams are more homogeneous, slow streams present a bursty behavior in the magnetic field variances, and the regions of transition are characterized by high levels of power in narrow structures around the transitions. The probability density functions of the magnetic field increments at several scales reveal a higher level of intermittency in the mixed streams, which is related to the presence of well localized features. It is concluded that, apart from the differences in the nature of fluctuations in flows of different coronal origin, there is a small-scale structuring that depends on the origin of streams themselves but it is also related to a bursty generation of the fluctuations.

  20. ACCELERATION OF THE SOLAR WIND BY ALFVEN WAVE PACKETS

    SciTech Connect

    Galinsky, V. L.; Shevchenko, V. I.

    2013-01-20

    A scale separation kinetic model of the solar wind acceleration is presented. The model assumes an isotropic Maxwellian distribution of protons and a constant influx of outward propagating Alfven waves with a single exponent Kolmogorov-type spectrum at the base of a coronal acceleration region ({approx}2 R {sub Sun }). Our results indicate that nonlinear cyclotron resonant interaction taking energy from Alfven waves and depositing it into mostly perpendicular heating of protons in initially weakly expanding plasma in a spherically non-uniform magnetic field is able to produce the typical fast solar wind velocities for the typical plasma and wave conditions after expansion to about 5-10 solar radii R {sub Sun }. The acceleration model takes into account the gravity force and the ambipolar electric field, as well as the mirror force, which plays the most important role in driving the solar wind acceleration. Contrary to the recent claims of Isenberg, the cold plasma dispersion only slightly slows down the acceleration and actually helps in obtaining the more realistic fast solar wind speeds.

  1. On the Origin of Mid-latitude Fast Wind: Challenging the Two-state Solar Wind Paradigm

    NASA Astrophysics Data System (ADS)

    Stakhiv, Mark; Landi, Enrico; Lepri, Susan T.; Oran, Rona; Zurbuchen, Thomas H.

    2015-03-01

    The bimodal paradigm of solar wind describes a slow solar wind situated near the heliospheric current sheet while a fast wind overexpands from the poles to fill in the remainder of the heliosphere. In this paper, we challenge this paradigm and focus here on mid-latitude wind using three fast-latitude passes completed by the Ulysses spacecraft. Based on its composition and dynamic properties, we discuss how this wind differs from both the fast, polar coronal hole wind and the low latitude, streamer-associated slow solar wind. Using a detailed analysis of ionic and elemental abundances, as well as solar wind dynamic properties, we conclude that there is a third quasi-stationary solar wind state, called the boundary wind. This boundary wind is characterized by a charge-state distribution that is similar to slow wind, but with an elemental composition that is coronal hole like. Based on these data, we present arguments for the location of the origin of this wind. We conclude that the boundary wind is a subset of the fast wind emanating from regions close to the boundaries of coronal holes and is accelerated by a similar process.

  2. Elemental and isotopic abundances in the solar wind

    NASA Technical Reports Server (NTRS)

    Geiss, J.

    1972-01-01

    The use of collecting foils and lunar material to assay the isotopic composition of the solar wind is reviewed. Arguments are given to show that lunar surface correlated gases are likely to be most useful in studying the history of the solar wind, though the isotopic abundances are thought to give a good approximation to the solar wind composition. The results of the analysis of Surveyor material are also given. The conditions leading to a significant component of the interstellar gas entering the inner solar system are reviewed and suggestions made for experimental searches for this fraction. A critical discussion is given of the different ways in which the basic solar composition could be modified by fractionation taking place between the sun's surface and points of observation such as on the Moon or in interplanetary space. An extended review is made of the relation of isotopic and elemental composition of the interplanetary gas to the dynamic behavior of the solar corona, especially processes leading to fractionation. Lastly, connection is made between the subject of composition, nucleosynthesis and the convective zone of the sun, and processes leading to modification of initial accretion of certain gases on the Earth and Moon.

  3. Slow and fast solar wind - data selection and statistical analysis

    NASA Astrophysics Data System (ADS)

    Wawrzaszek, Anna; Macek, Wiesław M.; Bruno, Roberto; Echim, Marius

    2014-05-01

    In this work we consider the important problem of selection of slow and fast solar wind data measured in-situ by the Ulysses spacecraft during two solar minima (1995-1997, 2007-2008) and solar maximum (1999-2001). To recognise different types of solar wind we use a set of following parameters: radial velocity, proton density, proton temperature, the distribution of charge states of oxygen ions, and compressibility of magnetic field. We present how this idea of the data selection works on Ulysses data. In the next step we consider the chosen intervals for fast and slow solar wind and perform statistical analysis of the fluctuating magnetic field components. In particular, we check the possibility of identification of inertial range by considering the scale dependence of the third and fourth orders scaling exponents of structure function. We try to verify the size of inertial range depending on the heliographic latitudes, heliocentric distance and phase of the solar cycle. Research supported by the European Community's Seventh Framework Programme (FP7/2007 - 2013) under grant agreement no 313038/STORM.

  4. Wind effects in solar fields with various collector designs

    NASA Astrophysics Data System (ADS)

    Paetzold, Joachim; Cochard, Steve; Fletcher, David F.; Vassallo, Anthony

    2016-05-01

    Parabolic trough power plants are often located in areas that are subjected to high wind speeds, as an open terrain without any obstructions is beneficial for the plant performance. The wind impacts both the structural requirements and the performance of the plant. The aerodynamic loads from the wind impose strong requirements on the support structure of the reflectors, and they also impact the tracking accuracy. On a thermal level the airflow around the glass envelope of the receiver tube cools its outer surface through forced convection, thereby contributing to the heat loss. Based on previous studies at the level of an individual row of collectors, this study analyses the wind effects in a full-scale solar field of different continuous and staggered trough designs. The airflow around several rows of parabolic trough collectors (PTC) is simulated at full scale in steady state simulations in an atmospheric boundary layer flow using the commercial computational fluid dynamics software ANSYSO® CFX 15.0. The effect of the wake of a collector row on the following collectors is analysed, and the aerodynamic loads are compared between the different geometries. The outermost collectors of a solar field experience the highest wind forces, as the rows in the interior of the solar field are protected from high wind speeds. While the aerodynamic forces in the interior of the solar field are almost independent of the collector shape, the deeper troughs (with large rim angles) tested in this study show a lower heat loss due to forced convection on the outer surface of the receiver tube than the shallower ones (with small rim angles) in most of the solar field.

  5. A Model fot the Sources of the Slow Solar Wind

    NASA Technical Reports Server (NTRS)

    Antiochos, S. K.; Mikic, Z.; Titov, V. S.; Lionello, R.; Linker, J. A.

    2011-01-01

    Models for the origin of the slow solar wind must account for two seemingly contradictory observations: the slow wind has the composition of the closed-field corona, implying that it originates from the continuous opening and closing of flux at the boundary between open and closed field. On the other hand, the slow wind also has large angular width, up to approx.60deg, suggesting that its source extends far from the open-closed boundary. We propose a model that can explain both observations. The key idea is that the source of the slow wind at the Sun is a network of narrow (possibly singular) open-field corridors that map to a web of separatrices and quasi-separatrix layers in the heliosphere. We compute analytically the topology of an open-field corridor and show that it produces a quasi-separatrix layer in the heliosphere that extends to angles far from the heliospheric current sheet. We then use an MHD code and MDI/SOHO observations of the photospheric magnetic field to calculate numerically, with high spatial resolution, the quasi-steady solar wind, and magnetic field for a time period preceding the 2008 August 1 total solar eclipse. Our numerical results imply that, at least for this time period, a web of separatrices (which we term an S-web) forms with sufficient density and extent in the heliosphere to account for the observed properties of the slow wind. We discuss the implications of our S-web model for the structure and dynamics of the corona and heliosphere and propose further tests of the model. Key words: solar wind - Sun: corona - Sun: magnetic topology

  6. Solar Wind Characteristics from SOHO-Sun-Ulysses Quadrature Observations

    NASA Technical Reports Server (NTRS)

    Poletto, Giannina; Suess, Steve T.; Six, N. Frank (Technical Monitor)

    2002-01-01

    Over the past few years, we have been running SOHO (Solar and Heliospheric Observatory)-Sun-Ulysses quadrature campaigns, aimed at comparing the plasma properties at coronal altitudes with plasma properties at interplanetary distances. Coronal plasma has been observed by SOHO experiments: mainly, we used LASCO (Large Angle and Spectrometric Coronagraph Experiment) data to understand the overall coronal configuration at the time of quadratures and analyzed SUMER (Solar Ultraviolet Measurements of Emitted Radiation), CDS (Coronal Diagnostic Spectrometer) and UVCS (Ultraviolet Coronagraph Spectrometer) data to derive its physical characteristics. At interplanetary distances, SWICS (Solar Wind Ion Composition Spectrometer) and SWOOPS (Solar Wind Observation over the Poles of the Sun) aboard Ulysses provided us with interplanetary plasma data. Here we report on results from some of the campaigns. We notice that, depending on the geometry of the quadrature, i.e. on whether the radial to Ulysses traverses the corona at high or low latitudes, we are able to study different kinds of solar wind. In particular, a comparison between low-latitude and high-latitude wind, allowed us to provide evidence for differences in the acceleration of polar, fast plasma and equatorial, slow plasma: the latter occurring at higher levels and through a more extended region than fast wind. These properties are shared by both the proton and heavy ions outflows. Quadrature observations may provide useful information also on coronal vs. in situ elemental composition. To this end, we analyzed spectra taken in the corona, at altitudes ranging between approx. 1.02 and 2.2 solar radii, and derived the abundances of a number of ions, including oxygen and iron. Values of the O/Fe ratio, at coronal levels, have been compared with measurements of this ratio made by SWICS at interplanetary distances. Our results are compared with previous findings and predictions from modeling efforts.

  7. Electric Solar Wind Sail (E-sail) mission to asteroids

    NASA Astrophysics Data System (ADS)

    Merikallio, Sini; Janhunen, Pekka; Toivanen, Petri; Jouni Envall, M.(Tech.).

    2012-07-01

    There are an estimated one to two million asteroids of diameter over 1 km in-between the orbits of Mars and Jupiter. Impact threat, mining prospects and the understanding of solar system history make asteroids interesting objects for further in-situ studies. Electric Solar Wind Sail (E-sail) [1] technology enables touring several different asteroids with the same spacecraft. It is a propulsion technology first proposed in 2006 and currently developed with the EUs FP7 funding (http://www.electric-sailing.fi/fp7). The E-sail utilizes long, conducting, highly charged tethers to gather momentum from the solar wind ions. It does not consume any propellant and is well maneuverable. The Electric Solar Wind Sail producing 1 N of thrust at 1 AU distance from the Sun could be manufactured to weigh 100-150 kg in total. The constant acceleration gives a large advantage over traditional methods when calculated over the mission lifetime. In a ten year mission a baseline 1 N E-sail could produce 300 MNs of total impulse, Itot. As an example, such a total impulse would be able to move a 3 million ton Earth-threatening asteroid to a safer track [2]. With chemical propellant it would take 100 000 tons of fuel to achieve the same feat. Scientists and miners could have a closer look at several targets and they could decide the next target and the duration of investigations once at the vicinity of the asteroid, so the operations would be very flexible. Such a mission could characterize and map several asteroids, some with rapid fly-bys and a few chosen ones during lengthier rendezvous. [1] Janhunen, P., et. al, Electric solar wind sail: Towards test missions (Invited article), Rev. Sci. Instrum., 81, 111301, 2010. [2] Merikallio, S. and P. Janhunen, Moving an asteroid with electric solar wind sail, Astrophys. Space Sci. Trans., 6, 41-48, 2010

  8. IMPLICATIONS OF THE RECENT LOW SOLAR MINIMUM FOR THE SOLAR WIND DURING THE MAUNDER MINIMUM

    SciTech Connect

    Lockwood, M.; Owens, M. J.

    2014-01-20

    The behavior of the Sun and near-Earth space during grand solar minima is not understood; however, the recent long and low minimum of the decadal-scale solar cycle gives some important clues, with implications for understanding the solar dynamo and predicting space weather conditions. The speed of the near-Earth solar wind and the strength of the interplanetary magnetic field (IMF) embedded within it can be reliably reconstructed for before the advent of spacecraft monitoring using observations of geomagnetic activity that extend back to the mid-19th century. We show that during the solar cycle minima around 1879 and 1901 the average solar wind speed was exceptionally low, implying the Earth remained within the streamer belt of slow solar wind flow for extended periods. This is consistent with a broader streamer belt, which was also a feature of the recent low minimum (2009), and yields a prediction that the low near-Earth IMF during the Maunder minimum (1640-1700), as derived from models and deduced from cosmogenic isotopes, was accompanied by a persistent and relatively constant solar wind of speed roughly half the average for the modern era.

  9. 76 FR 73783 - Residential, Business, and Wind and Solar Resource Leases on Indian Land

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-29

    ..., Business, and Wind and Solar Resource Leases on Indian Land; Proposed Rule #0;#0;Federal Register / Vol. 76... Indian Affairs 25 CFR Part 162 RIN 1076-AE73 Residential, Business, and Wind and Solar Resource Leases on...; business; wind resource evaluation and development; and solar resource development. Specifically, this...

  10. A review of solar wind ion and electron plasma distributions: Present understanding and Ulysses results

    SciTech Connect

    Goldstein, B. E.

    1996-07-20

    Unlike the oral version of this paper at Solar Wind 8, this written version is not intended as an overview of the observational aspects of solar wind ion and electron distributions, but discusses only recent results in this area with emphasis on Ulysses measurements. Although primarily a review, some new results on solar wind proton temperatures at high latitudes are presented.

  11. An overview of SMILE (Solar wind Magnetosphere Ionosphere Link Explorer)

    NASA Astrophysics Data System (ADS)

    Branduardi-Raymont, Graziella; Wang, Chi

    2016-07-01

    SMILE is a novel space mission, currently under development, dedicated to study the dynamic coupling of the solar wind with the Earth's magnetosphere in a global way never attempted so far. From a highly elliptical Earth orbit, SMILE will obtain X-ray images of the magnetosheath and polar cusps simultaneously with UV images of the Northern aurora, while also carrying out in situ solar wind/magnetosheath plasma and magnetic field measurements. For the first time we will be able to trace and link the processes of solar wind injection in the magnetosphere with those acting on the charged particles precipitating into the cusps and eventually the aurora. X-ray imaging of the dayside magnetosheath and cusps has been made possible thanks to the relatively recent discovery of solar wind charge exchange (SWCX) X-ray emission, first observed at comets, and subsequently found to occur in the vicinity of the Earth's magnetosphere. SMILE is the first fully collaborative space mission from inception to implementation and operations between ESA and the Chinese Academy of Sciences (CAS). This talk will present the science that SMILE will deliver and its impact, and will provide an overview of its payload and of the mission's development.

  12. Tsallis non-extensive statistics and solar wind plasma complexity

    NASA Astrophysics Data System (ADS)

    Pavlos, G. P.; Iliopoulos, A. C.; Zastenker, G. N.; Zelenyi, L. M.; Karakatsanis, L. P.; Riazantseva, M. O.; Xenakis, M. N.; Pavlos, E. G.

    2015-03-01

    This article presents novel results revealing non-equilibrium phase transition processes in the solar wind plasma during a strong shock event, which took place on 26th September 2011. Solar wind plasma is a typical case of stochastic spatiotemporal distribution of physical state variables such as force fields (B → , E →) and matter fields (particle and current densities or bulk plasma distributions). This study shows clearly the non-extensive and non-Gaussian character of the solar wind plasma and the existence of multi-scale strong correlations from the microscopic to the macroscopic level. It also underlines the inefficiency of classical magneto-hydro-dynamic (MHD) or plasma statistical theories, based on the classical central limit theorem (CLT), to explain the complexity of the solar wind dynamics, since these theories include smooth and differentiable spatial-temporal functions (MHD theory) or Gaussian statistics (Boltzmann-Maxwell statistical mechanics). On the contrary, the results of this study indicate the presence of non-Gaussian non-extensive statistics with heavy tails probability distribution functions, which are related to the q-extension of CLT. Finally, the results of this study can be understood in the framework of modern theoretical concepts such as non-extensive statistical mechanics (Tsallis, 2009), fractal topology (Zelenyi and Milovanov, 2004), turbulence theory (Frisch, 1996), strange dynamics (Zaslavsky, 2002), percolation theory (Milovanov, 1997), anomalous diffusion theory and anomalous transport theory (Milovanov, 2001), fractional dynamics (Tarasov, 2013) and non-equilibrium phase transition theory (Chang, 1992).

  13. Western Wind and Solar Integration Study: Executive Summary

    SciTech Connect

    none,

    2010-05-01

    This Study investigates the operational impact of up to 35% energy penetration of wind, photovoltaics (PVs), and concentrating solar power (CSP) on the power system operated by the WestConnect group of utilities in Arizona, Colorado, Nevada, New Mexico, and Wyoming.

  14. The Solar Wind in the Outer Heliosphere and Heliosheath

    NASA Technical Reports Server (NTRS)

    Richardson, J. D.; Burlaga, L. F.

    2011-01-01

    The solar wind environment has a large influence on the transport of cosmic rays. This chapter discusses the observations of the solar wind plasma and magnetic field in the outer heliosphere and the heliosheath. In the supersonic solar wind, interaction regions with large magnetic fields form barriers to cosmic ray transport. This effect, the "CR-B" relationship, has been quantified and is shown to be valid everywhere inside the termination shock (TS). In the heliosheath, this relationship breaks down, perhaps because of a change in the nature of the turbulence. Turbulence is compressive in the heliosheath, whereas it was non-compressive in the solar wind. The plasma pressure in the outer heliosphere is dominated by the pickup ions which gain most of the flow energy at the TS. The heliosheath plasma and magnetic field are highly variable on scales as small as ten minutes. The plasma flow turns away from the nose roughly as predicted, but the radial speeds at Voyager 1 are much less than those at Voyager 2, which is not understood. Despite predictions to the contrary, magnetic reconnection is not an important process in the inner heliosheath with only one observed occurrence to date.

  15. The solar wind-magnetosphere energy coupling and magnetospheric disturbances

    NASA Technical Reports Server (NTRS)

    Akasofu, S.-I.

    1980-01-01

    Energy coupling between the solar wind and the magnetosphere is examined and the influence of this coupling on magnetospheric disturbances is discussed. Following a review of the components of the total energy production rate of the magnetosphere and progress in the study of solar wind-magnetosphere correlations, the derivation of the solar wind-magnetosphere energy coupling function, which has been found to correlate well with the total magnetospheric energy production rate, is presented. Examination of the relations between the energy coupling function and the type of magnetic disturbance with which it is associated indicates that magnetic storms with a large sudden storm commencement and a weak main phase are associated with small energy coupling, while values of the coupling function greater than 5 x 10 to the 18th to 10 to the 19th erg/sec are required for the development of a major geomagnetic storm. The magnetospheric substorm is shown to be a direct result of increased solar wind-magnetosphere energy coupling rather than the sudden conversion of stored magnetic energy. Finally, it is indicated that at energy couplings greater than 10 to the 19th erg/sec, the positive feedback process responsible for substorms breaks down, resulting in the abnormal growth of the ring current.

  16. Solar Wind Simulations Based on Ooty IPS Data

    NASA Astrophysics Data System (ADS)

    Muehe, S. C.; Kim, T. K.; Pogorelov, N. V.

    2014-12-01

    The solar wind is a constantly-flowing stream of charged particles that expands from the sun's outer atmosphere into interplanetary space. This plasma carries the sun's magnetic field along with it, where it interacts with and causes disruptions in the earth's magnetic field. Our understanding of the solar wind is vital to efforts toward minimizing the impact of these disturbances on both ground and space-based systems. Using interplanetary scintillation data gathered by the ground-based Ooty Radio Telescope (ORT) in India, we have constructed boundary maps of solar wind velocities at 1 day intervals. For a simple, first approximation, we use what is called the "P-point" method to crudely estimate the solar wind velocity at the point of closest approach to the Sun along each line of sight. Then we trace the P-point values back to a spherical surface at 0.2 AU where we interpolate them to a structured gird. The resulting boundary maps can serve as the initial input to a time-dependent MHD tomography program being developed at the University of Alabama in Huntsville.

  17. How Reliable Is the Prediction of Solar Wind Background?

    NASA Astrophysics Data System (ADS)

    Jian, Lan K.; MacNeice, Peter; Taktakishvili, Aleksandre; Odstrcil, Dusan; Jackson, Bernard; Yu, Hsiu-Shan; Riley, Pete; Sokolov, Igor

    2015-04-01

    The prediction of solar wind background is a necessary part of space weather forecasting. Multiple coronal and heliospheric models have been installed at the Community Coordinated Modeling Center (CCMC) to produce the solar wind, including the Wang-Sheely-Arge (WSA)-Enlil model, MHD-Around-a-Sphere (MAS)-Enlil model, Space Weather Modeling Framework (SWMF), and heliospheric tomography using interplanetary scintillation (IPS) data. By comparing the modeling results with the OMNI data over 7 Carrington rotations in 2007, we have conducted a third-party validation of these models for the near-Earth solar wind. This work will help the models get ready for the transition from research to operation. Besides visual comparison, we have quantitatively assessed the models’ capabilities in reproducing the time series and statistics of solar wind parameters. Using improved algorithms, we have identified magnetic field sector boundaries (SBs) and slow-to-fast stream interaction regions (SIRs) as focused structures. The success rate of capturing them and the time offset vary largely with models. For this period, the 2014 version of MAS-Enlil model works best for SBs, and the heliospheric tomography works best for SIRs. General strengths and weaknesses for each model are identified to provide an unbiased reference to model developers and users.

  18. Livestock water pumping with wind and solar power

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent developments in pumping technologies have allowed for efficient use of renewable energies like wind and solar to power new pumps for remote water pumping. A helical type, positive displacement pump was developed a few years ago and recently modified to accept input from a variable power sourc...

  19. On the nature of the solar-wind-Mars interaction

    NASA Technical Reports Server (NTRS)

    Vaisberg, O. L.; Bogdanov, A. V.; Smirnov, V. N.; Romanov, S. A.

    1976-01-01

    Plasma measurements near Mars on the U.S.S.R. Mars-2, -3, and -5 spacecraft are considered. The data are compared with simultaneous magnetic measurements. Strong evidence is obtained in favor of a direct interaction and mass exchange between the solar wind plasma and the gaseous envelope of Mars.

  20. The Solar-Wind Interaction with Comet Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    Burch, James

    2015-04-01

    The instruments of the Rosetta Plasma Consortium are providing close-up views of the solar-wind interaction with a comet from its dormancy into a period of significant coma development. Although a bow shock has not yet developed, the interactions so far involve significant deflection of the solar wind; pickup of cometary ions, charge exchange of solar-wind ions by the coma resulting in He+ and H- ions being entrained in the solar wind; the generation of low-frequency 10 - 100 mHz magnetic waves near the comet; electric-fields and waves in the range from DC up to 3.5 MHz, and significant plasma density enhancements, particularly over the neck of the comet. Also observed are negatively-charged nanograins with energies exceeding 20 keV and monoenergetic electron beams (up to 400 eV) indicative of negative charging of shaded regions of the nucleus. As the comet moves closer to the Sun these effects should increase along with the appearance of other expected effects such as a diamagnetic cavity, ionopause, and bow shock along with possibly other new and unexpected plasma and field phenomena.

  1. Air emissions due to wind and solar power.

    PubMed

    Katzenstein, Warren; Apt, Jay

    2009-01-15

    Renewables portfolio standards (RPS) encourage large-scale deployment of wind and solar electric power. Their power output varies rapidly, even when several sites are added together. In many locations, natural gas generators are the lowest cost resource available to compensate for this variability, and must ramp up and down quickly to keep the grid stable, affecting their emissions of NOx and CO2. We model a wind or solar photovoltaic plus gas system using measured 1-min time-resolved emissions and heat rate data from two types of natural gas generators, and power data from four wind plants and one solar plant. Over a wide range of renewable penetration, we find CO2 emissions achieve approximately 80% of the emissions reductions expected if the power fluctuations caused no additional emissions. Using steam injection, gas generators achieve only 30-50% of expected NOx emissions reductions, and with dry control NOx emissions increase substantially. We quantify the interaction between state RPSs and NOx constraints, finding that states with substantial RPSs could see significant upward pressure on NOx permit prices, if the gas turbines we modeled are representative of the plants used to mitigate wind and solar power variability.

  2. Iron charge states observed in the solar wind

    NASA Technical Reports Server (NTRS)

    Ipavich, F. M.; Galvin, A. B.; Gloeckler, G.; Hovestadt, D.; Klecker, B.; Scholer, M.

    1983-01-01

    Solar wind measurements from the ULECA sensor of the Max-Planck-Institut/University of Maryland experiment on ISEE-3 are reported. The low energy section of approx the ULECA sensor selects particles by their energy per charge (over the range 3.6 keV/Q to 30 keV/Q) and simultaneously measures their total energy with two low-noise solid state detectors. Solar wind Fe charge state measurements from three time periods of high speed solar wind occurring during a post-shock flow and a coronal hole-associated high speed stream are presented. Analysis of the post-shock flow solar wind indicates the charge state distributions for Fe were peaked at approx +16, indicative of an unusually high coronal temperature (3,000,000 K). In contrast, the Fe charge state distribution observed in a coronal hole-associated high speed stream peaks at approx -9, indicating a much lower coronal temperature (1,400,000 K). This constitutes the first reported measurements of iron charge states in a coronal hole-associated high speed stream.

  3. The source of electrostatic fluctuations in the solar-wind

    NASA Technical Reports Server (NTRS)

    Lemons, D. S.; Asbridge, J. R.; Bame, S. J.; Feldman, W. C.; Gary, S. P.; Gosling, J. T.

    1979-01-01

    Solar wind electron and ion distribution functions measured simultaneously with or close to times of intense electrostatic fluctuations are subjected to a linear Vlasov stability analysis. Although all distributions tested were found to be stable, the analysis suggests that the ion beam instability is the most likely source of the fluctuations.

  4. Assessment of existing studies of wind loading on solar collectors

    SciTech Connect

    Murphy, L. M.

    1981-02-01

    In developing solar collectors, wind loading is the major structural design consideration. Wind loading investigations have focused on establishing safe bounds for steady state loading and verifying rational but initial and conservative design approaches for the various solar collector concepts. As such, the effort has been very successful, and has contributed greatly to both the recognition and qualitative understanding of many of the physical phenomena involved. Loading coefficients corresponding to mean wind velocities have been derived in these prior studies to measure the expected structural loading on the various solar collectors. Current design and testing procedures for wind loading are discussed. The test results corresponding to numerous wind tests on heliostats, parabolic troughs, parabolic dishes, and field mounted photovoltaic arrays are discussed and the applicability of the findings across the various technologies is assessed. One of the most significant consistencies in the data from all the technologies is the apparent benefit provided by fences and field shielding. Taken in toto, these data show that load reductions of three or possibly more seem feasible, though a more thorough understanding of the phenomena involved must be attained before this benefit can be realized. It is recommended that the required understanding be developed to take advantage of this benefit and that field tests be conducted to correlate with both analyses and tests.

  5. THREE-DIMENSIONAL EVOLUTION OF SOLAR WIND DURING SOLAR CYCLES 22-24

    SciTech Connect

    Manoharan, P. K.

    2012-06-01

    This paper presents an analysis of three-dimensional evolution of solar wind density turbulence and speed at various levels of solar activity between solar cycles 22 and 24. The solar wind data used in this study have been obtained from the interplanetary scintillation (IPS) measurements made at the Ooty Radio Telescope, operating at 327 MHz. Results show that (1) on average, there was a downward trend in density turbulence from the maximum of cycle 22 to the deep minimum phase of cycle 23; (2) the scattering diameter of the corona around the Sun shrunk steadily toward the Sun, starting from 2003 to the smallest size at the deepest minimum, and it corresponded to a reduction of {approx}50% in the density turbulence between the maximum and minimum phases of cycle 23; (3) the latitudinal distribution of the solar wind speed was significantly different between the minima of cycles 22 and 23. At the minimum phase of solar cycle 22, when the underlying solar magnetic field was simple and nearly dipole in nature, the high-speed streams were observed from the poles to {approx}30 Degree-Sign latitudes in both hemispheres. In contrast, in the long-decay phase of cycle 23, the sources of the high-speed wind at both poles, in accordance with the weak polar fields, occupied narrow latitude belts from poles to {approx}60 Degree-Sign latitudes. Moreover, in agreement with the large amplitude of the heliospheric current sheet, the low-speed wind prevailed in the low- and mid-latitude regions of the heliosphere. (4) At the transition phase between cycles 23 and 24, the high levels of density and density turbulence were observed close to the heliospheric equator and the low-speed solar wind extended from the equatorial-to-mid-latitude regions. The above results in comparison with Ulysses and other in situ measurements suggest that the source of the solar wind has changed globally, with the important implication that the supply of mass and energy from the Sun to the interplanetary

  6. Solar-wind krypton and solid/gas fractionation in the early solar nebula

    NASA Technical Reports Server (NTRS)

    Wiens, Roger C.; Burnett, D. S.; Neugebauer, M.; Pepin, R. O.

    1991-01-01

    The solar-system Kr abundance is calculated from solar-wind noble-gas ratios, determined previously by low-temperature oxidations of lunar ilmenite grains, normalized to Si by spacecraft solar-wind measurements. The estimated Kr-83 abundance of 4.1 + or - 1.5 per million Si atoms is within uncertainty of estimates assuming no fractionation, determined from CI-chondrite abundances of surrounding elements. This is significant because it is the first such constraint on solid/gas fractionation, though the large uncertainty only confines it to somewhat less than a factor of two.

  7. Genesis Science Team Report on Mission Status

    NASA Astrophysics Data System (ADS)

    Burnett, D. S.

    2005-12-01

    The Genesis Discovery Mission exposed pure materials to the solar wind at the L1 Lagrangian point for 27 months between December 2001 and April 2004. These were returned for analysis in terrestrial laboratories in Sept 2004. The general science objectives for Genesis are: (1) measure solar isotopic abundance ratios to the precision required for planetary science problems, (2) improve the accuracy of photospheric elemental abundances by a least a factor of three, (3) provide independent analyses of the 3 major solar wind regimes and (4) provide a reservoir of solar matter for subsequent studies. Based on these general objectives, we are working towards a list of 18 specific prioritized measurement objectives, the first 5 of which are isotopic measurements. The two highest priority objectives are the isotopic compositions of O and N; to obtain a higher signal to background ratio for these elements, a concentrator (focusing ion telescope) was built at LANL to provide a factor of 20 fluence enhancement for elements lighter than P on a 30 mm radius target. The concentrator performed well in flight. A variety of other collector materials, tailored to specific analytical approaches, were mounted in 5 arrays of 55 hexagons, 4 cm point to point. Three of the arrays were used to provide the independent regime (coronal hole, low speed interstream, and coronal mass ejection) samples. The solar wind regime was measured by LANL Solar Wind Monitors on the Genesis spacecraft and the appropriate array exposed while the inappropriate array remained shielded. Array switchouts were carried out flawlessly during flight. Sample analyses have been slowed considerably by a parachute deployment failure which caused a crash of the sample return capsule upon reentry and by the presence of an in-flight contamination film, affectionately referred to as the brown stain. The crash has led to major loss of collector materials, along with significant pitting and scratching of the surviving

  8. Ion‐driven instabilities in the solar wind: Wind observations of 19 March 2005

    PubMed Central

    Jian, Lan K.; Broiles, Thomas W.; Stevens, Michael L.; Podesta, John J.; Kasper, Justin C.

    2016-01-01

    Abstract Intervals of enhanced magnetic fluctuations have been frequently observed in the solar wind. But it remains an open question as to whether these waves are generated at the Sun and then transported outward by the solar wind or generated locally in the interplanetary medium. Magnetic field and plasma measurements from the Wind spacecraft under slow solar wind conditions on 19 March 2005 demonstrate seven events of enhanced magnetic fluctuations at spacecraft‐frame frequencies somewhat above the proton cyclotron frequency and propagation approximately parallel or antiparallel to the background magnetic field B o. The proton velocity distributions during these events are characterized by two components: a more dense, slower core and a less dense, faster beam. Observed plasma parameters are used in a kinetic linear dispersion equation analysis for electromagnetic fluctuations at k x B o = 0; for two events the most unstable mode is the Alfvén‐cyclotron instability driven by a proton component temperature anisotropy T⊥/T|| > 1 (where the subscripts denote directions relative to B o), and for three events the most unstable mode is the right‐hand polarized magnetosonic instability driven primarily by ion component relative flows. Thus, both types of ion anisotropies and both types of instabilities are likely to be local sources of these enhanced fluctuation events in the solar wind.

  9. Ion-driven instabilities in the solar wind: Wind observations of 19 March 2005

    DOE PAGESBeta

    Gary, S. Peter; Jian, Lan K.; Broiles, Thomas W.; Stevens, Michael L.; Podesta, John J.; Kasper, Justin C.

    2016-01-16

    Intervals of enhanced magnetic fluctuations have been frequently observed in the solar wind. However, it remains an open question as to whether these waves are generated at the Sun and then transported outward by the solar wind or generated locally in the interplanetary medium. Magnetic field and plasma measurements from the Wind spacecraft under slow solar wind conditions on 19 March 2005 demonstrate seven events of enhanced magnetic fluctuations at spacecraft-frame frequencies somewhat above the proton cyclotron frequency and propagation approximately parallel or antiparallel to the background magnetic field Bo. The proton velocity distributions during these events are characterized bymore » two components: a more dense, slower core and a less dense, faster beam. In conclusion, observed plasma parameters are used in a kinetic linear dispersion equation analysis for electromagnetic fluctuations at k x Bo = 0; for two events the most unstable mode is the Alfvén-cyclotron instability driven by a proton component temperature anisotropy T⊥/T|| > 1 (where the subscripts denote directions relative to Bo), and for three events the most unstable mode is the right-hand polarized magnetosonic instability driven primarily by ion component relative flows. Thus, both types of ion anisotropies and both types of instabilities are likely to be local sources of these enhanced fluctuation events in the solar wind.« less

  10. Model for energy transfer in the solar wind: Model results

    NASA Technical Reports Server (NTRS)

    Barnes, A. A., Jr.; Hartle, R. E.

    1972-01-01

    A description is given of the results of solar wind flow in which the heating is due to (1) propagation and dissipation of hydromagnetic waves generated near the base of the wind, and (2) thermal conduction. A series of models is generated for fixed values of density, electron and proton temperature, and magnetic field at the base by varying the wave intensity at the base of the model. This series of models predicts the observed correlation between flow speed and proton temperature for a large range of velocities. The wave heating takes place in a shell about the sun greater than or approximately equal to 10 R thick. We conclude that large-scale variations observed in the solar wind are probably due mainly to variation in the hydromagnetic wave flux near the sun.

  11. Large Scale Wind and Solar Integration in Germany

    SciTech Connect

    Ernst, Bernhard; Schreirer, Uwe; Berster, Frank; Pease, John; Scholz, Cristian; Erbring, Hans-Peter; Schlunke, Stephan; Makarov, Yuri V.

    2010-02-28

    This report provides key information concerning the German experience with integrating of 25 gigawatts of wind and 7 gigawatts of solar power capacity and mitigating its impacts on the electric power system. The report has been prepared based on information provided by the Amprion GmbH and 50Hertz Transmission GmbH managers and engineers to the Bonneville Power Administration (BPA) and Pacific Northwest National Laboratory representatives during their visit to Germany in October 2009. The trip and this report have been sponsored by the BPA Technology Innovation office. Learning from the German experience could help the Bonneville Power Administration engineers to compare and evaluate potential new solutions for managing higher penetrations of wind energy resources in their control area. A broader dissemination of this experience will benefit wind and solar resource integration efforts in the United States.

  12. Multi-Species Instability Thresholds in the Solar Wind

    NASA Astrophysics Data System (ADS)

    Chen, C. H. K.

    2015-12-01

    There has been much recent investigation into how various pressure anisotropy and drift instabilities constrain the distribution of solar wind parameters such as temperature anisotropy, beta, and differential flow between species. These investigations have tended to look at the major solar wind species (protons, alphas, electrons) separately, and how the distribution of the parameters of each species is separately constrained by the kinetic instability arising from free energy in its own distribution. However, the stability of the plasma depends on all species together, and here we present a first investigation of this using a combined proton/alpha/electron data set from the 3DP and SWE instruments on the Wind spacecraft. When all species are combined, the distributions appear to be remarkably well constrained by the fluid firehose and mirror thresholds. Non-proton species and drifts make significant contributions to the plasma being marginally firehose unstable. Theoretical implications of these results will be discussed.

  13. High amplitude waves in the expanding solar wind plasma

    NASA Technical Reports Server (NTRS)

    Schmidt, J. M.; Velli, M.; Grappin, R.

    1995-01-01

    We simulated the 1-D nonlinear time-evolution of high-amplitude Alfven, slow and fast magnetoacoustic waves in the solar wind propagating outward at different angles to the mean magnetic (spiral) field, using the expanding box model. The simulation results for Alfven waves and fast magnetoacustic waves fit the observational constraints in the solar wind best, showing decreasing trends for energies and other rms-quantities due to expansion and the appearance of inward propagating waves as minor species in the wind. Inward propagating waves are generated by reflection of Alfven waves propagating at large angles to the magnetic field or they coincide with the occurrence of compressible fluctuations. In our simulations, fast and slow magnetoacoustic waves seem to have a level in the density-fluctuations which is too high when we compare with the observations. Furthermore, the evolution of energies for slow magnetoacoustic waves differs strongly from the evolution of fluctuation energies in situ.

  14. Solar origins of solar wind properties during the cycle 23 solar minimum and rising phase of cycle 24

    PubMed Central

    Luhmann, Janet G.; Petrie, Gordon; Riley, Pete

    2012-01-01

    The solar wind was originally envisioned using a simple dipolar corona/polar coronal hole sources picture, but modern observations and models, together with the recent unusual solar cycle minimum, have demonstrated the limitations of this picture. The solar surface fields in both polar and low-to-mid-latitude active region zones routinely produce coronal magnetic fields and related solar wind sources much more complex than a dipole. This makes low-to-mid latitude coronal holes and their associated streamer boundaries major contributors to what is observed in the ecliptic and affects the Earth. In this paper we use magnetogram-based coronal field models to describe the conditions that prevailed in the corona from the decline of cycle 23 into the rising phase of cycle 24. The results emphasize the need for adopting new views of what is ‘typical’ solar wind, even when the Sun is relatively inactive. PMID:25685422

  15. Solar origins of solar wind properties during the cycle 23 solar minimum and rising phase of cycle 24.

    PubMed

    Luhmann, Janet G; Petrie, Gordon; Riley, Pete

    2013-05-01

    The solar wind was originally envisioned using a simple dipolar corona/polar coronal hole sources picture, but modern observations and models, together with the recent unusual solar cycle minimum, have demonstrated the limitations of this picture. The solar surface fields in both polar and low-to-mid-latitude active region zones routinely produce coronal magnetic fields and related solar wind sources much more complex than a dipole. This makes low-to-mid latitude coronal holes and their associated streamer boundaries major contributors to what is observed in the ecliptic and affects the Earth. In this paper we use magnetogram-based coronal field models to describe the conditions that prevailed in the corona from the decline of cycle 23 into the rising phase of cycle 24. The results emphasize the need for adopting new views of what is 'typical' solar wind, even when the Sun is relatively inactive.

  16. Global distribution of the solar wind and its evolution during cycles 22-24

    NASA Astrophysics Data System (ADS)

    Tokumaru, M.; Fujiki, K.; Kojima, M.; Iju, T.; Nakano, H.; Satonaka, D.; Shimoyama, T.; Hakamada, K.

    2016-03-01

    Ground-based observations of the solar wind using interplanetary scintillation (IPS) have been regularly performed since 1980s at the Solar-Terrestrial Environment Laboratory of Nagoya University using the 327-MHz multi-station system. It has been revealed from the IPS observations that the global distribution of the solar wind is well ordered by the Sun's magnetic field. This fact suggests that the magnetic field plays an important role in the formation of the solar wind. The IPS observations evidently demonstrate that global distribution of the solar wind systematically changes with the solar activity. Recently, some peculiar aspects of the solar wind have been found from the IPS observations; e.g. increase of low-latitude fast winds, global reduction of the fast wind area and the density fluctuation level, North-South asymmetry of polar fast winds. These are considered as a manifestation of weaker dynamo activity in this cycle.

  17. HEMISPHERIC ASYMMETRIES IN THE POLAR SOLAR WIND OBSERVED BY ULYSSES NEAR THE MINIMA OF SOLAR CYCLES 22 AND 23

    SciTech Connect

    Ebert, R. W.; Dayeh, M. A.; Desai, M. I.; McComas, D. J.; Pogorelov, N. V.

    2013-05-10

    We examined solar wind plasma and interplanetary magnetic field (IMF) observations from Ulysses' first and third orbits to study hemispheric differences in the properties of the solar wind and IMF originating from the Sun's large polar coronal holes (PCHs) during the declining and minimum phase of solar cycles 22 and 23. We identified hemispheric asymmetries in several parameters, most notably {approx}15%-30% south-to-north differences in averages for the solar wind density, mass flux, dynamic pressure, and energy flux and the radial and total IMF magnitudes. These differences were driven by relatively larger, more variable solar wind density and radial IMF between {approx}36 Degree-Sign S-60 Degree-Sign S during the declining phase of solar cycles 22 and 23. These observations indicate either a hemispheric asymmetry in the PCH output during the declining and minimum phase of solar cycles 22 and 23 with the southern hemisphere being more active than its northern counterpart, or a solar cycle effect where the PCH output in both hemispheres is enhanced during periods of higher solar activity. We also report a strong linear correlation between these solar wind and IMF parameters, including the periods of enhanced PCH output, that highlight the connection between the solar wind mass and energy output and the Sun's magnetic field. That these enhancements were not matched by similar sized variations in solar wind speed points to the mass and energy responsible for these increases being added to the solar wind while its flow was subsonic.

  18. Geomagnetic response to IMF and solar wind over different latitudes

    NASA Astrophysics Data System (ADS)

    Aslam, A. M.; Tripathi, Sharad Chandra; Mansoori, Azad Ahmad; Waheed, Malik Abdul

    2016-07-01

    In this paper a study on the response of geomagnetic field characteristics to the solar wind variation during three solar cycles (SC 21, SC 22, SC 23) have been conducted in a long term scale. The difference in the response of two different latitudinal characteristic indices has been investigated. For the purpose we have considered the high latitude index AE and the mid-latitude aa index and both gives the knowledge about the perturbations in the geomagnetic field conditions. Eventually we can infer the idea about the ionospheric current system changes in response to the solar wind conditions. The variation found in the AE and aa indices have been found to follow a 11 year cycle as similar to the sunspot variation. Also the correlation between the annual means of the solar wind parameters velocity V, magnetic filed B and the composite parameters BV and BV ^{2 } have been calculated . A difference was found between the correlations obtained for the AE and aa indices. We could also see that the difference in correlation follows a cyclic pattern i.e. the large difference is found during the solar maxima while a small difference is observed during the minima.

  19. Solar Wind Variability: from Macro to Micro Scales

    NASA Astrophysics Data System (ADS)

    Bruno, R.

    2015-12-01

    Several decades of in-situ observations by spacecraft unraveled the complex nature of the variability of solar wind magnetic field and plasma parameters. These fluctuations range from scales of the order of the solar rotation period to the smallest scales of the order of the ion and electron characteristic scale lengths. Some of these fluctuations belong to coronal transients, others to propagating modes and others are simply due to inhomogeneities and structures advected by the wind across the observer. In this talk I'll provide a short overview of the state of art of our current interpretation of the complex phenomenology observed so far, also in view of the next solar missions Solar Orbiter and SPP. I will start describing the solar wind large scale structure and its connection to the low corona. I will continue through the MHD regime, where turbulence energy is nonlinearly transferred to smaller and smaller scales, to end up at kinetic scales where this energy eventually is dissipated.

  20. Semiempirical Models of the Slow and Fast Solar Wind

    NASA Astrophysics Data System (ADS)

    Wang, Y.-M.

    2012-11-01

    Coronal holes can produce several types of solar wind with a variety of compositional properties, depending on the location and strength of the heating along their open magnetic field lines. High-speed wind is associated with (relatively) slowly diverging flux tubes rooted in the interiors of large holes with weak, uniform footpoint fields; heating is spread over a large radial distance, so that most of the energy is conducted outward and goes into accelerating the wind rather than increasing the mass flux. In the rapidly diverging open fields present at coronal hole boundaries and around active regions, the heating is concentrated at low heights and the temperature maximum is located near the coronal base, resulting in high oxygen freezing-in temperatures and low asymptotic wind speeds. Polar plumes have a strong additional source of heating at their bases, which generates a large downward conductive flux, raising the densities and enhancing the radiative losses. The relative constancy of the solar wind mass flux at Earth reflects the tendency for the heating rate in coronal holes to increase monotonically with the footpoint field strength, with very high mass fluxes at the Sun offsetting the enormous flux-tube expansion in active region holes. Although coronal holes are its main source, slow wind is also released continually from helmet streamer loops by reconnection processes, giving rise to plasma blobs (small flux ropes) and the heliospheric plasma sheet.

  1. Solar Energetic Particle Production by Shocks in Fast and Slow Solar Wind Structures

    NASA Astrophysics Data System (ADS)

    Kahler, S. W.; Reames, D. V.; Sheeley, N. R., Jr.

    2002-05-01

    Gradual solar energetic particle (SEP) events at 1 AU are produced by coronal and interplanetary shocks driven by coronal mass ejections (CMEs). Shocks from fast (V > 900 km/s) CMEs should be produced more easily in slow solar wind regions where the flow and fast-mode MHD wave speeds are low and less easily in fast solar wind regions where those speeds are high. We might therefore expect to observe more intense SEP events at 1 AU when the Earth lies in a slow wind region than when it lies in a fast wind region. While stream-stream interactions wash out the slow-fast stream boundaries in the solar wind speed profiles at 1 AU, the O+7/O+6 signatures of the streams are unchanged at 1 AU. We use the 20 MeV proton intensities from the EPACT instrument on Wind, the associated CMEs observed with the Lasco coronagraph on SOHO, and the ACE SWICS/SWIMS solar wind values of O+7/O+6 to look for variations of peak SEP intensities as a function of O+7/O+6. We find no significant dependence of the SEP intensities on O+7/O+6 for either poorly connected or well connected CME source regions or for different CME speed ranges. While a broad range of angular widths are associated with fast (V > 900 km/s) CMEs, we find that no fast CMEs with widths < 60 degrees are associated with SEP events. On the other hand, nearly all fast halo CMEs are associated with SEP events. Thus the CME widths are more important in SEP production than previously thought, but the solar wind source regions in which SEPs are produced are not a significant factor.

  2. THERMALIZATION OF HEAVY IONS IN THE SOLAR WIND

    SciTech Connect

    Tracy, Patrick J.; Kasper, Justin C.; Zurbuchen, Thomas H.; Raines, Jim M.; Shearer, Paul; Gilbert, Jason

    2015-10-20

    Observations of velocity distribution functions from the Advanced Composition Explorer/Solar Wind Ion Composition Spectrometer heavy ion composition instrument are used to calculate ratios of kinetic temperature and Coulomb collisional interactions of an unprecedented 50 ion species in the solar wind. These ions cover a mass per charge range of 1–5.5 amu/e and were collected in the time range of 1998–2011. We report the first calculation of the Coulomb thermalization rate between each of the heavy ion (A > 4 amu) species present in the solar wind along with protons (H{sup +}) and alpha particles (He{sup 2+}). From these rates, we find that protons are the dominant source of Coulomb collisional thermalization for heavy ions in the solar wind and use this fact to calculate a collisional age for those heavy ion populations. The heavy ion thermal properties are well organized by this collisional age, but we find that the temperature of all heavy ions does not simply approach that of protons as Coulomb collisions become more important. We show that He{sup 2+} and C{sup 6+} follow a monotonic decay toward equal temperatures with protons with increasing collisional age, but O{sup 6+} shows a noted deviation from this monotonic decay. Furthermore, we show that the deviation from monotonic decay for O{sup 6+} occurs in solar wind of all origins, as determined by its Fe/O ratio. The observed differences in heavy ion temperature behavior point toward a local heating mechanism that favors ions depending on their charge and mass.

  3. Plasma observations of the solar wind interaction with Mars

    NASA Technical Reports Server (NTRS)

    Vaisberg, O. L.; Luhmann, J. G.; Russell, C. T.

    1990-01-01

    Measurements with the plasma analyzers on the Mars-2, 3 and 5 spacecraft show that Mars deflects a large fraction of the incoming solar wind flow to form a strong bow shock. The bow shock is about 1.41 Rm from the center of the planet at the subsolar point and about 2.40 Rm at the terminator. These distances are similar to those for Venus at times of moderate solar activity. The inferred effective obstacle altitude is about 400-700 km. An ion cushion has been found which is similar in its properties to the Venus magnetic barrier. The formation of this cushion appears to cause the deflection of the solar wind. Inside the cushion but well above the ionosphere is found a region where the ions are at the background, the electrons are cool and the magnetic pressure dominates. This region may resemble a planetary magnetosphere.

  4. Global aspects of stream evolution in the solar wind

    SciTech Connect

    Gosling, J.T.

    1984-01-01

    A spatially variable coronal expansion, when coupled with solar rotation, leads to the formation of high speed solar wind streams which evolve considerably with increasing heliocentric distance. Initially the streams steepen for simple kinematic reasons, but this steepening is resisted by pressure forces, leading eventually to the formation of forward-reverse shock pairs in the distant heliosphere. The basic physical processes responsible for stream steepening an evolution are explored and model calculations are compared with actual spacecraft observations of the process. The solar wind stream evolution problem is relatively well understood both observationally and theoretically. Tools developed in achieving this understanding should be applicable to other astrophysical systems where a spatially or temporally variable outflow is associated with a rotating object. 27 references, 13 figures.

  5. The Contribution of Coronal Jets to the Solar Wind

    NASA Astrophysics Data System (ADS)

    Lionello, R.; Török, T.; Titov, V. S.; Leake, J. E.; Mikić, Z.; Linker, J. A.; Linton, M. G.

    2016-11-01

    Transient collimated plasma eruptions in the solar corona, commonly known as coronal (or X-ray) jets, are among the most interesting manifestations of solar activity. It has been suggested that these events contribute to the mass and energy content of the corona and solar wind, but the extent of these contributions remains uncertain. We have recently modeled the formation and evolution of coronal jets using a three-dimensional (3D) magnetohydrodynamic (MHD) code with thermodynamics in a large spherical domain that includes the solar wind. Our model is coupled to 3D MHD flux-emergence simulations, i.e., we use boundary conditions provided by such simulations to drive a time-dependent coronal evolution. The model includes parametric coronal heating, radiative losses, and thermal conduction, which enables us to simulate the dynamics and plasma properties of coronal jets in a more realistic manner than done so far. Here, we employ these simulations to calculate the amount of mass and energy transported by coronal jets into the outer corona and inner heliosphere. Based on observed jet-occurrence rates, we then estimate the total contribution of coronal jets to the mass and energy content of the solar wind to (0.4–3.0)% and (0.3–1.0)%, respectively. Our results are largely consistent with the few previous rough estimates obtained from observations, supporting the conjecture that coronal jets provide only a small amount of mass and energy to the solar wind. We emphasize, however, that more advanced observations and simulations (including parametric studies) are needed to substantiate this conjecture.

  6. Characteristics of the solar wind controlled auroral emissions

    NASA Astrophysics Data System (ADS)

    Liou, K.; Newell, P. T.; Meng, C.-I.; Brittnacher, M.; Parks, G.

    1998-08-01

    We performed a high-time resolution (5 min) correlative study of the energy deposition rate in the northern auroral zone with the concurrent solar wind plasma and interplanetary magnetic field (IMF) observations for a 4 month period from March 30 to July 29, 1996. Auroral power, inferred by auroral emissions, was derived from images acquired by the ultraviolet imager (UVI) on board the Polar satellite, and the interplanetary parameters were based on Wind observations. It is found that dayside aurorae in the afternoon sector (65°-80° magnetic latitude (MLAT) and 1300-1800 magnetic local time (MLT)) are more active for large IMF cone angles and large solar wind electric fields. This result can be attributed to the manifestation of the antiparallel magnetic field merging in different locations and the partial ``penetration'' of the IMF on the dayside magnetopause. The integrated nightside (60°-75° MLAT and 2000-0100 MLT) auroral brightness is moderately correlated with the north-south component of the IMF and the solar wind speed with correlation coefficients of 0.49 and 0.35, respectively. The mean nightside auroral power is found to be approximately linearly proportional to the IMF Bz with a constant slope of 2 GW/nT. The solar wind speed, however, affects the nightside auroral power for both polarities of IMF Bz. Interestingly, the solar wind dynamic pressure shows no effect on the nightside auroral brightness. All these findings indicate that both reconnection and viscous-like interaction mechanisms play an important role in producing auroral emissions in the night sector. It is also found that the nightside auroral brightness responds to the southward turning of the IMF with a peak delay time of ~60 min. This result favors the model of loading-unloading magnetosphere. We also found that a negative IMF By condition favors the nightside auroral activity, and we attributed this effect to the partial penetration of the IMF By. Finally, the response function for

  7. Solar Panel Buffeted by Wind at Phoenix Site

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Winds were strong enough to cause about a half a centimeter (.19 inch) of motion of a solar panel on NASA's Phoenix Mars lander when the lander's Surface Stereo Imager took this picture on Aug. 31, 2008, during the 96th Martian day since landing.

    The lander's telltale wind gauge has been indicating wind speeds of about 4 meters per second (9 miles per hour) during late mornings at the site.

    These conditions were anticipated and the wind is not expected to do any harm to the lander.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  8. A porcupine Sun? Implications for the solar wind and Earth

    NASA Astrophysics Data System (ADS)

    Gibson, Sarah E.; Zhao, Liang

    2012-07-01

    The recent minimum was unusually long, and it was not just the case of the ``usual story'' slowed down. The coronal magnetic field never became completely dipolar as in recent Space Age minima, but rather gradually evolved into an (essentially axisymmetric) global configuration possessing mixed open and closed magnetic structures at many latitudes. In the process, the impact of the solar wind at the Earth went from resembling that from a sequence of rotating ``fire-hoses'' to what might be expected from a weak, omnidirectional ``lawn-sprinkler''. The previous (1996) solar minimum was a more classic dipolar configuration, and was characterized by slow wind of hot origin localized to the heliospheric current sheet, and fast wind of cold origin emitted from polar holes, but filling most of the heliosphere. In contrast, the more recent minimum solar wind possessed a broad range of speeds and source temperatures (although cooler overall than the prior minimum). We discuss possible connections between these observations and the near-radial expansion and small spatial scales characteristic of the recent minimum's porcupine-like magnetic field.

  9. Genesis Silicon Carbide Concentrator Target 60003 Preliminary Ellipsometry Mapping Results

    NASA Technical Reports Server (NTRS)

    Calaway, M. J.; Rodriquez, M. C.; Stansbery, E. K.

    2007-01-01

    The Genesis concentrator was custom designed to focus solar wind ions primarily for terrestrial isotopic analysis of O-17/O-16 and O-18/O-16 to +/-1%, N-15/N-14 to +/-1%, and secondarily to conduct elemental and isotopic analysis of Li, Be, and B. The circular 6.2 cm diameter concentrator target holder was comprised of four quadrants of highly pure semiconductor materials that included one amorphous diamond-like carbon, one C-13 diamond, and two silicon carbide (SiC). The amorphous diamond-like carbon quadrant was fractured upon impact at Utah Test and Training Range (UTTR), but the remaining three quadrants survived fully intact and all four quadrants hold an important collection of solar wind. The quadrants were removed from the target holder at NASA Johnso n Space Center Genesis Curation Laboratory in April 2005, and have been housed in stainless steel containers under continual nitrogen purge since time of disintegration. In preparation for allocation of a silicon carbide target for oxygen isotope analyses at UCLA, the two SiC targets were photographed for preliminary inspection of macro particle contamination from the hard non-nominal landing as well as characterized by spectroscopic ellipsometry to evaluate thin film contamination. This report is focused on Genesis SiC target sample number 60003.

  10. Simulation and optimum design of hybrid solar-wind and solar-wind-diesel power generation systems

    NASA Astrophysics Data System (ADS)

    Zhou, Wei

    Solar and wind energy systems are considered as promising power generating sources due to its availability and topological advantages in local power generations. However, a drawback, common to solar and wind options, is their unpredictable nature and dependence on weather changes, both of these energy systems would have to be oversized to make them completely reliable. Fortunately, the problems caused by variable nature of these resources can be partially overcome by integrating these two resources in a proper combination to form a hybrid system. However, with the increased complexity in comparison with single energy systems, optimum design of hybrid system becomes more complicated. In order to efficiently and economically utilize the renewable energy resources, one optimal sizing method is necessary. This thesis developed an optimal sizing method to find the global optimum configuration of stand-alone hybrid (both solar-wind and solar-wind-diesel) power generation systems. By using Genetic Algorithm (GA), the optimal sizing method was developed to calculate the system optimum configuration which offers to guarantee the lowest investment with full use of the PV array, wind turbine and battery bank. For the hybrid solar-wind system, the optimal sizing method is developed based on the Loss of Power Supply Probability (LPSP) and the Annualized Cost of System (ACS) concepts. The optimization procedure aims to find the configuration that yields the best compromise between the two considered objectives: LPSP and ACS. The decision variables, which need to be optimized in the optimization process, are the PV module capacity, wind turbine capacity, battery capacity, PV module slope angle and wind turbine installation height. For the hybrid solar-wind-diesel system, minimization of the system cost is achieved not only by selecting an appropriate system configuration, but also by finding a suitable control strategy (starting and stopping point) of the diesel generator. The

  11. Ulysses sees differences in solar wind at high, low latitudes

    NASA Astrophysics Data System (ADS)

    1995-06-01

    Scientists presenting results today of their data at the spring meeting of the American Geophysical Union in Baltimore, Md., said the speed of the solar wind over the southern pole is high, compared to its low velocity near the Sun's equator. The solar wind is the hot ionized gas that escapes from the solar corona and expands into interplanetary space. At the present minimum of the solar activity cycle, the angle between the Sun's rotational and magnetic equators has decreased -- in these conditions Ulysses found that the region of low-speed solar winds were confined more closely to the rotational equator than in earlier portions of the solar cycle. Now on its way to the northern solar pole, Ulysses is nearly 62 degrees north of the Sun's equator today. The second phase of the primary mission -- to explore the northern pole of the Sun -- will begin on June 19, when the spacecraft reaches 70 degrees north latitude, The spacecraft will reach a maximum northern latitude of 80,2 degrees on 31 July 1995. Ulysses' trajectory from 80 degrees south of the equator in September 1994, back down to the Sun's equator in March 1995, also brought the spacecraft within 1.3 astronomical units (121 million miles, 194 million km) of the Sun, the closest Ulysses would ever travel to the Sun since it was launched on October 6, 1990. The spacecraft picked up speed during this phase allowing the entire region to be scanned in just six months time. Scientists refer to this phase of the mapping as the "fast latitude scan", Ulysses had left the equatorial plane in early 1992 after a gravitational swingby of Jupiter, and had gradually climbed in latitude until reaching 80 degrees south in September 1994. Ulysses' observations during the fast latitude scan have shown that the solar wind being continuously emitted by the Sun is distinctly different at high and low latitudes, said Dr. Edward J. Smith, Ulysses project scientist at NASA's Jet Propulsion Laboratory, for the joint NASA

  12. Solar wind heavy ions from flare-heated coronal plasma

    NASA Technical Reports Server (NTRS)

    Bame, S. J.; Asbridge, J. R.; Feldman, W. C.; Fenimore, E. E.; Gosling, J. T.

    1979-01-01

    Information concerning the coronal expansion is carried by solar-wind heavy ions. Distinctly different energy-per-charge ion spectra are found in two classes of solar wind having the low kinetic temperatures necessary for E/q resolution of the ion species. Heavy-ion spectra which can be resolved are most frequently observed in the low-speed interstream (IS) plasma found between high speed streams; the streams are thought to originate from coronal holes. Although the sources of the IS plasma are uncertain, the heavy-ion spectra found there contain identifiable peaks of O, Si, and Fe ions. Such spectra indicate that the IS ionization state of O is established in coronal gas at a temperature of approximately 1.6 million K, while that of Fe is frozen in farther out at about 1.5 million K. On occasion anomalous spectra are found outside IS flows in solar wind with abnormally depressed local kinetic temperatures. The anomalous spectra contain Fe(16+) ions, not usually found in IS flows, and the derived coronal freezing-in temperatures are significantly higher. The coronal sources of some of these ionizationally hot flows are identified as solar flares.

  13. Invited article: Electric solar wind sail: toward test missions.

    PubMed

    Janhunen, P; Toivanen, P K; Polkko, J; Merikallio, S; Salminen, P; Haeggström, E; Seppänen, H; Kurppa, R; Ukkonen, J; Kiprich, S; Thornell, G; Kratz, H; Richter, L; Krömer, O; Rosta, R; Noorma, M; Envall, J; Lätt, S; Mengali, G; Quarta, A A; Koivisto, H; Tarvainen, O; Kalvas, T; Kauppinen, J; Nuottajärvi, A; Obraztsov, A

    2010-11-01

    The electric solar wind sail (E-sail) is a space propulsion concept that uses the natural solar wind dynamic pressure for producing spacecraft thrust. In its baseline form, the E-sail consists of a number of long, thin, conducting, and centrifugally stretched tethers, which are kept in a high positive potential by an onboard electron gun. The concept gains its efficiency from the fact that the effective sail area, i.e., the potential structure of the tethers, can be millions of times larger than the physical area of the thin tethers wires, which offsets the fact that the dynamic pressure of the solar wind is very weak. Indeed, according to the most recent published estimates, an E-sail of 1 N thrust and 100 kg mass could be built in the rather near future, providing a revolutionary level of propulsive performance (specific acceleration) for travel in the solar system. Here we give a review of the ongoing technical development work of the E-sail, covering tether construction, overall mechanical design alternatives, guidance and navigation strategies, and dynamical and orbital simulations.

  14. Detection of fast nanoparticles in the solar wind

    NASA Astrophysics Data System (ADS)

    Meyer-Vernet, N.; Czechowski, A.; Mann, I.; Maksimovic, M.; Lecacheux, A.; Goetz, K.; Kaiser, M. L.; Cyr, O. C. St.; Bale, S. D.; Le Chat, G.

    2010-03-01

    Dust grains in the nanometer range bridge the gap between atoms and larger grains made of bulk material. Their small size embodies them with special properties. Due to their high relative surface area, they have a high charge-to-mass ratio, so that the Lorentz force in the solar wind magnetic field exceeds the gravitational force and other forces by a large amount, and they are accelerated to a speed of the order of magnitude of the solar wind speed. When such fast nanoparticles impact a spacecraft, they produce craters whose matter vaporises and ionises, yielding transient voltages as high as do much larger grains of smaller speed. These properties are at the origin of their recent detection at 1 AU in the solar wind. We discuss the detection of fast nanoparticles by wave instruments of different configurations, with applications to the recent detections on STEREO/WAVES and CASSINI/RPWS. Finally we discuss the opportunities for nanoparticle detection by wave instruments on future missions and/or projects in the inner heliosphere such as Bepi-Colombo and Solar Orbiter.

  15. Small solar wind transients: Stereo-A observations in 2009

    SciTech Connect

    Yu, W.; Farrugia, C. J.; Galvin, A. B.; Simunac, K. D. C.; Popecki, M. A.; Lugaz, N.; Kilpua, E. K. J.; Moestl, C.; Luhmann, J. G.; Opitz, A.; Sauvaud, J.-A.

    2013-06-13

    Year 2009 was the last year of a long and pronounced solar activity minimum. In this year the solar wind in the inner heliosphere was for 90% of the time slow (< 450 km s{sup -1}) and with a weaker magnetic field strength compared to the previous solar minimum 1995-1996. We choose this year to present the results of a systematic search for small solar wind transients (STs) observed by the STEREO-Ahead (ST-A) probe. The data are from the PLASTIC and IMPACT instrument suites. By 'small' we mean a duration from {approx}1 to 12 hours. The parameters we search for to identify STs are (i) the total field strength, (ii) the rotation of the magnetic field vector, (iii) its smoothness, (iv) proton temperature, (v) proton beta, and (vi) Alfven Mach number. We find 45 examples. The STs have an average duration of {approx}4 hours. Ensemble averages of key quantities are: (i) maximum B = 7.01 nT; (ii) proton {beta}= 0.18; (iii) proton thermal speed = 20.8 km s{sup -1}; and (iv) Alfven Mach number = 6.13. No distinctive feature is found in the pitch angle distributions of suprathermal electrons. Our statistical results are compared with those of STs observed near Earth by Wind during 2009.

  16. Turbulence generated by flux tube instabilities in the solar wind

    NASA Astrophysics Data System (ADS)

    Vörös, Zoltan; Zaqarashvili, Teimuraz; Sasunov, Jury; Semenov, Vladimir; Bruno, Roberto

    2015-04-01

    Magnetic flux tubes represent basic structures on the Sun and in the solar wind. Flux tubes of solar origin can become magnetically twisted at photospheric, chromospheric or coronal levels and transported into interplanetary space. Twisted or untwisted flux tubes can also be generated by magnetic reconnection in the solar wind. We show here that flux tube instabilities, such as the Kelvin-Helmholtz and the kink instabilities, may significantly contribute to the local generation of turbulence, reconnection and dissipation in the solar wind. The associated "fresh" turbulence may change the field and plasma conditions supporting different local dissipation mechanisms at their characteristic wavenumbers. Recent analytical and numerical calculations show that twisted tubes embedded into twisted external magnetic fields are Kelvin-Helmholtz unstable even for sub-Alfvenic flows. Moving tubes with strong twists are unstable against the kink instability resulting in magnetic reconnection and dissipation. Vörös et al., ApJL, 797:L10, 2014. Zaqarashvili et al., A&A, 561, A62, 2014. Zaqarashvili et al., ApJL, 783:L19, 2014.

  17. Some remarks on waves in the solar wind

    SciTech Connect

    Kellogg, P. J.; Goetz, K.; Monson, S. J.; Balogh, A.; Forsyth, R. J.

    1996-07-20

    Waves are significant to the solar wind in two ways--as modifiers of the particle distribution functions, and as diagnostics. In addition, the solar wind serves as an important laboratory for the study of plasma wave processes, as it is possible to make detailed measurements of phenomena which are too small to be easily measured by laboratory sized sensors. The waves, both electromagnetic and electrostatic, which are part of the solar type III burst phenomenon, have been extensively studied as examples of nonlinear plasma phenomena, and also used as remote sensors to trace the solar magnetic field. The observations made by Ulysses show that the field can be traced in this way out to perhaps a little more than an A.U., but then the electromagnetic part of the type III burst fades out. Nevertheless, sometimes Langmuir waves appear at Ulysses at an appropriate extrapolated time. This seems to support the picture in which the electromagnetic waves at the fundamental plasma frequency are trapped in density fluctuations. Recently it has been found that Langmuir waves are associated with magnetic holes. This may help to elucidate the nature of magnetic holes. Nonlinear processes are important in the transformation of wave energy to particle energy. Some recent examples from Wind data are shown.

  18. Western Wind and Solar Integration Study: Hydropower Analysis

    SciTech Connect

    Acker, T.; Pete, C.

    2012-03-01

    The U.S. Department of Energy's (DOE) study of 20% Wind Energy by 2030 was conducted to consider the benefits, challenges, and costs associated with sourcing 20% of U.S. energy consumption from wind power by 2030. This study found that with proactive measures, no insurmountable barriers were identified to meet the 20% goal. Following this study, DOE and the National Renewable Energy Laboratory (NREL) conducted two more studies: the Eastern Wind Integration and Transmission Study (EWITS) covering the eastern portion of the U.S., and the Western Wind and Solar Integration Study (WWSIS) covering the western portion of the United States. The WWSIS was conducted by NREL and research partner General Electric (GE) in order to provide insight into the costs, technical or physical barriers, and operational impacts caused by the variability and uncertainty of wind, photovoltaic, and concentrated solar power when employed to serve up to 35% of the load energy in the WestConnect region (Arizona, Colorado, Nevada, New Mexico, and Wyoming). WestConnect is composed of several utility companies working collaboratively to assess stakeholder and market needs to and develop cost-effective improvements to the western wholesale electricity market. Participants include the Arizona Public Service, El Paso Electric Company, NV Energy, Public Service of New Mexico, Salt River Project, Tri-State Generation and Transmission Cooperative, Tucson Electric Power, Xcel Energy and the Western Area Power Administration.

  19. A Model for the Sources of the Slow Solar Wind

    NASA Technical Reports Server (NTRS)

    Antiochos, Spiro K.; Mikic, Z.; Titov, V. S.; Lionello, R.; Linker, J. A.

    2010-01-01

    Models for the origin of the slow solar wind must account for two seemingly contradictory observations: The slow wind has the composition of the closed-field corona, implying that it originates from the continuous opening and closing of flux at the boundary between open and closed field. On the other hand, the slow wind has large angular width, up to approximately 60 degrees, suggesting that its source extends far from the open-closed boundary. We propose a model that can explain both observations. The key idea is that the source of the slow wind at the Sun is a network of narrow (possibly singular) open-field corridors that map to a web of separatrices and quasi-separatrix layers in the heliosphere. We compute analytically the topology of an open-field corridor and show that it produces a quasi-separatrix layer in the heliosphere that extends to angles far front the heliospheric current sheet. We then use an MHD code and MIDI/SOHO observations of the photospheric magnetic field to calculate numerically, with high spatial resolution, the quasi-steady solar wind and magnetic field for a time period preceding the August 1, 2008 total solar eclipse. Our numerical results imply that, at least for this time period, a web of separatrices (which we term an S-web) forms with sufficient density and extent in the heliosphere to account for the observed properties of the slow wind. We discuss the implications of our S-web model for the structure and dynamics of the corona and heliosphere, and propose further tests of the model.

  20. A MODEL FOR THE SOURCES OF THE SLOW SOLAR WIND

    SciTech Connect

    Antiochos, S. K.; Mikic, Z.; Titov, V. S.; Lionello, R.; Linker, J. A.

    2011-04-20

    Models for the origin of the slow solar wind must account for two seemingly contradictory observations: the slow wind has the composition of the closed-field corona, implying that it originates from the continuous opening and closing of flux at the boundary between open and closed field. On the other hand, the slow wind also has large angular width, up to {approx}60{sup 0}, suggesting that its source extends far from the open-closed boundary. We propose a model that can explain both observations. The key idea is that the source of the slow wind at the Sun is a network of narrow (possibly singular) open-field corridors that map to a web of separatrices and quasi-separatrix layers in the heliosphere. We compute analytically the topology of an open-field corridor and show that it produces a quasi-separatrix layer in the heliosphere that extends to angles far from the heliospheric current sheet. We then use an MHD code and MDI/SOHO observations of the photospheric magnetic field to calculate numerically, with high spatial resolution, the quasi-steady solar wind, and magnetic field for a time period preceding the 2008 August 1 total solar eclipse. Our numerical results imply that, at least for this time period, a web of separatrices (which we term an S-web) forms with sufficient density and extent in the heliosphere to account for the observed properties of the slow wind. We discuss the implications of our S-web model for the structure and dynamics of the corona and heliosphere and propose further tests of the model.

  1. Observations of the solar wind speed near the sun

    NASA Astrophysics Data System (ADS)

    Grall, R. R.; Coles, Wm. A.; Klinglesmith, M. T.

    1996-07-01

    Two-antenna scintillation (IPS) observations can provide accurate measurements of the velocity with which electron density fluctuations drift past the line of sight. These fluctuations can be used as tracers for the solar plasma and allow us to estimate the solar wind velocity near the Sun where spacecraft have not yet penetrated. We present recent IPS measurements made with the EISCAT and VLBA arrays. We have found that by using baselines which are several times the scale size of the diffraction pattern we are able to partially deconvolve the line of sight integration which affects remote sensing data. The long baselines allow the fast and slow components of the solar wind to be separated and their velocities estimated individually. In modeling IPS it is important that the scattering be ``weak'' because the model then requires only 1 spatial parameter instead of 3. EISCAT can only operate near 933MHz which limits the observation to outside of 18Rsolar, however the VLBA has higher frequency receivers which allow it to observe inside of 15Rsolar. The density variance δNe2 in the fast wind is a factor of 10-15 less than in the slow (Coles et al., 1995) making it necessary to consider the entire line of sight, particularly when the fast wind occupies the center portion. Using the point of closest approach and the average velocity to characterize the observation can lead to an incorrect interpretation of the data. We have compared our IPS observations with maps made from the Yohkoh soft X ray, HAO's white-light electron density, and Stanford magnetic field measurements as well as with the IMP8 and Ulysses spacecraft data to assist in placing the fast and slow wind. Here we have selected those observation from 1994 which were dominated by the southern coronal hole and have estimated a velocity acceleration profile for the fast solar wind between 7 and 100Rsolar which is presented in Figure 1. The observations suggest that the fast solar wind is fully developed by ~7

  2. Solar Wind Fluctuations and Their Consequences on the Magnetosphere

    NASA Technical Reports Server (NTRS)

    Li, Xin-Lin

    2005-01-01

    Efforts have been made to extract the physical meaning of each term in our prediction model of the Dst index using the solar wind as the only input. The work has been published Journal of Geophysical Research (Temerin and Li, 21002). We found different terms in the model representing different current in the magnetospheric system and each current has different rise and decay times, with the symmetric ring current the slowest, then the partial ring current, then the tail current. We also have been trying to understand the physical meaning of the diffusion coefficient used in our prediction model of relativistic electron fluxes at geostationary orbit. The model reproduced the observations of MeV electron flux variations well, the diffusion coefficient had be assumed only die to local magnetic field fluctuations, leading to its 10th power dependence on the L. We have studied the theoretical derivation of the diffusion coefficient and we believe that the effect electric field fluctuations at smaller L could become more significant. We have expanded our previous radiation belt electron prediction model, which predicted MeV electron geosynchronous orbit based on solar wind measurements, to predict MeV electrons inside geosynchronous orbit. The model results are compared with measurements from Polar/CEPPAD. Prediction efficiencies of 0.56 and 0.54, respectively, at L=6 and L=4, have been achieved over the entire year of 1998. This work wa reported at 2003 Fall AGU and has been accepted for publication in Space Weather (Barker et al., 2005). We also have used simultaneous measurements of the upstream solar wind and of energetic electrons at geosynchronous orbit to analyze the response of electrons over a very wide energy range, 50 keV-6MeV, to solar wind variations. Enhancements of energetic electron fluxes over this whole energy range are modulated by the solar wind speed and the polarity of the interplanetary magnetic field (IMF). The solar wind speed seems to be a

  3. Radar wind profiler observations of solar semidiurnal atmospheric tides

    SciTech Connect

    Whiteman, C.D.; Bian, X.

    1995-04-15

    Semidiurnal solar tides in the mid-latitude troposhphere are investigated using harmonic analysis of 404 MHz radar profiler wind data obtained from a wide longitude zone in the U.S. The tides are apparent above a 1000-m-deep surface layer and increase in amplitude with height, attaining speeds of 0.5-0.7 m/s at 5-7 km. Observed wind characteristics agree well with tidal characteristics obtained with a dynamical model driven by observed global semidiurnal horizontal pressure gradients. 10 refs., 6 figs., 1 tab.

  4. A STATISTICAL SURVEY OF DYNAMIC PRESSURE PULSES IN THE SOLAR WIND BASED ON WIND OBSERVATIONS

    SciTech Connect

    Zuo, Pingbing; Feng, Xueshang; Wang, Yi; Xie, Yanqiong; Xu, Xiaojun E-mail: fengx@spaceweather.ac.cn

    2015-07-20

    Solar wind dynamic pressure pulse (DPP) structures, across which the dynamic pressure changes abruptly over timescales from a few seconds to several minutes, are often observed in the near-Earth space environment. The space weather effects of DPPs on the magnetosphere–ionosphere coupling system have been widely investigated in the last two decades. In this study, we perform a statistical survey on the properties of DPPs near 1 AU based on nearly 20 years of observations from the WIND spacecraft. It is found that only a tiny fraction of DPPs (around 4.2%) can be regarded as interplanetary shocks. For most DPPs, the total pressure (the sum of the thermal pressure and magnetic pressure) remains in equilibrium, but there also exists a small fraction of DPPs that are not pressure-balanced. The overwhelming majority of DPPs are associated with solar wind disturbances, including coronal mass ejection-related flows, corotating interaction regions, as well as complex ejecta. The annual variations of the averaged occurrence rate of DPPs are roughly in phase with the solar activity during solar cycle 23, and during the rising phase of solar cycle 24.

  5. Reconstruction of Helio-Latitudinal Structure of the Solar Wind Proton Speed and Density

    NASA Astrophysics Data System (ADS)

    Sokół, Justyna M.; Swaczyna, Paweł; Bzowski, Maciej; Tokumaru, Munetoshi

    2015-09-01

    The modeling of the heliosphere requires continuous three-dimensional solar wind data. The in-situ out-of-ecliptic measurements are very rare, so that other methods of solar wind detection are needed. We use the remote-sensing data of the solar wind speed from observations of interplanetary scintillation (IPS) to reconstruct spatial and temporal structures of the solar wind proton speed from 1985 to 2013. We developed a method of filling the data gaps in the IPS observations to obtain continuous and homogeneous solar wind speed records. We also present a method to retrieve the solar wind density from the solar wind speed, utilizing the invariance of the solar wind dynamic pressure and energy flux with latitude. To construct the synoptic maps of the solar wind speed we use the decomposition into spherical harmonics of each of the Carrington rotation map. To fill the gaps in time we apply the singular spectrum analysis to the time series of the coefficients of spherical harmonics. We obtained helio-latitudinal profiles of the solar wind proton speed and density over almost three recent solar cycles. The accuracy in the reconstruction is, due to computational limitations, about 20 %. The proposed methods allow us to improve the spatial and temporal resolution of the model of the solar wind parameters presented in our previous paper (Sokół et al., Solar Phys. 285, 167, 2013) and give a better insight into the time variations of the solar wind structure. Additionally, the solar wind density is reconstructed more accurately and it fits better to the in-situ measurements from Ulysses.

  6. The solar origins of solar wind interstream flows - Near-equatorial coronal streamers

    NASA Technical Reports Server (NTRS)

    Feldman, W. C.; Asbridge, J. R.; Bame, S. J.; Fenimore, E. E.; Gosling, J. T.

    1981-01-01

    A class of low-speed solar wind flows with velocities of 450 km/s and less, ion temperatures of 40,000 K and less, and heavy ion distributions indicating moderate coronal freezing in temperatures in the range from 1 million to 2.5 millions K is considered. For brevity this class is termed interstream. Interstream flows have as yet, not firm identification with a coronal origin. The considered investigation is concerned with the identification of the coronal origins of interstream flows. It is found that major sources of low speed solar wind are the quiescent, near-equatorial coronal streamers. Such an identification provides a natural explanation for the long term variations of solar wind electron temperature and density observed at 1 AU by Feldman et al. (1979) in terms of the concurrent long term morphological variation in the coronal equatorial streamer belt observed using the Mauna Loa K-coronameters.

  7. Sheath-limited unipolar induction in the solar wind. [plasma interactions with solar system bodies

    NASA Technical Reports Server (NTRS)

    Srnka, L. J.

    1975-01-01

    A model of the steady-state interaction between the solar wind and an electrically conducting body having neither an atmosphere nor an intrinsic magnetic field sufficient enough to deflect the plasma flow is presented which considers some effects of a plasma surface sheath on unipolar induction. The Sonett-Colburn (1967, 1968) unipolar dynamo model is reviewed, and it is noted that the unipolar dynamo response of an electrically conducting body in the solar wind's motional field can be controlled by sheath effects in certain cases where the body radius is less than a certain critical value. It is shown that sheath effects do not limit the unipolar response of the moon or Mercury since their body radii are much larger than their critical radii. Sheath effects are also considered for asteroids, the Martian satellites, the irregular Jovian satellites, the outer satellites of Saturn, and meteorite parent bodies in a primordial enhanced solar wind.

  8. Solar winds surfs waves in the Sun's atmosphere!

    NASA Astrophysics Data System (ADS)

    1999-06-01

    The fact that this electrified plasma speeds up to almost 3 million kilometres per hour as it leaves the Sun - twice as fast as originally predicted - has been known for years. The interpretation of how it happens is the real and surprising novelty: "The waves in the Sun's atmosphere are produced by vibrating solar magnetic field lines, which give solar wind particles a push just like an ocean wave gives a surfer a ride" said Dr John Kohl, principal investigator for the Ultraviolet Coronal Spectrometer (UVCS) - the instrument among the 12 aboard SOHO which gathered the data - and for the Spartan 201 mission. The outermost solar atmosphere, or corona, is only seen from Earth during a total eclipse of the Sun, when it appears as a shimmering, white veil surrounding the black lunar disc. The corona is an extremely tenuous, electrically charged gas, known as plasma, that flows throughout the solar system as the solar wind. The waves are formed by rapidly vibrating magnetic fields in the coronal plasma. They are called magneto - hydro - dynamic (MHD) waves and are believed to accelerate the solar wind. The solar wind is made up of electrons and ions, electrically charged atoms that have lost electrons. The electric charge of the solar wind particles forces them to travel along invisible lines of magnetic force in the corona. The particles spiral around the magnetic field lines as they rush into space. "The magnetic field acts like a violin string: when it's touched, it vibrates. When the Sun's magnetic field vibrates with a frequency equal to that of the particle spiraling around the magnetic field, it heats it up, producing a force that accelerates the particle upward and away from the Sun," says Dr. Ester Antonucci, an astronomer at the observatory of Turin, Italy, and co-investigator for SOHO's UVCS an instrument developed with considerable financial support by the Italian Space Agency, ASI. In a way this is similar to what happens if two people hold a string at

  9. Solar winds surfs waves in the Sun's atmosphere!

    NASA Astrophysics Data System (ADS)

    1999-07-01

    The fact that this electrified plasma speeds up to almost 3 million kilometres per hour as it leaves the Sun - twice as fast as originally predicted - has been known for years. The interpretation of how it happens is the real and surprising novelty: "The waves in the Sun's atmosphere are produced by vibrating solar magnetic field lines, which give solar wind particles a push just like an ocean wave gives a surfer a ride" said Dr John Kohl, principal investigator for the Ultraviolet Coronal Spectrometer (UVCS) - the instrument among the 12 aboard SOHO which gathered the data - and for the Spartan 201 mission. The outermost solar atmosphere, or corona, is only seen from Earth during a total eclipse of the Sun, when it appears as a shimmering, white veil surrounding the black lunar disc. The corona is an extremely tenuous, electrically charged gas, known as plasma, that flows throughout the solar system as the solar wind. The waves are formed by rapidly vibrating magnetic fields in the coronal plasma. They are called magneto - hydro - dynamic (MHD) waves and are believed to accelerate the solar wind. The solar wind is made up of electrons and ions, electrically charged atoms that have lost electrons. The electric charge of the solar wind particles forces them to travel along invisible lines of magnetic force in the corona. The particles spiral around the magnetic field lines as they rush into space. "The magnetic field acts like a violin string: when it's touched, it vibrates. When the Sun's magnetic field vibrates with a frequency equal to that of the particle spiraling around the magnetic field, it heats it up, producing a force that accelerates the particle upward and away from the Sun," says Dr. Ester Antonucci, an astronomer at the observatory of Turin, Italy, and co-investigator for SOHO's UVCS an instrument developed with considerable financial support by the Italian Space Agency, ASI. In a way this is similar to what happens if two people hold a string at

  10. Solar Rotational Periodicities and the Semiannual Variation in the Solar Wind, Radiation Belt, and Aurora

    NASA Technical Reports Server (NTRS)

    Emery, Barbara A.; Richardson, Ian G.; Evans, David S.; Rich, Frederick J.; Wilson, Gordon R.

    2011-01-01

    The behavior of a number of solar wind, radiation belt, auroral and geomagnetic parameters is examined during the recent extended solar minimum and previous solar cycles, covering the period from January 1972 to July 2010. This period includes most of the solar minimum between Cycles 23 and 24, which was more extended than recent solar minima, with historically low values of most of these parameters in 2009. Solar rotational periodicities from S to 27 days were found from daily averages over 81 days for the parameters. There were very strong 9-day periodicities in many variables in 2005 -2008, triggered by recurring corotating high-speed streams (HSS). All rotational amplitudes were relatively large in the descending and early minimum phases of the solar cycle, when HSS are the predominant solar wind structures. There were minima in the amplitudes of all solar rotational periodicities near the end of each solar minimum, as well as at the start of the reversal of the solar magnetic field polarity at solar maximum (approx.1980, approx.1990, and approx. 2001) when the occurrence frequency of HSS is relatively low. Semiannual equinoctial periodicities, which were relatively strong in the 1995-1997 solar minimum, were found to be primarily the result of the changing amplitudes of the 13.5- and 27-day periodicities, where 13.5-day amplitudes were better correlated with heliospheric daily observations and 27-day amplitudes correlated better with Earth-based daily observations. The equinoctial rotational amplitudes of the Earth-based parameters were probably enhanced by a combination of the Russell-McPherron effect and a reduction in the solar wind-magnetosphere coupling efficiency during solstices. The rotational amplitudes were cross-correlated with each other, where the 27 -day amplitudes showed some of the weakest cross-correlations. The rotational amplitudes of the > 2 MeV radiation belt electron number fluxes were progressively weaker from 27- to 5-day periods

  11. Nitrogen isotope abundances in the recent solar wind.

    PubMed

    Kim, J S; Kim, Y; Marti, K; Kerridge, J F

    1995-06-01

    Although lunar crystalline rocks are essentially devoid of nitrogen, the same is not true of the lunar regolith. The nitrogen contents of individual regolith samples (which can be as high as 0.012% by mass) correlate strongly with abundances of noble gases known to be implanted in the lunar surface by solar radiation, indicating that lunar regolith nitrogen is also predominantly of solar origin. The large variability in 15N/14N ratios measured in different regolith samples may thus reflect long-term changes in the isotopic composition of the solar radiation. But attempts to explain these variations have been hampered by the lack of any firm constraint on 15N/14N in the present solar wind. Here we report measurements of nitrogen isotopes from two lunar samples that have had simple (and relatively recent) exposure histories. We find that nitrogen implanted in the lunar surface during the past 10(5) to 5 x 10(7) years has a 15N/14N ratio approximately 40% higher than that in the terrestrial atmosphere, which is substantially lower than most previous estimates. This isotopic signature probably represents the best measure of 15N/14N in the present-day solar wind.

  12. Conversion of magnetic field energy into kinetic energy in the solar wind

    NASA Technical Reports Server (NTRS)

    Whang, Y. C.

    1972-01-01

    The outflow of the solar magnetic field energy (the radial component of the Poynting vector) per steradian is inversely proportional to the solar wind velocity. It is a decreasing function of the heliocentric distance. When the magnetic field effect is included in the one-fluid model of the solar wind, the transformation of magnetic field energy into kinetic energy during the expansion process increases the solar wind velocity at 1 AU by 17 percent.

  13. Laser Subdivision of the Genesis Concentrator Target Sample 60000

    NASA Technical Reports Server (NTRS)

    Lauer, Howard V., Jr.; Burkett, P. J.; Rodriquez, M. C.; Nakamura-Messenger, K.; Clemett, S. J.; Gonzales, C. P.; Allton, J. H.; McNamara, K. M.; See, T. H.

    2013-01-01

    The Genesis Allocation Committee received a request for 1 square centimeter of the diamond-like-carbon (DLC) concentrator target for the analysis of solar wind nitrogen isotopes. The target consists of a single crystal float zone (FZ) silicon substrate having a thickness on the order of 550 micrometers with a 1.5-3.0 micrometer-thick coating of DLC on the exposed surface. The solar wind is implanted shallowly in the front side DLC. The original target was a circular quadrant with a radius of 3.1 cm; however, the piece did not survive intact when the spacecraft suffered an anomalous landing upon returning to Earth on September 8, 2004. An estimated 75% of the DLC target was recovered in at least 18 fragments. The largest fragment, Genesis sample 60000, has been designated for this allocation and is the first sample to be subdivided using our laser scribing system Laser subdivision has associated risks including thermal diffusion of the implant if heating occurs and unintended breakage during cleavage. A careful detailed study and considerable subdividing practice using non-flight FZ diamond on silicon, DOS, wafers has considerably reduced the risk of unplanned breakage during the cleaving process. In addition, backside scribing reduces the risk of possible thermal excursions affecting the implanted solar wind, implanted shallowly in the front side DLC.

  14. Solar wind iron abundance variations at solar wind speeds up to 600 km s sup -1, 1972 to 1976

    NASA Technical Reports Server (NTRS)

    Mitchell, D. G.; Roelof, E. C.; Bame, S. J.

    1982-01-01

    The Fe/H ratios in the peaks of high speed streams (HSS) were analyzed during the decline of Solar Cycle 20 and the following minimum (October 1972 to December 1976). The response of the 50 to 200 keV ion channel of the APL/JHU energetic particle experiment (EPE) on IMP-7 and 8 was utilized to solar wind iron ions at high solar wind speeds (V or = 600 km/sec). Fe measurements with solar wind H and He parameters were compared from the Los Alamos National Laboratory (LANL) instruments on the same spacecraft. In general, the Fe distribution parameters (bulk velocity, flow direction, temperature) are found to be similar to the LANL He parameters. Although the average Fe/H ration in many steady HSS peaks agrees within observational uncertainties with the nominal coronal ratio of 4.7 x 0.00001, abundance variations of a factor of up to 6 are obtained across a given coronal-hole associated HSS.

  15. Impact of solar wind tangential discontinuities on the Earth's magnetosphere

    NASA Astrophysics Data System (ADS)

    Grib, S. A.

    2012-12-01

    The collision of a solar wind tangential discontinuity with the bow shock and magnetopause is considered in the scope of an MHD approximation. Using MHD methods of trial calculations and generalized shock polars, it has been indicated that a fast shock refracted into the magnetosheath originates when density increases across a tangential discontinuity and a fast rarefaction wave is generated when density decreases at this discontinuity. It has been indicated that a shock front shift under the action of collisions with a tangential discontinuity is experimentally observed and a fast bow shock can be transformed into a slow shock. Using a specific event as an example, it has been demonstrated that solar wind tangential discontinuity affects the geomagnetic field behavior.

  16. Solar Wind Turbulent Spectrum at Plasma Kinetic Scales

    NASA Astrophysics Data System (ADS)

    Alexandrova, O.; Lacombe, C.; Mangeney, A.; Grappin, R.; Maksimovic, M.

    2012-12-01

    The description of the turbulent spectrum of magnetic fluctuations in the solar wind in the kinetic range of scales is not yet completely established. Here, we perform a statistical study of 100 spectra measured by the STAFF instrument on the Cluster mission, which allows us to resolve turbulent fluctuations from ion scales down to a fraction of electron scales, i.e., from ~102 km to ~300 m. We show that for k ρ e in [0.03, 3] (which corresponds approximately to the frequency in the spacecraft frame f in [3, 300] Hz), all the observed spectra can be described by a general law E(k )vpropk -8/3 exp (- k ρ e ), where k is the wavevector component normal to the background magnetic field and ρ e the electron Larmor radius. This exponential tail found in the solar wind seems compatible with the Landau damping of magnetic fluctuations onto electrons.

  17. Numerical simulation of MHD shock waves in the solar wind

    NASA Technical Reports Server (NTRS)

    Steinolfson, R. S.; Dryer, M.

    1978-01-01

    The effects of the interplanetary magnetic field on the propagation speed of shock waves through an ambient solar wind are examined by numerical solutions of the time-dependent nonlinear equations of motion. The magnetic field always increases the velocity of strong shocks. Although the field may temporarily slow down weak shocks inside 1 AU, it eventually also causes weak shocks to travel faster than they would without the magnetic field at larger distances. Consistent with the increase in the shock velocity, the gas pressure ratio across a shock is reduced considerably in the presence of the magnetic field. The numerical method is used to simulate (starting at 0.3 AU) the large deceleration of a shock observed in the lower corona by ground-based radio instrumentation and the more gradual deceleration of the shock in the solar wind observed by the Pioneer 9 and Pioneer 10 spacecraft.

  18. Identification of the Coronal Sources of the Fast Solar Wind.

    PubMed

    Giordano; Antonucci; Noci; Romoli; Kohl

    2000-03-01

    The present spectroscopic study of the ultraviolet coronal emission in a polar hole, detected on 1996 April 6-9 with the Ultraviolet Coronagraph Spectrometer aboard the Solar and Heliospheric Observatory spacecraft, identifies the interplume lanes and background coronal hole regions as the channels in which the fast solar wind is preferentially accelerated. In interplume lanes, at heliocentric distance 1.7 R middle dot in circle, the corona expands at a rate between 105 and 150 km s-1, that is, much faster than in plumes in which the outflow velocity is between 0 and 65 km s-1. The wind velocity is inferred from the Doppler dimming of the O vi lambdalambda1032, 1037 lines, within a range of values, whose lower and upper limit corresponds to anisotropic and isotropic velocity distribution of the oxygen coronal ions, respectively.

  19. Mass fractionation of the lunar surface by solar wind sputtering

    NASA Technical Reports Server (NTRS)

    Switkowski, Z. E.; Haff, P. K.; Tombrello, T. A.; Burnett, D. S.

    1975-01-01

    The sputtering of the lunar surface by the solar wind is examined as a possible mechanism of mass fractionation. Simple arguments based on current theories of sputtering and the ballistics of the sputtered atoms suggest that most ejected atoms will have sufficiently high energy to escape lunar gravity. However, the fraction of atoms which falls back to the surface is enriched in the heavier atomic components relative to the lighter ones. This material is incorporated into the heavily radiation-damaged outer surfaces of grains where it is subject to resputtering. Over the course of several hundred years an equilibrium surface layer, enriched in heavier atoms, is found to form. The dependence of the calculated results upon the sputtering rate and on the details of the energy spectrum of sputtered particles is investigated. It is concluded that mass fractionation by solar wind sputtering is likely to be an important phenomenon on the lunar surface.

  20. Scaling of Compressible Magnetohydrodynamic Turbulence in the Fast Solar Wind

    NASA Astrophysics Data System (ADS)

    Banerjee, S.; Hadid, L. Z.; Sahraoui, F.; Galtier, S.

    2016-10-01

    The role of compressible fluctuations in the energy cascade of fast solar wind turbulence is studied using a reduced form of an exact law derived recently for compressible isothermal magnetohydrodynamics and in situ observations from the THEMIS B/ARTEMIS P1 spacecraft. A statistical survey of the data revealed a turbulent energy cascade over a range of two decades of scales that is broader than the previous estimates made from an exact incompressible law. A term-by-term analysis of the compressible model reveals new insight into the role played by the compressible fluctuations in the energy cascade. The compressible fluctuations are shown to amplify by two to four times the turbulent cascade rate with respect to the incompressible model in ∼ 10 % of the analyzed samples. This new estimated cascade rate is shown to provide the adequate energy dissipation required to account for the local heating of the non-adiabatic solar wind.

  1. Solar wind and micrometeorite effects in the lunar regolith

    NASA Technical Reports Server (NTRS)

    Housley, R. M.

    1977-01-01

    Using available data from the literature, an outline is formulated for the major physical and chemical effects expected during solar-wind bombardment of the lunar regolith. In agreement with results of Auger and other analyses of the composition of lunar grain surfaces, this outline predicts that solar-wind sputtering will tend to clean exposed grain surfaces by ejecting material at velocities exceeding lunar escape velocity. Results are also discussed which show that Fe is partially reduced in the outer few 10 nm of grain surfaces and that this reduced Fe forms 10-nm-diameter metal spheres throughout the glass during agglutinate formation by micrometeorite impacts. These metal spheres give the agglutinates their distinctive optical and magnetic properties and are partially responsible for the decreasing albedo of the lunar surface with exposure age.

  2. Coronal sources of the intrastream structure of the solar wind

    NASA Technical Reports Server (NTRS)

    Sullivan, J. D.; Bridge, H. S.

    1983-01-01

    Short time scale changes in the bulk speed were found not to coincide with X-ray transients near the sub-earth point nor with the number of X-ray bright points within a coronal hole and near the equator. The changes in bulk speed, it is shown, are associated with changes in light areas in a hole which may be associated with the opening or closing of magnetic field lines within the coronal hole. That there is a causal connection between these sudden changes (apperance or disappearance) in light area and sudden changes in the bulk speed of the solar wind is further evidenced by the spatial proximity on the Sun of these changing light regions to the source position of stream lines from Levine's model that connect into the same solar wind streams.

  3. Electrodynamics of solar wind-magnetosphere-ionosphere interactions

    SciTech Connect

    Kan, J.R.; Akasofu, S.I.

    1989-04-01

    Significant progress has been made in the last two decades in understanding the workings of the solar wind-magnetosphere-ionosphere (SW-M-I) coupling system. In this paper the authors present a coherent picture of fundamental physical processes in three basic elements of the SW-M-I coupling system: (i) The field-aligned potential structure which leads to the formation of auroral arcs; (ii) the magnetosphere-ionosphere coupling which leads to the onset of magnetospheric substorms, and (iii) the solar wind-magnetosphere dynamo which supplies the power for driving various magnetospheric processes. Future research efforts to improve our understanding of the SW-M-I coupling processes should focus on integrating these three elements into a single quantitative model.

  4. THREE-DIMENSIONAL STRUCTURE OF SOLAR WIND TURBULENCE

    SciTech Connect

    Chen, C. H. K.; Bale, S. D.; Mallet, A.; Schekochihin, A. A.; Horbury, T. S.; Wicks, R. T.

    2012-10-20

    We present a measurement of the scale-dependent, three-dimensional structure of the magnetic field fluctuations in inertial range solar wind turbulence with respect to a local, physically motivated coordinate system. The Alfvenic fluctuations are three-dimensionally anisotropic, with the sense of this anisotropy varying from large to small scales. At the outer scale, the magnetic field correlations are longest in the local fluctuation direction, consistent with Alfven waves. At the proton gyroscale, they are longest along the local mean field direction and shortest in the direction perpendicular to the local mean field and the local field fluctuation. The compressive fluctuations are highly elongated along the local mean field direction, although axially symmetric perpendicular to it. Their large anisotropy may explain why they are not heavily damped in the solar wind.

  5. Kinetic theory analysis of solar wind interaction with planetary objects

    NASA Technical Reports Server (NTRS)

    Wu, S. T.; Dryer, M.

    1973-01-01

    A purely kinetic treatment is proposed for the interaction of the solar wind with any small planetary object. Small refers to those cases where the solar wind proton's thermal gyroradius is arbitrarily taken to be greater than 0.1 radius of the object under investigation. The 'object' may possibly include an ionosphere or magnetosphere. The collisionless Boltzmann equation, neglecting the magnetic field, is used to calculate steady-state profiles of density and velocity around the obstacle. A low density plasma void in the umbral region and a compression in the penumbral region are clearly found. The present technique, despite its neglect of the interplanetary magnetic field, is proposed as an alternative zeroth order approach to the continuum, local magnetic anomaly, and guiding center approaches used by others for the particular case of moon. Some recent, potentially relevant, observations on and in front of the moon are discussed.

  6. Solar wind collimation of the Jupiter high velocity dust streams

    NASA Astrophysics Data System (ADS)

    Flandes, A.; Krueger, H.

    2006-12-01

    The dust bursts discovered by the Ulysses dust sensor when approaching Jupiter in 1992 were later confirmed as collimated streams of high velocity (~200 km/s) charged (~5V) dust grains escaping from Jupiter and dominated by the interplanetary Magnetic field (IMF). With Cassini, a similar phenomenon was observed in Saturn. It was demonstrated that the Jovian dust streams are closely related to the solar wind compressed regions, either Corotating interaction regions (CIRs) or Coronal mass ejections (CMEs) ¨Cto a minor extent-. Actually the dust streams seem ultimately to be generated by such events. This can be explained considering that dust grains are accelerated as they gain substantial energy while compressed at the forward and reverse shocks that bound or precede these solar wind regions.

  7. Solar Wind Influence on the Oxygen Content of Ion Outflow in the High Altitude Polar Cap During Solar Minimum Conditions

    NASA Technical Reports Server (NTRS)

    Elliott, Heather A.; Comfort, Richard H.; Craven, Paul D.; Chandler, Michael O.; Moore, Thomas E.

    2000-01-01

    We correlate solar wind and IMF properties with the properties of O(+) and H(+) in the polar cap in early 1996 during solar minimum conditions at altitudes between 5.5 and 8.9 Re geocentric using the Thermal Ion Dynamics Experiment (TIDE) on the POLAR satellite. Throughout the high altitude polar cap, we observe H(+) to be more abundant than O(+). H(+) is a significant fraction of both the ionosphere and the solar wind, and O(+) is not a significant species in the solar wind. O(+) is the major species in the ionosphere so the faction of O(+) present in the magnetosphere is commonly used as a measure of the ionospheric contribution to the magnetosphere. For these reasons, 0+ is of primary interest in this study. We observe O(+) to be most abundant at lower latitudes when the solar wind speed is low (and low Kp), and at higher solar wind speeds (and high Kp) O(+) is observed across most of the polar cap. We also find that O(+) density and parallel flux are well organized by solar wind dynamic pressure; they both increase with solar wind dynamic pressure. H(+) is not as highly correlated with solar wind and IMF parameters, but H(+) density and parallel flux have some negative correlation with IMF By, and some positive correlation with VswBIMF. In this solar minimum data set, H(+) is dominant so that contributions of this plasma to the plasma sheet would have a very low O(+) to H(+) ratio.

  8. A desalination plant with solar and wind energy

    NASA Astrophysics Data System (ADS)

    Chen, H.; Ye, Z.; Gao, W.

    2013-12-01

    The shortage of freshwater resources has become a worldwide problem. China has a water shortage, although the total amount of water resources is the sixth in the world, the per capita water capacity is the 121th (a quarter of the world's per capita water capacity), and the United Nations considers China one of the poorest 13 countries in the world in terms of water. In order to increase the supply of fresh water, a realistic way is to make full use of China's long and narrow coastline for seawater desalination. This paper discusses a sea water desalination device, the device adopts distillation, uses the greenhouse effect principle and wind power heating principle, and the two-type start is used to solve the problem of vertical axis wind turbine self-starting. Thrust bearings are used to ensure the stability of the device, and to ensure absorbtion of wind energy and solar energy, and to collect evaporation of water to achieve desalination. The device can absorb solar and wind energy instead of input energy, so it can be used in ship, island and many kinds of environment. Due to the comprehensive utilization of wind power and solar power, the efficiency of the device is more than other passive sea water desalting plants, the initial investment and maintenance cost is lower than active sea water desalting plant. The main part of the device cannot only be used in offshore work, but can also be used in deep sea floating work, so the device can utilise deep sea energy. In order to prove the practicability of the device, the author has carried out theory of water production calculations. According to the principle of conservation of energy, the device ais bsorbing solar and wind power, except loose lost part which is used for water temperature rise and phase transition. Assume the inflow water temperature is 20 °C, outflow water temperature is 70 °C, the energy utilization is 60%, we can know that the water production quantity is 8 kg/ m2 per hour. Comparing with the

  9. Langmuir Turbulence in the Solar Wind : Numerical Simulations

    NASA Astrophysics Data System (ADS)

    Krafft, C.; Volokitin, A.; Krasnoselskikh, V.

    2014-12-01

    Observations performed in the solar wind by different satellites show that electron beams accelerated in the low corona during solar flares can propagate up to distances around 1 AU, that Langmuir waves' packets can be clumped into spikes with peak amplitudes three orders of magnitude above the mean and that the average level of density fluctuations in the solar wind plasmas can reach several percents. A Hamiltonian model is built describing the properties of Langmuir waves propagating in a plasma with random density fluctuations by the Zakharov's equations and the beam by means of particles moving self-consistently in the fields of the waves. Numerical simulations, performed using parameters relevant to solar type III conditions at 1 AU, show that when the average level of density fluctuations is sufficiently low, the beam relaxation and the wave excitation processes are similar to those in a homogeneous plasma and can be described by the quasilinear equations of the weak turbulence theory. On the contrary, when the average level of density fluctuations overcomes some threshold depending on the ratio of the thermal velocity to the beam velocity, the plasma inhomogeneities crucially influence on the characteristics of the Langmuir turbulence and the beam-plasma interaction. In this case, fluxes of accelerated particles are observed, whose density and kinetic energy can be calculated as a function of the beam and plasma characteristics. Langmuir waveforms are presented in the form they would appear if recorded by a satellite moving in the solar wind. Comparison with recent measurements by the STEREO and WIND satellites shows that their characteristic features are very similar to the observations. Moreover, wave-wave coupling and three wave decay processes are studied as a function of the average level of plasma density fluctuations. References Volokitin, V. V. Krasnoselskikh, C. Krafft, and E. Kuznetsov, Modelling of the beam-plasma interaction in a strongly

  10. Substorm probabilities are best predicted from solar wind speed

    NASA Astrophysics Data System (ADS)

    Newell, P. T.; Liou, K.; Gjerloev, J. W.; Sotirelis, T.; Wing, S.; Mitchell, E. J.

    2016-08-01

    Most measures of magnetospheric activity - including auroral power (AP), magnetotail stretching, and ring current intensity - are best predicted by solar wind-magnetosphere coupling functions which approximate the frontside magnetopause merging rate. However radiation belt fluxes are best predicted by a simpler function, namely the solar wind speed, v. Since most theories of how these high energy electrons arise are associated with repeated rapid dipolarizations such as associated with substorms, this apparent discrepancy could be reconciled under the hypothesis that the frequency of substorms tracks v rather than the merging rate - despite the necessity of magnetotail flux loading prior to substorms. Here we investigate this conjecture about v and substorm probability. Specifically, a continuous list of substorm onsets compiled from SuperMAG covering January 1, 1997 through December 31, 2007 are studied. The continuity of SuperMAG data and near continuity of solar wind measurements minimize selection bias. In fact v is a much better predictor of onset probability than is the overall merging rate, with substorm odds rising sharply with v. Some loading by merging is necessary, and frontside merging does increase substorm probability, but nearly as strongly as does v taken alone. Likewise, the effects of dynamic pressure, p, are smaller than simply v taken by itself. Changes in the solar wind matter, albeit modestly. For a given level of v (or Bz), a change in v (or Bz) will increase the odds of a substorm for at least 2 h following the change. A decrease in driving elevates substorm probabilities to a greater extent than does an increase, partially supporting external triggering. Yet current v is the best single predictor of subsequently observing a substorm. These results explain why geomagnetically quiet years and active years are better characterized by low or high v (respectively) than by the distribution of merging estimators. It appears that the flow of energy

  11. Interpretation of Solar Wind Ion Composition Measurements from ULYSSES

    NASA Astrophysics Data System (ADS)

    Esser, Ruth

    1996-02-01

    Knowledge of the plasma conditions in the inner corona is essential for solar wind modeling since any attempt to explain the expansion of the solar wind plasma depends on information in the inner corona to select and constrain the solar wind expansion models. Of particular interest are the temperatures of the different particle species. The temperatures of protons and heavy ions such as oxygen can only be derived from measurements of spectral lines. As the width of spectral lines reflects both thermal and non-thermal random motions only an upper limit can be placed on the temperature of these particles. The electron temperature on the other hand can be derived from measurements of spectral line intensities by comparing the measured line ratios to the ratios calculated from theoretical models, and from in situ charge state measurements. The idea is that the charge state of the considered element is a function of the local electron temperature only, and that the charge state 'freezes in' at a certain heliocentric distance and remains constant beyond that distance. Therefore, the in situ charge state ratio reflects the electron temperature in the inner corona. In deriving these charge state temperatures it is assumed that all elements and charge states have the same flow speed and the same temperature. Also inherent in these temperature estimates is the assumption that the electron velocity distribution function is Maxwellian. The effect of non-Maxwellian velocity distribution functions and differential flow speeds have been discussed in Owocki and Scudder (1983) and Esser and Leer (1990), respectively. Since the message carried by the charge states is obscured by these different assumptions, model calculations are necessary to extract the desired information from the observations. The goal of the funded study is to develop the necessary solar wind models, and to compare the derived electron temperatures to those derived from spectral line intensity measurements

  12. (abstract) Ulysses Observations of Magnetic Nulls in the Solar Wind

    NASA Technical Reports Server (NTRS)

    Winterhalter, D.; Murphy, N.; Tsurutani, B. T.; Smith, E. J.; Balogh, A.; Erdos, G.

    1993-01-01

    High time resolution magnetic field measurements (1 vector/s) at radial distances out to 5.3 AU and heliographic latitudes from 0(deg) to > 35(deg) S reveal the presence of solitary pulses lasting tens of seconds in which the field magnitude approaches or reaches zero. The properties of these nulls, their spatial distribution and relation to solar wind structures and to similar-apppearing interplanetary and magnetospheric impulses will be discussed.

  13. OMNI: A Description of Near-Earth Solar Wind Environment

    NASA Astrophysics Data System (ADS)

    Papitashvili, Natasha; Bilitza, Dieter; King, Joseph

    OMNI is an hourly resolution multi-source data set of near-Earth solar wind's magnetic field and plasma parameters spanning the period from November 1963 (IMP 1 launch) to today, and it is being updated regularly with new data. OMNI is widely used in the heliospheric community as is documented by the large number of acknowledgements in scientific papers. OMNI provides the IMF (magnitude and vector), flow velocity (magnitude and vector), flow pressure, proton density, alpha particle to proton density ratio, and several additional parameters including sunspot and geomagnetic indices and energetic proton fluxes from IMP and GOES. Spacecraft data used for compiling the OMNI solar wind reference include IMP-8, ACE, Wind, ISEE-3, and Geotail. The data from ISEE-3, Wind, and ACE were time-shifted because they are about an hour upstream of the Earth's magnetosphere. Extensive quality control and cross- comparisons of overlapping data sets were made in creating OMNI. This presentation will describe the OMNI data set and highlight its wide use in the space science community. We will also present some of the many capabilities of the OMNIweb interface (http://omniweb.gsfc.nasa.gov/ow.html) that provides access to the entire OMNI data set. OMNIWeb allows users to generate plots vs. time, to create scatter plots of any two OMNI parameters, to filter with user-specified parameter range criteria, to list and download OMNI parameters, to generate distributions of OMNI parameter values, and to browse and retrieve a static (but periodically updated) daily-resolution IMF polarity plot covering the entire OMNI time span. The Omni data set represents a thorough description of various characteristics of near-Earth solar wind magnetic field and plasma, which could be used as a basis for that space environment's standard.

  14. Ionic Composition and Electron Heating in the Fast Solar Wind

    NASA Astrophysics Data System (ADS)

    Lepri, Susan T.; Laming, J. M.

    2006-06-01

    In-situ observations of charge states of fast solar wind ions reveal higher average charges than the coronal hole source regions as derived from spectroscopy, implying that some extra electron heating and ionization must have occurred in the wind acceleration region prior to freeze-in. We present an extensive analysis of Ulysses and ACE charge state data near the boundaries of different coronal holes, and from different regions within coronal holes to compare with the predictions of a model by Laming (2004). In this model, electrons are heated by lower-hybrid waves, which are in turn generated by solar wind ions gyrating in cross-B density gradients. The observed charge states place constraints on the steepness and ubiquity of cross-field density gradients, which may arise as the end-result of MHD turbulent cascade.In this talk we give a brief overview of the subject and highlight our important findings. We find that, in general, oxygen and carbon charge states behave similarly in both equatorial and polar coronal holes. The charge states of both are lower in the coronal holes than in the solar wind, as previously reported by in-situ studies. For heavier ions, such as silicon and iron, there is not an appreciable difference between the ionic composition outside of coronal holes and at different regions inside of coronal holes. This may be due to processes that take place further out in the corona where these heavier ions freeze-in. We find slightly lower ionic charge states in the fast wind that have been previously reported, which reduces the amount of electron heating required. This work is sponsored by grants from the NSF and NASA.

  15. Magnetic dips in the solar wind

    NASA Technical Reports Server (NTRS)

    Dobrowolny, M.; Bavassano, B.; Mariani, F.; Ness, N.; Burlaga, L. F.

    1978-01-01

    Using magnetic data from the HELIOS 1 fluxgate magnetometer, with a 0.2 sec resolution, the structures of several interplanetary discontinuities involving magnetic dips and rotations of the magnetic field vector were investigated. A minimum variance analysis illustrates the behavior of the magnetic field through the transition in the plane of its maximum variation. Using this analysis, quite different structures have been individuated and, in particular, narrow transitions resembling almost one dimensional reconnected neutral sheets. For the thinner cases (scale lengths of the magnetic rotation of the order or smaller than 1,000 km), results show the observed structures could be the nonlinear effect of a resistive tearing mode instability having developed on an originally one dimensional neutral sheet at the solar corona.

  16. Solar Wind Plasma Flows and Space Weather Aspects Recent Solar Cycle

    NASA Astrophysics Data System (ADS)

    Kaushik, Sonia; Kaushik, Subhash Chandra

    2016-07-01

    Solar transients are responsible for initiating short - term and long - term variations in earth's magnetosphere. These variations are termed as geomagnetic disturbances, and driven by the interaction of solar wind features with the geo-magnetosphere. The strength of this modulation process depends upon the magnitude and orientation of the Interplanetary Magnetic Field and solar wind parameters. These interplanetary transients are large scale structures containing plasma and magnetic field expelled from the transient active regions of solar atmosphere. As they come to interplanetary medium the interplanetary magnetic field drape around them. This field line draping was thought as possible cause of the characteristic eastward deflection and giving rise to geomagnetic activities as well as a prime factor in producing the modulation effects in the near Earth environment. The Solar cycle 23 has exhibited the unique extended minima and peculiar effects in the geomagnetosphere. Selecting such transients, occurred during this interval, an attempt has been made to determine quantitative relationships of these transients with solar/ interplanetary and Geophysical Parameters. In this work we used hourly values of IMF data obtained from the NSSD Center. The analysis mainly based on looking into the effects of these transients on earth's magnetic field. The high-resolution data IMF Bz and solar wind data obtained from WDC-A, through its omniweb, available during the selected period. Dst and Ap obtained from WDC-Kyoto are taken as indicator of geomagnetic activities. It is found that Dst index, solar wind velocity, proton temperature and the Bz component of magnetic field have higher values and increase just before the occurrence of these events. Larger and varying magnetic field mainly responsible for producing the short-term changes in geomagnetic intensity are observed during these events associated with coronal holes.

  17. Alfven Waves in the Solar Wind, Magnetosheath, and Outer Magnetosphere

    NASA Technical Reports Server (NTRS)

    Sibeck, D. G.

    2007-01-01

    Alfven waves Propagating outward from the Sun are ubiquitous in the solar wind and play a major role in the solar wind-magnetosphere interaction. The passage of the waves generally occurs in the form of a series of discrete steepened discontinuities, each of which results in an abrupt change in the interplanetary magnetic field direction. Some orientations of the magnetic field permit particles energized at the Earth's bow shock to gain access to the foreshock region immediately upstream from the Earth's bow shock. The thermal pressure associated with these particles can greatly perturb solar wind plasma and magnetic field parameters shortly prior to their interaction with the Earth's bow shock and magnetosphere. The corresponding dynamic pressure variations batter the magnetosphere, driving magnetopause motion and transient compressions of the magnetospheric magnetic field. Alfven waves transmit information concerning the dynamic pressure variations applied to the magnetosphere to the ionosphere, where they generate the traveling convection vortices (TCVs) seen in high-latitude ground magnetograms. Finally, the sense of Alfvenic perturbations transmitted into the magnetosheath reverses across local noon because magnetosheath magnetic field lines drape against the magnetopause. The corresponding change in velocity perturbations must apply a weak torque to the Earth's magnetosphere.

  18. Modelling of Solar Wind, CME Initiation and CME Propagation

    NASA Astrophysics Data System (ADS)

    van der Holst, B.; Poedts, S.; Chané, E.; Jacobs, C.; Dubey, G.; Kimpe, D.

    2005-11-01

    Simulations of coronal mass ejections (CMEs) evolving in the interplanetary (IP) space from the Sun up to 1 AU are performed in the framework of ideal magnetohydrodynamics (MHD) by the means of a finite-volume, explicit solver. The aim is to quantify the effect of the background solar wind and of the CME initiation parameters, such as the initial magnetic polarity, on the evolution and on the geo-effectiveness of CMEs. First, three different solar wind models are reconstructed using the same numerical grid and the same numerical scheme. Then, different CME initiation models are considered: Magnetic foot point shearing and magnetic flux emergence. For the fast CME evolution studies, a very simple CME model is considered: A high-density and high-pressure magnetized plasma blob is superposed on a background steady state solar wind model with an initial velocity and launch direction. The simulations show that the initial magnetic polarity substantially affects the IP evolution of the CMEs influencing the propagation velocity, the shape, the trajectory (and thus, the geo-effectiveness).

  19. Solar wind dynamic pressure control of the dayside magnetopause location

    NASA Astrophysics Data System (ADS)

    Simunek, Jiri; Nemecek, Zdenek; Safrankova, Jana; Prech, Lubomir; Shue, Jih-Hong

    2016-07-01

    The solar wind dynamic pressure is the principal factor controlling the magnetopause location. Their mutual relation is usually written in a power-law form and suggested indices vary from -1/4.8 to -1/6.6 according to a particular magnetopause model. The paper analyzes about six thousands of THEMIS dayside magnetopause crossings observed in a broad range of upstream pressures (0.2-20 nPa). We found that (1) the power-law form provides the best description of variations of the magnetopause stand-off distance with upstream pressures; (2) the most appropriate value of the power index resulting from the present study is -1/4.4 if only solar wind dynamic pressure is considered; (3) the value of the power index varies slightly with other investigated parameters like the orientation of interplanetary magnetic field or solar wind speed; and (4) the value of the power index increases to or above -1/6 if the orbital limitations are not handled properly.

  20. Influence of solar wind ions on photoemission charging of dust

    NASA Astrophysics Data System (ADS)

    Nouzak, Libor; Richterova, Ivana; Pavlu, Jiri; Safrankova, Jana; Nemecek, Zdenek

    2016-04-01

    The lunar surface covered by a layer of dust grains is exposed to solar wind particles and photons coming from the Sun on the sunlit side. Solar wind ions cause sputtering of dust grains or can be implanted into grains. We suppose that as a consequence of ion implantation, an additional energy is transferred to grains, more valence band electrons are excited, and the photoelectron yield is increased. An increase of the photoelectron current causes the enhanced density of electrons that form a sheet above the illuminated lunar surface. Thus, an influence of solar wind ions on the Debye length and photoelectron sheet formation is expected. We present laboratory estimations of work functions and photoelectron yields of a single micron-sized silica grain before and after ion implantation. The silica grain used as a lunar simulant is caught in the electrodynamic trap. Grain's specific charge is evaluated by an analysis of the grain motion within the trap, while its work function is determined from observations of a time evolution of the charge-to-mass ratio when the grain is irradiated by photons of different emission lines. By comparison of the photoelectron current (from grain) with photon flux (from UV source), we establish the photoelectron yield of the trapped object. The influence of ion implantation is thoroughly analyzed and discussed.