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Sample records for solar wind irradiation

  1. Air pollution is pushing wind speed into a regulator of surface solar irradiance in China

    NASA Astrophysics Data System (ADS)

    Wang, Y. W.; Yang, Y. H.; Zhou, X. Y.; Zhao, N.; Zhang, J. H.

    2014-05-01

    Analysis in 27 cities across China shows that surface solar irradiance (SSI) and wind speed track similar decadal trends in 1961-2011, suggesting wind speed as a possible regulator of SSI. This assumption is further confirmed by the continuously widening gap in annually averaged daily SSI between windy and windless clear-sky days with worsening air pollution. Wider gaps are noted for more polluted cities and seasons. The gap in SSI between windy and windless conditions could therefore serve as a good indicator for air quality. The regulatory effect of wind speed on SSI starts to be important when air pollution index exceeds the boundary of 125. A plausible mechanism of wind speed regulating SSI through interactions with aerosols is proposed. There are two cut-off points of 2.5 m s-1 and 3.5 m s-1 wind speeds. Winds <2.5 m s-1 noticeably disperse air pollutants and thereby enhance SSI. Above the 2.5 m s-1 threshold, air pollution and SSI become largely insensitive to changing wind speeds. Winds in excess of 3.5 m s-1 could enhance aerosol concentration probably by inducing dust-storms, which in turn attenuate SSI.

  2. Electrostatic lofting variability of lunar dust under solar wind and solar uv irradiance

    NASA Astrophysics Data System (ADS)

    Cihan Örger, Necmi; Rodrigo Cordova Alarcon, Jose; Cho, Mengu; Toyoda, Kazuhiro

    2016-07-01

    It has been considered that lunar horizon glow is produced by forward scattering of the sunlight above the terminator region by the electrically charged dust grains. Previous lunar missions showed that lunar horizon glow is highly varying phenomenon; therefore, it is required to understand how this physical mechanism fundamentally occurs in order to be able to observe it. Therefore, terminator region and the dayside of the moon are the focus areas of this study in order to explain forward scattering of the sunlight towards night side region in the future steps of this work. In this paper, the results of lunar dust height calculations are presented as a function of solar zenith angle and solar wind properties. First, equilibrium surface potential, Debye length and surface electric field have been calculated to be used in the dust model to predict the lofting of lunar dust under various solar wind conditions. Dependence of the dust lofting on different parameters such as electron temperature or plasma density can be explained from the initial results. In addition, these results showed that zero potential occurs between subsolar point and terminator region as it is expected, where the maximum height of dust particles are minimum, and its position changes according to the solar wind properties and photoemission electron temperature. Relative to this work, a CubeSat mission is currently being developed in Kyushu Institute of Technology to observe lunar horizon glow.

  3. Variability of Electrostatically Charged Lunar Dust Lofting Due to Solar Wind and Solar Irradiance

    NASA Astrophysics Data System (ADS)

    Orger, N. C.; Cordova Alarcon, J. R.; Toyoda, K.; Cho, M.

    2016-12-01

    Lunar horizon glow has been considered as a production of electrically charged dust grains, which causes forward scattering of sunlight above the terminator region; however, previous lunar missions showed that lunar horizon glow is highly varying phenomenon. For this reason, it is required to understand how this physical phenomenon occurs in order to increase the chance for future observations. Since it is related to terminator region and forward scattering of sunlight, the focus areas of this study have been selected as the regions from subsolar point to terminator on the lunar surface. In this work, the lunar dust height calculations are presented as a function solar zenith angle and solar wind properties. First, equilibrium surface potential, Debye length and surface electric field have been calculated to be used in the dust model. These results are used to predict the dust lofting under various solar wind conditions in order to investigate dependence on different parameters such as electron temperature or plasma density. In addition, these results showed that there is a location where the heights of lofted dust grains are minimum between subsolar point and terminator region as it is expected, and its position changes according to the solar wind properties and photoemission electron current. In the near future, laboratory experiments will be performed in order to improve the dust model by focusing on the electrostatic interaction between charged dust grains in plasma by utilizing the surface charge and electric field results, and the simulation environment will be improved. Relative to this work, a CubeSat mission is currently being planned in Kyushu Institute of Technology to observe lunar horizon glow.

  4. Dependence of Lunar Surface Charging on Solar Wind Plasma Conditions and Solar Irradiation

    NASA Technical Reports Server (NTRS)

    Stubbs, T. J.; Farrell, W. M.; Halekas, J. S.; Burchill, J. K.; Collier, M. R.; Zimmerman, M. I.; Vondrak, R. R.; Delory, G. T.; Pfaff, R. F.

    2014-01-01

    The surface of the Moon is electrically charged by exposure to solar radiation on its dayside, as well as by the continuous flux of charged particles from the various plasma environments that surround it. An electric potential develops between the lunar surface and ambient plasma, which manifests itself in a near-surface plasma sheath with a scale height of order the Debye length. This study investigates surface charging on the lunar dayside and near-terminator regions in the solar wind, for which the dominant current sources are usually from the pohotoemission of electrons, J(sub p), and the collection of plasma electrons J(sub e) and ions J(sub i). These currents are dependent on the following six parameters: plasma concentration n(sub 0), electron temperature T(sub e), ion temperature T(sub i), bulk flow velocity V, photoemission current at normal incidence J(sub P0), and photo electron temperature T(sub p). Using a numerical model, derived from a set of eleven basic assumptions, the influence of these six parameters on surface charging - characterized by the equilibrium surface potential, Debye length, and surface electric field - is investigated as a function of solar zenith angle. Overall, T(sub e) is the most important parameter, especially near the terminator, while J(sub P0) and T(sub p) dominate over most of the dayside.

  5. Dependence of Lunar Surface Charging on Solar Wind Plasma Conditions and Solar Irradiation

    NASA Technical Reports Server (NTRS)

    Stubbs, T. J.; Farrell, W. M.; Halekas, J. S.; Burchill, J. K.; Collier, M. R.; Zimmerman, M. I.; Vondrak, R. R.; Delory, G. T.; Pfaff, R. F.

    2014-01-01

    The surface of the Moon is electrically charged by exposure to solar radiation on its dayside, as well as by the continuous flux of charged particles from the various plasma environments that surround it. An electric potential develops between the lunar surface and ambient plasma, which manifests itself in a near-surface plasma sheath with a scale height of order the Debye length. This study investigates surface charging on the lunar dayside and near-terminator regions in the solar wind, for which the dominant current sources are usually from the pohotoemission of electrons, J(sub p), and the collection of plasma electrons J(sub e) and ions J(sub i). These currents are dependent on the following six parameters: plasma concentration n(sub 0), electron temperature T(sub e), ion temperature T(sub i), bulk flow velocity V, photoemission current at normal incidence J(sub P0), and photo electron temperature T(sub p). Using a numerical model, derived from a set of eleven basic assumptions, the influence of these six parameters on surface charging - characterized by the equilibrium surface potential, Debye length, and surface electric field - is investigated as a function of solar zenith angle. Overall, T(sub e) is the most important parameter, especially near the terminator, while J(sub P0) and T(sub p) dominate over most of the dayside.

  6. Influence of solar UV irradiance on the quasi-biennial oscillation of zonal winds in the equatorial stratosphere

    NASA Astrophysics Data System (ADS)

    Gabis, I.; Troshichev, O.

    2006-12-01

    The vertical wind profiles in the equatorial stratosphere for 1953 2005 have been examined in relation to variations of solar F10.7 index to reveal influence of solar UV irradiance on the quasi-biennial oscillation (QBO) of zonal winds. Previously it was shown (Gabis, I.P., Troshichev, O.A., 2005. QBO cycle identified by changes in height profile of the zonal winds: new regularities. Journal of Atmospheric and Solar-Terrestrial Physics 67, 33 44) that Stage 1, with the easterly winds above 20 30 hPa and westerly winds below this layer, always starts in solstice (winter or summer) and can be of different but quite quantized (about 3, 9, or 15 months) duration. The present investigation shows that course of the subsequent, after Stage 1 beginning, evolution of the zonal winds depends on intensity of solar UV flux. The easterly winds descend below ˜30 hPa (Stage 2) only under condition of high level of the UV irradiance or steady increase of the UV flux happening in time of the first equinox in course of QBO cycle. If level of UV irradiance is low or UV flux decreases during the equinox, the easterly winds typical of the upper layer, do not descend below 30 hPa, and Stage 1 persists till next equinox. In other words, the stopping of easterly shear zone at ˜30 hPa is defined by the level of UV irradiance in a proper time. Since the length of the QBO cycle is determined by duration of Stage 1, the cycle length (24, 30, or 36 months) can be predicted setting the time of transformation from Stage 1 to Stage 2.

  7. Detection of solar wind-produced water in irradiated rims on silicate minerals

    PubMed Central

    Bradley, John P.; Ishii, Hope A.; Gillis-Davis, Jeffrey J.; Ciston, James; Nielsen, Michael H.; Bechtel, Hans A.; Martin, Michael C.

    2014-01-01

    The solar wind (SW), composed of predominantly ∼1-keV H+ ions, produces amorphous rims up to ∼150 nm thick on the surfaces of minerals exposed in space. Silicates with amorphous rims are observed on interplanetary dust particles and on lunar and asteroid soil regolith grains. Implanted H+ may react with oxygen in the minerals to form trace amounts of hydroxyl (−OH) and/or water (H2O). Previous studies have detected hydroxyl in lunar soils, but its chemical state, physical location in the soils, and source(s) are debated. If −OH or H2O is generated in rims on silicate grains, there are important implications for the origins of water in the solar system and other astrophysical environments. By exploiting the high spatial resolution of transmission electron microscopy and valence electron energy-loss spectroscopy, we detect water sealed in vesicles within amorphous rims produced by SW irradiation of silicate mineral grains on the exterior surfaces of interplanetary dust particles. Our findings establish that water is a byproduct of SW space weathering. We conclude, on the basis of the pervasiveness of the SW and silicate materials, that the production of radiolytic SW water on airless bodies is a ubiquitous process throughout the solar system. PMID:24449869

  8. Detection of solar wind-produced water in irradiated rims on silicate minerals.

    PubMed

    Bradley, John P; Ishii, Hope A; Gillis-Davis, Jeffrey J; Ciston, James; Nielsen, Michael H; Bechtel, Hans A; Martin, Michael C

    2014-02-04

    The solar wind (SW), composed of predominantly ∼1-keV H(+) ions, produces amorphous rims up to ∼150 nm thick on the surfaces of minerals exposed in space. Silicates with amorphous rims are observed on interplanetary dust particles and on lunar and asteroid soil regolith grains. Implanted H(+) may react with oxygen in the minerals to form trace amounts of hydroxyl (-OH) and/or water (H2O). Previous studies have detected hydroxyl in lunar soils, but its chemical state, physical location in the soils, and source(s) are debated. If -OH or H2O is generated in rims on silicate grains, there are important implications for the origins of water in the solar system and other astrophysical environments. By exploiting the high spatial resolution of transmission electron microscopy and valence electron energy-loss spectroscopy, we detect water sealed in vesicles within amorphous rims produced by SW irradiation of silicate mineral grains on the exterior surfaces of interplanetary dust particles. Our findings establish that water is a byproduct of SW space weathering. We conclude, on the basis of the pervasiveness of the SW and silicate materials, that the production of radiolytic SW water on airless bodies is a ubiquitous process throughout the solar system.

  9. Solar wind and cosmic ray irradiation of grains and ices - application to erosion and synthesis of organic compounds in the solar system

    NASA Technical Reports Server (NTRS)

    Rocard, F.; Benit, J.; Meunier, J. P.; Bibring, R.; Vassent, B.

    1984-01-01

    Solar wind and cosmic and cosmic ray irradiation of grains induces physical and chemical effects including their erosion and the synthesis of molecular compounds within the implanted layers. The experiments performed with H2O ice implanted by keV ions are presented. The ion implantation is intended to simulate the irradiation of comets, ring grains, and satellites of outer planets, either by the primitive solar particles or by contemporary solar wind (SW) or solar cosmic rays (SCR) fluxes. The detection of molecules was obtained through in-situ infrared spectroscopy. A model is proposed for the formation of organic matter within icy solar system bodies which is in agreement with experimental results of erosion rates. The organic molecules, frozen-in within the icy mantles of the grains present in the protosolar nebula, would originate from their primitive irradiation. Such an irradiation would have taken place during an early stage of the proto-sun, when both the SW and SCR particles were more intense by orders of magnitude.

  10. Combined effects of wind and solar irradiance on the spatial variation of midday air temperature over a mountainous terrain

    NASA Astrophysics Data System (ADS)

    Kim, Soo-Ock; Kim, Jin-Hee; Kim, Dae-Jun; Shim, Kyo Moon; Yun, Jin I.

    2015-08-01

    When the midday temperature distribution in a mountainous region was estimated using data from a nearby weather station, the correction of elevation difference based on temperature lapse caused a large error. An empirical approach reflecting the effects of solar irradiance and advection was suggested in order to increase the reliability of the results. The normalized slope irradiance, which was determined by normalizing the solar irradiance difference between a horizontal surface and a sloping surface from 1100 to 1500 LST on a clear day, and the deviation relationship between the horizontal surface and the sloping surface at the 1500 LST temperature on each day were presented as simple empirical formulas. In order to simulate the phenomenon that causes immigrant air parcels to push out or mix with the existing air parcels in order to decrease the solar radiation effects, an advection correction factor was added to exponentially reduce the solar radiation effect with an increase in wind speed. In order to validate this technique, we estimated the 1500 LST air temperatures on 177 clear days in 2012 and 2013 at 10 sites with different slope aspects in a mountainous catchment and compared these values to the actual measured data. The results showed that this technique greatly improved the error bias and the overestimation of the solar radiation effect in comparison with the existing methods. By applying this technique to the Korea Meteorological Administration's 5-km grid data, it was possible to determine the temperature distribution at a 30-m resolution over a mountainous rural area south of Jiri Mountain National Park, Korea.

  11. Modeling of the environmental factors influence on solar irradiance reflectance and transmittance through the wind-ruffled sea surface

    NASA Astrophysics Data System (ADS)

    Wozniak, Slawomir B.

    1997-02-01

    The spectral model of solar irradiance transmittance through the wind - ruffled sea surface was developed. Modified dependencies for both wind - ruffled sea surface slope distribution based on Cox and Munk and foam coverage of the sea surface based on Gordon and Jacobs were used, with incorporation of effects of hydrometeorological factors and basin geometry. Snell and Fresnel laws were applied for light transmission through the surface. Spectral dependencies of light refraction in the range 350-18000 nm were taken into account. Polarization effects were neglected. This approach seems to be much more accurate than presented in known monographs, such as Mullamaa. This model is a part of the model of radiation inflow to the Baltic developed by the team from the Institute of Oceanology PAS Sopot.

  12. 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.

  13. 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.

  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 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.

  16. UV solar irradiance low during recent solar minimum

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2011-10-01

    Solar irradiance, which varies with the 11-year solar cycle and on longer time scales, can affect temperatures and winds in the atmosphere, influencing Earth's climate. As the Sun currently wakes up from a period of low sunspot activity, researchers want to know how irradiance during the recent solar minimum compares to historical levels. In addition to understanding the total received power, it is important to know how various spectral bands behave, in particular, the ultraviolet, which causes heating and winds in the stratosphere. Lockwood analyzed solar ultraviolet spectral irradiance data from May 2003 to August 2005 from both the Solar Ultraviolet Spectral Irradiance Monitor (SUSIM) instrument on board the Upper Atmosphere Research Satellite (UARS) and the Solar Stellar Irradiance Comparison Experiment (SOLSTICE) instrument on the Solar Radiation and Climate Experiment (SORCE) satellite. Using several different methods to intercalibrate the data, he developed a data composite that can be used to determine differences between the recent solar minimum and previous minima. The author found that solar irradiance during the recent sunspot minimum has been especially low. (Journal of Geophysical Research-Atmospheres, doi:10.1029/2010JD014746, 2011)

  17. 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.

  18. Basics of the Solar Wind

    NASA Astrophysics Data System (ADS)

    Meyer-Vernet, Nicole

    2012-09-01

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

  19. The Solar Wind

    NASA Technical Reports Server (NTRS)

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

    1960-01-01

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

  20. Flank solar wind interaction

    NASA Technical Reports Server (NTRS)

    Moses, Stewart L.; Greenstadt, Eugene W.

    1992-01-01

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

  1. Acceleration of the solar wind

    NASA Technical Reports Server (NTRS)

    Barnes, Aaron

    1992-01-01

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

  2. Models of Solar Irradiance Variability

    NASA Astrophysics Data System (ADS)

    Solanki, Sami K.

    2015-08-01

    Models of solar irradiance variability have an important role to play due to the relatively short (although steadily increasing) length of measured irradiance time series. Advanced models also allow identifying the source of solar irradiance variations and give insight into the variation of irradiance as a function of wavelength. The first generation of models of solar irradiance were proxy-based, i.e. purely empirical. These were followed by models that combine spectra computed from semi-empirical model atmospheres, with a measure of solar activity variations. In future, models will build increasingly on 3D MHD simulations instead of 1D model atmospheres to compute the spectra. On longer timescales models are generally simpler, although there too considerable progress has been made, with irradiance reconstructions now available for multiple millennia, albeit with lower resolution and accuracy than at shorter timescales.

  3. Composition of the Solar Wind

    NASA Technical Reports Server (NTRS)

    Suess, S. T.

    2007-01-01

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

  4. Personal overview of solar wind 6

    SciTech Connect

    Gosling, J.T.

    1987-01-01

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

  5. 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.

  6. Clouds blown by the solar wind

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  7. Computing Solar EUV Irradiance Variability

    NASA Astrophysics Data System (ADS)

    Warren, H. P.

    2014-12-01

    The solar EUV irradiance plays a central role in determining the state of the Earth's upper atmosphere. The EUV irradiance at the shortest wavelengths, which is highly variable over time scales from seconds to decades, is particularly important for many aspects of space weather. Systematic spectrally resolved observations at the shortest EUV wavelengths, however, have been rare and there is a need to develop a methodology for estimating and forecasting the solar irradiance at all EUV wavelengths from sparse data sets. In this presentation we report on our efforts to use AIA DEM calculations to estimate the solar EUV irradiance at wavelength below 450 Å, where the emission is predominately optically thin. To validate our AIA DEM calculations we have performed extensive comparisons with simultaneous observations from the EVE instrument on SDO and the EIS instrument on Hinode and find that with the proper constraints we can generally reproduce the results obtained with detailed spectroscopic observations. Using a proxy for solar activity derived from photospheric magnetic field measurements we extend our model calculations to previous solar cycles and discuss how the model can be used to forecast EUV irradiance variability over short time scales. Finally, we speculate on what is needed to further develop semi-empirical and physical models for use in understanding the solar spectral irradiance at these wavelengths.

  8. Venus: Interaction with Solar Wind

    NASA Astrophysics Data System (ADS)

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

    2002-07-01

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

  9. 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.

  10. Modeling Solar Lyman Alpha Irradiance

    NASA Technical Reports Server (NTRS)

    Pap, J.; Hudson, H. S.; Rottman, G. J.; Willson, R. C.; Donnelly, R. F.; London, J.

    1990-01-01

    Solar Lyman alpha irradiance is estimated from various solar indices using linear regression analyses. Models developed with multiple linear regression analysis, including daily values and 81-day running means of solar indices, predict reasonably well both the short- and long-term variations observed in Lyman alpha. It is shown that the full disk equivalent width of the He line at 1083 nm offers the best proxy for Lyman alpha, and that the total irradiance corrected for sunspot effect also has a high correlation with Lyman alpha.

  11. Forecasting Solar Wind Speeds

    NASA Astrophysics Data System (ADS)

    Suzuki, Takeru K.

    2006-03-01

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

  12. Wind and solar powered turbine

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  13. Measuring the Turbulent Solar Wind

    NASA Astrophysics Data System (ADS)

    DeForest, Craig; Matthaeus, William; Howard, Tim

    2015-04-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2004-12-01

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

  15. Solar Wind and Interplanetary Disturbances

    NASA Technical Reports Server (NTRS)

    Watari, Shinichi

    2002-01-01

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

  16. 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.

  17. Solar wind acceleration in the solar corona

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

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

  18. 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.

  19. Solar wind collisional heating

    NASA Astrophysics Data System (ADS)

    Pezzi, Oreste

    2017-06-01

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

  20. 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…

  1. 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…

  2. Solar cycle variations in the solar wind

    NASA Technical Reports Server (NTRS)

    Freeman, John W.; Lopez, Ramon E.

    1986-01-01

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

  3. Solar wind precipitation on Mars

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

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

  4. Periodic solar wind density structures

    NASA Astrophysics Data System (ADS)

    Viall, Nicholeen Mary

    2010-01-01

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

  5. 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.

  6. Persistence of solar wind features

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

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

  7. Variability of solar ultraviolet irradiance

    NASA Technical Reports Server (NTRS)

    Pap, J. M.; Donnelly, R. F.; Hudson, H. S.; Rottman, G. J.; Willson, R. C.

    1991-01-01

    A model of solar Lyman alpha irradiance developed by multiple linear regression analysis, including the daily values and 81-day running means of the full disk equivalent width of the Helium line at 1083 nm, predicts reasonably well both the short- and long-term variations observed in Lyman alpha. In contrast, Lyman alpha models calculated from the 10.7-cm radio flux overestimate the observed variations in the rising portion and maximum period of solar cycle, and underestimates them during solar minimum. Models are shown of Lyman alpha based on the He-line equivalent width and 10.7-cm radio flux for those time intervals when no satellite observations exist, namely back to 1974 and after April 1989, when the measurements of the Solar Mesosphere Satellite were terminated.

  8. Solar irradiance dictates settlement timing and intensity of marine mussels

    NASA Astrophysics Data System (ADS)

    Fuentes-Santos, Isabel; Labarta, Uxío; Álvarez-Salgado, X. Antón; Fernández-Reiriz, Mª José

    2016-07-01

    Identifying the environmental factors driving larval settlement processes is crucial to understand the population dynamics of marine invertebrates. This work aims to go a step ahead and predict larval presence and intensity. For this purpose we consider the influence of solar irradiance, wind regime and continental runoff on the settlement processes. For the first time, we conducted a 5-years weekly monitoring of Mytilus galloprovincialis settlement on artificial suspended substrates, which allowed us to search for interannual variability in the settlement patterns. Comparison between the seasonal pattern of larval settlement and solar irradiance, as well as the well-known effect of solar irradiance on water temperature and food availability, suggest that solar irradiance indirectly influences the settlement process, and support the use of this meteorological variable to predict settlement occurrence. Our results show that solar irradiance allows predicting the beginning and end of the settlement cycle a month in advance: Particularly we have observed that solar irradiance during late winter indirectly drives the timing and intensity of the settlement onset, Finally, a functional generalise additive model, which considers the influence of solar irradiance and continental runoff on the settlement process, provides an accurate prediction of settlement intensity a fortnight in advance.

  9. Solar irradiance dictates settlement timing and intensity of marine mussels

    PubMed Central

    Fuentes-Santos, Isabel; Labarta, Uxío; Álvarez-Salgado, X. Antón; Fernández-Reiriz, Mª José

    2016-01-01

    Identifying the environmental factors driving larval settlement processes is crucial to understand the population dynamics of marine invertebrates. This work aims to go a step ahead and predict larval presence and intensity. For this purpose we consider the influence of solar irradiance, wind regime and continental runoff on the settlement processes. For the first time, we conducted a 5-years weekly monitoring of Mytilus galloprovincialis settlement on artificial suspended substrates, which allowed us to search for interannual variability in the settlement patterns. Comparison between the seasonal pattern of larval settlement and solar irradiance, as well as the well-known effect of solar irradiance on water temperature and food availability, suggest that solar irradiance indirectly influences the settlement process, and support the use of this meteorological variable to predict settlement occurrence. Our results show that solar irradiance allows predicting the beginning and end of the settlement cycle a month in advance: Particularly we have observed that solar irradiance during late winter indirectly drives the timing and intensity of the settlement onset, Finally, a functional generalise additive model, which considers the influence of solar irradiance and continental runoff on the settlement process, provides an accurate prediction of settlement intensity a fortnight in advance. PMID:27384527

  10. 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.

  11. ASYMMETRIC SOLAR WIND ELECTRON DISTRIBUTIONS

    SciTech Connect

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

    2012-08-20

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

  12. Future Satellite Observations of Solar Irradiance

    NASA Technical Reports Server (NTRS)

    Cahalan, R. F.; Rottman, G.; Woods, T.; Lawrence, G.; Harder, J.; McClintock, W.; Kopp, G.

    2003-01-01

    Required solar irradiance measurements for climate studies include those now being made by the Total Irradiance Monitor (TIM) and the Spectral Irradiance Monitor (SIM) onboard the SORCE satellite, part of the Earth Observing System fleet of NASA satellites. Equivalent or better measures of Total Solar Irradiance (TSI) and Spectral Solar Irradiance (SSI, 200 to 2000 nm) are planned for the post-2010 satellites of the National Polar-orbiting Operational Environmental Satellite System ("OESS). The design life of SORCE is 5 years, so a "Solar Irradiance Gap Filler" EOS mission is being planned for launch in the 2007 time frame, to include the same TSI and SSI measurements. Besides avoiding any gap, overlap of the data sources is also necessary for determination of possible multi-decadal trends in solar irradiance. We discuss these requirements and the impacts of data gaps, and data overlaps, that may occur in the monitoring of the critical solar radiative forcing.

  13. 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

  14. 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.

  15. The solar wind throughout the solar cycle

    NASA Astrophysics Data System (ADS)

    von Steiger, Rudolf

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

  16. Imaging the Variable Solar Wind

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

  17. 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.

  18. Data on total and spectral solar irradiance

    SciTech Connect

    Mecherikunnel, A.T.; Gatlin, J.A.; Richmond, J.C.

    1983-05-01

    This paper presents a brief survey of the data available on solar constant and extraterrestrial solar spectral irradiance. The spectral distribution of solar radiation at ground surface, computed from extraterrestrial solar spectral irradiance for several air mass values and for four levels of atmospheric pollution, is also presented. The total irradiance at ground level is obtained by integration of the area under the spectral irradiance curves. It is significant that, as air mass increases or as turbidity increases, the amount of energy in the infrared relative to the total increases and that the energy in the UV and visible decreases.

  19. Solar Wind Speed Charged Dust

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

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

  20. Charge States of Krypton and Xenon in the Solar Wind

    NASA Astrophysics Data System (ADS)

    Bochsler, Peter; Fludra, Andrzej; Giunta, Alessandra

    2017-09-01

    We calculate charge state distributions of Kr and Xe in a model for two different types of solar wind using the effective ionization and recombination rates provided from the OPEN_ADAS data base. The charge states of heavy elements in the solar wind are essential for estimating the efficiency of Coulomb drag in the inner corona. We find that xenon ions experience particularly low Coulomb drag from protons in the inner corona, comparable to the notoriously weak drag of protons on helium ions. It has been found long ago that helium in the solar wind can be strongly depleted near interplanetary current sheets, whereas coronal mass ejecta are sometimes strongly enriched in helium. We argue that if the extraordinary variability of the helium abundance in the solar wind is due to inefficient Coulomb drag, the xenon abundance must vary strongly. In fact, a secular decrease of the solar wind xenon abundance relative to the other heavier noble gases (Ne, Ar, Kr) has been postulated based on a comparison of noble gases in recently irradiated and ancient samples of ilmenite in the lunar regolith. We conclude that decreasing solar activity and decreasing frequency of coronal mass ejections over the solar lifetime might be responsible for a secularly decreasing abundance of xenon in the solar wind.

  1. Historical Variations in Solar UV Irradiance

    NASA Astrophysics Data System (ADS)

    DeLand, M. T.

    2011-12-01

    Satellite measurements of solar UV variability have been made by at least fifteen different instruments since 1978. While it is difficult to keep a single UV irradiance instrument operating throughout a complete solar cycle, many of these instruments (Nimbus-7 SBUV, SME, NOAA-9 SBUV/2, NOAA-11 SBUV/2, UARS SUSIM, UARS SOLSTICE) were able to observe both maximum and minimum irradiance levels during either rising or declining phases of solar activity. Comparisons of these published results for solar cycles 21, 22, and 23 show consistent solar cycle irradiance changes at key wavelengths for terrestrial effects (e.g. 205 nm, 240 nm) within instrumental uncertainties. All historical data sets also show the same relative spectral dependence in the ultraviolet for both short-term (rotational) and long-term (solar cycle) variations. Empirical solar irradiance models that employ multiple proxy data sets to represent spectral irradiance produce long-term solar UV variations that are in good agreement with merged observational data through 2005. Recent UV irradiance data from the SORCE mission covering the declining phase of Cycle 23 present a different picture of long-term solar variations, with significantly larger temporal changes and different spectral dependence. We present comparisons of the SORCE irradiance data with previous solar UV observations and current model predictions. Scaling factors for use with solar UV proxy indexes have been derived from SORCE SIM and SORCE SOLSTICE data during 2004-2005. These scale factors, based on short-term irradiance variations, agree very well with results derived from concurrent NOAA-17 SBUV/2 and UARS SUSIM measurements. The 2004-2005 scale factors are consistent with previously derived scale factors that produce calculated long-term irradiance changes in good agreement with observations. The SORCE long-term solar UV irradiance results, corresponding to the early part of the mission, are consistent with undercorrection of

  2. Solar wind ion precipitation on Mars

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

  3. CIRA Solar Irradiances and Solar/Geomagnetic Indices

    NASA Astrophysics Data System (ADS)

    Tobiska, W. Kent

    Solar and geomagnetic inputs are required for use in empirical thermospheric density models. The constituent species in the thermosphere absorb spectrally resolved solar irradiances from soft X-ray (XUV) to Far Ultraviolet (FUV) wavelengths which deposit their energy at varying optical depths. In the high latitude regions, Joule heating and particle precipitation contribute secondary heating, which can be transported to lower latitudes by meridional winds. However, empirical models generally do not use the sophistication of spectrally resolved solar irradiances or Joule heating and particle precipitation. Instead, simplification of an energy input is accomplished in the form solar and geomagnetic surrogates, i.e., proxies and indices. A proxy is a substitute for a distinctly different energy input while an index expresses the activity level of an energy input. Recently, in addition to the traditional 10.7-cm flux (F10.7) that is a proxy for solar Extreme Ultraviolet (EUV) irradiances, a new solar irradiance index (S10.7) and a new proxy (M10.7) have been developed for use in empirical thermospheric density models. These three solar indices and proxies best represent the complex interaction between the solar emission source (photosphere, chromosphere, corona) with the irradiances' penetration into the thermosphere (unit optical depth in the middle and lower thermosphere) and the length of time for energy transfer between thermospheric layers (thermal process of molecular conduction or kinetic process of molecular diffusion). The S10.7 index (previously called SEUV) accounts for the majority of the daily density variability with a 1-day lag, is reported in units of F10.7, is the chromospheric EUV energy between 26-34 nm as measured by the SOHO SEM instrument, and is deposited above 200 km. The M10.7 proxy accounts for the next significant factor of the daily density variability with a 5-day lag and is the Mg II core-to-wing ratio reported in units of F10.7. It is

  4. The Colorado Solar Wind Experiment

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

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

  5. Characterizing the Solar Wind at L1

    NASA Astrophysics Data System (ADS)

    Jahn, J.; Elliott, H. A.

    2008-12-01

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

  6. 77 FR 61597 - Avalon Wind, LLC; Avalon Wind 2, LLC; Catalina Solar, LLC; Catalina Solar 2, LLC; Pacific Wind...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-10

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

  7. Astrospheres and Solar-like Stellar Winds.

    PubMed

    Wood, Brian E

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

  8. Distributed Wind Cost Reduction: Learning from Solar

    SciTech Connect

    Tegen, Suzanne

    2016-02-23

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

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

    DTIC Science & Technology

    2012-03-05

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

  10. Comet Borrelly Slows Solar Wind

    NASA Technical Reports Server (NTRS)

    2001-01-01

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

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

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

  11. Numerical modeling of the solar wind turbulence

    DOE PAGES

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

    2012-05-21

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

  12. Origin of Solar Irradiance Variability

    NASA Astrophysics Data System (ADS)

    Fröhlich, C.; Appourchaux, T.; Gough, D.

    2003-04-01

    The changes of total solar irradiance during the course of the solar cycle correlate extremely well with changes of low-degree p-mode frequencies as observed in intensity and velocity by VIRGO/SOHO and BISON. Moreover, the slope of the linear regression between the two quantities depend on the degree of the mode, indicating an asphericity of the responsible perturbation, and the observed increase of the correlation coefficient with the degree of the modes points to the importance of higher orders in the expansion of the perturbation in latitude on the Sun. Using only degrees 0dots2, two peaks are determined, one at the equator and the other at the poles, and interestingly enough the polar peak is about 20% higher than the equatorial one and about three times the minimum value. On the other hand, the analysis of the latitudinal distribution of the excitation of low degree p modes shows a shift towards the poles with increasing activity. When first detected this was a rather unexpected result. In the light of the former results, however, it may indicate that still another component, other than from the direct effects of magnetic fields, is contributing to the change of both, the luminosity and p-mode oscillation frequencies.

  13. Solar irradiance measurements - Minimum through maximum solar activity

    NASA Technical Reports Server (NTRS)

    Lee, R. B., III; Gibson, M. A.; Shivakumar, N.; Wilson, R.; Kyle, H. L.; Mecherikunnel, A. T.

    1991-01-01

    The Earth Radiation Budget Satellite (ERBS) and the NOAA-9 spacecraft solar monitors were used to measure the total solar irradiance during the period October 1984 to December 1989. Decreasing trends in the irradiance measurements were observed as sunspot activity decreased to minimum levels in 1986; after 1986, increasing trends were observed as sunspot activity increased. The magnitude of the irradiance variability was found to be approximately 0.1 percent between sunspot minimum and maximum (late 1989). When compared with the 1984 to 1989 indices of solar magnetic activity, the irradiance trends appear to be in phase with the 11-year sunspot cycle. Both irradiance series yielded 1,365/sq Wm as the mean value of the solar irradiance, normalized to the mean earth/sun distance. The monitors are electrical substitution, active-cavity radiometers with estimated measurement precisions and accuracies of less than 0.02 and 0.2 percent, respectively.

  14. Solar irradiance measurements - Minimum through maximum solar activity

    NASA Technical Reports Server (NTRS)

    Lee, R. B., III; Gibson, M. A.; Shivakumar, N.; Wilson, R.; Kyle, H. L.; Mecherikunnel, A. T.

    1991-01-01

    The Earth Radiation Budget Satellite (ERBS) and the NOAA-9 spacecraft solar monitors were used to measure the total solar irradiance during the period October 1984 to December 1989. Decreasing trends in the irradiance measurements were observed as sunspot activity decreased to minimum levels in 1986; after 1986, increasing trends were observed as sunspot activity increased. The magnitude of the irradiance variability was found to be approximately 0.1 percent between sunspot minimum and maximum (late 1989). When compared with the 1984 to 1989 indices of solar magnetic activity, the irradiance trends appear to be in phase with the 11-year sunspot cycle. Both irradiance series yielded 1,365/sq Wm as the mean value of the solar irradiance, normalized to the mean earth/sun distance. The monitors are electrical substitution, active-cavity radiometers with estimated measurement precisions and accuracies of less than 0.02 and 0.2 percent, respectively.

  15. Correlations Between Neutral and Ionized Solar Wind

    NASA Astrophysics Data System (ADS)

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

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

  16. The Next Spaceflight Solar Irradiance Sensor: TSIS

    NASA Astrophysics Data System (ADS)

    Kopp, Greg; Pilewskie, Peter; Richard, Erik

    2016-05-01

    The Total and Spectral Solar Irradiance Sensor (TSIS) will continue measurements of the solar irradiance with improved accuracies and stabilities over extant spaceflight instruments. The two TSIS solar-observing instruments include the Total Irradiance Monitor (TIM) and the Spectral Irradiance Monitor (SIM) for measuring total- and spectral- solar-irradiance, respectively. The former provides the net energy powering the Earth’s climate system while the latter helps attribute where that energy is absorbed by the Earth’s atmosphere and surface. Both spaceflight instruments are assembled and being prepared for integration on the International Space Station. With operations commencing in late 2017, the TSIS is intended to overlap with NASA’s ongoing SOlar Radiation and Climate Experiment (SORCE) mission, which launched in 2003 and contains the first versions of both the TIM and SIM instruments, as well as with the TSI Calibration Transfer Experiment (TCTE), which began total solar irradiance measurements in 2013. We summarize the TSIS’s instrument improvements and intended solar-irradiance measurements.

  17. Wind loading on solar collectors

    NASA Astrophysics Data System (ADS)

    Bhaduri, S.; Murphy, L. M.

    1985-06-01

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

  18. 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.

  19. 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.

  20. Extraterrestrial spectral solar irradiance data for modeling spectral solar irradiance at the earth's surface

    SciTech Connect

    Riordan, C.

    1987-05-01

    This report describes the extraterrestrial (air mass zero, AMO) spectral solar irradiance data used by the Solar Energy Research Institute's Resource Assessment Branch in models to calculate spectral solar irradiance at the earth's surface. The report contains tables and graphs of the AMO spectrum updated by the World Radiation Center in Daveos, Switzerland, in 1985.

  1. Solar wind thermal electron distributions

    SciTech Connect

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

    1991-01-01

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

  2. Global solar wind variations over the last four centuries.

    PubMed

    Owens, M J; Lockwood, M; Riley, P

    2017-01-31

    The most recent "grand minimum" of solar activity, the Maunder minimum (MM, 1650-1710), is of great interest both for understanding the solar dynamo and providing insight into possible future heliospheric conditions. Here, we use nearly 30 years of output from a data-constrained magnetohydrodynamic model of the solar corona to calibrate heliospheric reconstructions based solely on sunspot observations. Using these empirical relations, we produce the first quantitative estimate of global solar wind variations over the last 400 years. Relative to the modern era, the MM shows a factor 2 reduction in near-Earth heliospheric magnetic field strength and solar wind speed, and up to a factor 4 increase in solar wind Mach number. Thus solar wind energy input into the Earth's magnetosphere was reduced, resulting in a more Jupiter-like system, in agreement with the dearth of auroral reports from the time. The global heliosphere was both smaller and more symmetric under MM conditions, which has implications for the interpretation of cosmogenic radionuclide data and resulting total solar irradiance estimates during grand minima.

  3. Global solar wind variations over the last four centuries

    PubMed Central

    Owens, M. J.; Lockwood, M.; Riley, P.

    2017-01-01

    The most recent “grand minimum” of solar activity, the Maunder minimum (MM, 1650–1710), is of great interest both for understanding the solar dynamo and providing insight into possible future heliospheric conditions. Here, we use nearly 30 years of output from a data-constrained magnetohydrodynamic model of the solar corona to calibrate heliospheric reconstructions based solely on sunspot observations. Using these empirical relations, we produce the first quantitative estimate of global solar wind variations over the last 400 years. Relative to the modern era, the MM shows a factor 2 reduction in near-Earth heliospheric magnetic field strength and solar wind speed, and up to a factor 4 increase in solar wind Mach number. Thus solar wind energy input into the Earth’s magnetosphere was reduced, resulting in a more Jupiter-like system, in agreement with the dearth of auroral reports from the time. The global heliosphere was both smaller and more symmetric under MM conditions, which has implications for the interpretation of cosmogenic radionuclide data and resulting total solar irradiance estimates during grand minima. PMID:28139769

  4. Global solar wind variations over the last four centuries

    NASA Astrophysics Data System (ADS)

    Owens, M. J.; Lockwood, M.; Riley, P.

    2017-01-01

    The most recent “grand minimum” of solar activity, the Maunder minimum (MM, 1650–1710), is of great interest both for understanding the solar dynamo and providing insight into possible future heliospheric conditions. Here, we use nearly 30 years of output from a data-constrained magnetohydrodynamic model of the solar corona to calibrate heliospheric reconstructions based solely on sunspot observations. Using these empirical relations, we produce the first quantitative estimate of global solar wind variations over the last 400 years. Relative to the modern era, the MM shows a factor 2 reduction in near-Earth heliospheric magnetic field strength and solar wind speed, and up to a factor 4 increase in solar wind Mach number. Thus solar wind energy input into the Earth’s magnetosphere was reduced, resulting in a more Jupiter-like system, in agreement with the dearth of auroral reports from the time. The global heliosphere was both smaller and more symmetric under MM conditions, which has implications for the interpretation of cosmogenic radionuclide data and resulting total solar irradiance estimates during grand minima.

  5. 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.

  6. Average thermal characteristics of solar wind electrons

    NASA Technical Reports Server (NTRS)

    Montgomery, M. D.

    1972-01-01

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

  7. Solar Wind Elemental Abundances from GENESIS Collectors

    NASA Astrophysics Data System (ADS)

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

    2007-03-01

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

  8. Magnetospheric balance of solar wind dynamic pressure

    NASA Astrophysics Data System (ADS)

    Lopez, Ramon E.; Gonzalez, Walter D.

    2017-04-01

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

  9. 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.

  10. 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

  11. 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.

  12. Locating solar and wind energy sources

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

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

  13. Titan Observed Naked in the Solar Wind

    NASA Image and Video Library

    2015-01-28

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

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

    NASA Technical Reports Server (NTRS)

    Gloeckler, George; Geiss, Johannes

    1988-01-01

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

  15. 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.

  16. The quiescent corona and slow solar wind

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

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

  17. 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.

  18. A Solar Irradiance Climate Data Record

    NASA Astrophysics Data System (ADS)

    Coddington, O.; Lean, J. L.; Pilewskie, P.; Snow, M.; Lindholm, D.

    2016-08-01

    We present a new climate data record for total solar irradiance and solar spectral irradiance between 1610 and the present day with associated wavelength and time-dependent uncertainties and quarterly updates. The data record, which is part of the National Oceanic and Atmospheric Administration’s (NOAA) Climate Data Record (CDR) program, provides a robust, sustainable, and scientifically defensible record of solar irradiance that is of sufficient length, consistency, and continuity for use in studies of climate variability and climate change on multiple time scales and for user groups spanning climate modeling, remote sensing, and natural resource and renewable energy industries. The data record, jointly developed by the University of Colorado’s Laboratory for Atmospheric and Space Physics (LASP) and the Naval Research Laboratory (NRL), is constructed from solar irradiance models that determine the changes with respect to quiet sun conditions when facular brightening and sunspot darkening features are present on the solar disk where the magnitude of the changes in irradiance are determined from the linear regression of a proxy magnesium (Mg) II index and sunspot area indices against the approximately decade-long solar irradiance measurements of the Solar Radiation and Climate Experiment (SORCE). To promote long-term data usage and sharing for a broad range of users, the source code, the dataset itself, and supporting documentation are archived at NOAA's National Centers for Environmental Information (NCEI). In the future, the dataset will also be available through the LASP Interactive Solar Irradiance Data Center (LISIRD) for user-specified time periods and spectral ranges of interest.

  19. Distribution Strategies for Solar and Wind Renewables in NW Europe

    NASA Astrophysics Data System (ADS)

    Smedley, Andrew; Webb, Ann

    2017-04-01

    Whilst the UNFCCC Paris Agreement Climate change was ratified in November, 2016 saw the highest global temperature anomaly on record at 1.2°C above pre-industrial levels. As such there is urgent need to reduce CO2 emissions by a move away from fossil fuels and towards renewable electricity energy technologies. As the principal renewable technologies of solar PV and wind turbines contribute an increasing fraction to the electricity grid, questions of cumulative intermittency and the large-scale geographic distribution of each technology need to be addressed. In this study our initial emphasis is on a calculation of a relatively high spatial resolution (0.1° × 0.1°) daily gridded dataset of solar irradiance data, over a 10 year period (2006-2015). This is achieved by coupling established sources of satellite data (MODIS SSF level2 instantaneous footprint data) to a well-validated radiative transfer model, here LibRadTran. We utilise both a morning and afternoon field for two cloud layers (optical depth and cloud fraction) interpolated to hourly grids, together with aerosol optical depth, topographic height and solar zenith angle. These input parameters are passed to a 5-D LUT of LibRadTran results to construct hourly estimates of the solar irradiance field, which is then integrated to a daily total. For the daily wind resource we rely on the 6 hourly height-adjusted ECMWF ERA-Interim reanalysis wind fields, but separated into onshore, offshore and deep water components. From these datasets of the solar and wind resources we construct 22 different distribution strategies for solar PV and wind turbines based on the long-term availability of each resource. Combining these distributions with the original daily gridded datasets enables each distribution strategy to be then assessed in terms of the day-to-day variability, the installed capacity required to maintain a baseline supply, and the relative proportions of each technology. Notably for the NW European area

  20. Solar EUV irradiance for space weather applications

    NASA Astrophysics Data System (ADS)

    Viereck, R. A.

    2015-12-01

    Solar EUV irradiance is an important driver of space weather models. Large changes in EUV and x-ray irradiances create large variability in the ionosphere and thermosphere. Proxies such as the F10.7 cm radio flux, have provided reasonable estimates of the EUV flux but as the space weather models become more accurate and the demands of the customers become more stringent, proxies are no longer adequate. Furthermore, proxies are often provided only on a daily basis and shorter time scales are becoming important. Also, there is a growing need for multi-day forecasts of solar EUV irradiance to drive space weather forecast models. In this presentation we will describe the needs and requirements for solar EUV irradiance information from the space weather modeler's perspective. We will then translate these requirements into solar observational requirements such as spectral resolution and irradiance accuracy. We will also describe the activities at NOAA to provide long-term solar EUV irradiance observations and derived products that are needed for real-time space weather modeling.

  1. The LASP Interactive Solar IRradiance Datacenter (LISIRD)

    NASA Astrophysics Data System (ADS)

    Snow, M.; Woods, T. N.; Eparvier, F. G.; Fontenla, J.; Harder, J.; McClintock, W. E.; Pankratz, C.; Richard, E.; Windnagel, A.; Woodraska, D.

    2005-12-01

    LASP has created an online resource for combined solar irradiance datasets from the SORCE, TIMED, UARS, and SME missions. The LASP Interactive Solar IRradiance Datacenter (LISIRD) not only provides unified access to the individual datasets, but also combines them for ease of use by scientists, educators, and the general public. In particular, LISIRD makes available composite spectra and time series. The TIMED SEE, SORCE SOLSTICE, and SORCE SIM instruments produce spectra that together cover the solar spectrum from 1 to 2700 nm. Through the LISIRD interface, the user can get data that bridges the various missions in both wavelength and time. LISIRD also hosts data products of interest to the space weather community. They have slightly different needs than the atmospheric modelers that are the typical users of irradiance data. For space weather applications, high time cadence and near real-time data delivery are key. For these users, we make our observations available shortly after spacecraft contact, and append the observations to a single data file which they can retrieve using anonymous ftp every few hours. The third component of LISIRD is the Solar Physical Radiation Model (SPRM) results of Fontenla et al. It provides a model of current solar activity, the synthetic spectral irradiance, and tools that permit one to model the solar activity source of the spectral irradiance variations.

  2. 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.

  3. Bimodal Solar Wind-Magnetosphere-Ionosphere Coupling

    NASA Astrophysics Data System (ADS)

    Siscoe, G.

    2005-05-01

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

  4. Solar oscillations and helioseismology from ACRIM/SMM irradiance data.

    NASA Astrophysics Data System (ADS)

    Fröhlich, C.

    An introduction to solar oscillations, their properties and diagnostic potential, and a review of our present knowledge is presented. The solar irradiance data from the ACRIM (Active Cavity Radiometer for Irradiance Monitoring) solar constant experiment on board the Solar Maximum Mission satellite (SMM) are used to search for solar gravity modes, which yield a direct information on the structure of the solar core.

  5. Wave Modeling of the Solar Wind.

    PubMed

    Ofman, Leon

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

  6. Radial Evolution of the Solar Wind

    NASA Astrophysics Data System (ADS)

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

    2016-12-01

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

  7. Solar Wind Earth Exchange Project (SWEEP)

    DTIC Science & Technology

    2016-10-28

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

  8. On periodicity of solar wind phenomena

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

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

  9. DSCOVR High Time Resolution Solar Wind Measurements

    NASA Technical Reports Server (NTRS)

    Szabo, Adam

    2012-01-01

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

  10. Solar wind contribution to surficial lunar water: Laboratory investigations

    NASA Astrophysics Data System (ADS)

    Burke, D. J.; Dukes, C. A.; Kim, J.-H.; Shi, J.; Famá, M.; Baragiola, R. A.

    2011-02-01

    Remote infrared spectroscopic measurements have recently re-opened the possibility that water is present on the surface of the Moon. Analyses of infrared absorption spectra obtained by three independent space instruments have identified water and hydroxyl (-OH) absorption bands at ˜3 μm within the lunar surface. These reports are surprising since there are many mechanisms that can remove water but no clear mechanism for replenishment. One hypothesis, based on the spatial distribution of the -OH signal, is that water is formed by the interaction of the solar wind with silicates and other oxides in the lunar basalt. To test this hypothesis, we have performed a series of laboratory simulations that examine the effect of proton irradiation on two minerals: anorthite and ilmenite. Bi-directional infrared reflection absorption spectra do not show any discernable enhancement of infrared absorption in the 3 μm spectral region following 1 or 100 keV proton irradiation at fluences between 10 16 and 10 18 ions cm -2. In fact, the post-irradiation spectra are characterized by a decrease in the residual O-H band within both minerals. Similarly, secondary ion mass spectrometry shows a decrease rather than an increase of the water group ions following proton bombardment of ilmenite. The absence of significant formation of either -OH or H 2O is ascribed to the preferential depletion of oxygen by sputtering during proton irradiation, which is confirmed by post-irradiation surface analysis using X-ray photoelectron spectroscopy measurements. Our results provide no evidence to support the formation of H 2O in the lunar regolith via implantation of solar wind protons as a mechanism responsible for the significant O-H absorption in recent spacecraft data. We determine an upper limit for the production of surficial -OH on the lunar surface by solar wind irradiation to be 0.5% (absorption depth).

  11. 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.

  12. Interplanetary shocks and solar wind extremes

    NASA Astrophysics Data System (ADS)

    Vats, Hari

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

  13. Properties of the very slow solar wind

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  14. Solar Wind Overview of Cycle 24

    NASA Astrophysics Data System (ADS)

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

    2017-04-01

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

  15. Prospects for future solar-wind missions

    NASA Technical Reports Server (NTRS)

    Bochsler, P.; Moebius, E.

    1993-01-01

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

  16. The solar wind interaction with Venus

    NASA Technical Reports Server (NTRS)

    Luthmann, J. G.

    1992-01-01

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

  17. Nanostructured Solar Irradiation Control Materials for Solar Energy Conversion

    NASA Technical Reports Server (NTRS)

    Kang, Jinho; Marshall, I. A.; Torrico, M. N.; Taylor, C. R.; Ely, Jeffry; Henderson, Angel Z.; Kim, J.-W.; Sauti, G.; Gibbons, L. J.; Park, C.; hide

    2012-01-01

    Tailoring the solar absorptivity (alpha(sub s)) and thermal emissivity (epsilon(sub T)) of materials constitutes an innovative approach to solar energy control and energy conversion. Numerous ceramic and metallic materials are currently available for solar absorbance/thermal emittance control. However, conventional metal oxides and dielectric/metal/dielectric multi-coatings have limited utility due to residual shear stresses resulting from the different coefficient of thermal expansion of the layered materials. This research presents an alternate approach based on nanoparticle-filled polymers to afford mechanically durable solar-absorptive and thermally-emissive polymer nanocomposites. The alpha(sub s) and epsilon(sub T) were measured with various nano inclusions, such as carbon nanophase particles (CNPs), at different concentrations. Research has shown that adding only 5 wt% CNPs increased the alpha(sub s) and epsilon(sub T) by a factor of about 47 and 2, respectively, compared to the pristine polymer. The effect of solar irradiation control of the nanocomposite on solar energy conversion was studied. The solar irradiation control coatings increased the power generation of solar thermoelectric cells by more than 380% compared to that of a control power cell without solar irradiation control coatings.

  18. 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.

  19. Solar and Wind Site Screening Decision Trees

    EPA Pesticide Factsheets

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

  20. 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.

  1. Solar Total and Spectral Irradiance Reconstruction over Last 9000 Years

    NASA Astrophysics Data System (ADS)

    Wu, C. J.; Krivova, N.; Solanki, S. K.; Usoskin, I. G.

    2016-12-01

    Although the mechanisms of solar influence on Earth climate system are not yet fully understood, solar total and spectral irradiance are considered to be among the main determinants. Solar total irradiance is the total flux of solar radiative energy entering Earth's climate system, whereas the spectral irradiance describes this energy is distributed over the spectrum. Solar irradiance in the UV band is of special importance since it governs chemical processes in the middle and upper atmosphere. On timescales of the 11-year solar cycle and shorter, solar irradiance is measured by space-based instruments while models are needed to reconstruct solar irradiance on longer timescale. The SATIRE-M model (Spectral And Total Irradiance Reconstruction over millennia) is employed in this study to reconstruct solar irradiance from decadal radionuclide isotope data such as 14C and 10Be stored in tree rings and ice cores, respectively. A reconstruction over the last 9000 years will be presented.

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

    NASA Astrophysics Data System (ADS)

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

    1996-05-01

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

  3. Solar Rotational Modulations of Spectral Irradiance and Correlations with the Variability of Total Solar Irradiance

    NASA Technical Reports Server (NTRS)

    Lee, Jae N.; Cahalan, Robert F.; Wu, Dong L.

    2016-01-01

    Aims: We characterize the solar rotational modulations of spectral solar irradiance (SSI) and compare them with the corresponding changes of total solar irradiance (TSI). Solar rotational modulations of TSI and SSI at wavelengths between 120 and 1600 nm are identified over one hundred Carrington rotational cycles during 2003-2013. Methods: The SORCE (Solar Radiation and Climate Experiment) and TIMED (Thermosphere Ionosphere Mesosphere Energetics and Dynamics)/SEE (Solar EUV Experiment) measured and SATIRE-S modeled solar irradiances are analyzed using the EEMD (Ensemble Empirical Mode Decomposition) method to determine the phase and amplitude of 27-day solar rotational variation in TSI and SSI. Results: The mode decomposition clearly identifies 27-day solar rotational variations in SSI between 120 and 1600 nm, and there is a robust wavelength dependence in the phase of the rotational mode relative to that of TSI. The rotational modes of visible (VIS) and near infrared (NIR) are in phase with the mode of TSI, but the phase of the rotational mode of ultraviolet (UV) exhibits differences from that of TSI. While it is questionable that the VIS to NIR portion of the solar spectrum has yet been observed with sufficient accuracy and precision to determine the 11-year solar cycle variations, the temporal variations over one hundred cycles of 27-day solar rotation, independent of the two solar cycles in which they are embedded, show distinct solar rotational modulations at each wavelength.

  4. Solar Rotational Modulations of Spectral Irradiance and Correlations with the Variability of Total Solar Irradiance

    NASA Technical Reports Server (NTRS)

    Lee, Jae N.; Cahalan, Robert F.; Wu, Dong L.

    2016-01-01

    Aims: We characterize the solar rotational modulations of spectral solar irradiance (SSI) and compare them with the corresponding changes of total solar irradiance (TSI). Solar rotational modulations of TSI and SSI at wavelengths between 120 and 1600 nm are identified over one hundred Carrington rotational cycles during 2003-2013. Methods: The SORCE (Solar Radiation and Climate Experiment) and TIMED (Thermosphere Ionosphere Mesosphere Energetics and Dynamics)/SEE (Solar EUV Experiment) measured and SATIRE-S modeled solar irradiances are analyzed using the EEMD (Ensemble Empirical Mode Decomposition) method to determine the phase and amplitude of 27-day solar rotational variation in TSI and SSI. Results: The mode decomposition clearly identifies 27-day solar rotational variations in SSI between 120 and 1600 nm, and there is a robust wavelength dependence in the phase of the rotational mode relative to that of TSI. The rotational modes of visible (VIS) and near infrared (NIR) are in phase with the mode of TSI, but the phase of the rotational mode of ultraviolet (UV) exhibits differences from that of TSI. While it is questionable that the VIS to NIR portion of the solar spectrum has yet been observed with sufficient accuracy and precision to determine the 11-year solar cycle variations, the temporal variations over one hundred cycles of 27-day solar rotation, independent of the two solar cycles in which they are embedded, show distinct solar rotational modulations at each wavelength.

  5. Solar rotational modulations of spectral irradiance and correlations with the variability of total solar irradiance

    NASA Astrophysics Data System (ADS)

    Lee, Jae N.; Cahalan, Robert F.; Wu, Dong L.

    2016-09-01

    Aims: We characterize the solar rotational modulations of spectral solar irradiance (SSI) and compare them with the corresponding changes of total solar irradiance (TSI). Solar rotational modulations of TSI and SSI at wavelengths between 120 and 1600 nm are identified over one hundred Carrington rotational cycles during 2003-2013. Methods: The SORCE (Solar Radiation and Climate Experiment) and TIMED (Thermosphere Ionosphere Mesosphere Energetics and Dynamics)/SEE (Solar EUV Experiment) measured and SATIRE-S modeled solar irradiances are analyzed using the EEMD (Ensemble Empirical Mode Decomposition) method to determine the phase and amplitude of 27-day solar rotational variation in TSI and SSI. Results: The mode decomposition clearly identifies 27-day solar rotational variations in SSI between 120 and 1600 nm, and there is a robust wavelength dependence in the phase of the rotational mode relative to that of TSI. The rotational modes of visible (VIS) and near infrared (NIR) are in phase with the mode of TSI, but the phase of the rotational mode of ultraviolet (UV) exhibits differences from that of TSI. While it is questionable that the VIS to NIR portion of the solar spectrum has yet been observed with sufficient accuracy and precision to determine the 11-year solar cycle variations, the temporal variations over one hundred cycles of 27-day solar rotation, independent of the two solar cycles in which they are embedded, show distinct solar rotational modulations at each wavelength.

  6. 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.

  7. Efforts to Simulate Solar Wind Turbulence

    NASA Technical Reports Server (NTRS)

    Goldstein, Melvyn L.

    2007-01-01

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

  8. 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.

  9. 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.

  10. Ionospheric Change and Solar EUV Irradiance

    NASA Astrophysics Data System (ADS)

    Sojka, J. J.; David, M.; Jensen, J. B.; Schunk, R. W.

    2011-12-01

    The ionosphere has been quantitatively monitored for the past six solar cycles. The past few years of observations are showing trends that differ from the prior cycles! Our good statistical relationships between the solar radio flux index at 10.7 cm, the solar EUV Irradiance, and the ionospheric F-layer peak density are showing indications of divergence! Present day discussion of the Sun-Earth entering a Dalton Minimum would suggest change is occurring in the Sun, as the driver, followed by the Earth, as the receptor. The dayside ionosphere is driven by the solar EUV Irradiance. But different components of this spectrum affect the ionospheric layers differently. For a first time the continuous high cadence EUV spectra from the SDO EVE instrument enable ionospheric scientists the opportunity to evaluate solar EUV variability as a driver of ionospheric variability. A definitive understanding of which spectral components are responsible for the E- and F-layers of the ionosphere will enable assessments of how over 50 years of ionospheric observations, the solar EUV Irradiance has changed. If indeed the evidence suggesting the Sun-Earth system is entering a Dalton Minimum periods is correct, then the comprehensive EVE solar EUV Irradiance data base combined with the ongoing ionospheric data bases will provide a most fortuitous fiduciary reference baseline for Sun-Earth dependencies. Using the EVE EUV Irradiances, a physics based ionospheric model (TDIM), and 50 plus years of ionospheric observation from Wallops Island (Virginia) the above Sun-Earth ionospheric relationship will be reported on.

  11. Electron irradiation of modern solar cells

    NASA Technical Reports Server (NTRS)

    Anspaugh, B. E.; Miyahira, T. F.

    1977-01-01

    A number of modern solar cell types representing 1976 technology (as well as some older types) were irradiated with 1 MeV electrons (and a limited number with 2 MeV electrons and 10 MeV protons). After irradiation, the cells were annealed, with I-V curves measured under AMO at 30 C. The purpose was to provide data to be incorporated in the revision of the solar cell radiation handbook. Cell resistivities ranged from 2 to 20 ohm-cm, and cell thickness from 0.05 to 0.46 mm. Cell types examined were conventional, shallow junction, back surface field (BSF), textured, and textured with BSF.

  12. Correlations between neutral and ionized solar wind

    NASA Astrophysics Data System (ADS)

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

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

  13. BMSW - Fast solar wind monitor in operation

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

  14. Origin of the Ubiquitous Fast Solar Wind

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

  16. Solar Irradiance Observations during Solar Cycles 22 and 23

    NASA Astrophysics Data System (ADS)

    White, O. R.; de Toma, G.; Chapman, G. A.; Walton, S. R.; Preminger, D. G.; Cookson, A. M.; Harvey, K. L.; Livingston, W. C.

    2002-05-01

    We present a study of Total Solar Irradiance (TSI) variations during solar cycles 22 and 23 from 1986 to the present. We will review the recent measurements of solar magnetism, solar activity, and radiative variability from both ground-based and space observatories and compare TSI observations with empirical models of solar irradiance variability based on facular and sunspot observations. To estimate facular/plage and sunspot contribution to TSI we use the photometric indices derived from the SFO full-disk solar images from 1988 to the present in the CaIIK line at 393.4nm and in the red continuum at 672.3 nm. In these indices, each solar structure is included with its measured contrast and area. We also use the MgII core-to-wing index from space observatories as an alternative index for plages and network. Comparison of the rising and maximum phases of the two solar cycles, shows that cycle 23 is magnetically weaker with sunspot and facular area almost a factor of two lower than in solar cycle 22. However, analysis of multi-wavelength observations indicate that different wavelengths respond differently to the decreased magnetic activity during solar cycle 23.

  17. 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.

  18. Mars ionospheric response to solar wind variability

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

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

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

    NASA Astrophysics Data System (ADS)

    Hsu, T. S.

    2015-12-01

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

  20. Dynamics of solar wind speed: Cycle 23

    NASA Astrophysics Data System (ADS)

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

    2017-04-01

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

  1. 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.

  2. 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.

  3. Are There Natural Categories of Solar Wind?

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  4. Parameterization of daily solar global ultraviolet irradiation.

    PubMed

    Feister, U; Jäkel, E; Gericke, K

    2002-09-01

    Daily values of solar global ultraviolet (UV) B and UVA irradiation as well as erythemal irradiation have been parameterized to be estimated from pyranometer measurements of daily global and diffuse irradiation as well as from atmospheric column ozone. Data recorded at the Meteorological Observatory Potsdam (52 degrees N, 107 m asl) in Germany over the time period 1997-2000 have been used to derive sets of regression coefficients. The validation of the method against independent data sets of measured UV irradiation shows that the parameterization provides a gain of information for UVB, UVA and erythemal irradiation referring to their averages. A comparison between parameterized daily UV irradiation and independent values of UV irradiation measured at a mountain station in southern Germany (Meteorological Observatory Hohenpeissenberg at 48 degrees N, 977 m asl) indicates that the parameterization also holds even under completely different climatic conditions. On a long-term average (1953-2000), parameterized annual UV irradiation values are 15% and 21% higher for UVA and UVB, respectively, at Hohenpeissenberg than they are at Potsdam. Daily global and diffuse irradiation measured at 28 weather stations of the Deutscher Wetterdienst German Radiation Network and grid values of column ozone from the EPTOMS satellite experiment served as inputs to calculate the estimates of the spatial distribution of daily and annual values of UV irradiation across Germany. Using daily values of global and diffuse irradiation recorded at Potsdam since 1937 as well as atmospheric column ozone measured since 1964 at the same site, estimates of daily and annual UV irradiation have been derived for this site over the period from 1937 through 2000, which include the effects of changes in cloudiness, in aerosols and, at least for the period of ozone measurements from 1964 to 2000, in atmospheric ozone. It is shown that the extremely low ozone values observed mainly after the eruption of Mt

  5. The Total Solar Irradiance Climate Data Record

    NASA Astrophysics Data System (ADS)

    Dewitte, Steven; Nevens, Stijn

    2016-10-01

    We present the composite measurements of total solar irradiance (TSI) as measured by an ensemble of space instruments. The measurements of the individual instruments are put on a common absolute scale, and their quality is assessed by intercomparison. The composite time series is the average of all available measurements. From 1984 April to the present the TSI shows a variation in phase with the 11 yr solar cycle and no significant changes of the quiet-Sun level in between the three covered solar minima.

  6. Studies of Solar EUV Irradiance from SOHO

    NASA Technical Reports Server (NTRS)

    Floyd, Linton

    2002-01-01

    The Extreme Ultraviolet (EUV) irradiance central and first order channel time series (COC and FOC) from the Solar EUV Monitor aboard the Solar and Heliospheric observatory (SOHO) issued in early 2002 covering the time period 1/1/96-31/1201 were analyzed in terms of other solar measurements and indices. A significant solar proton effect in the first order irradiance was found and characterized. When this effect is removed, the two irradiance time series are almost perfectly correlated. Earlier studies have shown good correlation between the FOC and the Hall core-to-wing ratio and likewise, it was the strongest component of the COC. Analysis of the FOC showed dependence on the F10.7 radio flux. Analysis of the CDC signals showed additional dependences on F10.7 and the GOES x-ray fluxes. The SEM FOC was also well correlated with thein 30.4 nm channel of the SOHO EUV Imaging Telescope (EIT). The irradiance derived from all four EIT channels (30.4 nm, 17.1 nm, 28.4 nm, and 19.5 nm) showed better correlation with MgII than F10.7.

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

    NASA Astrophysics Data System (ADS)

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

    2005-03-01

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

  8. Solar wind origin in coronal funnels.

    PubMed

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

    2005-04-22

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

  9. 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

  10. Solar EUV and UV spectral irradiances and solar indices

    NASA Astrophysics Data System (ADS)

    Floyd, Linton; Newmark, Jeff; Cook, John; Herring, Lynn; McMullin, Don

    2005-01-01

    Several experiments have measured solar EUV/UV flux in the last 10 15 years including SUSIM UARS, SOHO CELIAS SEM, and SOHO EIT and have generated multi-year spectral irradiance time series. Empirical models of these important sources of radiant energy are often based on solar activity proxies, most often, the solar 10.7 cm radio flux (F10.7). The short- and long-term correspondence of four solar activity index time series International Sunspot Number, the He 1083 Equivalent Width, F10.7, and the Mg II core-to-wing ratio are analyzed. All of these show well-correlated long-term behavior with F10.7 and Mg II showing the greatest long-term agreement among all of the index pairs. However, during the recent maximum period of solar cycle 23, both the ISN and He 1083 have diverged significantly from the others. Recent UV and EUV measurements are compared with Mg II and F10.7 to assess their value as solar activity proxies. In every case, Mg II was found to correlate more strongly than F10.7 with the UV and EUV time series which correspond to a range of solar atmospheric temperatures of 4000K 2 MK. This correspondence indicates that the mechanisms underlying irradiances changes from upper photospheric chromospheric, transition region, and lower coronal solar atmospheric layers are closely linked.

  11. Slow Solar Wind: Observations and Modeling

    NASA Technical Reports Server (NTRS)

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

    2016-01-01

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

  12. Slow Solar Wind: Observations and Modeling

    NASA Technical Reports Server (NTRS)

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

    2016-01-01

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

  13. Slow Solar Wind: Observations and Modeling

    NASA Astrophysics Data System (ADS)

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

    2016-11-01

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

  14. 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.

  15. Ancient solar wind in lunar microbreccias

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

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

  16. 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.

  17. Pluto-Charon solar wind interaction dynamics

    NASA Astrophysics Data System (ADS)

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

    2017-05-01

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

  18. Mars Ionospheric Response to Solar Wind Variability

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

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

  19. Darkening of silicate rock powders by solar wind sputtering.

    NASA Technical Reports Server (NTRS)

    Hapke, B.

    1973-01-01

    Hydrogen ion irradiation of powdered igneous rocks, including Apollo rocks, has been observed in the laboratory to darken the powders and to make their optical properties similar to the moon's. An extensive series of investigations shows that this darkening is not spurious. These results are consistent with those of other investigators, including Nash (1967). Darkening of lunar igneous rock powders by the formation of solar wind-sputtered glass films is a real process which occurs on the moon. The time scale for darkening of undisturbed lunar soil is of the order of 50,000-100,000 yr. Comparison of the rates of the formation of glasses on the lunar surface by solar wind sputter-deposition, meteorite impact melting, and impact vaporization-deposition indicates that these processes are of comparable importance under the present flux of meteorites.

  20. Solar wind propagation by magnetic lasso

    NASA Astrophysics Data System (ADS)

    Dósa, Melinda; Opitz, Andrea

    2017-04-01

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

  1. Forecasting solar extreme and far ultraviolet irradiance

    NASA Astrophysics Data System (ADS)

    Henney, C. J.; Hock, R. A.; Schooley, A. K.; Toussaint, W. A.; White, S. M.; Arge, C. N.

    2015-03-01

    A new method is presented to forecast the solar irradiance of selected wavelength ranges within the extreme ultraviolet (EUV) and far ultraviolet (FUV) bands. The technique is similar to a method recently published by Henney et al. (2012) to predict solar 10.7 cm (2.8 GHz) radio flux, abbreviated F10.7, utilizing advanced predictions of the global solar magnetic field generated by a flux transport model. In this and the previous study, we find good correlation between the absolute value of the observed photospheric magnetic field and selected EUV/FUV spectral bands. By evolving solar magnetic maps forward 1 to 7 days with a flux transport model, estimations of the Earth side solar magnetic field distribution are generated and used to forecast irradiance. For example, Pearson correlation coefficient values of 0.99, 0.99, and 0.98 are found for 1 day, 3 day, and 7 day predictions, respectively, of the EUV band from 29 to 32 nm. In the FUV, for example, the 160 to 165 nm spectral band, correlation values of 0.98, 0.97, and 0.96 are found for 1 day, 3 day, and 7 day predictions, respectively. In the previous study, the observed F10.7 signal is found to correlate well with strong magnetic field (i.e., sunspot) regions. Here we find that solar EUV and FUV signals are significantly correlated with the weaker magnetic fields associated with plage regions, suggesting that solar magnetic indices may provide an improved indicator (relative to the widely used F10.7 signal) of EUV and FUV nonflaring irradiance variability as input to ionospheric and thermospheric models.

  2. Solar wind ion composition and charge states

    NASA Technical Reports Server (NTRS)

    vonSteiger, R.

    1995-01-01

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

  3. Complexity induced solar wind turbulence and evolution

    NASA Astrophysics Data System (ADS)

    Chang, T.

    2003-04-01

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

  4. Solar wind charge exchange during geomagnetic storms

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

  5. 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.

  6. Solar wind proton temperature-velocity relationship

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

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

  7. 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.

  8. 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.

  9. 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.

  10. The effects of sunspots on solar irradiance

    NASA Technical Reports Server (NTRS)

    Hudson, H. S.; Silva, S.; Woodard, M.; Willson, R. C.

    1982-01-01

    It is pointed out that the darkness of a sunspot on the visible hemisphere of the sun will reduce the solar irradiance on the earth. Approaches are discussed for obtaining a crude estimate of the irradiance deficit produced by sunspots and of the total luminosity reduction for the whole global population of sunspots. Attention is given to a photometric sunspot index, a global measure of spot flux deficit, and models for the compensating flux excess. A model is shown for extrapolating visible-hemisphere spot areas to the invisible hemisphere. As an illustration, this extrapolation is used to calculate a very simple model for the reradiation necessary to balance the flux deficit.

  11. Temporal Variations in Solar Irradiance Since 1947

    NASA Astrophysics Data System (ADS)

    Tebabal, A.; Damtie, B.; Nigussie, M.; Yizengaw, E.

    2017-08-01

    The study of variations in total solar irradiance (TSI) and spectral irradiance is important for understanding how the Sun affects the Earth's climate. A data-driven approach is used in this article to analyze and model the temporal variation of the TSI and Mg ii index back to 1947. In both cases, observed data in the time interval of the satellite era, 1978 - 2013, were used for neural network (NN) model-design and testing. For this particular purpose, the evolution of the solar magnetic field is assumed to be the main driver for the day-to-day irradiance variability. First, we design a model for the Mg ii index data from F10.7 cm solar radio-flux using the NN approach in the time span of 1978 through 2013. Results of Mg ii index model were tested using various numbers of hidden nodes. The predicted values of the hidden layer with five nodes correspond well to the composite Mg ii values. The model reproduces 94% of the variability in the composite Mg ii index, including the secular decline between the 1996 and 2008 solar cycle minima. Finally, the extrapolation of the Mg ii index was performed using the developed model from F10.7 cm back to 1947. Similarly, the NN model was designed for TSI variability study over the time span of the satellite era using data from the Physikalisch-Meteorologisches Observatorium Davos (PMOD) as a target, and solar activity indices as model inputs. This model was able to reproduce the daily irradiance variations with a correlation coefficient of 0.937 from sunspot and facular measurements in the time span of 1978 - 2013. Finally, the temporal variation of the TSI was analyzed using the designed NN model back to 1947 from the Photometric Sunspot Index (PSI) and the extrapolated Mg ii index. The extrapolated TSI result indicates that the amplitudes of Solar Cycles 19 and 21 are closely comparable to each other, and Solar Cycle 20 appears to be of lower irradiance during its maximum.

  12. Escape for the Slow Solar Wind

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2017-05-01

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

  13. Parameterization of Solar Global Uv Irradiation

    NASA Astrophysics Data System (ADS)

    Feister, U.; Jaekel, E.; Gericke, K.

    Daily doses of solar global UV-B, UV-A, and erythemal irradiation have been param- eterized to be calculated from pyranometer data of global and diffuse irradiation as well as from atmospheric column ozone measured at Potsdam (52 N, 107 m asl). The method has been validated against independent data of measured UV irradiation. A gain of information is provided by use of the parameterization for the three UV compo- nents (UV-B, UV-A and erythemal) referring to average values of UV irradiation. Ap- plying the method to UV irradiation measured at the mountain site Hohenpeissenberg (48 N, 977 m asl) shows that the parameterization even holds under completely differ- ent climatic conditions. On a long-term average (1953 - 2000), parameterized annual UV irradiation values are by 15 % (UV-A) and 21 % (UV-B), respectively, higher at Hohenpeissenberg, than they are at Potsdam. Using measured input data from 27 Ger- man weather stations, the method has been also applied to estimate the spatial distribu- tion of UV irradiation across Germany. Daily global and diffuse irradiation measured at Potsdam (1937 -2000) as well as atmospheric column ozone measured at Potsdam between1964 - 2000 have been used to derive long-term estimates of daily and annual totals of UV irradiation that include the effects of changes in cloudiness, in aerosols and, at least for the period 1964 to 2000, also in atmospheric ozone. It is shown that the extremely low ozone values observed mainly after the volcanic eruptions of Mt. Pinatubo in 1991 have substantially enhanced UV-B irradiation in the first half of the 90ies of the last century. The non-linear long-term changes between 1968 and 2000 amount to +4% ...+5% for annual global and UV-A irradiation mainly due to changing cloudiness, and +14% ... +15% for UV-B and erythemal irradiation due to both chang- ing cloudiness and decreasing column ozone. Estimates of long-term changes in UV irradiation derived from data measured at other German sites are

  14. Influence of solar UV irradiance on quasi-biennial oscillations in the Earth's atmosphere

    NASA Astrophysics Data System (ADS)

    Gabis, I.; Troshichev, O.

    2003-04-01

    A study of relationships between variations in the solar ultraviolet irradiance and quasi-biennial oscillations (QBO) in the Earth's atmosphere has been carried out by using the composite MgII index as a proxy of the solar UV irradiance. Detail analysis of changes in the stratospheric wind directions at layers from 10 mB to 70 mB for 1978-2001 showed that the wind changes start at higher altitudes and go down to lower ones, the wind intensity being the greatest in layer of the maximum ozone content (about 20 mB). The definite relationship between periodicity of changes in the solar UV irradiance and QBO is found: the averaged UV irradiance is obviously larger for the east QBO phase than for the west QBO phase. The reversal of stratospheric winds proceeds from the top to down with the certain ciclicity, and efficiency of the UV irradiation influence on stratosphere seems to be different at various stages of this ciclicity. As a result, the character and duration of the mean zonal wind direction in the equatorial stratosphere is determined by proper combination of the UV variation and seasonal changes in atmospheric circulation.

  15. Active-region evolution and solar rotation variations in solar UV irradiance, total solar irradiance, and soft X rays

    NASA Technical Reports Server (NTRS)

    Donnelly, R. F.; Heath, D. F.; Lean, J. L.

    1982-01-01

    Variations in the total solar irradiance, solar UV spectral irradiance, and solar soft X-ray emission caused by active region evolution and solar rotation are analyzed by using concurrent measurements from the NIMBUS 7 and GOES satellites. The observations are interpreted by using simple empirical models that relate ground-based observations of the size and location of sunspots and plages to the full-disk temporal variations. It is found that the major dips in the photospheric total solar irradiance S, which are evident in both satellite measurements and model predictions, are usually not accompanied by outstanding enhancements in the chromospheric and upper photospheric UV spectral irradiance or coronal X rays. The main cause of this difference between the variability of S and of the UV flux is that the total chromospheric plage enhancements are not outstanding at those times when the total sunspot are outstanding. X rays are even more variable because of a much wider CMD sensitivity.

  16. Solar wind turbulence: Observations of MHD effects

    NASA Technical Reports Server (NTRS)

    Bavassano, B.

    1995-01-01

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

  17. Solar Wind Change Exchange from the Magnetosheath

    NASA Technical Reports Server (NTRS)

    Snowden, Steve

    2008-01-01

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

  18. Solar wind controls on Mercury's magnetospheric cusp

    NASA Astrophysics Data System (ADS)

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

    2017-06-01

    This study assesses the response of the cusp to solar wind changes comprehensively, using 2848 orbits of MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) observation. The assessment entails four steps: (1) propose and validate an approach to estimate the solar wind magnetic field (interplanetary magnetic field (IMF)) for MESSENGER's cusp transit; (2) define an index σ measuring the intensity of the magnetic disturbance which significantly peaks within the cusp and serves as an indicator of the cusp activity level; (3) construct an empirical model of σ as a function of IMF and Mercury's heliocentric distance rsun, through linear regression; and (4) use the model to estimate and compare the polar distribution of the disturbance σ under different conditions for a systematic comparison. The comparison illustrates that the disturbance peak over the cusp is strongest and widest extending in local time for negative IMF Bx and negative IMF Bz, and when Mercury is around the perihelion. Azimuthal shifts are associated with both IMF By and rsun: the cusp moves toward dawn when IMF By or rsun decrease. These dependences are explained in terms of the IMF Bx-controlled dayside magnetospheric topology, the component reconnection model applied to IMF By and Bz, and the variability of solar wind ram pressure associated with heliocentric distance rsun. The applicability of the component reconnection model on IMF By indicates that at Mercury reconnection occurs at lower shear angles than at Earth.Plain Language SummaryMercury's magnetosphere was suggested to be particularly sensitive to <span class="hlt">solar</span> <span class="hlt">wind</span> conditions. This study investigates the response of the magnetospheric cusp to <span class="hlt">solar</span> <span class="hlt">wind</span> conditions systematically. For this purpose, we analyze the statistical predictability of interplanetary magnetic field (IMF) at Mercury, develop an approach for estimating the <span class="hlt">solar</span> <span class="hlt">wind</span> magnetic field (IMF) for MErcury Surface</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080043891&hterms=snowden&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsnowden','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080043891&hterms=snowden&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsnowden"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Change Exchange from the Magnetosheath</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Snowden, Steve</p> <p>2008-01-01</p> <p>We report the results of a long (approximately 100 ks) XMM-Newton observation designed to observe <span class="hlt">solar</span> <span class="hlt">wind</span> charge exchange emission (SWCX) from Earth's magnetosheath. By luck, the observation took place during a period of minimal <span class="hlt">solar</span> <span class="hlt">wind</span> flux so the SWCX emission was also minimal. Never-the-less, there is a significant if not stunning correlation between the observed O VIII count rate and our model for magnetosheath emission. We also report on the observed O VII and O VII emission.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960014426&hterms=kuhn&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dkuhn','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960014426&hterms=kuhn&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dkuhn"><span><span class="hlt">Solar</span> variability in <span class="hlt">irradiance</span> and oscillations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kuhn, Jeff R.</p> <p>1995-01-01</p> <p>The signature of the <span class="hlt">solar</span> cycle appears in helioseismic frequencies and splittings. It is known that the changing outer superadiabatic region of the sun is responsible for this. The deeper <span class="hlt">solar</span>-cycle mechanism from the surface changes, and, in particular, how magnetic fields perturb the global modes, the <span class="hlt">solar</span> <span class="hlt">irradiance</span> and the luminosity, is discussed. The <span class="hlt">irradiance</span> and helioseismic changes are described. The interpretation of seismic and photometric data is discussed, considering current one-dimensional models and phenomenology. It is discussed how the long term <span class="hlt">solar</span>-cycle luminosity effect could be caused by changes occurring near the base of the convection zone (CZ). It is shown that a thin toroidal flux sheath at the top of the radiative zone changed the thermal stratification immediately below the CZ over a <span class="hlt">solar</span>-cycle timescale in two ways: the temperature of the magnetized fluid becomes hotter than the surrounding fluid, and the temperature gradient steepens above the magnetized region. The testing of CZ dynamics and extension of numerical experiments to global scales are considered.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960014426&hterms=Kuhn&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DKuhn','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960014426&hterms=Kuhn&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DKuhn"><span><span class="hlt">Solar</span> variability in <span class="hlt">irradiance</span> and oscillations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kuhn, Jeff R.</p> <p>1995-01-01</p> <p>The signature of the <span class="hlt">solar</span> cycle appears in helioseismic frequencies and splittings. It is known that the changing outer superadiabatic region of the sun is responsible for this. The deeper <span class="hlt">solar</span>-cycle mechanism from the surface changes, and, in particular, how magnetic fields perturb the global modes, the <span class="hlt">solar</span> <span class="hlt">irradiance</span> and the luminosity, is discussed. The <span class="hlt">irradiance</span> and helioseismic changes are described. The interpretation of seismic and photometric data is discussed, considering current one-dimensional models and phenomenology. It is discussed how the long term <span class="hlt">solar</span>-cycle luminosity effect could be caused by changes occurring near the base of the convection zone (CZ). It is shown that a thin toroidal flux sheath at the top of the radiative zone changed the thermal stratification immediately below the CZ over a <span class="hlt">solar</span>-cycle timescale in two ways: the temperature of the magnetized fluid becomes hotter than the surrounding fluid, and the temperature gradient steepens above the magnetized region. The testing of CZ dynamics and extension of numerical experiments to global scales are considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994AdSpR..14..161B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994AdSpR..14..161B"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> composition from the Moon;</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bochsler, P.</p> <p>1994-06-01</p> <p>The lunar regolith contains the best accessible record of the <span class="hlt">solar</span> <span class="hlt">wind</span> composition of the past few billion years. Interpreting this record crucially depends on our understanding of the implantation mechanisms, potential alternative sources other than the <span class="hlt">solar</span> <span class="hlt">wind</span>, storage and degradation processes, and transport- and loss-mechanisms of trapped particles in the regolith. We therefore suggest that a future mission to the Moon should contain the following objectives: (1) A thorough in-situ investigation of the contemporary <span class="hlt">solar</span> <span class="hlt">wind</span> composition by means of long-duration exposure experiments with various techniques as baseline for investigation of the historic and ancient <span class="hlt">solar</span> <span class="hlt">wind</span>. (2) A multidisciplinary program, involving an experimental investigation of implantation-, storage- and loss-processes of <span class="hlt">solar</span> particles at the conditions of the lunar environment. This program is complementary to an elaborated systematic sampling of all layers of the lunar regolith, based on the experience from the Apollo- and the Luna-missions. Difficulties with the interpretation of the lunar record are illuminated in the case of surface correlated nitrogen. (3) A complementary goal for the extensive sampling of the lunar surface is the documentation of the lunar regolith for future generations, prior to extended human activites which could have detrimental effects to the lunar environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009LNP...778..223I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009LNP...778..223I"><span>Diagnostics of the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Plasma</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Issautier, K.</p> <p></p> <p>The <span class="hlt">solar</span> <span class="hlt">wind</span> is a fully ionized plasma, coming from the outer atmosphere of the Sun, the so-called <span class="hlt">solar</span> corona, which expands as a supersonic flow into the interplanetary medium [55]. The first observations indicating that the Sun might be emitting a <span class="hlt">wind</span> were made by Biermann in 1946 of comet tails [1], which are observed to point away from the Sun. Comets usually exhibit two tails: a dust tail driven by the radiation pressure and a plasma tail, which points in slightly different directions pushed by the “<span class="hlt">solar</span> corpuscular radiation” of the Sun. In 1958, E.N. Parker explained theoretically this “particle radiation” using a simple fluid model [55], showing that the <span class="hlt">solar</span> atmosphere is not in hydrostatic equilibrium but must expand into the interplanetary medium as a <span class="hlt">wind</span>. The existence of this <span class="hlt">solar</span> <span class="hlt">wind</span> was debated until it was indeed confirmed by spacecraft Lunik 2 and 3 [16] and continuously observed by Mariner 2 [53]. The Parker theory is discussed fully in Chap. 7 (Velli).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170005311','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170005311"><span>Marshall Space Flight Center's <span class="hlt">Solar</span> <span class="hlt">Wind</span> Facility</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wright, K. H.; Schneider, T. A.; Vaughn, J. A.; Whittlesey, P. L.</p> <p>2017-01-01</p> <p>Historically, NASA's Marshall Space Flight Center (MSFC) has operated a <span class="hlt">Solar</span> <span class="hlt">Wind</span> Facility (SWF) to provide long term particle and photon exposure to material samples. The requirements on the particle beam details were not stringent as the cumulative fluence level is the test goal. Motivated by development of the faraday cup instrument on the NASA <span class="hlt">Solar</span> Probe Plus (SPP) mission, the MSFC SWF has been upgraded to included high fidelity particle beams providing broadbeam ions, broadbeam electrons, and narrow beam protons or ions, which cover a wide dynamic range of <span class="hlt">solar</span> <span class="hlt">wind</span> velocity and flux conditions. The large vacuum chamber with integrated cryo-shroud, combined with a 3-axis positioning system, provides an excellent platform for sensor development and qualification. This short paper provides some details of the SWF charged particle beams characteristics in the context of the <span class="hlt">Solar</span> Probe Plus program requirements. Data will be presented on the flux and energy ranges as well as beam stability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930067663&hterms=ion+Composition+Experiment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dion%2BComposition%2BExperiment','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930067663&hterms=ion+Composition+Experiment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dion%2BComposition%2BExperiment"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> composition measurements by the Ulysses SWICS experiment during transient <span class="hlt">solar</span> <span class="hlt">wind</span> flows</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Galvin, A. B.; Gloeckler, G.; Ipavich, F. M.; Shafer, C. M.; Geiss, J.; Ogilvie, K.</p> <p>1993-01-01</p> <p>For the March/April 1991 time period, the alpha/proton abundance ratio, the proton kinetic temperature and speed distributions, and the relative abundance of O(+7) to O(+6) is determined over each 13-minute duty cycle of the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Ion Composition Spectrometer (SWICs) experiment on Ulysses. The ratio O(+7)/O(+6) (as a relative measure of ionization temperature) is shown to be useful in identifying possible coronal mass ejection (CME) events. We report measurements of silicon/oxygen abundance ratios and silicon and oxygen charge state distributions in the <span class="hlt">solar</span> <span class="hlt">wind</span> during a CME event and compare these compositions to a 'normal' <span class="hlt">solar</span> <span class="hlt">wind</span> time period.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996AAS...188.3615L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996AAS...188.3615L"><span><span class="hlt">Solar</span> <span class="hlt">Irradiance</span>, Plage and SOHO UV Images</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lopresto, James C.; Manross, Kevin</p> <p>1996-05-01</p> <p>Calcium K and H alpha plage and sunspot area have been monitored using Big Bear Observatory images on the INTERNET since November of 1992. The purpose of the project is to determine the correlation of changing plage area and <span class="hlt">solar</span> <span class="hlt">irradiance</span> changes. We also monitor changes in the K2 spec- tral index provided daily from Sacramento Peak. With the recent launching of the SOHO satellite, we are able to monitor the plage in the He II 304 Angstroms UV image. This image is near the top of the chromosphere nar or just under the transition region. The images show limb brightening as expected. Since it is widely believed that short time scale changes in the UV may be the dominant cause for low amplitude <span class="hlt">solar</span> <span class="hlt">irradiance</span> changes, the comparison of the "plage" ara in these UV images to those in conventional visible images should prove instructive.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920017194','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920017194"><span>Workshop on <span class="hlt">Solar</span> Activity, <span class="hlt">Solar</span> <span class="hlt">Wind</span>, Terrestrial Effects, and <span class="hlt">Solar</span> Acceleration</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1992-01-01</p> <p>A summary of the proceedings from the workshop are presented. The areas covered were <span class="hlt">solar</span> activity, <span class="hlt">solar</span> <span class="hlt">wind</span>, terrestrial effects, and <span class="hlt">solar</span> acceleration. Specific topics addressed include: (1) <span class="hlt">solar</span> cycle manifestations, both large and small scale, as well as long-term and short-term changes, including transients such as flares; (2) sources of <span class="hlt">solar</span> <span class="hlt">wind</span>, as identified by interplanetary observations including coronal mass ejections (CME's) or x-ray bright points, and the theory for and evolution of large-scale and small-scale structures; (3) magnetosphere responses, as observed by spacecraft, to variable <span class="hlt">solar</span> <span class="hlt">wind</span> and transient energetic particle emissions; and (4) origin and propagation of <span class="hlt">solar</span> cosmic rays as related to <span class="hlt">solar</span> activity and terrestrial effects, and <span class="hlt">solar</span> <span class="hlt">wind</span> coronal-hole relationships and dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/570069','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/570069"><span><span class="hlt">Wind/solar</span> resource in Texas</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nelson, V.; Starcher, K.; Gaines, H.</p> <p>1997-12-31</p> <p>Data are being collected at 17 sites to delineate a baseline for the <span class="hlt">wind</span> and <span class="hlt">solar</span> resource across Texas. <span class="hlt">Wind</span> data are being collected at 10, 25, and 40 m (in some cases at 50 m) to determine <span class="hlt">wind</span> shear and power at hub heights of large turbines. Many of the sites are located in areas of predicted terrain enhancement. The typical day in a month for power and <span class="hlt">wind</span> turbine output was calculated for selected sites and combination of sites; distributed systems. Major result to date is that there is the possibility of load matching in South Texas during the summer months, even though the average values by month indicate a low <span class="hlt">wind</span> potential.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MNRAS.463....2S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MNRAS.463....2S"><span>Implications of <span class="hlt">solar</span> <span class="hlt">wind</span> measurements for <span class="hlt">solar</span> models and composition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Serenelli, Aldo; Scott, Pat; Villante, Francesco L.; Vincent, Aaron C.; Asplund, Martin; Basu, Sarbani; Grevesse, Nicolas; Peña-Garay, Carlos</p> <p>2016-11-01</p> <p>We critically examine recent claims of a high <span class="hlt">solar</span> metallicity by von Steiger & Zurbuchen (2016, vSZ16) based on in situ measurements of the <span class="hlt">solar</span> <span class="hlt">wind</span>, rather than the standard spectroscopically inferred abundances (Asplund et al. 2009, hereafter AGSS09). We test the claim by Vagnozzi et al. (2016) that a composition based on the <span class="hlt">solar</span> <span class="hlt">wind</span> enables one to construct a standard <span class="hlt">solar</span> model in agreement with helioseismological observations and thus solve the decades-old <span class="hlt">solar</span> modelling problem. We show that, although some helioseismological observables are improved compared to models computed with spectroscopic abundances, most are in fact worse. The high abundance of refractory elements leads to an overproduction of neutrinos, with a predicted 8B flux that is nearly twice its observed value, and 7Be and CNO fluxes that are experimentally ruled out at high confidence. A combined likelihood analysis shows that models using the vSZ16 abundances are worse than AGSS09 despite a higher metallicity. We also present astrophysical and spectroscopic arguments showing the vSZ16 composition to be an implausible representation of the <span class="hlt">solar</span> interior, identifying the first ionization potential effect in the outer <span class="hlt">solar</span> atmosphere and <span class="hlt">wind</span> as the likely culprit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20110016220&hterms=solar+wind&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsolar%2Bwind','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20110016220&hterms=solar+wind&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsolar%2Bwind"><span>Coronal Plumes in the Fast <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Velli, Marco; Lionello, Roberto; Linker, Jon A.; Mikic, Zoran</p> <p>2011-01-01</p> <p>The expansion of a coronal hole filled with a discrete number of higher density coronal plumes is simulated using a time-dependent two-dimensional code. A <span class="hlt">solar</span> <span class="hlt">wind</span> model including an exponential coronal heating function and a flux of Alfven waves propagating both inside and outside the structures is taken as a basic state. Different plasma plume profiles are obtained by using different scale heights for the heating rates. Remote sensing and <span class="hlt">solar</span> <span class="hlt">wind</span> in situ observations are used to constrain the parameter range of the study. Time dependence due to plume ignition and disappearance is also discussed. Velocity differences of the order of approximately 50 km/s, such as those found in microstreams in the high-speed <span class="hlt">solar</span> <span class="hlt">wind</span>, may be easily explained by slightly different heat deposition profiles in different plumes. Statistical pressure balance in the fast <span class="hlt">wind</span> data may be masked by the large variety of body and surface waves which the higher density filaments may carry, so the absence of pressure balance in the microstreams should not rule out their interpretation as the extension of coronal plumes into interplanetary space. Mixing of plume-interplume material via the Kelvin-Helmholtz instability seems to be possible within the parameter ranges of the models defined here, only at large di stances from the Sun, beyond 0.2-0.3 AU. Plasma and composition measurements in the inner heliosphere, such as those which will become available with <span class="hlt">Solar</span> Orbiter and <span class="hlt">Solar</span> Probe Plus, should therefore definitely be able to identify plume remnants in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20110016220&hterms=solar+wind&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsolar%2Bwind','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20110016220&hterms=solar+wind&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsolar%2Bwind"><span>Coronal Plumes in the Fast <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Velli, Marco; Lionello, Roberto; Linker, Jon A.; Mikic, Zoran</p> <p>2011-01-01</p> <p>The expansion of a coronal hole filled with a discrete number of higher density coronal plumes is simulated using a time-dependent two-dimensional code. A <span class="hlt">solar</span> <span class="hlt">wind</span> model including an exponential coronal heating function and a flux of Alfven waves propagating both inside and outside the structures is taken as a basic state. Different plasma plume profiles are obtained by using different scale heights for the heating rates. Remote sensing and <span class="hlt">solar</span> <span class="hlt">wind</span> in situ observations are used to constrain the parameter range of the study. Time dependence due to plume ignition and disappearance is also discussed. Velocity differences of the order of approximately 50 km/s, such as those found in microstreams in the high-speed <span class="hlt">solar</span> <span class="hlt">wind</span>, may be easily explained by slightly different heat deposition profiles in different plumes. Statistical pressure balance in the fast <span class="hlt">wind</span> data may be masked by the large variety of body and surface waves which the higher density filaments may carry, so the absence of pressure balance in the microstreams should not rule out their interpretation as the extension of coronal plumes into interplanetary space. Mixing of plume-interplume material via the Kelvin-Helmholtz instability seems to be possible within the parameter ranges of the models defined here, only at large di stances from the Sun, beyond 0.2-0.3 AU. Plasma and composition measurements in the inner heliosphere, such as those which will become available with <span class="hlt">Solar</span> Orbiter and <span class="hlt">Solar</span> Probe Plus, should therefore definitely be able to identify plume remnants in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRA..119.2978P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRA..119.2978P"><span>Substorm occurrence during quiet <span class="hlt">solar</span> <span class="hlt">wind</span> driving</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pulkkinen, T. I.; Partamies, N.; Kilpua, E. K. J.</p> <p>2014-04-01</p> <p>We examine the OMNI database and International Monitor for Auroral Geomagnetic Effects (IMAGE) magnetometer chain records to study the substorm occurrence and characteristics during quiet <span class="hlt">solar</span> driving periods, especially during the <span class="hlt">solar</span> minimum period in 2009. We define substorm-like activations as periods where the hourly average AL is below -200 nT. Using the OMNI data set, we demonstrate that there are limiting <span class="hlt">solar</span> <span class="hlt">wind</span> speed, interplanetary magnetic field magnitude, and driving electric field values below which substorm-like activations (AL < 200 nT, intensification and decay of the electrojet) do not occur. These minimum parameter values are V < 266 km/s, B < 1.4 nT, and E < 0.025 mV/m such low values are observed less than 1% of the time. We also show that for the same level of driving <span class="hlt">solar</span> <span class="hlt">wind</span> electric field, the electrojet intensity is smaller (by few tens of nT), and the electrojet resides farther poleward (by over 1°) during extended quiet <span class="hlt">solar</span> driving in 2009 than during average <span class="hlt">solar</span> activity conditions. During the <span class="hlt">solar</span> minimum period in 2009, we demonstrate that substorm-like activations can be identified from the IMAGE magnetometer chain observations during periods when the hourly average IL index is below -100 nT. When the hourly IL activity is smaller than that, which covers 87% of the nighttime observations, the electrojet does not show coherent behavior. We thus conclude that substorm recurrence time during very quiet <span class="hlt">solar</span> <span class="hlt">wind</span> driving conditions is about 5-8 h, which is almost double that of the average <span class="hlt">solar</span> activity conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMGC23A0931L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMGC23A0931L"><span><span class="hlt">Solar</span> <span class="hlt">Irradiance</span> Data Products at the LASP Interactive <span class="hlt">Solar</span> <span class="hlt">IRradiance</span> Datacenter (LISIRD)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lindholm, D. M.; Ware DeWolfe, A.; Wilson, A.; Pankratz, C. K.; Snow, M. A.; Woods, T. N.</p> <p>2011-12-01</p> <p>The Laboratory for Atmospheric and Space Physics (LASP) has developed the LASP Interactive <span class="hlt">Solar</span> <span class="hlt">IRradiance</span> Datacenter (LISIRD, http://lasp.colorado.edu/lisird/) web site to provide access to a comprehensive set of <span class="hlt">solar</span> <span class="hlt">irradiance</span> measurements and related datasets. Current data holdings include products from NASA missions SORCE, UARS, SME, and TIMED-SEE. The data provided covers a wavelength range from soft X-ray (XUV) at 0.1 nm up to the near infrared (NIR) at 2400 nm, as well as Total <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> (TSI). Other datasets include <span class="hlt">solar</span> indices, spectral and flare models, <span class="hlt">solar</span> images, and more. The LISIRD web site features updated plotting, browsing, and download capabilities enabled by dygraphs, JavaScript, and Ajax calls to the LASP Time Series Server (LaTiS). In addition to the web browser interface, most of the LISIRD datasets can be accessed via the LaTiS web service interface that supports the OPeNDAP standard. OPeNDAP clients and other programming APIs are available for making requests that subset, aggregate, or filter data on the server before it is transported to the user. This poster provides an overview of the LISIRD system, summarizes the datasets currently available, and provides details on how to access <span class="hlt">solar</span> <span class="hlt">irradiance</span> data products through LISIRD's interfaces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17742848','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17742848"><span>Apollo 11 <span class="hlt">solar</span> <span class="hlt">wind</span> composition experiment: first results.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bühler, F; Eberhardt, P; Geiss, J; Meister, J; Signer, P</p> <p>1969-12-19</p> <p>The helium-4 <span class="hlt">solar</span> <span class="hlt">wind</span> flux during the Apollo 11 lunar surface excursion was (6.3 +/- 1.2) x 10(6) atoms per square centimeter per second. The <span class="hlt">solar</span> <span class="hlt">wind</span> direction and energy are essentially not perturbed by the moon. Evidence for a lunar <span class="hlt">solar</span> <span class="hlt">wind</span> albedo was found.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AIPC.1203.1025T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AIPC.1203.1025T"><span>Combined <span class="hlt">Solar</span> and <span class="hlt">Wind</span> Energy Systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tripanagnostopoulos, Y.; Souliotis, M.; Makris, Th.</p> <p>2010-01-01</p> <p>In this paper we present the new concept of combined <span class="hlt">solar</span> and <span class="hlt">wind</span> energy systems for buildings applications. Photovoltaics (PV) and small <span class="hlt">wind</span> turbines (WTs) can be install on buildings, in case of sufficient <span class="hlt">wind</span> potential, providing the building with electricity. PVs can be combined with thermal collectors to form the hybrid photovoltaic/thermal (PV/T) systems. The PVs (or the PV/Ts) and WT subsystems can supplement each other to cover building electrical load. In case of using PV/T collectors, the surplus of electricity, if not used or stored in batteries, can increase the temperature of the thermal storage tank of the <span class="hlt">solar</span> thermal unit. The description of the experimental set-up of the suggested PV/T/WT system and experimental results are presented. In PV/T/WT systems the output from the <span class="hlt">solar</span> part depends on the sunshine time and the output of the <span class="hlt">wind</span> turbine part depends on the <span class="hlt">wind</span> speed and is obtained any time of day or night. The use of the three subsystems can cover a great part of building energy load, contributing to conventional energy saving and environment protection. The PV/T/WT systems are considered suitable in rural and remote areas with electricity supply from stand-alone units or mini-grid connection. PV/T/WT systems can also be used in typical grid connected applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1062443','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1062443"><span>Identifying <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Ramping Events: Preprint</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Florita, A.; Hodge, B. M.; Orwig, K.</p> <p>2013-01-01</p> <p><span class="hlt">Wind</span> and <span class="hlt">solar</span> power are playing an increasing role in the electrical grid, but their inherent power variability can augment uncertainties in power system operations. One solution to help mitigate the impacts and provide more flexibility is enhanced <span class="hlt">wind</span> and <span class="hlt">solar</span> power forecasting; however, its relative utility is also uncertain. Within the variability of <span class="hlt">solar</span> and <span class="hlt">wind</span> power, repercussions from large ramping events are of primary concern. At the same time, there is no clear definition of what constitutes a ramping event, with various criteria used in different operational areas. Here the Swinging Door Algorithm, originally used for data compression in trend logging, is applied to identify variable generation ramping events from historic operational data. The identification of ramps in a simple and automated fashion is a critical task that feeds into a larger work of 1) defining novel metrics for <span class="hlt">wind</span> and <span class="hlt">solar</span> power forecasting that attempt to capture the true impact of forecast errors on system operations and economics, and 2) informing various power system models in a data-driven manner for superior exploratory simulation research. Both allow inference on sensitivities and meaningful correlations, as well as the ability to quantify the value of probabilistic approaches for future use in practice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM42B..02R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM42B..02R"><span>Hemispheric differences in <span class="hlt">solar</span> <span class="hlt">wind</span> - magnetosphere interactions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reistad, J. P.; Ostgaard, N.; Laundal, K.; Snekvik, K.; Tenfjord, P.; Oksavik, K.</p> <p>2014-12-01</p> <p>Although the aurora to a large degree behave similar in the two hemispheres, recent simultaneous observations of the global aurora from space have revealed that sometimes rather large intensity and location asymmetries are present in the global aurora. From event studies using e.g. conjugate imaging, multiple mechanisms have been proposed to be responsible for the asymmetric aurora. However, we know very little about their general importance. We have investigated the general importance of an asymmetric <span class="hlt">solar</span> <span class="hlt">wind</span> dynamo. It has been suggested that the radial component of the IMF can modify the energy conversion between the <span class="hlt">solar</span> <span class="hlt">wind</span> and magnetosphere differently in the two hemispheres in a general sense. By looking at the global aurora using IMAGE WIC during carefully selected events minimally contaminated by other mechanisms affecting the two hemispheres differently, we find that the dusk side aurora depend oppositely on the radial IMF direction in the two hemispheres. These results are consistent with an asymmetric <span class="hlt">solar</span> <span class="hlt">wind</span> dynamo where the hemispheric preference is controlled by the radial IMF. This is the first study indicating the importance of the asymmetric <span class="hlt">solar</span> <span class="hlt">wind</span> dynamo in a general sense. A different mechanism, the asymmetric loading of magnetic flux during IMF By conditions is also expected to account for North-South asymmetries in the nightside global aurora. This will be investigated using a similar approach to establish the general importance of of this IMF By mechanism on the global aurora in the two hemispheres.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=biomass&pg=7&id=ED114270','ERIC'); return false;" href="https://eric.ed.gov/?q=biomass&pg=7&id=ED114270"><span>Energy Primer: <span class="hlt">Solar</span>, Water, <span class="hlt">Wind</span>, and Biofuels.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Portola Inst., Inc., Menlo Park, CA.</p> <p></p> <p>This is a comprehensive, fairly technical book about renewable forms of energy--<span class="hlt">solar</span>, water, <span class="hlt">wind</span>, and biofuels. The biofuels section covers biomass energy, agriculture, aquaculture, alcohol, methane, and wood. The focus is on small-scale systems which can be applied to the needs of the individual, small group, or community. More than one-fourth…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Biomass+AND+energy&pg=3&id=ED114270','ERIC'); return false;" href="http://eric.ed.gov/?q=Biomass+AND+energy&pg=3&id=ED114270"><span>Energy Primer: <span class="hlt">Solar</span>, Water, <span class="hlt">Wind</span>, and Biofuels.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Portola Inst., Inc., Menlo Park, CA.</p> <p></p> <p>This is a comprehensive, fairly technical book about renewable forms of energy--<span class="hlt">solar</span>, water, <span class="hlt">wind</span>, and biofuels. The biofuels section covers biomass energy, agriculture, aquaculture, alcohol, methane, and wood. The focus is on small-scale systems which can be applied to the needs of the individual, small group, or community. More than one-fourth…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730002063','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730002063"><span>Magnetic field merging in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schindler, K.</p> <p>1972-01-01</p> <p>Magnetic field merging in the <span class="hlt">solar</span> <span class="hlt">wind</span> is discussed in terms of steady-state merging, which involves a steady flow field, and of spontaneous merging, which involves an instability such as the tearing instability. Spontaneous merging is found to be more effective than steady-state merging.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.4843L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.4843L"><span>THOR Cold <span class="hlt">Solar</span> <span class="hlt">Wind</span> (CSW) instrument</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lavraud, Benoit</p> <p>2017-04-01</p> <p>Turbulence Heating ObserveR (THOR) is the first mission concept dedicated to the study of plasma turbulence. We present the Cold <span class="hlt">Solar</span> <span class="hlt">Wind</span> (CSW) instrument that is being designed for THOR. CSW will measure the full three dimensional distribution function of <span class="hlt">solar</span> <span class="hlt">wind</span> protons and alphas with unprecedented accuracies. It will measure <span class="hlt">solar</span> <span class="hlt">wind</span> proton distributions down to at least 50 ms with energy resolution of 7% and angular resolution of 1.5°. CSW is based on a top-hat electrostatic analyzer (with very large geometric factor) design with deflectors at the entrance. The particle detection system uses Channel Electron Multipliers (CEM) associated with an analog front end Application-Specific Integrated Circuit (ASIC). CSW electronics comprises a fast sweeping high voltage board, as well as an FPGA and low voltage power supply boards to perform its operations. CSW is designed to address many of the key science objectives of THOR, in particular regarding ion-scale kinetic aspects of <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080019653&hterms=wind+night+day&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dwind%2Bnight%2Bday','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080019653&hterms=wind+night+day&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dwind%2Bnight%2Bday"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Drivers for Steady Magnetospheric Convection</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>McPherron, Robert L.; O'Brien, T. Paul; Thompson, Scott; Lui, A. T. Y. (Editor)</p> <p>2005-01-01</p> <p>Steady magnetospheric convection (SMC) also known as convection bays, is a particular mode of response of the magnetosphere to <span class="hlt">solar</span> <span class="hlt">wind</span> coupling. It is characterized by convection lasting for times longer than a typical substorm recovery during which no substorms expansions can be identified. It is generally believed that the <span class="hlt">solar</span> <span class="hlt">wind</span> must be unusually steady for the magnetosphere to enter this state. However, most previous studies have assumed this is true and have used such conditions to identify events. In a preliminary investigation using only the AE and AL indices to select events we have shown that these expectations are generally correct. SMC events seem to be associated with slow speed <span class="hlt">solar</span> <span class="hlt">wind</span> and moderate, stable IMF Bz. In this report we extend our previous study including additional parameters and the time variations in various statistical quantities. For the intervals identified as SMCs we perform a detailed statistical analysis of the properties of different <span class="hlt">solar</span> <span class="hlt">wind</span> variables. We compare these statistics to those determined from all data, and from intervals in which substorms but not SMCs are present. We also consider the question of whether substorms are required to initiate and terminate an SMC. We conclude that the intervals we have identified as SMC are likely to be examples of the original Dungey concept of balanced reconnection at a pair of x-lines on the day and night side of the Earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080019653&hterms=LUI&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DLUI','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080019653&hterms=LUI&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DLUI"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Drivers for Steady Magnetospheric Convection</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>McPherron, Robert L.; O'Brien, T. Paul; Thompson, Scott; Lui, A. T. Y. (Editor)</p> <p>2005-01-01</p> <p>Steady magnetospheric convection (SMC) also known as convection bays, is a particular mode of response of the magnetosphere to <span class="hlt">solar</span> <span class="hlt">wind</span> coupling. It is characterized by convection lasting for times longer than a typical substorm recovery during which no substorms expansions can be identified. It is generally believed that the <span class="hlt">solar</span> <span class="hlt">wind</span> must be unusually steady for the magnetosphere to enter this state. However, most previous studies have assumed this is true and have used such conditions to identify events. In a preliminary investigation using only the AE and AL indices to select events we have shown that these expectations are generally correct. SMC events seem to be associated with slow speed <span class="hlt">solar</span> <span class="hlt">wind</span> and moderate, stable IMF Bz. In this report we extend our previous study including additional parameters and the time variations in various statistical quantities. For the intervals identified as SMCs we perform a detailed statistical analysis of the properties of different <span class="hlt">solar</span> <span class="hlt">wind</span> variables. We compare these statistics to those determined from all data, and from intervals in which substorms but not SMCs are present. We also consider the question of whether substorms are required to initiate and terminate an SMC. We conclude that the intervals we have identified as SMC are likely to be examples of the original Dungey concept of balanced reconnection at a pair of x-lines on the day and night side of the Earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19810063258&hterms=flare+gas&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dflare%2Bgas','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19810063258&hterms=flare+gas&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dflare%2Bgas"><span><span class="hlt">Solar</span> flare <span class="hlt">irradiation</span> records in Antarctic meteorites</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Goswami, J. N.</p> <p>1981-01-01</p> <p>The observation of tracks from <span class="hlt">solar</span> flare heavy nuclei in Antarctic meteorite samples is reported. In an analysis of nuclear track densities in eight L and H chondrites of low metamorphic grade, it was found that two interior specimens of sample 77216, an L-3 chondrite, contain olivine grains with track densities much higher than the average track densities, indicating precompaction <span class="hlt">irradiation</span> by <span class="hlt">solar</span> flares in different shielding conditions. Preliminary data from mass spectroscopic analyses show a large excess of noble gases, with a Ne-20/Ne-22 ratio of greater than or equal to 10, indicating the presence of <span class="hlt">solar</span>-type noble gas. Results of track density measurements in the other Antarctic meteorites range from 10,000 to 4,000,000/sq cm, which is within the range observed in non-Antarctic L-group meteorites</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060026059','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060026059"><span>Material Interactions with <span class="hlt">Solar</span> <span class="hlt">Wind</span> Ion Environments</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Minow, Joseph I.; McWilliams, Brett</p> <p>2006-01-01</p> <p><span class="hlt">Solar</span> <span class="hlt">wind</span> composition is dominated by hydrogen (approx.96%) and helium (approx.3 to 4%) with a minor fraction (less than or equal to 1%) of heavy ions. Hydrogen (helium) ions impact spacecraft surfaces with energies from 0.5 to 5 keV (1.8 to 21 keV) due to variations in <span class="hlt">solar</span> <span class="hlt">wind</span> velocity from 300 km/s to 1000 km/sec with extremes of a few 10 s keV during periods of extremely high <span class="hlt">solar</span> <span class="hlt">wind</span> velocity exceeding 1000 km/sec. Mean impact energies are typically on the order of approximately 1 keV and 4 keV for hydrogen ions and helium ions, respectively. These energies are typically of the peak of the energy dependent light ion sputter yields for hydrogen and helium on many metals. In addition, light ions with kilovolt energies have been shown to produce blister (or exfoliation) damage to metal surfaces due to formation of high pressure gas bubbles within the materials when exposed to ion fluences on the order of 10(exp 16 to (10(exp 17 ions/sq cm. A number of spacecraft designs for current and future missions include gossamer polymer structures with thin metallic reflection coatings to shield instruments from the Sun or <span class="hlt">solar</span> sail propulsion systems for use in a variety of locations in the inner <span class="hlt">solar</span> system from 0.5 to 1 AU. In addition, there is interest in designing spacecraft for <span class="hlt">solar</span> physics missions requiring operations as close to the Sun as 0.16 to 0.2 AU. Integrity of the metallic coatings is critical in many of these applications since degradation will result in modification of material thermal properties or exposure of polymers to <span class="hlt">solar</span> UV photons which can compromise mission requirements. This paper will evaluate the relative contributions of sputtering and blister formation to material degradation in <span class="hlt">solar</span> <span class="hlt">wind</span> environments over a range of radial distances from the Sun to demonstrate where <span class="hlt">solar</span> <span class="hlt">wind</span> environments become important for materials selection. We will first review the physics and results from laboratory measurements of light ion sputtering</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19800058887&hterms=Turley&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DTurley','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19800058887&hterms=Turley&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DTurley"><span><span class="hlt">Solar</span> cycle changes in the polar <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Coles, W. A.; Rickett, B. J.; Rumsey, V. H.; Kaufman, J. J.; Turley, D. G.; Ananthakrishnan, S.; Armstrong, J. W.; Harmons, J. K.; Scott, S. L.; Sime, D. G.</p> <p>1980-01-01</p> <p>It is noted that although the 11 year <span class="hlt">solar</span> cycle was first recognized in 1843, it is still only poorly understood. Further, while there are satisfactory models for the magnetic variations, the underlying physics is still obscure. New observations on the changing three-dimensional form of the <span class="hlt">solar</span> <span class="hlt">wind</span> are presented which help relate some of the modulations observed in geomagnetic activity, the ionosphere, and the flux of galactic cosmic rays.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021273&hterms=solar+energy+generated&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsolar%2Benergy%2Bgenerated','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021273&hterms=solar+energy+generated&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsolar%2Benergy%2Bgenerated"><span>The origin of the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Axford, W. I.; McKenzie, J. F.</p> <p>1995-01-01</p> <p>The high speed <span class="hlt">solar</span> <span class="hlt">wind</span>, which is associated with coronal holes and unipolar interplanetary magnetic field, has now been observed in situ beyond 0.3 a.u. and at latitudes up to 80 degrees. Its important characteristics are that it is remarkably steady in terms of flow properties and composition and that the ions, especially minor species, are favored in terms of heating and acceleration. We have proposed that the high speed <span class="hlt">wind</span>, with its associated coronal holes, forms the basic mode of <span class="hlt">solar</span> <span class="hlt">wind</span> flow. In contrast, the low speed <span class="hlt">wind</span> is inherently non-stationary, filamentary and not in equilibrium with conditions at the coronal base. It is presumably the result of continual reconfigurations of the force-free magnetic field in the low-latitude closed corona which allow trapped plasma to drain away along transiently open flux tubes. Observations of high speed <span class="hlt">solar</span> <span class="hlt">wind</span> close to its source are hampered by the essential heterogeneity of the corona, even at sunspot minimum. In particular it is difficult to determine more than limits to the density, temperature and wave amplitude near the coronal base as a result of contamination from fore- and back-ground plasma. We interpret the observations as indicating that the high speed <span class="hlt">solar</span> <span class="hlt">wind</span> originates in the chromospheric network, covering only about 1% of the surface of the sun, where the magnetic field is complex and not unipolar. As a result of small-scale reconnection events in this 'furnace', Alfven waves are generated with a flat spectrum covering the approximate range 10 kHz to 10 Hz. The plasma is likely to be produced as a result of downwards thermal conduction and possibly photoionization at the top of the low density chromospheric interface to the furnace, thus controlling the mass flux in the <span class="hlt">wind</span>. The immediate source of free (magnetic) energy is in the form of granule-sized loops which are continually carried into the network from the sides. The resulting wave spectrum is such that energy can be</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AmSci..90..532W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AmSci..90..532W"><span>The Origin of the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Woo, Richard; Habbal, Shadia Rifai</p> <p>2002-12-01</p> <p>Nearly 1,400 years ago, Chinese astronomers noticed that comet tails always point away from the Sun. They concluded that the Sun must have chi</em>—a basic life force—that blows the tails away. It wasn't until the middle of the 20th century that scientists understood that this "force" actually consisted of little pieces of the sun itself—protons and electrons—blowing out into the <span class="hlt">solar</span> system as a "<span class="hlt">wind</span>" at more than a million kilometers per hour. The traditional view of the <span class="hlt">solar</span> <span class="hlt">wind</span>'s origins suggests that it originates from special regions on the Sun, called coronal holes. Woo and Habbal present new evidence showing that the <span class="hlt">wind</span> actually emanates from all regions on the Sun.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EPJST.223.2637T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EPJST.223.2637T"><span>Kolmogorov spectrum of renewable <span class="hlt">wind</span> and <span class="hlt">solar</span> power fluctuations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tabar, M. Reza Rahimi; Anvari, M.; Lohmann, G.; Heinemann, D.; Wächter, M.; Milan, P.; Lorenz, E.; Peinke, Joachim</p> <p>2014-10-01</p> <p>With increasing the contribution of renewable energies in power production, the task of reducing dynamic instability in power grids must also be addressed from the generation side, because the power delivered from such sources is spatiotemporally stochastic in nature. Here we characterize the stochastic properties of the <span class="hlt">wind</span> and <span class="hlt">solar</span> energy sources by studying their spectrum and multifractal exponents. The computed power spectrum from high frequency time series of <span class="hlt">solar</span> <span class="hlt">irradiance</span> and <span class="hlt">wind</span> power reveals a power-law behaviour with an exponent ˜ 5/3 (Kolmogorov exponent) for the frequency domain 0.001 Hz < f < 0.05 Hz, which means that the power grid is being fed by turbulent-like sources. Our results bring important evidence on the stochastic and turbulent-like behaviour of renewable power production from <span class="hlt">wind</span> and <span class="hlt">solar</span> energies, which can cause instability in power grids. Our statistical analysis also provides important information that must be used as a guideline for an optimal design of power grids that operate under intermittent renewable sources of power.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.3954N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.3954N"><span>Influence of <span class="hlt">solar</span> <span class="hlt">wind</span> ions on photoemission charging of dust</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nouzak, Libor; Richterova, Ivana; Pavlu, Jiri; Safrankova, Jana; Nemecek, Zdenek</p> <p>2016-04-01</p> <p>The lunar surface covered by a layer of dust grains is exposed to <span class="hlt">solar</span> <span class="hlt">wind</span> particles and photons coming from the Sun on the sunlit side. <span class="hlt">Solar</span> <span class="hlt">wind</span> 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 <span class="hlt">solar</span> <span class="hlt">wind</span> 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 <span class="hlt">irradiated</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SpWea..14..724B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SpWea..14..724B"><span>Decoding <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere coupling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beharrell, M. J.; Honary, F.</p> <p>2016-10-01</p> <p>We employ a new NARMAX (Nonlinear Auto-Regressive Moving Average with eXogenous inputs) code to disentangle the time-varying relationship between the <span class="hlt">solar</span> <span class="hlt">wind</span> and SYM-H. The NARMAX method has previously been used to formulate a Dst model, using a preselected <span class="hlt">solar</span> <span class="hlt">wind</span> coupling function. In this work, which uses the higher-resolution SYM-H in place of Dst, we are able to reveal the individual components of different <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere interaction processes as they contribute to the geomagnetic disturbance. This is achieved with a graphics processing unit (GPU)-based NARMAX code that is around 10 orders of magnitude faster than previous efforts from 2005, before general-purpose programming on GPUs was possible. The algorithm includes a composite cost function, to minimize overfitting, and iterative reorthogonalization, which reduces computational errors in the most critical calculations by a factor of ˜106. The results show that negative deviations in SYM-H following a southward interplanetary magnetic field (IMF) are first a measure of the increased magnetic flux in the geomagnetic tail, observed with a delay of 20-30 min from the time the <span class="hlt">solar</span> <span class="hlt">wind</span> hits the bow shock. Terms with longer delays are found which represent the dipolarization of the magnetotail, the injections of particles into the ring current, and their subsequent loss by flowout through the dayside magnetopause. Our results indicate that the contribution of magnetopause currents to the storm time indices increase with <span class="hlt">solar</span> <span class="hlt">wind</span> electric field, E = v × B. This is in agreement with previous studies that have shown that the magnetopause is closer to the Earth when the IMF is in the tangential direction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21535178','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21535178"><span>Numerical simulations to study <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sharma, R. P.; Sharma, Nidhi; Kumar, Sanjay; Kumar, Sachin; Singh, H. D.</p> <p>2011-02-15</p> <p>Numerical simulation of coupled equations of kinetic Alfven wave (KAW) and ion acoustic wave is presented in the <span class="hlt">solar</span> <span class="hlt">wind</span>. The nonlinear dynamical equations satisfy the modified Zakharov system of equations by taking the nonadiabatic response of the background density. The ponderomotive nonlinearity is incorporated in the wave dynamics. The effect of Landau damping of KAW is taken into account. Localization of magnetic field intensity and the wavenumber spectra (perpendicular and parallel) of magnetic fluctuations are studied in <span class="hlt">solar</span> plasmas around 1 a.u. Our results reveal the formation of damped localized structures and the steeper spectra that are in good agreement with the observations. These damped structures and steeper turbulent spectra can be responsible for plasma heating and particle acceleration in <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040200985&hterms=IMP&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DIMP','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040200985&hterms=IMP&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DIMP"><span><span class="hlt">Wind</span> and IMP 8 <span class="hlt">Solar</span> <span class="hlt">Wind</span>, Magnetosheath and Shock Data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2004-01-01</p> <p>The purpose of this project was to provide the community access to magnetosheath data near Earth. We provided 27 years of IMP 8 magnetosheath proton velocities, densities, and temperatures with our best (usually 1-min.) time resolution. IMP 8 crosses the magnetosheath twice each 125 day orbit, and we provided magnetosheath data for the roughly 27 years of data for which magnetometer data are also available (which are needed to reliably pick boundaries). We provided this 27 years of IMP 8 magnetosheath data to the NSSDC; this data is now integrated with the IMP 8 <span class="hlt">solar</span> <span class="hlt">wind</span> data with flags indicating whether each data point is in the <span class="hlt">solar</span> <span class="hlt">wind</span>, magnetosheath, or at the boundary between the two regions. The plasma speed, density, and temperature are provided for each magnetosheath point. These data are also available on the MIT web site ftp://space .mit.edu/pub/plasma/imp/www/imp.html. We provide ASCII time-ordered rows of data giving the observation time, the spacecraft position in GSE, the velocity is GSE, the density and temperature for protons. We also have analyzed and archived on our web site the <span class="hlt">Wind</span> magnetosheath plasma parameters. These consist of ascii files of the proton and alpha densities, speeds, and thermal speeds. These data are available at ftp://space.mit.edu/pub/plasma/<span class="hlt">wind</span>/sheath These are the two products promised in the work statement and they have been completed in full.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040200985&hterms=ftp&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dftp','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040200985&hterms=ftp&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dftp"><span><span class="hlt">Wind</span> and IMP 8 <span class="hlt">Solar</span> <span class="hlt">Wind</span>, Magnetosheath and Shock Data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2004-01-01</p> <p>The purpose of this project was to provide the community access to magnetosheath data near Earth. We provided 27 years of IMP 8 magnetosheath proton velocities, densities, and temperatures with our best (usually 1-min.) time resolution. IMP 8 crosses the magnetosheath twice each 125 day orbit, and we provided magnetosheath data for the roughly 27 years of data for which magnetometer data are also available (which are needed to reliably pick boundaries). We provided this 27 years of IMP 8 magnetosheath data to the NSSDC; this data is now integrated with the IMP 8 <span class="hlt">solar</span> <span class="hlt">wind</span> data with flags indicating whether each data point is in the <span class="hlt">solar</span> <span class="hlt">wind</span>, magnetosheath, or at the boundary between the two regions. The plasma speed, density, and temperature are provided for each magnetosheath point. These data are also available on the MIT web site ftp://space .mit.edu/pub/plasma/imp/www/imp.html. We provide ASCII time-ordered rows of data giving the observation time, the spacecraft position in GSE, the velocity is GSE, the density and temperature for protons. We also have analyzed and archived on our web site the <span class="hlt">Wind</span> magnetosheath plasma parameters. These consist of ascii files of the proton and alpha densities, speeds, and thermal speeds. These data are available at ftp://space.mit.edu/pub/plasma/<span class="hlt">wind</span>/sheath These are the two products promised in the work statement and they have been completed in full.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18..416S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18..416S"><span>Martian ionosphere response to <span class="hlt">solar</span> <span class="hlt">wind</span> variability during <span class="hlt">solar</span> minimum</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sanchez-Cano, Beatriz; Lester, Mark; Witasse, Olivier; Mays, M. Leila; Hall, Benjamin E. S.; Milan, Stephen E.; Cartacci, Marco; Blelly, Pierre-Louis; Andrews, David; Opgenoorth, Hermann; Odstrcil, Dusan</p> <p>2016-04-01</p> <p><span class="hlt">Solar</span> cycle variations in <span class="hlt">solar</span> radiation create notable density changes in the Martian ionosphere. In addition to this long-term variability, there are numerous short-term and non-recurrent <span class="hlt">solar</span> events that hit Mars which need to be considered, such as Interplanetary Coronal Mass Ejections (ICMEs), Co-Rotation Interaction Regions (CIRs), <span class="hlt">solar</span> flares, or <span class="hlt">solar</span> <span class="hlt">wind</span> high speed streams. The response of the Martian plasma system to each of these events is often unusual, especially during the long period of extreme low <span class="hlt">solar</span> activity in 2008 and 2009. This work shows the long-term <span class="hlt">solar</span> cycle impact on the ionosphere of Mars using data from The Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS), and The Analyzer of Space Plasma and Energetic Atoms (ASPERA-3), and with empirical and numerical models on Mars Express. Particular attention is given to the different ionospheric responses observed during the last, extended <span class="hlt">solar</span> minimum. Mars' ionospheric response followed a similar pattern to the response observed in the Earth's ionosphere, despite the large differences related to the inner-origin of the magnetic field of both planets. The ionospheric temperature was cooler, the topside scale height was smaller and almost constant with altitude, the secondary ionospheric layer practically disappeared and the whole atmospheric total electron content (TEC) suffered an extreme reduction of about 30-40%, not predicted before by models. Moreover, there is a larger probability for the induced magnetic field to be present in the ionosphere, than in other phases of the <span class="hlt">solar</span> cycle. The short-term variability is also addressed with the study of an ICME followed by a fast stream that hit Mars in March 2008, where <span class="hlt">solar</span> <span class="hlt">wind</span> data are provided by ACE and STEREO-B and supported by simulations using the WSA-ENLIL Model. The <span class="hlt">solar</span> <span class="hlt">wind</span> conditions lead to the formation of a CIR centred on the interface of the fast and the slow <span class="hlt">solar</span> <span class="hlt">wind</span> streams. Mars' system reacted to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/978002','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/978002"><span>The Genesis Mission: <span class="hlt">Solar</span> <span class="hlt">Wind</span> Conditions, and Implications for the FIP Fractionation of the <span class="hlt">Solar</span> <span class="hlt">Wind</span>.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Reisenfeld, D. B.; Wiens, R. C.; Barraclough, B. L.; Steinberg, J. T; Dekoning, C. A.; Zurbuchen, T. H.; Burnett, D. S.</p> <p>2005-01-01</p> <p>The NASA Genesis mission collected <span class="hlt">solar</span> <span class="hlt">wind</span> 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 <span class="hlt">solar</span> elemental and isotopic composition (Burnett et al. 2003). Further, the photospheric composition is thought to be representative of the <span class="hlt">solar</span> nebula, so that the Genesis mission will provide a new baseline for the average <span class="hlt">solar</span> 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 <span class="hlt">solar</span> and <span class="hlt">solar</span> <span class="hlt">wind</span> conditions under which they were collected. <span class="hlt">Solar</span> <span class="hlt">wind</span> 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 <span class="hlt">solar</span> <span class="hlt">wind</span> 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 <span class="hlt">solar</span> <span class="hlt">wind</span> samples sorted into three regimes: 'fast <span class="hlt">wind</span>' or 'coronal hole' (CH), 'slow <span class="hlt">wind</span>' or 'interstream' (IS), and 'coronal mass ejection' (CME). To carry this out, plasma ion and electron spectrometers (Barraclough et al., 2003) continuously monitored the <span class="hlt">solar</span> <span class="hlt">wind</span> 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 <span class="hlt">solar</span> <span class="hlt">wind</span> regime (Neugebauer et al., 2003). At any given time, only one of three</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ThApC.119..465V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ThApC.119..465V"><span>Estimating probability distributions of <span class="hlt">solar</span> <span class="hlt">irradiance</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Voskrebenzev, A.; Riechelmann, S.; Bais, A.; Slaper, H.; Seckmeyer, G.</p> <p>2015-02-01</p> <p>In the presence of clouds the ability to calculate instantaneous spectral <span class="hlt">irradiance</span> values is limited by the ability to acquire appropriate input parameters for radiative transfer solvers. However, the knowledge of the statistical characteristics of spectral <span class="hlt">irradiance</span> as a function of season and time of the day is relevant for <span class="hlt">solar</span> energy and health applications. For this purpose a method to derive the wavelength dependent probability density functions (PDFs) and its seasonal site variability is presented. In contrast to the UVB range, the derived PDFS at three stations in Europe (Bilthoven, Garmisch-Partenkirchen and Thessaloniki) show only minor wavelength dependence above 315 nm. But there are major differences of the PDFs that are attributed to the site specific cloud climatology at these stations. Furthermore the results suggest that the previously described relationship between air mass and bimodality is the consequence of seasonal cloud variations. For Thessaloniki it is shown that the pyranometer sample spread around the cloudless value is proportional to the secant of the <span class="hlt">solar</span> zenith angle and therefore scales according to air mass. Cloud amount observations are utilized to associate the local maxima of the multimodal PDFs with rough cloudiness states confirming the already established interpretation of broadband data for spectral data as well. As one application example the likelihood of <span class="hlt">irradiance</span> enhancements over the clear sky case due to clouds is assessed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040000595&hterms=Multivariate+analysis&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DMultivariate%2Banalysis','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040000595&hterms=Multivariate+analysis&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DMultivariate%2Banalysis"><span>Multivariate Analysis of <span class="hlt">Solar</span> Spectral <span class="hlt">Irradiance</span> Measurements</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pilewskie, P.; Rabbette, M.</p> <p>2001-01-01</p> <p>Principal component analysis is used to characterize approximately 7000 downwelling <span class="hlt">solar</span> <span class="hlt">irradiance</span> spectra retrieved at the Southern Great Plains site during an Atmospheric Radiation Measurement (ARM) shortwave intensive operating period. This analysis technique has proven to be very effective in reducing a large set of variables into a much smaller set of independent variables while retaining the information content. It is used to determine the minimum number of parameters necessary to characterize atmospheric spectral <span class="hlt">irradiance</span> or the dimensionality of atmospheric variability. It was found that well over 99% of the spectral information was contained in the first six mutually orthogonal linear combinations of the observed variables (flux at various wavelengths). Rotation of the principal components was effective in separating various components by their independent physical influences. The majority of the variability in the downwelling <span class="hlt">solar</span> <span class="hlt">irradiance</span> (380-1000 nm) was explained by the following fundamental atmospheric parameters (in order of their importance): cloud scattering, water vapor absorption, molecular scattering, and ozone absorption. In contrast to what has been proposed as a resolution to a clear-sky absorption anomaly, no unexpected gaseous absorption signature was found in any of the significant components.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20100024507&hterms=atmosphere+super+earth&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Datmosphere%2Bsuper%2Bearth','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20100024507&hterms=atmosphere+super+earth&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Datmosphere%2Bsuper%2Bearth"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Ablation of Terrestrial Planet Atmospheres</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moore, Thomas Earle; Fok, Mei-Ching H.; Delcourt, Dominique C.</p> <p>2009-01-01</p> <p>Internal plasma sources usually arise in planetary magnetospheres as a product of stellar ablation processes. With the ignition of a new star and the onset of its ultraviolet and stellar <span class="hlt">wind</span> emissions, much of the volatiles in the stellar system undergo a phase transition from gas to plasma. Condensation and accretion into a disk is replaced by radiation and stellar <span class="hlt">wind</span> ablation of volatile materials from the system- Planets or smaller bodies that harbor intrinsic magnetic fields develop an apparent shield against direct stellar <span class="hlt">wind</span> impact, but UV radiation still ionizes their gas phases, and the resulting internal plasmas serve to conduct currents to and from the central body along reconnected magnetic field linkages. Photoionization and thermalization of electrons warms the ionospheric topside, enhancing Jeans' escape of super-thermal particles, with ambipolar diffusion and acceleration. Moreover, observations and simulations of auroral processes at Earth indicate that <span class="hlt">solar</span> <span class="hlt">wind</span> energy dissipation is concentrated by the geomagnetic field by a factor of 10-100, enhancing heavy species plasma and gas escape from gravity, and providing more current carrying capacity. Thus internal plasmas enable coupling with the plasma, neutral gas and by extension, the entire body. The stellar <span class="hlt">wind</span> is locally loaded and slowed to develop the required power. The internal source plasma is accelerated and heated, inflating the magnetosphere as it seeks escape, and is ultimately blown away in the stellar <span class="hlt">wind</span>. Bodies with little sensible atmosphere may still produce an exosphere of sputtered matter when exposed to direct <span class="hlt">solar</span> <span class="hlt">wind</span> impact. Bodies with a magnetosphere and internal sources of plasma interact more strongly with the stellar <span class="hlt">wind</span> owing to the magnetic linkage between the two created by reconnection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998SPIE.3442...34F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998SPIE.3442...34F"><span>Bolometric imager for <span class="hlt">solar</span> <span class="hlt">irradiance</span> studies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Foukal, Peter V.</p> <p>1998-11-01</p> <p>We are presently developing a <span class="hlt">solar</span> imager with spectrally uniform photometric response over all wavelengths between the UV and IR. Such a <span class="hlt">Solar</span> Bolometric Imager (SBI) will be capable of accurately measuring heat flow inhomogeneities at the sun's photosphere and will provide an innovative new tool for identifying mechanisms of long-term <span class="hlt">solar</span> luminosity variation. Our work builds on recent advances in uncooled, relatively high-definition thermal arrays. We have shown that the spectral absorptance of these arrays can be modified by deposition of gold blacks, to provide spectrally uniform response over at least the wavelength range between about 0.3(mu) and 2.5(mu) containing over 95 percent of the total <span class="hlt">solar</span> <span class="hlt">irradiance</span>. Our ongoing work is intended to show that quantitative photometry of the <span class="hlt">solar</span> disc can be performed with such a modified array. We are constructing a breadboard SBI for immediate use with an 8-bit ferro- electric camera, developing a 12-bit camera to make full use of the ferro-electric array's capabilities, and optimizing our process of gold-blacking the TI arrays. Much of the science potential of the SBI could be realized in a balloon experiment. The combination of the SBI and a cavity radiometer would also constitute an excellent SMEX experiment to address a key challenge identified in the Sun- Earth Connection Roadmap recently issued by NASA/OSS.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840019567','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840019567"><span><span class="hlt">Solar</span> <span class="hlt">Irradiance</span> Variations on Active Region Time Scales</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Labonte, B. J. (Editor); Chapman, G. A. (Editor); Hudson, H. S. (Editor); Willson, R. C. (Editor)</p> <p>1984-01-01</p> <p>The variations of the total <span class="hlt">solar</span> <span class="hlt">irradiance</span> is an important tool for studying the Sun, thanks to the development of very precise sensors such as the ACRIM instrument on board the <span class="hlt">Solar</span> Maximum Mission. The largest variations of the total <span class="hlt">irradiance</span> occur on time scales of a few days are caused by <span class="hlt">solar</span> active regions, especially sunspots. Efforts were made to describe the active region effects on total and spectral <span class="hlt">irradiance</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110013409','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110013409"><span>Reconstructing the <span class="hlt">Solar</span> VUV <span class="hlt">Irradiance</span> Over the Past 60 Years</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chamberlin, Phillip C.</p> <p>2011-01-01</p> <p>Actual observations of the <span class="hlt">solar</span> spectral <span class="hlt">irradiance</span> are extremely limited on climate time scales; therefore, various empirical models use <span class="hlt">solar</span> proxies to reconstruct the actual output of the Sun over long time scales. The Flare <span class="hlt">Irradiance</span> Spectral Model (FISM) is an empirical model of the <span class="hlt">solar</span> <span class="hlt">irradiance</span> spectrum from 0.1 to 190 nm at 1 nm spectral resolution and on a I-minute time cadence. The goal of FISM is to provide accurate <span class="hlt">solar</span> spectral <span class="hlt">irradiances</span> over the vacuum ultraviolet (VUV: 0-200 nm) range as input for ionospheric and thermospheric. A brief overview of the proxies used in the FISM model will be given, and also discussed is how the <span class="hlt">Solar</span> Dynamics Observatory (SDO) EUV Variability Experiment (EVE) will contribute to improving FISM estimates and its accuracies. Also presented will be a discussion of other <span class="hlt">solar</span> <span class="hlt">irradiance</span> proxies and measurements, and their associated uncertainties, used for <span class="hlt">solar</span> spectral reconstructions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999AIPC..471..585P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999AIPC..471..585P"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> correlations: Statistical and case studies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Paularena, K. I.; Richardson, J. D.; Zastenker, G. N.; Dalin, P. A.</p> <p>1999-06-01</p> <p>Recent work on <span class="hlt">solar</span> <span class="hlt">wind</span> plasma correlations using data from several widely-separated spacecraft (IMP 8, INTERBALL-1, <span class="hlt">WIND</span>, and ISEE-3) has shown that, for 6-hour periods, the average plasma correlation is ~0.7. The focus of these studies has been directed toward a statistical understanding of gross <span class="hlt">solar</span> <span class="hlt">wind</span> correlation behavior. In all correlations examined, lower average correlations are caused by the presence of many points from the low correlation subpopulation; nevertheless, data points from the high correlation population are still present. No single organizational factor has yet been found which adequately separates low-correlation periods from high-correlation periods. Some of the spread in correlations is due to the spatial orientations and dimensions of <span class="hlt">solar</span> <span class="hlt">wind</span> structures, and thus to the locational alignments of the spacecraft being correlated, but this does not adequately explain all the good or poor correlations since sometimes three nearby spacecraft show poor correlations, while sometimes three widely-separated space-craft show good correlations. Thus, in order to understand the underlying physics, detailed investigation of individual cases has been undertaken. These results will be important in assigning quality measures to space weather predictions using satellite measurements taken at L1, for example.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140012675','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140012675"><span><span class="hlt">Solar</span> Spectral <span class="hlt">Irradiance</span> Changes During Cycle 24</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Marchenko, Sergey; Deland, Matthew</p> <p>2014-01-01</p> <p>We use <span class="hlt">solar</span> spectra obtained by the Ozone Monitoring Instrument (OMI) on board the Aura satellite to detect and follow long-term (years) and short-term (weeks) changes in the <span class="hlt">solar</span> spectral <span class="hlt">irradiance</span> (SSI) in the 265-500 nm spectral range. During <span class="hlt">solar</span> Cycle 24, in the relatively line-free regions the SSI changed by approximately 0.6% +/- 0.2% around 265 nm. These changes gradually diminish to 0.15% +/- 0.20% at 500 nm. All strong spectral lines and blends, with the notable exception of the upper Balmer lines, vary in unison with the <span class="hlt">solar</span> "continuum." Besides the lines with strong chromospheric components, the most involved species include Fe I blends and all prominent CH, NH, and CN spectral bands. Following the general trend seen in the <span class="hlt">solar</span> "continuum," the variability of spectral lines also decreases toward longer wavelengths. The long-term <span class="hlt">solar</span> cycle SSI changes are closely, to within the quoted 0.1%-0.2% uncertainties, matched by the appropriately adjusted short-term SSI variations derived from the 27 day rotational modulation cycles. This further strengthens and broadens the prevailing notion about the general scalability of the UV SSI variability to the emissivity changes in the Mg II 280 nm doublet on timescales from weeks to years. We also detect subtle deviations from this general rule: the prominent spectral lines and blends at lambda approximately or greater than 350 nm show slightly more pronounced 27 day SSI changes when compared to the long-term (years) trends. We merge the <span class="hlt">solar</span> data from Cycle 21 with the current Cycle 24 OMI and GOME-2 observations and provide normalized SSI variations for the 170-795 nm spectral region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22365695','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22365695"><span><span class="hlt">Solar</span> spectral <span class="hlt">irradiance</span> changes during cycle 24</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Marchenko, S. V.; DeLand, M. T.</p> <p>2014-07-10</p> <p>We use <span class="hlt">solar</span> spectra obtained by the Ozone Monitoring Instrument (OMI) on board the Aura satellite to detect and follow long-term (years) and short-term (weeks) changes in the <span class="hlt">solar</span> spectral <span class="hlt">irradiance</span> (SSI) in the 265-500 nm spectral range. During <span class="hlt">solar</span> Cycle 24, in the relatively line-free regions the SSI changed by ∼0.6% ± 0.2% around 265 nm. These changes gradually diminish to 0.15% ± 0.20% at 500 nm. All strong spectral lines and blends, with the notable exception of the upper Balmer lines, vary in unison with the <span class="hlt">solar</span> 'continuum'. Besides the lines with strong chromospheric components, the most involved species include Fe I blends and all prominent CH, NH, and CN spectral bands. Following the general trend seen in the <span class="hlt">solar</span> 'continuum', the variability of spectral lines also decreases toward longer wavelengths. The long-term <span class="hlt">solar</span> cycle SSI changes are closely, to within the quoted 0.1%-0.2% uncertainties, matched by the appropriately adjusted short-term SSI variations derived from the 27 day rotational modulation cycles. This further strengthens and broadens the prevailing notion about the general scalability of the UV SSI variability to the emissivity changes in the Mg II 280 nm doublet on timescales from weeks to years. We also detect subtle deviations from this general rule: the prominent spectral lines and blends at λ ≳ 350 nm show slightly more pronounced 27 day SSI changes when compared to the long-term (years) trends. We merge the <span class="hlt">solar</span> data from Cycle 21 with the current Cycle 24 OMI and GOME-2 observations and provide normalized SSI variations for the 170-795 nm spectral region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730002078','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730002078"><span>Corotation of an intermittent <span class="hlt">solar</span> <span class="hlt">wind</span> source</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Croft, T. A.</p> <p>1972-01-01</p> <p>The measured electron content of the <span class="hlt">solar</span> <span class="hlt">wind</span> in mid-1970 exhibited a region of relatively high electron density that reappeared at intervals of about 27.8 days. It is shown that the repeating event cannot be reconciled with the concept of a long-enduring steady flow, even though the recurrence period is close to the rotation period of the sun. This evidence of transients is inferred from the short duration of each appearance of the interval of higher density; each should last for roughly one corotation interval if it is caused by a steady stream. The radio path was approximately 0.8 AU long, and the corotation interval exceeded 3 days. Other aspects of the content data patterns support the view that such transient events are common in the <span class="hlt">solar</span> <span class="hlt">wind</span>. The mid-1970 repeating event is an unusually good example of the intermittent character of flow regions in the <span class="hlt">solar</span> <span class="hlt">wind</span> that fluctuate on a time scale of days but endure as identifiable regions for many months. A sputtering corotating source of thin <span class="hlt">solar</span> plasma streams could explain this series of events; it could also be explained in terms of a stream that is steady in density and speed but undulating north-south so that it passes into and out of the 0.8 AU radio path in a matter of a day or less.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016cosp...41E1604P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016cosp...41E1604P"><span>Magnetosheath influence on <span class="hlt">solar</span> <span class="hlt">wind</span> - magnetosphere coupling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pulkkinen, Tuija; Kilpua, Emilia; Dimmock, Andrew; Myllys, Minna; Osmane, Adnane; Nykyri, Katariina; Lakka, Antti</p> <p>2016-07-01</p> <p>We have shown that the <span class="hlt">solar</span> <span class="hlt">wind</span> - magnetosphere - ionosphere coupling is different during due northward IMF from that during due southward IMF, and that the Poynting flux at the magnetopause is not a simple function of the upstream <span class="hlt">solar</span> <span class="hlt">wind</span> conditions upstream of the bow shock. These results are indicative of multiple transport processes taking place on various temporal and spatial scales, and therefore more detailed analysis is required to identify these mechanisms and quantify their contributions to <span class="hlt">solar</span> <span class="hlt">wind</span> - magnetosphere coupling. We combine the OMNI, IMAGE and THEMIS observations to statistically examine the properties incident at the magnetopause in the quasi-perpendicular and quasi-parallel shock sides separately. We use local and global MHD simulations to examine the energy and plasma transport properties across the bow shock, in the magnetosheath, and across the magnetopause. We focus especially on the anomalously quiet period during the deep <span class="hlt">solar</span> minimum in 2008-2010, comparing the results with steady but stronger drivers during magnetic cloud events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1914278P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1914278P"><span>The magnetosphere of Venus under unusual <span class="hlt">Solar</span> <span class="hlt">Wind</span> conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pope, Simon A.; Siung Chong, Ghai; Collinson, Glyn A.; Zhang, Tielong; Balikhin, Michael A.</p> <p>2017-04-01</p> <p>Due to its lack of an intrinsic magnetic field, the structure of the induced magnetosphere and associated plasma processes in and near Venus can be strongly influenced by the prevailing <span class="hlt">solar</span> <span class="hlt">wind</span> conditions. Examples include the shock structure/location, the occurrence of reconnection in the <span class="hlt">solar</span> <span class="hlt">wind</span> and tail and the occurrence of the Kelvin-Helmholtz instability at the ionopause. However, the interaction of the <span class="hlt">solar</span> <span class="hlt">wind</span> with Venus is a complex processes and with observations being limited to single spacecraft missions with restricted orbit, it can be difficult to link observations with particular <span class="hlt">solar</span> <span class="hlt">wind</span> conditions. To better understand this relationship, Venus Express magnetic field and plasma data is used to identify and analyse changes to the structure of the magnetosphere and local plasma processes that are related to unusual <span class="hlt">solar</span> <span class="hlt">wind</span> conditions. By examining Venus under unusual <span class="hlt">solar</span> <span class="hlt">wind</span> conditions the resulting changes, if out of the ordinary, can be more directly linked to particular <span class="hlt">solar</span> <span class="hlt">wind</span> conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSM41C2457P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSM41C2457P"><span>The magnetosphere of Venus under unusual <span class="hlt">Solar</span> <span class="hlt">Wind</span> condition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pope, S. A.; Chong, G. S.; Collinson, G.; Zhang, T.; Balikhin, M. A.</p> <p>2016-12-01</p> <p>Due to its lack of an intrinsic magnetic field, the structure of the induced magnetosphere and associated plasma processes in and near Venus can be strongly influenced by the prevailing <span class="hlt">solar</span> <span class="hlt">wind</span> conditions. Examples include the shock structure/location, the occurrence of reconnection in the <span class="hlt">solar</span> <span class="hlt">wind</span> and tail and the occurrence of the Kelvin-Helmholtz instability at the ionopause. However, the interaction of the <span class="hlt">solar</span> <span class="hlt">wind</span> with Venus is a complex processes and with observations being limited to single spacecraft missions with restricted orbit, it can be difficult to link observations with particular <span class="hlt">solar</span> <span class="hlt">wind</span> conditions. To better understand this relationship, Venus Express magnetic field and plasma data is used to identify and analyse changes to the structure of the magnetosphere and local plasma processes that are related to unusual <span class="hlt">solar</span> <span class="hlt">wind</span> conditions. By examining Venus under unusual <span class="hlt">solar</span> <span class="hlt">wind</span> conditions the resulting changes, if out of the ordinary, can be more directly linked to particular <span class="hlt">solar</span> <span class="hlt">wind</span> conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040074203','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040074203"><span>Properties of Minor Ions in the <span class="hlt">Solar</span> <span class="hlt">Wind</span> and Implications for the Background <span class="hlt">Solar</span> <span class="hlt">Wind</span> Plasma</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wagner, William (Technical Monitor); Esser, Ruth</p> <p>2004-01-01</p> <p>The scope of the investigation is to extract information on the properties of the bulk <span class="hlt">solar</span> <span class="hlt">wind</span> from the minor ion observations that are provided by instruments on board NASA space craft and theoretical model studies. Ion charge states measured in situ in interplanetary space are formed in the inner coronal regions below 5 <span class="hlt">solar</span> radii, hence they carry information on the properties of the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma in that region. The plasma parameters that are important in the ion forming processes are the electron density, the electron temperature and the flow speeds of the individual ion species. In addition, if the electron distribution function deviates from a Maxwellian already in the inner corona, then the enhanced tail of that distribution function, also called halo, greatly effects the ion composition. This study is carried out using <span class="hlt">solar</span> <span class="hlt">wind</span> models, coronal observations, and ion calculations in conjunction with the in situ observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750022915','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750022915"><span>The total and spectral <span class="hlt">solar</span> <span class="hlt">irradiance</span> and its possible variations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thekaekara, M. P.</p> <p>1975-01-01</p> <p>The present status of knowledge of the total and spectral <span class="hlt">irradiance</span> of the sun is briefly reviewed. Currently accepted values of the <span class="hlt">solar</span> constant and the extraterrestrial <span class="hlt">solar</span> spectral <span class="hlt">irradiance</span> are presented along with a discussion of how they were derived. Data on the variability of the <span class="hlt">solar</span> constant are shown to be conflicting and inconclusive. Some of the alleged sun-weather relationships are cited in support of the need of knowing more precisely the variations in total and spectral <span class="hlt">solar</span> <span class="hlt">irradiance</span>. An overview of a <span class="hlt">solar</span> monitoring program is discussed, with special emphasis on the <span class="hlt">Solar</span> Energy Monitor in Space experiment which was proposed for several spacecraft missions. It is a combination of a <span class="hlt">solar</span> constant detector and a prism monochromator. The determination of absolute values and the possible variations of the total and spectral <span class="hlt">solar</span> <span class="hlt">irradiance</span>, from measurements outside of the atmosphere is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMSH33B1506W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMSH33B1506W"><span>Accessing <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> Data Products From the LASP Interactive <span class="hlt">Solar</span> <span class="hlt">IRradiance</span> Datacenter (LISIRD)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ware Dewolfe, A.; Wilson, A.; Lindholm, D. M.; Pankratz, C. K.; Snow, M.; Woods, T. N.</p> <p>2009-12-01</p> <p>The Laboratory for Atmospheric and Space Physics (LASP) is enhancing the LASP Interactive <span class="hlt">Solar</span> <span class="hlt">IRradiance</span> Datacenter (LISIRD) to provide access to a comprehensive set of <span class="hlt">solar</span> spectral <span class="hlt">irradiance</span> measurements. LISIRD has recently been updated to serve many new datasets and models, including sunspot index, photometric sunspot index, Lyman-alpha, and magnesium-II core-to-wing ratio. A new user interface emphasizes web-based interactive visualizations, allowing users to explore and compare this data before downloading it for analysis. The data provided covers a wavelength range from soft X-ray (XUV) at 0.1 nm up to the near infrared (NIR) at 2400 nm, as well as wavelength-independent Total <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> (TSI). Combined data from the SORCE, TIMED-SEE, UARS-SOLSTICE, and SME instruments provide almost continuous coverage from 1981 to the present, while Hydrogen Lyman-alpha (121.6 nm) measurements / models date from 1947 to the present. This poster provides an overview of the LISIRD system, summarizes the data sets currently available, describes future plans and capabilities, and provides details on how to access <span class="hlt">solar</span> <span class="hlt">irradiance</span> data through LISIRD interfaces at http://lasp.colorado.edu/lisird/.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSH43A4168P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSH43A4168P"><span>Characteristics of <span class="hlt">solar</span> <span class="hlt">wind</span> density depletions during <span class="hlt">solar</span> cycles 23 and 24</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Park, K.; Lee, J.; Oh, S.; Yi, Y.</p> <p>2014-12-01</p> <p><span class="hlt">Solar</span> <span class="hlt">wind</span> density depletions are generally believed to be caused by the interplanetary (IP) shocks. However, there are other cases that are hardly associated with IP shocks. To better understand the cause of the density depletions, we investigate the <span class="hlt">solar</span> <span class="hlt">wind</span> parameters and interplanetary magnetic field (IMF) data related to the <span class="hlt">solar</span> <span class="hlt">wind</span> density depletion events during the period from 1996 to 2013 that are obtained with the Advanced Composition Explorer (ACE) and the <span class="hlt">WIND</span> satellite. As a result, we found that the <span class="hlt">solar</span> <span class="hlt">wind</span> density has an anti-correlation with IMF strength during all events of <span class="hlt">solar</span> <span class="hlt">wind</span> density depletion, regardless of the presence of IP shocks. We thus argue that IMF strength is an important factor in understanding the nature of <span class="hlt">solar</span> <span class="hlt">wind</span> density depletion. Since IMF strength varies with <span class="hlt">solar</span> cycle, we also investigate the characteristics of <span class="hlt">solar</span> <span class="hlt">wind</span> density depletion events in different phases of <span class="hlt">solar</span> cycle as an attempt to find its connection to the sun.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JSWSC...6A..40M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JSWSC...6A..40M"><span><span class="hlt">Solar</span> spectral <span class="hlt">irradiance</span> variability in cycle 24: observations and models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marchenko, Sergey V.; DeLand, Matthew T.; Lean, Judith L.</p> <p>2016-12-01</p> <p>Utilizing the excellent stability of the Ozone Monitoring Instrument (OMI), we characterize both short-term (<span class="hlt">solar</span> rotation) and long-term (<span class="hlt">solar</span> cycle) changes of the <span class="hlt">solar</span> spectral <span class="hlt">irradiance</span> (SSI) between 265 and 500 nm during the ongoing cycle 24. We supplement the OMI data with concurrent observations from the Global Ozone Monitoring Experiment-2 (GOME-2) and <span class="hlt">Solar</span> Radiation and Climate Experiment (SORCE) instruments and find fair-to-excellent, depending on wavelength, agreement among the observations, and predictions of the Naval Research Laboratory <span class="hlt">Solar</span> Spectral <span class="hlt">Irradiance</span> (NRLSSI2) and Spectral And Total <span class="hlt">Irradiance</span> REconstruction for the Satellite era (SATIRE-S) models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17755527','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17755527"><span>Deimos: an obstacle to the <span class="hlt">solar</span> <span class="hlt">wind</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sauer, K; Dubinin, E; Baumgärtel, K; Bogdanov, A</p> <p>1995-08-25</p> <p>Two isolated <span class="hlt">solar</span> <span class="hlt">wind</span> disturbances about 5 minutes in duration were detected aboard the Russian spacecraft Phobos-2 upon its crossing the wake of the martian moon Deimos about 15,000 kilometers downstream from the moon on 1 February 1989. These plasma and magnetic events are interpreted as the inbound and outbound crossings of a Mach cone that is formed as a result of an effective interaction of the <span class="hlt">solar</span> <span class="hlt">wind</span> with Deimos. Possible mechanisms such as remanent magnetization, cometary type interaction caused by heavy ion or charged dust production, and unipolar induction resulting from the finite conductivity of the body are discussed. Although none of the present models is fully satisfactory, neutral gas emission through water loss by Deimos at a rate of about 10(23) molecules per second, combined with a charged dust coma, is favored.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19750035055&hterms=infancy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dinfancy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19750035055&hterms=infancy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dinfancy"><span>The <span class="hlt">solar</span> <span class="hlt">wind</span> and magnetospheric dynamics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Russell, C. T.</p> <p>1974-01-01</p> <p>The dynamic processes involved in the interaction between the <span class="hlt">solar</span> <span class="hlt">wind</span> and the earth's magnetosphere are reviewed. The evolution of models of the magnetosphere is first surveyed. The existence of the auroral substorm and the cyclical polar magnetic substorm is evidence that the magnetosphere is a dynamic system. The dynamic changes occurring in the magnetosphere, including erosion of the magnetopause, changes in the size of the polar cap, variations in the flaring angle of the tail, neutral point formation, plasma sheet motions, and the inward collapse of the midnight magnetosphere, are discussed. The cyclical variations of geomagnetic activity are explained in terms of the control of the <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere interaction by the north-south component of the interplanetary magnetic field. Present phenomenological models allow prediction of geomagnetic activity from interplanetary measurements, but modeling of detailed magnetospheric processes is still in its infancy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760018046','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760018046"><span><span class="hlt">Solar-wind</span> interaction with planetary ionospheres</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cloutier, P. A.</p> <p>1976-01-01</p> <p>Planetary encounters by numerous spacecraft have furnished information concerning the <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with the planets Mercury, Venus, Mars, and Jupiter. While direct measurements have indicated a wide range of atmospheric densities and intrinsic magnetic field strengths, the data seem to indicate that the flow pattern around nonmagnetized or weakly magnetized planets with atmospheres optically thick at ionizing wavelengths is basically the same as that around a strongly magnetized planet's magnetosphere, such as the earth's. The planetary ionosphere apparently presents a hard obstacle to the flow, with bow shock formation required in the supersonic, super-Alfvenic flow to slow and direct most of the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma around the planetary ionosphere. Various aspects of the interaction are examined in the context of theoretical models in an attempt to explain observed details of the interaction regions of Venus and Mars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24996092','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24996092"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> thermally induced magnetic fluctuations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Navarro, R E; Moya, P S; Muñoz, V; Araneda, J A; F-Viñas, A; Valdivia, J A</p> <p>2014-06-20</p> <p>A kinetic description of Alfvén-cyclotron magnetic fluctuations for anisotropic electron-proton quasistable plasmas is studied. An analytical treatment, based on the fluctuation-dissipation theorem, consistently shows that spontaneous fluctuations in plasmas with stable distributions significantly contribute to the observed magnetic fluctuations in the <span class="hlt">solar</span> <span class="hlt">wind</span>, as seen, for example, in [S. D. Bale et al., Phys. Rev. Lett. 103, 211101 (2009)], even far below from the instability thresholds. Furthermore, these results, which do not require any adjustable parameters or wave excitations, are consistent with the results provided by hybrid simulations. It is expected that this analysis contributes to our understanding of the nature of magnetic fluctuations in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25848082','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25848082"><span>Anisotropy in <span class="hlt">solar</span> <span class="hlt">wind</span> plasma turbulence.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Oughton, S; Matthaeus, W H; Wan, M; Osman, K T</p> <p>2015-05-13</p> <p>A review of spectral anisotropy and variance anisotropy for <span class="hlt">solar</span> <span class="hlt">wind</span> fluctuations is given, with the discussion covering inertial range and dissipation range scales. For the inertial range, theory, simulations and observations are more or less in accord, in that fluctuation energy is found to be primarily in modes with quasi-perpendicular wavevectors (relative to a suitably defined mean magnetic field), and also that most of the fluctuation energy is in the vector components transverse to the mean field. Energy transfer in the parallel direction and the energy levels in the parallel components are both relatively weak. In the dissipation range, observations indicate that variance anisotropy tends to decrease towards isotropic levels as the electron gyroradius is approached; spectral anisotropy results are mixed. Evidence for and against wave interpretations and turbulence interpretations of these features will be discussed. We also present new simulation results concerning evolution of variance anisotropy for different classes of initial conditions, each with typical background <span class="hlt">solar</span> <span class="hlt">wind</span> parameters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910003152','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910003152"><span><span class="hlt">Solar</span> <span class="hlt">Irradiance</span> Observed from PVO and Inferred <span class="hlt">Solar</span> Rotation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wolff, Charles L.; Hoegy, Walter R.</p> <p>1990-01-01</p> <p><span class="hlt">Solar</span> <span class="hlt">irradiance</span> in the extreme ultraviolet flux (EUV) has been monitored for 11 years by the Pioneer Venus Orbiter (PVO). Since the experiment moves around the Sun with the orbital rate of Venus rather than that of Earth, the measurement gives us a second viewing location from which to begin unravelling which <span class="hlt">irradiance</span> variations are intrinsic to the Sun, and which are merely rotational modulations whose periods depend on the motion of the observer. Researchers confirm an earlier detection, made with only 8.6 years of data, that the EUV <span class="hlt">irradiance</span> is modulated by rotation rates of two families of global oscillation modes. One family is assumed to be r-modes occupying the convective envelope and sharing its rotation, while the other family (g-modes) lies in the radiative interior which as a slower rotation. Measured power in r-modes of low angular harmonic number indicates that the Sun's envelope rotated about 0.7 percent faster near the last <span class="hlt">solar</span> maximum (1979 thru 1982) than it did during the next rise to maximum (1986 to 1989). No change was seen in the g-mode family of lines, as would be expected from the much greater rotational inertia of the radiative interior.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA201119','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA201119"><span>Corona-<span class="hlt">Solar</span> <span class="hlt">Wind</span> Coupling Review</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1987-06-01</p> <p>Spitzer which should be valid if the magne:ic field is radial and the plasma is collision dominated. Although both of these conditions are expected to hold...conduction has been studied by introducing a heat flux density given by the classical Spitzer value times the square of the cosine of the angle...Broussard, R. M., N. R. Shecley, Jr ., R. Tousey, and J. H. Underwood. A survey of coronal holes and their <span class="hlt">solar</span> <span class="hlt">wind</span> associations throughout sunspot cycle</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993EM%26P...60...23K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993EM%26P...60...23K"><span>Interplanetary dust particles and <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klacka, J.; Saniga, M.</p> <p>1993-01-01</p> <p>An effect of the <span class="hlt">solar</span> <span class="hlt">wind</span> on the motion of interplanetary dust particles is investigated. An equation of motion is derived. It is pointed out that the 'Pseudo-Poynting-Robertson effect' (and its special case - a 'corpuscular drag') and the 'corpuscular sputtering' represent in reality one and the same effect within the framework of special relativity. In this context perturbation equations of celestial mechanics are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5030602','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5030602"><span>Turbulence and waves in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Roberts, D.A.; Goldstein, M.L. )</p> <p>1991-01-01</p> <p>Studies of turbulence and waves in the <span class="hlt">solar</span> <span class="hlt">wind</span> is discussed. Consideration is given to the observations and theory concerning the origin and evolution of interplanetary MHD fluctuations and to the observations, theory, and simulations of compressive fluctuations. Particular attention is given to extrapolations to near-sun and polar fields regions. Results obtained on turbulence at comets and magnetic turbulence of low-frequency waves excited by unstable distributions of ions are discussed. 230 refs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MsT..........2G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MsT..........2G"><span>An evaluation on the cost efficiency of <span class="hlt">wind</span> and <span class="hlt">solar</span> hybrid power system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gonzalez, Hugo</p> <p></p> <p><span class="hlt">Solar</span> energy generation is intermittent due to the limitation of night time and weather, so batteries are normally used to stabilize the <span class="hlt">solar</span> energy output in the distributed generation system. However, batteries are still expensive and have relatively short life span. The motivation of this research is to evaluate if <span class="hlt">wind</span> energy can be a more cost efficient solution to replace battery storage. An algorithm is created to analyze the <span class="hlt">solar</span> <span class="hlt">irradiance</span>, <span class="hlt">wind</span> speed and load data from two different cities, Atlantic City and San Diego. Then find the most cost efficient renewable energy solution for each city under different renewable energy penetration level. The result shows that the <span class="hlt">wind</span> energy is not a good substitution for battery. The <span class="hlt">solar</span> and <span class="hlt">wind</span> hybrid system can reach higher renewable energy penetration level, but the cost of the system and the wasted energy percentage is also extremely high. In San Diego, the integration of <span class="hlt">wind</span> energy does not bring any economic benefit to the <span class="hlt">solar</span> system. In Atlantic City, where the <span class="hlt">wind</span> energy resource is abundant, adding <span class="hlt">wind</span> turbines to the <span class="hlt">solar</span> battery system can lower the system cost while maintaining the same level of renewable energy penetration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017IAUS..328..162J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017IAUS..328..162J"><span><span class="hlt">Solar</span> and stellar coronae and <span class="hlt">winds</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jardine, Moira</p> <p>2017-10-01</p> <p><span class="hlt">Solar</span>-like stars influence their environments through their coronal emis- sion and <span class="hlt">winds</span>. These processes are linked through the physics of the stellar magnetic field, whose strength and geometry has now been explored for a large number of stars through spectropolarimetric observations. We have now detected trends with mass and rotation rate in the distribution of magnetic energies in different geometries and on also different length scales. This has implications both for the dynamo processes that generate the fields and also for the dynamics and evolution of the coronae and <span class="hlt">winds</span>. Modelling of the surface driving processes on stars of various masses and rotation rates has revealed tantalising clues about the dynamics of stellar coronae and their ejecta. These new observations have also prompted a resurgence in the modelling of stellar <span class="hlt">winds</span>, which is now uncovering the range of different interplanetary conditions that exoplanets might experience as they evolve.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMGC51C0987L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMGC51C0987L"><span>LISIRD: LASP Interactive <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> Data Center</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lindholm, D. M.; Wilson, A.</p> <p>2013-12-01</p> <p>The Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado Boulder has been involved in numerous space-borne missions to directly measure and understand the variability of the Sun's energy output and its impact on global climate change. The LASP Interactive <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> Data Center (LISIRD) provides a web site with interactive graphics to explore, subset, and download these and other <span class="hlt">solar</span> related datasets. The LISIRD collections include observations of total and spectral <span class="hlt">irradiance</span> with coverage from the X-ray to the infrared from projects such as SME, UARS SOLSTICE, SNOE, TIMED SEE, SORCE, and SDO EVE plus a growing number of related data products, proxies, and models. The LISIRD data services are backed by the LaTiS data server which presents a unified RESTful web service interface to slice, dice, and perform select server-side operations as the data are dynamically streamed to files of your desired format or directly into your code or analysis tools. Come see the data products and services that LISIRD has available and help us to improve them to better meet your needs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...838...50F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...838...50F"><span>Kinetic Properties of the Neutral <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Florinski, V.; Heerikhuisen, J.</p> <p>2017-03-01</p> <p>Charge-exchange collisions between the <span class="hlt">solar</span> <span class="hlt">wind</span> protons and interstellar hydrogen produce a distinctive population of neutral hydrogen streaming radially at nearly the <span class="hlt">solar-wind</span> speed. This tenuous population, known as the neutral <span class="hlt">solar</span> <span class="hlt">wind</span> (NSW) is thought to play a key role in the appearance of the Interplanetary Boundary EXplorer ribbon, a bright circular band in the sky that is the source of neutral hydrogen with energies near 1 keV. According to the leading model of the ribbon, the velocity distribution of NSW hydrogen is imparted on the pickup ions (PUIs) generated via charge exchange with the interstellar protons beyond the heliopause, and in this way controls the stability of the resulting ring distribution of PUIs against hydromagnetic wave generation. In this paper, we examine the velocity distributions of the NSW atoms in the heliosphere and the outer heliosheath regions by following the phase-space trajectories of the Boltzmann equation. It is demonstrated that these distributions are highly anisotropic, with the parallel (radial) temperature greatly exceeding the perpendicular temperature. Ions picked up near 90° from the anisotropic NSW would form a stable ring distribution capable of generating the ribbon flux. We also discuss a second population of neutrals born in charge transfer collisions with interstellar PUIs, the so-called neutralized pickup ion (NPI) component. Their high thermal velocities translate into large parallel velocity spread of the daughter ribbon PUIs, which would adversely affect plasma stability in local interstellar space.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20120011917&hterms=storm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dstorm','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20120011917&hterms=storm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dstorm"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Charge Exchange During Geomagnetic Storms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Robertson, Ina P.; Cravens, Thomas E.; Sibeck, David G.; Collier, Michael R.; Kuntz, K. D.</p> <p>2012-01-01</p> <p>On March 31st. 2001, a coronal mass ejection pushed the subsolar magnetopause to the vicinity of geosynchronous orbit at 6.6 RE. The NASA/GSFC Community Coordinated Modeling Center (CCMe) employed a global magnetohydrodynamic (MHD) model to simulate the <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere interaction during the peak of this geomagnetic storm. Robertson et aL then modeled the expected 50ft X-ray emission due to <span class="hlt">solar</span> <span class="hlt">wind</span> charge exchange with geocoronal neutrals in the dayside cusp and magnetosheath. The locations of the bow shock, magnetopause and cusps were clearly evident in their simulations. Another geomagnetic storm took place on July 14, 2000 (Bastille Day). We again modeled X-ray emission due to <span class="hlt">solar</span> <span class="hlt">wind</span> charge exchange, but this time as observed from a moving spacecraft. This paper discusses the impact of spacecraft location on observed X-ray emission and the degree to which the locations of the bow shock and magnetopause can be detected in images.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20120011917&hterms=solar+storms&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsolar%2Bstorms','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20120011917&hterms=solar+storms&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsolar%2Bstorms"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Charge Exchange During Geomagnetic Storms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Robertson, Ina P.; Cravens, Thomas E.; Sibeck, David G.; Collier, Michael R.; Kuntz, K. D.</p> <p>2012-01-01</p> <p>On March 31st. 2001, a coronal mass ejection pushed the subsolar magnetopause to the vicinity of geosynchronous orbit at 6.6 RE. The NASA/GSFC Community Coordinated Modeling Center (CCMe) employed a global magnetohydrodynamic (MHD) model to simulate the <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere interaction during the peak of this geomagnetic storm. Robertson et aL then modeled the expected 50ft X-ray emission due to <span class="hlt">solar</span> <span class="hlt">wind</span> charge exchange with geocoronal neutrals in the dayside cusp and magnetosheath. The locations of the bow shock, magnetopause and cusps were clearly evident in their simulations. Another geomagnetic storm took place on July 14, 2000 (Bastille Day). We again modeled X-ray emission due to <span class="hlt">solar</span> <span class="hlt">wind</span> charge exchange, but this time as observed from a moving spacecraft. This paper discusses the impact of spacecraft location on observed X-ray emission and the degree to which the locations of the bow shock and magnetopause can be detected in images.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840005052','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840005052"><span>Quasi-steady <span class="hlt">solar</span> <span class="hlt">wind</span> dynamics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pizzo, V. J.</p> <p>1983-01-01</p> <p>Progress in understanding the large scale dynamics of quasisteady, corotating <span class="hlt">solar</span> <span class="hlt">wind</span> structure was reviewed. The nature of the <span class="hlt">solar</span> <span class="hlt">wind</span> at large heliocentric distances preliminary calculations from a 2-D MHD model are used to demonstrate theoretical expectations of corotating structure out to 30 AU. It is found that the forward and reverse shocks from adjacent CIR's begin to interact at about 10 AU, producing new shock pairs flanking secondary CIR's. These sawtooth secondary CIR's interact again at about 20 AU and survive as visible entities to 30 AU. The model predicts the velocity jumps at the leading edge of the secondary CIR's at 30 AU should be very small but there should still be sizable variations in the thermodynamic and magnetic parameters. The driving dynamic mechanism in the distant <span class="hlt">solar</span> <span class="hlt">wind</span> is the relaxation of pressure gradients. The second topic is the influence of weak, nonimpulsive time dependence in quasisteady dynamics. It is suggested that modest large scale variations in the coronal flow speed on periods of several hours to a day may be responsible for many of the remaining discrepancies between theory and observation. Effects offer a ready explanation for the apparent rounding of stream fronts between 0.3 and 1.0 AU discovered by Helios.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AdSpR..34..355G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AdSpR..34..355G"><span>Influence of <span class="hlt">solar</span> UV <span class="hlt">irradiance</span> on quasi-biennial oscillations in the Earth's atmosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gabis, I.; Troshichev, O.</p> <p>2004-01-01</p> <p>A study of relationships between variations in the <span class="hlt">solar</span> ultraviolet (UV) <span class="hlt">irradiance</span> and quasi-biennial oscillations (QBO) of mean zonal <span class="hlt">wind</span> in the Earth's equatorial stratosphere has been carried out with use of the composite MgII index as a proxy for the <span class="hlt">solar</span> UV <span class="hlt">irradiance</span>. The middle-term changes in the UV-<span class="hlt">irradiation</span> have been separated after removing the long-term (≈11 years) and short-term (≈27 days) variations. The results of the analysis show that the average UV <span class="hlt">irradiance</span> tends to be higher for east QBO-phase and lower for west phase. The detail analysis of rotation in the stratospheric <span class="hlt">wind</span> profiles reveals that the quiet periods alternate with active periods, characterizing by strong disturbing <span class="hlt">winds</span>. Some of these stages occur only in certain seasons, which implies that they are guided by the internal atmospheric mechanisms. Duration of active stages can be affected by level of the UV <span class="hlt">irradiance</span>. Conclusion is made that variability of the QBO-phase duration in the equatorial stratosphere can be interpreted if influence of the <span class="hlt">solar</span> UV medium-term variation on basic stratospheric processes is taken into account.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1052886','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1052886"><span>Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study (Fact Sheet)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Not Available</p> <p>2012-09-01</p> <p>Initiated in 2007 to examine the operational impact of up to 35% penetration of <span class="hlt">wind</span>, photovoltaic (PV), and concentrating <span class="hlt">solar</span> power (CSP) energy on the electric power system, the Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study (WWSIS) is one of the largest regional <span class="hlt">wind</span> and <span class="hlt">solar</span> integration studies to date. The goal is to understand the effects of variability and uncertainty of <span class="hlt">wind</span>, PV, and CSP on the grid. In the Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study Phase 1, <span class="hlt">solar</span> penetration was limited to 5%. Utility-scale PV was not included because of limited capability to model sub-hourly, utility-scale PV output . New techniques allow the Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study Phase 2 to include high penetrations of <span class="hlt">solar</span> - not only CSP and rooftop PV but also utility-scale PV plants.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760018041','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760018041"><span><span class="hlt">Solar-wind</span> control of the extent of planetary ionospheres</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bauer, S. J.</p> <p>1976-01-01</p> <p>In our <span class="hlt">solar</span> system there are at least four magnetic planets: Earth, Jupiter, Mercury, and Mars; while at least one planet, Venus, appears to be essentially nonmagnetic. The ionospheres of the magnetic planets are imbedded in their magnetosphere and thus shielded from the <span class="hlt">solar</span> <span class="hlt">wind</span>, whereas the ionosphere of Venus, at least, interacts directly with the <span class="hlt">solar</span> <span class="hlt">wind</span>. However, the <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with the planetary environment, in both cases, affects the behavior of their ionospheres. The role the <span class="hlt">solar</span> <span class="hlt">wind</span> interaction plays in limiting the extent of the ionospheres of both magnetic and nonmagnetic planets is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003ESASP.535..265W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003ESASP.535..265W"><span>Modeling the total <span class="hlt">solar</span> <span class="hlt">irradiance</span>: recent progress and new questions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Walton, Stephen R.; Preminger, Dora G.; Chapman, Gary A.</p> <p>2003-09-01</p> <p>We report on the recent results from the San Fernando Observatory (SFO) in our efforts to understand the sources of <span class="hlt">solar</span> <span class="hlt">irradiance</span> variability. The results are based on the SFO's ongoing full disk photometric images program, which has now accumulated about 1-1/2 <span class="hlt">solar</span> cycles of data. The results are in three parts: (1) statistics of <span class="hlt">solar</span> active regions and their possible variation during the <span class="hlt">solar</span> cycle; (2) modeling of the total <span class="hlt">solar</span> <span class="hlt">irradiance</span> using the photometry of both individual features and the entire disk; and (3) the relative contribution of bright features to increases in total <span class="hlt">solar</span> <span class="hlt">irradiance</span>. Our main conclusions are, respectively: <span class="hlt">solar</span> active regions change in ways which affect their use in total <span class="hlt">irradiance</span> modeling; the <span class="hlt">solar</span> cycle change in total <span class="hlt">irradiance</span> is dominated by changes in the line blanketing; and that large faculae dominate the <span class="hlt">solar</span> cycle in <span class="hlt">irradiance</span>. Because resolved absolute photometry of the <span class="hlt">solar</span> disk has not yet been carried out, all of these results are based on regression analyses. We discuss what progress we can still make with such analyses, and close with a prediction of what future absolute <span class="hlt">solar</span> photometry may tell us.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19720029841&hterms=directed+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Ddirected%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720029841&hterms=directed+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Ddirected%2Benergy"><span>Electron energy flux in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ogilvie, K. W.; Scudder, J. D.; Sugiura, M.</p> <p>1971-01-01</p> <p>Description of studies of electrons between 10 eV and 9.9 keV in the <span class="hlt">solar</span> <span class="hlt">wind</span>. The transport of energy in the rest frame of the plasma is evaluated and shown to be parallel to the interplanetary magnetic field. The presence of electrons from <span class="hlt">solar</span> events causes this energy-flux density to exceed the heat flow due to thermal electrons. In one such event, the observations are shown to be consistent with the <span class="hlt">solar</span>-electron observations made at higher energies. When observations are made at a point connected to the earth's bow shock by an interplanetary-field line, a comparatively large energy flux along the field toward the sun is observed, but the heat flow remains outwardly directed during this time interval. In either situation the heat flow is found to be consistent with measurements made on Vela satellites by a different method. These values, less than .01 ergs/sq cm/sec, are sufficiently low to require modifications to the Spitzer-Harm conductivity formula for use in <span class="hlt">solar-wind</span> theories.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1981AdSpR...1....3S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1981AdSpR...1....3S"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> and its interaction with the magnetosphere - Measured parameters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schwenn, R.</p> <p></p> <p>The sun and the <span class="hlt">solar</span> <span class="hlt">wind</span> are considered in terms of the 'ballerina' model first proposed by Alfven (1977), taking into account high speed streams, the slow <span class="hlt">solar</span> <span class="hlt">wind</span>, stream-stream interactions, the relation of streams and magnetic structure, and transients caused by <span class="hlt">solar</span> activity. The main features of the <span class="hlt">solar</span> <span class="hlt">wind</span> behavior are illustrated with the aid of data, covering one complete <span class="hlt">solar</span> rotation in 1974/1975, which were obtained with instruments aboard the Helios-1 <span class="hlt">solar</span> probe. It is pointed out that the <span class="hlt">solar</span> <span class="hlt">wind</span> acts like a huge buffer pushing onto the earth's magnetosphere with a highly variable pressure. Of the energy in the highly variable <span class="hlt">solar</span> <span class="hlt">wind</span> reservoir only a tiny fraction is absorbed by the magnetosphere in an obviously very nonstationary way.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910003184','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910003184"><span>Long-term <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> Variability: 1984-1989 Observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lee, Robert B., III</p> <p>1990-01-01</p> <p>Long-term variability in the total <span class="hlt">solar</span> <span class="hlt">irradiance</span> has been observed in the Earth Radiation Budget Experiment (ERBE) <span class="hlt">solar</span> monitor measurements. The monitors have been used to measure the <span class="hlt">irradiance</span> from the Earth Radiation Budget Satellite (ERBS) and the National Oceanic and Atmospheric Administration NOAA-9 and NOAA-10 spacecraft platforms since October 25, 1984, January 23, 1985, and October 22, 1986, respectively. Before September 1986, the ERBS <span class="hlt">irradiance</span> values were found to be decreasing -0.03 percent per year. This period was marked by decreasing <span class="hlt">solar</span> magnetic activity. Between September 1986 and mid-1989, the <span class="hlt">irradiance</span> values increased approximately 0.1 percent. The latter period was marked by increasing <span class="hlt">solar</span> activity which was associated with the initiations of the sunspot cycle number 22 and of a new 22-year Hale <span class="hlt">solar</span> magnetic cycle. Therefore, long-term <span class="hlt">solar-irradiance</span> variability appears to be correlated directly with <span class="hlt">solar</span> activity. The maximum smoothed sunspot number occurred during September 1989, according to the Sunspot Index Data Center. Therefore, the recent <span class="hlt">irradiance</span> increasing trend should disappear during early 1990 and change into a decreasing trend if the observed <span class="hlt">irradiance</span> variability is correlated more so with the 11-year sunspot cycle than the 22-year Hale cycle. The ERBE <span class="hlt">irradiance</span> values are presented and compared with sunspot activity for the 1984 to 1989 period. The ERBE values are compared with those available from the Nimbus-7 and <span class="hlt">Solar</span> Maximum Mission spacecraft experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5023417','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5023417"><span><span class="hlt">Solar</span> <span class="hlt">irradiance</span> variations due to active regions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Oster, L.; Schatten, K.H.; Sofia, S.</p> <p>1982-05-15</p> <p>We have been able to reproduce the variations of the <span class="hlt">solar</span> <span class="hlt">irradiance</span> observed by ACRIM to an accuracy of better than +- 0.4 W m/sup -2/, assuming that during the 6 month observation period in 1980 the <span class="hlt">solar</span> luminosity was constant. The improvement over previous attempts is primarily due to the inclusion of faculae. The reproduction scheme uses simple geometrical data on spot and facula areas, and conventional parameters for the respective fluxes and angular dependencies. The quality of reproduction is not very sensitive to most of the details of these parameters; nevertheless, there conventional parameters cannot be very different from their actual values in the <span class="hlt">solar</span> atmosphere. It is interesting that the time average of the integrated excess emission (over directions) of the faculae cancels out the integrated deficit produced by the spots, within an accuracy of about 10%. If this behavior were maintained over longer periods of time, say, on the order of an activity cycle, active regions could be viewed as a kind of lighthouse where the energy deficit near the normal direction, associated with the spots, is primarily reemitted close to the tangential directions by the faculae. The currently available data suggest that energy ''storage'' associated with the redirection of flux near active regions on the Sun is comparable to the lifetime of the faculae.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMSH43B..07A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMSH43B..07A"><span>Topological Origins of the Slow <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Antiochos, S.</p> <p>2008-12-01</p> <p>Although the slow <span class="hlt">solar</span> <span class="hlt">wind</span> has been studied for decades with both in situ and remote sensing observations, its origin is still a matter of intense debate. In the standard quasi-steady model, the slow <span class="hlt">wind</span> is postulated to originate near coronal hole boundaries that define topologically well-behaved separatrices between open and closed field regions. In the interchange model, on the other hand, the slow <span class="hlt">wind</span> is postulated to originate on open flux that is dynamically diffusing throughout the seemingly closed-field corona. We argue in favor of the quasi-steady scenario and propose that the slow <span class="hlt">wind</span> is due to two effects: First, the open-closed boundary is highly complex due to the complexity of the photospheric flux distribution. Second, this boundary is continuously driven by the transport of magnetic helicity from the closed field region into the open. The implications of this model for the structure and dynamics of the corona and slow <span class="hlt">wind</span> are discussed, and observational tests of the model are presented. This work has been supported, in part, by the NASA LWS, HTP, and SR&T programs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20090006612&hterms=Debate&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DDebate','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20090006612&hterms=Debate&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DDebate"><span>Topological Origins of the Slow <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Antiochos, Spiro</p> <p>2008-01-01</p> <p>Although the slow <span class="hlt">solar</span> <span class="hlt">wind</span> has been studied for decades with both in situ and remote sensing observations, its origin is still a matter of intense debate. In the standard quasi-steady model, the slow <span class="hlt">wind</span> is postulated to originate near coronal hole boundaries that define topologically well-behaved separatrices between open and closed field regions. In the interchange model, on the other hand, the slow <span class="hlt">wind</span> is postulated to originate on open flux that is dynamically diffusing throughout the seemingly closed-field corona. We argue in favor of the quasi-steady scenario and propose that the slow <span class="hlt">wind</span> is due to two effects: First, the open-closed boundary is highly complex due to the complexity of the photospheric flux distribution. Second, this boundary is continuously driven by the transport of magnetic helicity from the closed field region into the open. The implications of this model for the structure and dynamics of the corona and slow <span class="hlt">wind</span> are discussed, and observational tests of the mode</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007SoPh..240..315V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007SoPh..240..315V"><span>Coronal Holes and <span class="hlt">Solar</span> <span class="hlt">Wind</span> High-Speed Streams: I. Forecasting the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Parameters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vršnak, Bojan; Temmer, Manuela; Veronig, Astrid M.</p> <p>2007-02-01</p> <p>We analyze the relationship between the coronal hole (CH) area/position and physical characteristics of the associated corotating high-speed stream (HSS) in the <span class="hlt">solar</span> <span class="hlt">wind</span> at 1 AU. For the analysis we utilize the data in the period DOY 25 125 of 2005, characterized by a very low coronal mass ejection (CME) activity. Distinct correlations between the daily averaged CH parameters and the <span class="hlt">solar</span> <span class="hlt">wind</span> characteristics are found, which allows us to forecast the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity v, proton temperature T, proton density n, and magnetic field strength B, several days in advance in periods of low CME activity. The forecast is based on monitoring fractional areas A, covered by CHs in the meridional slices embracing the central meridian distance ranges [-40°,-20°], [-10°,10°], and [20°,40°]. On average, the peaks in the daily values of n, B, T, and v appear delayed by 1, 2, 3, and 4 days, respectively, after the area A attains its maximum in the central-meridian slice. The peak values of the <span class="hlt">solar</span> <span class="hlt">wind</span> parameters are correlated to the peak values of A, which provides also forecasting of the peak values of n, B, T, and v. The most accurate prediction can be obtained for the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity, for which the average relative difference between the calculated and the observed peak values amounts to overline{\\vertδ\\vert}≈10 %. The forecast reliability is somewhat lower in the case of T, B, and n ( overline{\\vertδ\\vert}≈20 , 30, and 40%, respectively). The space weather implications are discussed, including the perspectives for advancing the real-time calculation of the Sun Earth transit times of coronal mass ejections and interplanetary shocks, by including more realistic real-time estimates of the <span class="hlt">solar</span> <span class="hlt">wind</span> characteristics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSA51B2427B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSA51B2427B"><span>The SORCE <span class="hlt">Solar</span> Spectral <span class="hlt">Irradiance</span> Data and Degradation Models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beland, S.; Harder, J. W.; Snow, M. A.; Woods, T. N.; Vanier, B.; Lindholm, C.; Elliott, J. P.; Sandoval, L.</p> <p>2016-12-01</p> <p>The Spectral <span class="hlt">Irradiance</span> Monitor (SIM) and the <span class="hlt">SOlar</span> Stellar <span class="hlt">Irradiance</span> Comparison Experiment (SOLSTICE) instruments on board the <span class="hlt">Solar</span> Radiation and Climate Experiment (SORCE) mission have been taking daily <span class="hlt">Solar</span> spectral <span class="hlt">irradiance</span> (SSI) measurements since April 2003. It is critical to accurately track the instrument degradation over time to be able to measure the small SSI variations with the <span class="hlt">solar</span> cycle over the wavelength range covered by SOLSTICE (115-310nm) and by SIM (220-2400nm). The instrument degradation is constantly being updated and the corresponding model has been refined over the years to account for changes and a better understanding of the instrument's behavior over time. We present the improvements made in the latest versions of the SOLSTICE and SIM data, and the work in progress in preparation of the upcoming releases. We compare these new data release with the Total <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> (TSI) measured by the SORCE Total <span class="hlt">Irradiance</span> Monitor (TIM) instrument.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002cosp...34E1724G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002cosp...34E1724G"><span>Influence of variations in <span class="hlt">solar</span> UV <span class="hlt">irradiance</span> on quasi-biennial oscillations in the stratosphere and on atmospheric circulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gabis, I.; Troshichev, O.</p> <p></p> <p>A study of relationships between variations in the <span class="hlt">solar</span> ultraviolet <span class="hlt">irradiance</span> and quasi-biennial oscillations (QBO) in the Earth's atmosphere has been carried out by using the composite Mg II index as a proxy of the <span class="hlt">solar</span> UV <span class="hlt">irradiance</span>. Detail analysis of changes in the stratospheric <span class="hlt">wind</span> direction at layers from 10 mB to 70 mB for 1978-2001 showed that the <span class="hlt">wind</span> changes start at higher altitudes and go down to lower ones, the <span class="hlt">wind</span> intensity being the greatest in layer of the maximum ozone content (about 20 mB). The definite relationship between periodicity of changes in <span class="hlt">solar</span> UV <span class="hlt">irradiance</span> and quasi-biennial oscillations (QBO) is found if the QBO phase is defined in conformity with the <span class="hlt">wind</span> observations at altitude of 20 km: the mean level of UV <span class="hlt">irradiance</span>, averaged for 10 east QBO phases, is about twice as large as that for the west QBO phases. The conclusion is made that <span class="hlt">solar</span> UV <span class="hlt">irradiance</span> is subjected to quasi-biennial periodicity (QBP), the UV <span class="hlt">irradiance</span> being increased for the east QPB phase, and being reduced for the west QBP phase. The reversal of stratospheric <span class="hlt">winds</span> proceeds from the top down with certain cyclicity and efficiency of the UV <span class="hlt">irradiation</span> influence on stratosphere seems to be different at various steps of the cyclicity. This circumstance can cause inconsistency between the QBP and QBO phases for some specific periods. Variations of the <span class="hlt">solar</span> UV <span class="hlt">irradiation</span> affect the atmospheric circulation structure. In particular, the rate of the ozone gap filling during the Antarctic spring depends on level of the UV <span class="hlt">irradiation</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19800009702&hterms=silverman&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsilverman','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19800009702&hterms=silverman&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsilverman"><span>Variations of the <span class="hlt">solar</span> <span class="hlt">wind</span> and <span class="hlt">solar</span> cycle in the last 300 years</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Feynman, J.; Silverman, S.</p> <p>1980-01-01</p> <p>The past history of the <span class="hlt">solar</span> <span class="hlt">wind</span> and <span class="hlt">solar</span> cycle, inferred from records of geomagnetics and aurora, is examined. Records show that the <span class="hlt">solar</span> <span class="hlt">wind</span> apparently varied in a systematic manner throughout the period from 1770 to 1857 and that the period around 1810 resembled the 1901 minimum geomagnetic disturbance. Results show that the <span class="hlt">solar</span> <span class="hlt">wind</span> and hence the Sun changes on a time scale long compared to a <span class="hlt">solar</span> cycle and short compared to the Maunder minimum. The inclusion of a study on the <span class="hlt">solar</span> <span class="hlt">wind</span> and <span class="hlt">solar</span> cycle variations for the SCADM mission is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22086402','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22086402"><span>ISOTOPIC MASS FRACTIONATION OF <span class="hlt">SOLAR</span> <span class="hlt">WIND</span>: EVIDENCE FROM FAST AND SLOW <span class="hlt">SOLAR</span> <span class="hlt">WIND</span> COLLECTED BY THE GENESIS MISSION</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Heber, Veronika S.; Baur, Heinrich; Wieler, Rainer; Bochsler, Peter; McKeegan, Kevin D.; Neugebauer, Marcia; Reisenfeld, Daniel B.; Wiens, Roger C.</p> <p>2012-11-10</p> <p>NASA's Genesis space mission returned samples of <span class="hlt">solar</span> <span class="hlt">wind</span> collected over {approx}2.3 years. We present elemental and isotopic compositions of He, Ne, and Ar analyzed in diamond-like carbon targets from the slow and fast <span class="hlt">solar</span> <span class="hlt">wind</span> collectors to investigate isotopic fractionation processes during <span class="hlt">solar</span> <span class="hlt">wind</span> formation. The <span class="hlt">solar</span> <span class="hlt">wind</span> provides information on the isotopic composition for most volatile elements for the <span class="hlt">solar</span> atmosphere, the bulk Sun and hence, on the <span class="hlt">solar</span> nebula from which it formed 4.6 Ga ago. Our data reveal a heavy isotope depletion in the slow <span class="hlt">solar</span> <span class="hlt">wind</span> compared to the fast <span class="hlt">wind</span> composition by 63.1 {+-} 2.1 per mille for He, 4.2 {+-} 0.5 per mille amu{sup -1} for Ne and 2.6 {+-} 0.5 per mille amu{sup -1} for Ar. The three Ne isotopes suggest that isotopic fractionation processes between fast and slow <span class="hlt">solar</span> <span class="hlt">wind</span> are mass dependent. The He/H ratios of the collected slow and fast <span class="hlt">solar</span> <span class="hlt">wind</span> samples are 0.0344 and 0.0406, respectively. The inefficient Coulomb drag model reproduces the measured isotopic fractionation between fast and slow <span class="hlt">wind</span>. Therefore, we apply this model to infer the photospheric isotopic composition of He, Ne, and Ar from our <span class="hlt">solar</span> <span class="hlt">wind</span> data. We also compare the isotopic composition of oxygen and nitrogen measured in the <span class="hlt">solar</span> <span class="hlt">wind</span> with values of early <span class="hlt">solar</span> system condensates, probably representing <span class="hlt">solar</span> nebula composition. We interpret the differences between these samples as being due to isotopic fractionation during <span class="hlt">solar</span> <span class="hlt">wind</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19720019110&hterms=helium+neon&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dhelium%2Bneon','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720019110&hterms=helium+neon&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dhelium%2Bneon"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> rare gas analysis: Trapped <span class="hlt">solar</span> <span class="hlt">wind</span> helium and neon in Surveyor 3 material</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Buehler, F.; Eberhardt, P.; Geiss, J.; Schwarzmueller, J.</p> <p>1972-01-01</p> <p>The He-4 and Ne-20 contents in sections of the Surveyor 3 support strut samples were determined by optical and scanning electron microscopy and are compared to the results of the Apollo <span class="hlt">solar</span> <span class="hlt">wind</span> composition (SWC) experiments. The He-4/Ne-20 ratio in the samples from the sunlit side of the strut was approximately 300; the ratios determined in Apollo 12 lunar fines and SWC foil were below 100. The He-4/He-3 ratios were also determined, and the ratio obtained from Surveyor 3 material is higher than those found with Apollo 11 and 12 SWC experiments. The effects of spallation by cosmic rays or <span class="hlt">solar</span> protons, stripping by cosmic ray or energetic <span class="hlt">solar</span> alpha particles, recycling of <span class="hlt">solar</span> <span class="hlt">wind</span> He and radiogenic Ne, He from terrestrial atmosphere, mass discrimination near the moon, mass dependence of trapping probability, diffusion, and contamination by lunar dust are considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19720019110&hterms=Helium+gas&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DHelium%2Bgas','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720019110&hterms=Helium+gas&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DHelium%2Bgas"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> rare gas analysis: Trapped <span class="hlt">solar</span> <span class="hlt">wind</span> helium and neon in Surveyor 3 material</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Buehler, F.; Eberhardt, P.; Geiss, J.; Schwarzmueller, J.</p> <p>1972-01-01</p> <p>The He-4 and Ne-20 contents in sections of the Surveyor 3 support strut samples were determined by optical and scanning electron microscopy and are compared to the results of the Apollo <span class="hlt">solar</span> <span class="hlt">wind</span> composition (SWC) experiments. The He-4/Ne-20 ratio in the samples from the sunlit side of the strut was approximately 300; the ratios determined in Apollo 12 lunar fines and SWC foil were below 100. The He-4/He-3 ratios were also determined, and the ratio obtained from Surveyor 3 material is higher than those found with Apollo 11 and 12 SWC experiments. The effects of spallation by cosmic rays or <span class="hlt">solar</span> protons, stripping by cosmic ray or energetic <span class="hlt">solar</span> alpha particles, recycling of <span class="hlt">solar</span> <span class="hlt">wind</span> He and radiogenic Ne, He from terrestrial atmosphere, mass discrimination near the moon, mass dependence of trapping probability, diffusion, and contamination by lunar dust are considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002cosp...34E.116M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002cosp...34E.116M"><span>The Sun and the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Variability of Different Time - Scale and the Climate Dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Makarova, L.; Shirochkov, A.</p> <p></p> <p>The Space originated energy is universally adopted as a factor capable to control the Earth's climate dynamics. A level of the Sun UV radiation expressed as the total <span class="hlt">solar</span> <span class="hlt">irradiance</span> (TSI) or the "<span class="hlt">solar</span> constant" is taken as the most reliable indicator of amount of the <span class="hlt">solar</span> energy transferred to the Earth. On the other hand the Sun variability includes other electromagnetic emissions of different intensity and duration which certainly contribute to total energy of the <span class="hlt">solar</span> <span class="hlt">wind</span>-a well established permanent component of the <span class="hlt">solar</span> activity whose influence on the climate dynamics has been ignored so far. The <span class="hlt">solar</span> <span class="hlt">wind</span> permanently affecting near-Earth space could provide substantial amount of energy to sustain active atmospheric processes Quantitatively this energy could be evaluated crudely as the dynamic pressure of the <span class="hlt">solar</span> <span class="hlt">wind</span>. More accurately influence of the <span class="hlt">solar</span> <span class="hlt">wind</span> on the Earth's magnetosphere-ionosphere-atmosphere system could be expressed by means of the subsolar distance between the Earth and external boundary of the magnetosphere -magnetopause. We found that the temporal variations of the coronal index of <span class="hlt">solar</span> activity (<span class="hlt">solar</span> UV radiation level at wavelength of 530 nm - FeXIY green corona line) measured at the Earth surface correlate nicely with the <span class="hlt">solar</span> <span class="hlt">wind</span> energy level expressed as subsolar distance between the Earth and magnetopause. It could mean that the absorption of the UV radiation by the Earth atmosphere depends on energy of the <span class="hlt">solar</span> <span class="hlt">wind</span>. Our analysis of the results of the atmospheric baloon measurements (day-to-day) demonstrated that temperature at h= 300-30 mB changes with a position the magnetopause relative to the Earth in subsolar point. The data for wintertime were analysed in order to minimize influence of the <span class="hlt">solar</span> UV radiation. The highest coefficients of correlation (up to 0,8) were obtained for 30 mB surface (~23 km) at many stations. We found that the <span class="hlt">solar</span> <span class="hlt">wind</span> energy controls magnitude of the relative humidity on the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20090006630&hterms=Goldstein&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DGoldstein','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20090006630&hterms=Goldstein&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DGoldstein"><span>Variations of Strahl Properties with Fast and Slow <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Figueroa-Vinas, Adolfo; Goldstein, Melvyn L.; Gurgiolo, Chris</p> <p>2008-01-01</p> <p>The interplanetary <span class="hlt">solar</span> <span class="hlt">wind</span> electron velocity distribution function generally shows three different populations. Two of the components, the core and halo, have been the most intensively analyzed and modeled populations using different theoretical models. The third component, the strahl, is usually seen at higher energies, is confined in pitch-angle, is highly field-aligned and skew. This population has been more difficult to identify and to model in the <span class="hlt">solar</span> <span class="hlt">wind</span>. In this work we make use of the high angular, energy and time resolution and three-dimensional data of the Cluster/PEACE electron spectrometer to identify and analyze this component in the ambient <span class="hlt">solar</span> <span class="hlt">wind</span> during high and slow speed <span class="hlt">solar</span> <span class="hlt">wind</span>. The moment density and fluid velocity have been computed by a semi-numerical integration method. The variations of <span class="hlt">solar</span> <span class="hlt">wind</span> density and drift velocity with the general build <span class="hlt">solar</span> <span class="hlt">wind</span> speed could provide some insight into the source, origin, and evolution of the strahl.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20090006630&hterms=Goldstein&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DGoldstein','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20090006630&hterms=Goldstein&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DGoldstein"><span>Variations of Strahl Properties with Fast and Slow <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Figueroa-Vinas, Adolfo; Goldstein, Melvyn L.; Gurgiolo, Chris</p> <p>2008-01-01</p> <p>The interplanetary <span class="hlt">solar</span> <span class="hlt">wind</span> electron velocity distribution function generally shows three different populations. Two of the components, the core and halo, have been the most intensively analyzed and modeled populations using different theoretical models. The third component, the strahl, is usually seen at higher energies, is confined in pitch-angle, is highly field-aligned and skew. This population has been more difficult to identify and to model in the <span class="hlt">solar</span> <span class="hlt">wind</span>. In this work we make use of the high angular, energy and time resolution and three-dimensional data of the Cluster/PEACE electron spectrometer to identify and analyze this component in the ambient <span class="hlt">solar</span> <span class="hlt">wind</span> during high and slow speed <span class="hlt">solar</span> <span class="hlt">wind</span>. The moment density and fluid velocity have been computed by a semi-numerical integration method. The variations of <span class="hlt">solar</span> <span class="hlt">wind</span> density and drift velocity with the general build <span class="hlt">solar</span> <span class="hlt">wind</span> speed could provide some insight into the source, origin, and evolution of the strahl.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19750032355&hterms=wind+night+day&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dwind%2Bnight%2Bday','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19750032355&hterms=wind+night+day&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dwind%2Bnight%2Bday"><span>Steady state asymmetric planetary electrical induction. [by <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Horning, B. L.; Schubert, G.</p> <p>1974-01-01</p> <p>An analytic solution is presented for the steady state electric and magnetic fields induced by the motional electric field of the <span class="hlt">solar</span> <span class="hlt">wind</span> in the atmosphere or interior of a planet that is asymmetrically surrounded by <span class="hlt">solar</span> <span class="hlt">wind</span> plasma. The electrically conducting ionosphere or interior must be in direct electrical contact with the <span class="hlt">solar</span> <span class="hlt">wind</span> over the day side of the planet. The conducting region of the planet is modeled by a sphere or a spherical shell of arbitrarily stratified electrical conductivity. A monoconducting cylindrical cavity is assumed to extend downstream on the night side of the planet. The <span class="hlt">solar</span> <span class="hlt">wind</span> is assumed to be highly conducting so that the induced fields are confined to the planet and cavity. Induced currents close as sheet currents at the <span class="hlt">solar</span> <span class="hlt">wind</span>-cavity and <span class="hlt">solar</span> <span class="hlt">wind</span>-planet interfaces. Numerical evaluations of the analytic formulas are carried out for a uniformly conducting spherical model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980018115','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980018115"><span>Interpretation of <span class="hlt">Solar</span> <span class="hlt">Wind</span> Ion Composition Measurements from Ulysses</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Esser, Ruth</p> <p>1998-01-01</p> <p>The ion compositions measured in situ in the <span class="hlt">solar</span> <span class="hlt">wind</span> are important since the ion fractions carry information on the plasma conditions in the inner corona. The conditions in the inner corona define the properties of the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma flow. Thus, if the ion fraction measurements can be used to unravel some of the plasma parameters in the inner corona, they will provide a valuable contribution to solving the heating and acceleration problem of the <span class="hlt">solar</span> <span class="hlt">wind</span>. The ion charge states in the <span class="hlt">solar</span> <span class="hlt">wind</span> carry information on electron temperature, electron density and ion flow speed. They are also sensitive to the shape of the electron distribution function. Through carefully modeling the <span class="hlt">solar</span> <span class="hlt">wind</span> and calculating the ion fractions predicted for different <span class="hlt">solar</span> <span class="hlt">wind</span> conditions, constraints on the electron temperature and ion flow speeds can be placed if the electron density is measured using polarization brightness measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...837...75S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...837...75S"><span>Turbulent Transport in a Three-dimensional <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shiota, D.; Zank, G. P.; Adhikari, L.; Hunana, P.; Telloni, D.; Bruno, R.</p> <p>2017-03-01</p> <p>Turbulence in the <span class="hlt">solar</span> <span class="hlt">wind</span> can play essential roles in the heating of coronal and <span class="hlt">solar</span> <span class="hlt">wind</span> plasma and the acceleration of the <span class="hlt">solar</span> <span class="hlt">wind</span> and energetic particles. Turbulence sources are not well understood and thought to be partly enhanced by interaction with the large-scale inhomogeneity of the <span class="hlt">solar</span> <span class="hlt">wind</span> and the interplanetary magnetic field and/or transported from the <span class="hlt">solar</span> corona. To investigate the interaction with background inhomogeneity and the turbulence sources, we have developed a new 3D MHD model that includes the transport and dissipation of turbulence using the theoretical model of Zank et al. We solve for the temporal and spatial evolution of three moments or variables, the energy in the forward and backward fluctuating modes and the residual energy and their three corresponding correlation lengths. The transport model is coupled to our 3D model of the inhomogeneous <span class="hlt">solar</span> <span class="hlt">wind</span>. We present results of the coupled <span class="hlt">solar</span> <span class="hlt">wind</span>-turbulence model assuming a simple tilted dipole magnetic configuration that mimics <span class="hlt">solar</span> minimum conditions, together with several comparative intermediate cases. By considering eight possible <span class="hlt">solar</span> <span class="hlt">wind</span> and turbulence source configurations, we show that the large-scale <span class="hlt">solar</span> <span class="hlt">wind</span> and IMF inhomogeneity and the strength of the turbulence sources significantly affect the distribution of turbulence in the heliosphere within 6 au. We compare the predicted turbulence distribution results from a complete <span class="hlt">solar</span> minimum model with in situ measurements made by the Helios and Ulysses spacecraft, finding that the synthetic profiles of the turbulence intensities show reasonable agreement with observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5384968','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5384968"><span><span class="hlt">Solar</span> <span class="hlt">irradiance</span> modulation by active regions from 1969 through 1980</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Schatten, K.H.; Miller, N.; Sofia, S.; Oster, L.</p> <p>1982-01-01</p> <p>The <span class="hlt">solar</span> <span class="hlt">irradiance</span> variations resulting from sunspot deficits and facular excesses in emission have been calculated from 1969 through 1980. Agreement appears to exist between our calculations and the major features seen with the Nimbus 7 cavity pyrheliometer and with both the major and minor features detected by The <span class="hlt">Solar</span> Maximum Mission ACRIM experiment. The 12-year <span class="hlt">irradiance</span> variations we calculate suggest a larger variance with increased <span class="hlt">solar</span> activity, and little change in the average <span class="hlt">irradiance</span> with <span class="hlt">solar</span> activity. The largest excursions over these 12 years show a 0.4% variation. Removal of the activity influences upon <span class="hlt">solar</span> <span class="hlt">irradiance</span> during the numerous rocket experiments observing the <span class="hlt">solar</span> ''constant'' may allow a better value for this quantity to be determined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017E%26ES...75a2007B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017E%26ES...75a2007B"><span>Design of Hybrid <span class="hlt">Solar</span> and <span class="hlt">Wind</span> Energy Harvester for Fishing Boat</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Banjarnahor, D. A.; Hanifan, M.; Budi, E. M.</p> <p>2017-07-01</p> <p>In southern beach of West Java, Indonesia, there are many villagers live as fishermen. They use small boats for fishing, in one to three days. Therefore, they need a fish preservation system. Fortunately, the area has high potential of <span class="hlt">solar</span> and <span class="hlt">wind</span> energy. This paper presents the design of a hybrid <span class="hlt">solar</span> and <span class="hlt">wind</span> energy harvester to power a refrigerator in the fishing boat. The refrigerator should keep the fish in 2 - 4 °C. The energy needed is 720 Wh daily. In the area, the daily average <span class="hlt">wind</span> velocity is 4.27 m/s and the sun <span class="hlt">irradiation</span> is 672 W/m2. The design combined two 100W <span class="hlt">solar</span> panels and a 300W <span class="hlt">wind</span> turbine. The testing showed that the <span class="hlt">solar</span> panels can harvest 815 - 817 Wh of energy, while the <span class="hlt">wind</span> turbine can harvest 43 - 62 Wh of energy daily. Therefore, the system can fulfil the energy requirement in fishing boat, although the <span class="hlt">solar</span> panels were more dominant. To install the <span class="hlt">wind</span> turbine on the fishing-boat, a computational design had been conducted. The boat hydrostatic dimension was measured to determine its stability condition. To reach a stable equilibrium condition, the <span class="hlt">wind</span> turbine should be installed no more than 1.7 m of height.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730002081','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730002081"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> helium enhancements following major <span class="hlt">solar</span> flares</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hirshberg, J.</p> <p>1972-01-01</p> <p>The observations of <span class="hlt">solar</span> <span class="hlt">wind</span> helium enhancements following major <span class="hlt">solar</span> flares are reviewed, and the hypothesis that helium enhancements often mark flare piston plasma is confirmed. Helium enhancements were observed during each of the three periods (March 1966, July 1966, August/September 1966) of major <span class="hlt">solar</span> activity that occurred from October 1965 to October 1966. No enhancements were seen during the long quiet periods that occurred that year. At 1 AU, the helium-enhanced plasma pistons had slowed so that the velocity was 80 percent of the mean transit velocity, in general agreement with theoretical models of the propagation of flare disturbances. A qualitative model, in which the piston plasma is accelerated from the flare site deep in the corona, is discussed briefly. If the model is valid in general outline, the piston plasmas provide samples of material from the lower levels of the corona.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021499&hterms=solar+energy+you&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsolar%2Benergy%2Byou','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021499&hterms=solar+energy+you&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsolar%2Benergy%2Byou"><span>Radial evolution of the energy density of <span class="hlt">solar</span> <span class="hlt">wind</span> fluctuations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zank, G. P.; Matthaeus, W. H.; Smith, C. W.</p> <p>1995-01-01</p> <p>On the basis of transport theories appropriate to a radially expanding <span class="hlt">solar</span> <span class="hlt">wind</span>, we describe new results for the radial evolution of the energy density in <span class="hlt">solar</span> <span class="hlt">wind</span> fluctuations at MHD scales. These models include the effects of 'mixing' and driving as well as the possibility of non-isotropic MHD turbulence. Implications of these results for <span class="hlt">solar</span> <span class="hlt">wind</span> heating, cosmic ray diffusion and interstellar pick-up ions will also be addressed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021499&hterms=evolution+theory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Devolution%2Btheory','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021499&hterms=evolution+theory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Devolution%2Btheory"><span>Radial evolution of the energy density of <span class="hlt">solar</span> <span class="hlt">wind</span> fluctuations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zank, G. P.; Matthaeus, W. H.; Smith, C. W.</p> <p>1995-01-01</p> <p>On the basis of transport theories appropriate to a radially expanding <span class="hlt">solar</span> <span class="hlt">wind</span>, we describe new results for the radial evolution of the energy density in <span class="hlt">solar</span> <span class="hlt">wind</span> fluctuations at MHD scales. These models include the effects of 'mixing' and driving as well as the possibility of non-isotropic MHD turbulence. Implications of these results for <span class="hlt">solar</span> <span class="hlt">wind</span> heating, cosmic ray diffusion and interstellar pick-up ions will also be addressed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730020094','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730020094"><span>The large scale structure of the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wolfe, J. H.</p> <p>1971-01-01</p> <p>The <span class="hlt">solar</span> <span class="hlt">wind</span> structure is reviewed based on experimental space measurements acquired over approximately the last decade. The character of the interplanetary medium is considered from the viewpoint of the temporal behavior of the <span class="hlt">solar</span> <span class="hlt">wind</span> over increasingly longer time intervals, the average properties of the various <span class="hlt">solar</span> <span class="hlt">wind</span> parameters and their interrelationships. A brief discussion is included of interplanetary-terrestrial relationships and the expected effects of heliographic latitude and radial distance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021279&hterms=Bern&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DBern','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021279&hterms=Bern&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DBern"><span>Elemental and charge state composition of the fast <span class="hlt">solar</span> <span class="hlt">wind</span> observed with SMS instruments on <span class="hlt">WIND</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gloeckler, G.; Galvin, A. B.; Ipavich, F. M.; Hamilton, D. C.; Bochsler, P.; Geiss, J.; Fisk, L. A.; Wilken, B.</p> <p>1995-01-01</p> <p>The elemental composition and charge state distributions of heavy ions of the <span class="hlt">solar</span> <span class="hlt">wind</span> provide essential information about: (1) atom-ion separation processes in the <span class="hlt">solar</span> atmosphere leading to the 'FIP effect' (the overabundance of low First Ionization potential (FIP) elements in the <span class="hlt">solar</span> <span class="hlt">wind</span> compared to the photosphere); and (2) coronal temperature profiles, as well as mechanisms which heat the corona and accelerate the <span class="hlt">solar</span> <span class="hlt">wind</span>. This information is required for <span class="hlt">solar</span> <span class="hlt">wind</span> acceleration models. The SWICS instrument on Ulysses measures for all <span class="hlt">solar</span> <span class="hlt">wind</span> flow conditions the relative abundance of about 8 elements and 20 charge states of the <span class="hlt">solar</span> <span class="hlt">wind</span>. Furthermore, the Ulysses high-latitude orbit provides an unprecedented look at the <span class="hlt">solar</span> <span class="hlt">wind</span> from the polar coronal holes near <span class="hlt">solar</span> minimum conditions. The MASS instrument on the <span class="hlt">WIND</span> spacecraft is a high-mass resolution <span class="hlt">solar</span> <span class="hlt">wind</span> ion mass spectrometer that will provide routinely not only the abundances and charge state of all elements easily measured with SWICS, but also of N, Mg, S. The MASS sensor was fully operational at the end of 1994 and has sampled the in-ecliptic <span class="hlt">solar</span> <span class="hlt">wind</span> composition in both the slow and the corotating fast streams. This unique combination of SWICS on Ulysses and MASS on <span class="hlt">WIND</span> allows us to view for the first time the <span class="hlt">solar</span> <span class="hlt">wind</span> from two regions of the large coronal hole. Observations with SWICS in the coronal hole <span class="hlt">wind</span>: (1) indicate that the FIP effect is small; and (2) allow us determine the altitude of the maximum in the electron temperature profile, and indicate a maximum temperature of approximately 1.5 MK. New results from the SMS instruments on <span class="hlt">Wind</span> will be compared with results from SWICS on Ulysses.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPD....47.0324P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPD....47.0324P"><span>Morphology of Pseudostreamers and <span class="hlt">Solar</span> <span class="hlt">Wind</span> Properties</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Panasenco, Olga; Velli, Marco</p> <p>2016-05-01</p> <p>The <span class="hlt">solar</span> dynamo and photospheric convection lead to three main types of structures extending from the <span class="hlt">solar</span> surface into the corona - active regions, <span class="hlt">solar</span> filaments (prominences when observed at the limb) and coronal holes. These structures exist over a wide range of scales, and are interlinked with each other in evolution and dynamics. Active regions can form clusters of magnetic activity and the strongest overlie sunspots. In the decay of active regions, the boundaries separating opposite magnetic polarities (neutral lines) develop the specific structures called filament channels above which filaments form. In the presence of flux imbalance decaying active regions can also give birth to lower latitude coronal holes. The accumulation of magnetic flux at coronal hole boundaries also creates the conditions for filament formation: polar crown filaments are permanently present at the boundaries of the polar coronal holes. Middle-latitude and equatorial coronal holes - the result of active region evolution - can create pseudostreamers (PSs) if other coronal holes of the same polarity are present. While helmet streamers form between open fields of opposite polarities, the pseudostreamer, characterized by a smaller coronal imprint, typically shows a more prominent straight ray or stalk extending from the corona. The pseudostreamer base at photospheric heights is multipolar; often one observes tripolar magnetic configurations with two neutral lines - where filaments can form - separating the coronal holes. Here we discuss the specific role of filament channels on pseudostreamer topology and on <span class="hlt">solar</span> <span class="hlt">wind</span> properties. 1D numerical analysis of PSs shows that the properties of the <span class="hlt">solar</span> <span class="hlt">wind</span> from around PSs depend on the presence/absence of filament channels, number of channels and chirality at the PS base low in the corona.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFMSH23A1164M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFMSH23A1164M"><span>Eigenmode Structure in <span class="hlt">Solar</span> <span class="hlt">Wind</span> Langmuir Waves</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Malaspina, D. M.; Ergun, R.; Bougeret, J.; Kaiser, M. L.; Bale, S.; Cairns, I. H.; Cattell, C. A.; Kellogg, P. J.; Newman, D. L.</p> <p>2007-12-01</p> <p>Bursty Langmuir waves associated with space plasma phenomena including type II and type III <span class="hlt">solar</span> radio bursts, auroral field-aligned electrons, and radiation from shocks often exhibit localized beat-type waveforms. A consensus view on the modulation mechanism remains elusive. Current theories include multi-wave interactions, turbulence, or non-linear growth such as kinetic localization. Most of these theories start with the assumption that the density of the background plasma is near-uniform, in spite of numerous observations to the contrary. An alternative approach is to start with the assumption that density perturbations pre-exist. We construct an analytical electric field solution, describing Langmuir waves as a combination of trapped eigenmodes within a parabolic density well. This hypothesis is supported by discreet frequency structure in auroral Langmuir wave observations observed to be associated with density fluctuations, and by the high degree of localization observed in <span class="hlt">solar</span> <span class="hlt">wind</span> borne Langmuir waves. This simple, one-dimensional model can reproduce waveform and frequency structure of localized Langmuir waves observed by STEREO/SWAVES. The waveforms can be reasonably reproduced using linear combinations of only a few low-mode eigenmode solutions. The eigenmode solutions are sensitive to plasma environmental parameters such as the electron temperature and <span class="hlt">solar</span> <span class="hlt">wind</span> velocity. The trapped-eigenmode solutions can form a theoretical basis to explore the non-linear behavior of Langmuir waves which may allow for efficient conversion and escape of electromagnetic emissions and second harmonic production.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUSMSH24A..04S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUSMSH24A..04S"><span>What Determines the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Speed ?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Suzuki, T. K.; Fujiki, K.; Kojima, M.; Tokumaru, M.; Hirano, M.; Baba, D.; Yamasita, M.; Hakamada, K.</p> <p>2005-05-01</p> <p>Recent observations by Interplanetary Scintillation measurements by Nagoya-STEL group (Hirano et al.2003; Kojima et al.2004) show that <span class="hlt">solar</span> <span class="hlt">wind</span> speed is well-correlated with B/f, where B is radial magnetic field strength at the <span class="hlt">solar</span> surface and f is a super-radial expansion factor of open flux tubes. We show that this correlation is nicely explained by dissipation of Alfven waves no matter what types of the wave dissipation processes operate. B determines the input energy flux of Alfven waves and f controls adiabatic loss of the wave energy, so that B/f is an important control parameter which determines the <span class="hlt">solar</span> <span class="hlt">wind</span> speed. (reference ) [1] Hirano, M., Kojima, M., Tokumaru, M., Fujiki, K., Ohmi, T., Yamashita, M, Hakamada, K., and Hayashi, K. 2003,, Eos Trans. AGU, 84(46), Fall Meet. Suppl., Abstract SH21B-0164 [2] Kojima, M., K. Fujiki, M. Hirano, M. Tokumaru, T. Ohmi, and K. Hakamada, 2004, "The Sun and the heliosphere as an Integrated System", Giannina Poletto and Steven T. Suess, Eds. Kluwer Academic Publishers, in press</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.1156V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.1156V"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> influence on Jupiter's magnetosphere and aurora</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vogt, Marissa; Gyalay, Szilard; Withers, Paul</p> <p>2016-04-01</p> <p>Jupiter's magnetosphere is often said to be rotationally driven, with strong centrifugal stresses due to large spatial scales and a rapid planetary rotation period. For example, the main auroral emission at Jupiter is not due to the magnetosphere-<span class="hlt">solar</span> <span class="hlt">wind</span> interaction but is driven by a system of corotation enforcement currents that arises to speed up outflowing Iogenic plasma. Additionally, processes like tail reconnection are also thought to be driven, at least in part, by processes internal to the magnetosphere. While the <span class="hlt">solar</span> <span class="hlt">wind</span> is generally expected to have only a small influence on Jupiter's magnetosphere and aurora, there is considerable observational evidence that the <span class="hlt">solar</span> <span class="hlt">wind</span> does affect the magnetopause standoff distance, auroral radio emissions, and the position and brightness of the UV auroral emissions. We will report on the results of a comprehensive, quantitative study of the influence of the <span class="hlt">solar</span> <span class="hlt">wind</span> on various magnetospheric data sets measured by the Galileo mission from 1996 to 2003. Using the Michigan <span class="hlt">Solar</span> <span class="hlt">Wind</span> Model (mSWiM) to predict the <span class="hlt">solar</span> <span class="hlt">wind</span> conditions upstream of Jupiter, we have identified intervals of high and low <span class="hlt">solar</span> <span class="hlt">wind</span> dynamic pressure. We can use this information to quantify how a magnetospheric compression affects the magnetospheric field configuration, which in turn will affect the ionospheric mapping of the main auroral emission. We also consider whether there is evidence that reconnection events occur preferentially during certain <span class="hlt">solar</span> <span class="hlt">wind</span> conditions or that the <span class="hlt">solar</span> <span class="hlt">wind</span> modulates the quasi-periodicity seen in the magnetic field dipolarizations and flow bursts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950046571&hterms=PMO&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DPMO','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950046571&hterms=PMO&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DPMO"><span>Long-term variations in total <span class="hlt">solar</span> <span class="hlt">irradiance</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pap, Judit M.; Willson, Richard C.; Froelich, Claus; Donnelly, Richard F.; Puga, Larry</p> <p>1994-01-01</p> <p>For more than a decade total <span class="hlt">solar</span> <span class="hlt">irradiance</span> has been monitored simultaneously from space by different satellites. The detection of total <span class="hlt">solar</span> <span class="hlt">irradiance</span> variations by satellite-based experiments during the past decade and a half has stimulated modeling efforts to help identify their causes and to provide estimates of <span class="hlt">irradiance</span> data, using `proxy' indicators of <span class="hlt">solar</span> activity, for time intervals when no satellite observations exist. In this paper total <span class="hlt">solar</span> <span class="hlt">irradiance</span> observed by the Nimbus-7/Earth Radiation Budget (ERB), <span class="hlt">Solar</span> Maximum Mission (SMM)/Active Cavity Radiometer <span class="hlt">Irradiance</span> Monitor (ACRIM) 1, and Upper Atmosphere Research Satellite (UARS)/ACRIM 2 radiometers is modeled with the Photometric Sunspot Index and the Mg II core-to-wing ratio. Since the formation of the Mg II line is very similar to that of the Ca II K line, the Mg core-to-wing ratio, derived from the <span class="hlt">irradiance</span> observations of the Nimbus-7 and NOAA9 satellites, is used as a proxy for the bright magnetic elements. It is shown that the observed changes in <span class="hlt">solar</span> <span class="hlt">irradiance</span> are underestimated by the proxy models at the time of maximum and during the beginning of the declining portion of <span class="hlt">solar</span> cycle 22 similar to behavior just before the maximum of <span class="hlt">solar</span> cycle 21. This disagreement between total <span class="hlt">irradiance</span> observations and their model estimates is indicative of the fact that the underlying physical mechanism of the changes observed in the <span class="hlt">solar</span> radiative output is not well-understood. Furthermore, the uncertainties in the proxy data used for <span class="hlt">irradiance</span> modeling and the resulting limitation of the models should be taken into account, especially when the <span class="hlt">irradiance</span> models are used for climatic studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016cosp...41E1065K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016cosp...41E1065K"><span>Mesopause region <span class="hlt">wind</span>, temperature and airglow <span class="hlt">irradiance</span> above Eureka, Nunavut</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kristoffersen, Samuel; Ward, William E.; Vail, Christopher; Shepherd, Marianna</p> <p>2016-07-01</p> <p>The PEARL All Sky Imager (PASI, airglow images), the Spectral Airglow Temperature Imager (SATI, airglow <span class="hlt">irradiance</span> and temperature) and the E-Region <span class="hlt">Wind</span> Interferometer II (ERWIN2, <span class="hlt">wind</span>, airglow <span class="hlt">irradiance</span> and temperature) are co-located at the Polar Environment Atmospheric Research Laboratory (PEARL)in Eureka, Nunavut (80 N, 86 W). These instruments view the <span class="hlt">wind</span>, temperature and airglow <span class="hlt">irradiance</span> of hydroxyl (all three) O2 (ERWIN2 and SATI), sodium (PASI), and oxygen green line (PASI and ERWIN2). The viewing locations and specific emissions of the various instruments differ. Nevertheless, the co-location of these instruments provides an excellent opportunity for case studies of specific events and for intercomparison between the different techniques. In this paper we discuss the approach we are using to combine observations from the different instruments. Case studies show that at times the various instruments are in good agreement but at other times they differ. Of particular interest are situations where gravity wave signatures are evident for an extended period of time and one such situation is presented. The discussion includes consideration of the filtering effect of viewing through airglow layers and the extent to which <span class="hlt">wind</span>, airglow and temperature variations can be associated with the same gravity wave.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840010164&hterms=balsiger&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dbalsiger','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840010164&hterms=balsiger&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dbalsiger"><span>The ISPM <span class="hlt">solar-wind</span> ion composition spectrometer</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gloeckler, G.; Geiss, J.; Balsiger, H.; Fisk, L. A.; Gliem, F.; Ipavich, F. M.; Ogilvie, K. W.; Stuedemann, W.; Wilken, B.</p> <p>1983-01-01</p> <p>The International <span class="hlt">Solar</span> Polar Mission (ISPM) <span class="hlt">Solar-Wind</span> Ion Composition Spectrometer which determines elemental and ionic-charge composition, and the temperatures and mean speeds of all major <span class="hlt">solar-wind</span> ions, from H through Fe, at <span class="hlt">solar</span> <span class="hlt">wind</span> speeds ranging from 145 km/sec (protons) to 1352 km/sec (Fe+8) is described. The instrument, which covers an energy per charge range from 110 eV/q to 66.7 keV/q in 13 min, combines an electrostatic analyzer with postacceleration, followed by a time-of-flight and energy measurement. Conditions and processes in the region of the corona where the <span class="hlt">solar</span> <span class="hlt">wind</span> is accelerated; location of the source regions of the <span class="hlt">solar</span> <span class="hlt">wind</span> in the corona; coronal heating processes; the extent and causes of variations in the composition of the <span class="hlt">solar</span> atmosphere; plasma processes in the <span class="hlt">solar</span> <span class="hlt">wind</span>; acceleration of energetic particles in the <span class="hlt">solar</span> <span class="hlt">wind</span>; the thermalization and acceleration of interstellar ions in the <span class="hlt">solar</span> <span class="hlt">wind</span>, and their composition; and the composition and behavior of the plasma in the Jovian magnetosphere are studied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EGSGA..27.6304I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27.6304I"><span>Time Variable <span class="hlt">Solar</span> <span class="hlt">Wind</span> Interaction of Mercury</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ip, W.-H.; Kopp, A.</p> <p></p> <p>A three-dimensional MHD code was used to simulate the solr <span class="hlt">wind</span> interaction of Mercury's magnetosphere with interplanetary magnetic field (IMF) of different orien- tations. It can be shown that for northward pointing IMF, the Hermean magnetosphere is nearly closed with the polar cap shrinking to a small area. On the other hand, the boundary of the polar cap expands to mid-latitude region (about 30 degrees latitude) for south-pointing IMF. Such large changes in the size and morphology of the polar cap in response to directional variations of the IMF could be related to the observed temporal variabilities of the atomic sodium emission on Mercury's disk. That is, the production rate of the sodium atoms could be significantly modulated i.e., weak for northward IMF and large for southward IMF) if <span class="hlt">solar</span> <span class="hlt">wind</span> sputtering of the surface material is an important source mechanism of the sodium atoms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUFMSM42A0828T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUFMSM42A0828T"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Disturbances Related to Geomagnetic Storms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tan, A.; Lyatsky, W. B.</p> <p>2001-12-01</p> <p>We used the superposed epoch method to reconstruct a typical behavior of <span class="hlt">solar</span> <span class="hlt">wind</span> parameters before and during strong isolated geomagnetic storms. For this analysis we used 130 such geomagnetic storms during the period of 1966-2000. The results obtained show that a typical disturbance in the <span class="hlt">solar</span> <span class="hlt">wind</span> responsible for geomagnetic storm generation is associated with the propagation of high-speed plasma flow compressing ambient <span class="hlt">solar</span> <span class="hlt">wind</span> plasma and interplanetary magnetic field (IMF) ahead of this high-speed flow. This gives rise to enhanced magnetic field, plasma density, plasma turbulence and temperature, which start to increase several hours before geomagnetic storm onset. However, the IMF Bz (responsible for geomagnetic storm onset) starts to increase significantly later (approximately 6-7 hours after maximal variations in plasma density and IMF By). The time delay between peaks in IMF Bz and plasma density (and IMF By) may be a result of draping of high-speed plasma streams with ambient magnetic field in the (z-y) plane as discussed by some authors. This leads to an increase first in plasma density and IMF By ahead of a high-speed flow, which is followed by an increase in IMF Bz. This simple model allows us to predict that the probability for geomagnetic storm generation should depend on which edge of a high-speed flow encounters the Earth's magnetosphere. The probability for geomagnetic storm generation is expected to be maximal when the flow encounters the magnetosphere by its north-west edge for negative IMF By and south-west edge for positive IMF By.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160002412','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160002412"><span>Genesis <span class="hlt">Solar</span> <span class="hlt">Wind</span> Science Canister Components Curated as Potential <span class="hlt">Solar</span> <span class="hlt">Wind</span> Collectors and Reference Contamination Sources</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Allton, J. H.; Gonzalez, C. P.; Allums, K. K.</p> <p>2016-01-01</p> <p>The Genesis mission collected <span class="hlt">solar</span> <span class="hlt">wind</span> 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 <span class="hlt">solar</span> <span class="hlt">wind</span> 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 <span class="hlt">solar</span> <span class="hlt">wind</span> or component materials adjacent to <span class="hlt">solar</span> <span class="hlt">wind</span> collectors which may have contributed contamination.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840005003','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840005003"><span>Spectroscopic measurements of <span class="hlt">solar</span> <span class="hlt">wind</span> generation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kohl, J. L.; Withbroe, G. L.; Zapata, C. A.; Noci, G.</p> <p>1983-01-01</p> <p>Spectroscopically observable quantities are described which are sensitive to the primary plasma parameters of the <span class="hlt">solar</span> <span class="hlt">wind</span>'s source region. The method is discussed in which those observable quantities are used as constraints in the construction of empirical models of various coronal structures. Simulated observations are used to examine the fractional contributions to observed spectral intensities from coronal structures of interest which co-exist with other coronal structures along simulated lines-of-sight. The sensitivity of spectroscopic observables to the physical parameters within each of those structures is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740013297','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740013297"><span>Sweet's mechanism in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burlaga, L. F.; Scudder, J. D.</p> <p>1974-01-01</p> <p>Sweet's mechanism occurs in the <span class="hlt">solar</span> <span class="hlt">wind</span>, at D-sheets near 1 AU. Conductivities on the order of 10,000 esu are obtained, which is on the order of the local plasma frequency. This implies that the effective collision frequency is on the order of the plasma frequency. The lateral extent of D-sheets is approximately 0.01 AU to 0.001 AU. Hundreds of such D-sheets are probably present between the orbits of Venus and Earth at any instant.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150001629','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150001629"><span>Genesis <span class="hlt">Solar</span> <span class="hlt">Wind</span> Samples: Update of Availability</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gonzalez, C. P.; Allums, K. K.; Allton, J. H.</p> <p>2015-01-01</p> <p>The Genesis mission collected <span class="hlt">solar</span> <span class="hlt">wind</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720003183','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720003183"><span>Dynamics of the <span class="hlt">solar</span> <span class="hlt">wind</span> and its interaction with bodies in the <span class="hlt">solar</span> system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Spreiter, J. R.</p> <p>1971-01-01</p> <p>A discussion of the <span class="hlt">solar</span> <span class="hlt">wind</span> and its interaction with bodies of the <span class="hlt">solar</span> system is presented. An overall unified account of the role of shock waves in the heating of the <span class="hlt">solar</span> corona, the transmission of <span class="hlt">solar</span> disturbances to the <span class="hlt">solar</span> system, the flow fields of planets and natural satellites, and biological effects are provided. An analysis of magnetometer data from Explorer 33 and Vela 3A satellites to identify characteristics of <span class="hlt">solar</span> <span class="hlt">wind</span> shock waves is included.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880001356','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880001356"><span>A numerical study of transient, thermally-conductive <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Han, S. M.; Wu, S. T.; Dryer, M.</p> <p>1987-01-01</p> <p>A numerical analysis of transient <span class="hlt">solar</span> <span class="hlt">wind</span> starting at the <span class="hlt">solar</span> surface and arriving at 1 AU is performed by an implicit numerical method. The model hydrodynamic equations include thermal conduction terms for both steady and unsteady simulations. Simulation results show significant influence of thermal conduction on both steady and time-dependent <span class="hlt">solar</span> <span class="hlt">wind</span>. Higher thermal conduction results in higher <span class="hlt">solar</span> <span class="hlt">wind</span> speed, higher temperature, but lower plasma density at 1 AU. Higher base temperature at the <span class="hlt">solar</span> surface gives lower plasma speed, lower temperature, but higher density at 1 AU. Higher base density, on the other hand, gives lower velocity, lower temperature, but higher density at 1 AU.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820033354&hterms=forces+distance&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dforces%2Bdistance','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820033354&hterms=forces+distance&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dforces%2Bdistance"><span>On rotational forces in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hollweg, J. V.; Isenberg, P. A.</p> <p>1981-01-01</p> <p><span class="hlt">Solar</span> rotational forces affecting the flow of minor ions in the <span class="hlt">solar</span> <span class="hlt">wind</span> are considered as corotating with the sun. Cold, noninteracting charged particles in the magnetic and gravitational fields of the sun rotate with the angular velocity of the sun, and calculations of lowest bulk order velocities show that differences in particle velocities decrease with increasing distance from the sun. A centrifugal potential in the corotating frame implies that ion motion is independent of protons, with velocities determined by the potential, which monotonically decreases without limit. The potential dominates the initial kinetic energy of the particles, and the equality of velocities within the potential is not due to interactions between particles as claimed by Mackenzie et al. (1979).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.A24E..05L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.A24E..05L"><span>Near-term Forecasting of <span class="hlt">Solar</span> Total and Direct <span class="hlt">Irradiance</span> for <span class="hlt">Solar</span> Energy Applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Long, C. N.; Riihimaki, L. D.; Berg, L. K.</p> <p>2012-12-01</p> <p>Integration of <span class="hlt">solar</span> renewable energy into the power grid, like <span class="hlt">wind</span> energy, is hindered by the variable nature of the <span class="hlt">solar</span> resource. One challenge of the integration problem for shorter time periods is the phenomenon of "ramping events" where the electrical output of the <span class="hlt">solar</span> power system increases or decreases significantly and rapidly over periods of minutes or less. Advance warning, of even just a few minutes, allows power system operators to compensate for the ramping. However, the ability for short-term prediction on such local "point" scales is beyond the abilities of typical model-based weather forecasting. Use of surface-based <span class="hlt">solar</span> radiation measurements has been recognized as a likely solution for providing input for near-term (5 to 30 minute) forecasts of <span class="hlt">solar</span> energy availability and variability. However, it must be noted that while fixed-orientation photovoltaic panel systems use the total (global) downwelling <span class="hlt">solar</span> radiation, tracking photovoltaic and <span class="hlt">solar</span> concentrator systems use only the direct normal component of the <span class="hlt">solar</span> radiation. Thus even accurate near-term forecasts of total <span class="hlt">solar</span> radiation will under many circumstances include inherent inaccuracies with respect to tracking systems due to lack of information of the direct component of the <span class="hlt">solar</span> radiation. We will present examples and statistical analyses of <span class="hlt">solar</span> radiation partitioning showing the differences in the behavior of the total/direct radiation with respect to the near-term forecast issue. We will present an overview of the possibility of using a network of unique new commercially available total/diffuse radiometers in conjunction with a near-real-time adaptation of the Shortwave Radiative Flux Analysis methodology (Long and Ackerman, 2000; Long et al., 2006). The results are used, in conjunction with persistence and tendency forecast techniques, to provide more accurate near-term forecasts of cloudiness, and both total and direct normal <span class="hlt">solar</span> <span class="hlt">irradiance</span> availability and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.P11D..08D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.P11D..08D"><span>Effects of <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> on Ion Fluxes at Mars. MARS EXPRESS and MAVEN Observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dubinin, E.; Fraenz, M.; McFadden, J. P.; Eparvier, F. G.; Brain, D. A.; Jakosky, B. M.; Andrews, D. J.; Barbash, S.</p> <p>2016-12-01</p> <p>Recent observations by Mars Express and MAVEN spacecraft have shown that the Martian atmosphere/ionosphere is exposed to the impact of <span class="hlt">solar</span> <span class="hlt">wind</span> which results in losses of volatiles from Mars. This erosion is an important factor for the evolution of the Martian atmosphere and its water inventory. To estimate the escape forced by the <span class="hlt">solar</span> <span class="hlt">wind</span> during the early <span class="hlt">Solar</span> system conditions we need to know how the ionosphere of Mars and escape fluxes depend on variations in the strength of the external drivers, in particularly, of <span class="hlt">solar</span> <span class="hlt">wind</span> and <span class="hlt">solar</span> EUV flux. We present multi-instrument observations of the influence of the <span class="hlt">solar</span> <span class="hlt">irradiance</span> on the Martian ionosphere and escape fluxes. We use data obtained by the ASPERA-3 and MARSIS experiments on Mars Express and by the STATIC instrument and EUV monitor on MAVEN. Observations by Mars Express supplemented by the EUV monitoring at Earth orbit and translated to Mars orbit provide us information about this dependence over more than 10 years whereas the measurements made by MAVEN provide us for the first time the opportunity to study these processes with simultaneous monitoring of the ionospheric variations, planetary ion fluxes and <span class="hlt">solar</span> <span class="hlt">irradiance</span>. We can show that fluxes of planetary ions through different escape channels (trans-terminator fluxes, ion plume, plasma sheet) respond differently on the EUV variations. The most significant effect on the ion scavenging with increase of the <span class="hlt">solar</span> <span class="hlt">irradiance</span> is observed for low energy ions extracted from the ionosphere while the ion fluxes in the plume are almost insensitive to the EUV variations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1914789H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1914789H"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> controls on Mercury's magnetospheric cusp</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>He, Maosheng; Vogt, Joachim; Heyner, Daniel; Zhong, Jun</p> <p>2017-04-01</p> <p>Mercury's magnetospheric cusp results from the interaction between the planetary intrinsic magnetic field and the <span class="hlt">solar</span> <span class="hlt">wind</span>. In this study, we assemble 2848 orbits of MESSENGER data for a comprehensive assessment of <span class="hlt">solar</span> <span class="hlt">wind</span> control on Mercury's cusp. We propose and validate an IMF estimation approach for the cusp transit, and construct an index to measure the magnetic disturbance. The index maximizes within the cusp, more intense than in the adjacent magnetosphere by several orders of magnitude. We develop an empirical model of the index as a function of IMFvector and Mercury's <span class="hlt">solar</span> orbital phase. The model is used to study the cusp activity under different conditions. Comparisons reveal the cusp activity is more intense and extends further in local time, under antisunward IMF (IMFx<0) than sunward (IMFx>0), under southward IMF (IMFz<0) than northward (IMFz>0), and when Mercury orbits at its perihelion than at aphelion. Besides, the cusp shifts azimuthally towards dawn when IMF reverses from westward (IMFy<0) to eastward (IMFy>0), and when Mercury approaches its perihelion. The IMFx dependence is consistent with existing observations and simulations which are ascribed to the asymmetry of dayside magnetospheric configuration between sunward and anti-sunward IMF conditions. We explain the IMFy and IMFz dependences in terms of component reconnection of the magnetospheric field merging with By-dominant and Bz-dominant IMF, respectively. The control of the Mercury <span class="hlt">solar</span> orbit phase on the intensity and local time location of the disturbance peak are possibly arising from the modulations of the heliocentric distance on the <span class="hlt">solar</span> <span class="hlt">wind</span> ram pressure. The existence of significant IMF dependence suggests the IMF orientation plays a role in the convection configuration at Mercury. The IMFy-dependence at Mercury is opposite to that at Earth, suggesting that component reconnection at the dayside magnetopause is more important in the Hermean system than in the terrestrial</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008cosp...37.3191T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008cosp...37.3191T"><span>Guide to <span class="hlt">solar</span> reference spectra and <span class="hlt">irradiance</span> models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tobiska, W. Kent</p> <p></p> <p>The international standard for determining <span class="hlt">solar</span> <span class="hlt">irradiances</span> was published by the International Standards Organization (ISO) in May 2007. The document, ISO 21348 Space Environment (natural and artificial) - Process for determining <span class="hlt">solar</span> <span class="hlt">irradiances</span>, describes the process for representing <span class="hlt">solar</span> <span class="hlt">irradiances</span>. We report on the next progression of standards work, i.e., the development of a guide that identifies <span class="hlt">solar</span> reference spectra and <span class="hlt">irradiance</span> models for use in engineering design or scientific research. This document will be produced as an AIAA Guideline and ISO Technical Report. It will describe the content of the reference spectra and models, uncertainties and limitations, technical basis, data bases from which the reference spectra and models are formed, publication references, and sources of computer code for reference spectra and <span class="hlt">solar</span> <span class="hlt">irradiance</span> models, including those which provide spectrally-resolved lines as well as <span class="hlt">solar</span> indices and proxies and which are generally recognized in the <span class="hlt">solar</span> sciences. The document is intended to assist aircraft and space vehicle designers and developers, heliophysicists, geophysicists, aeronomers, meteorologists, and climatologists in understanding available models, comparing sources of data, and interpreting engineering and scientific results based on different <span class="hlt">solar</span> reference spectra and <span class="hlt">irradiance</span> models.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ASPC..484..263Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ASPC..484..263Z"><span>Latitudinal Dependence of Coronal Hole-Associated Fast <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, L.; Landi, E.</p> <p>2014-05-01</p> <p>The fast <span class="hlt">solar</span> <span class="hlt">wind</span> can have at least two different coronal sources: high-latitude, polar coronal holes (PCH) and low-latitude, equatorial coronal holes (ECH). The in-situ differences in the PCH and ECH <span class="hlt">winds</span> have not been well studied, nor have the differences in their evolution over the <span class="hlt">solar</span> cycles. Ulysses' 19 years of observations from 1990 to 2009, combined with ACE observations from 1998 to the present, provide us with measurements of <span class="hlt">solar</span> <span class="hlt">wind</span> properties that span two entire <span class="hlt">solar</span> cycles, which allow us to study the in-situ properties and evolution of the coronal hole-associated <span class="hlt">solar</span> <span class="hlt">wind</span> at different latitudes. In this work, we focus on the PCH and ECH <span class="hlt">solar</span> <span class="hlt">winds</span> during the minima between <span class="hlt">solar</span> cycles 22-23 and 23-24. We use data from SWICS, SWOOPS, and VHM/FGM on board Ulysses, and SWICS, SWEPAM, and MAG on board ACE to analyze the proton dynamics, heavy ion composition, elemental abundance, and magnetic field properties of the PCH <span class="hlt">wind</span> and ECH <span class="hlt">wind</span>, with a special focus on their differences during the recent two <span class="hlt">solar</span> minima. We also include the slow and hot, streamer-associated (ST) <span class="hlt">wind</span> as a reference in the comparison. The comparison of PCH and ECH <span class="hlt">wind</span> shows that: 1) the in-situ properties of ECH and PCH <span class="hlt">winds</span> are significantly different during the two <span class="hlt">solar</span> minima, and 2) the two types of coronal hole-associated <span class="hlt">solar</span> <span class="hlt">wind</span> respond differently to changes in <span class="hlt">solar</span> activity strength from cycle 23 to cycle 24.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSH42A..02D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSH42A..02D"><span>Alfvénic Slow <span class="hlt">Solar</span> <span class="hlt">Wind</span>: characteristics and origin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>D'Amicis, R.</p> <p>2016-12-01</p> <p>The <span class="hlt">solar</span> <span class="hlt">wind</span> is a turbulent medium whose behavior is mostly determined by the nonlinear interaction between inward and outward propagating Alfvén waves. The purest examples of Alfvénic fluctuations are found in the trailing edges of fast <span class="hlt">solar</span> <span class="hlt">wind</span> streams. The slow <span class="hlt">wind</span> usually has a lower degree of Alfvénicity being more strongly intermixed with structures of non-Alfvénic nature. However, as already found in the past, our recent analysis shows that under certain circumstances, even slow <span class="hlt">wind</span> can be highly Alfvénic with fluctuations sometimes as wide as that of the fast <span class="hlt">wind</span>. In this study we explore many facets of the Alfvénic slow <span class="hlt">solar</span> <span class="hlt">wind</span> spanning from the study of the source regions and their connection to coronal structures, to the micro-physics of distribution functions, anisotropies, to the role of turbulence and wave-particle interactions in <span class="hlt">solar</span> <span class="hlt">wind</span> heating, which are among the main topics of this session. It has been found that the Alfvénic slow <span class="hlt">wind</span> is more similar to the fast <span class="hlt">wind</span> rather than to the typical slow <span class="hlt">wind</span> suggesting a similar origin for the two types of <span class="hlt">solar</span> <span class="hlt">wind</span>. Actually the Alfvénic slow <span class="hlt">wind</span> does not originate from active regions or the cusp of the helmet streamers as the typical slow <span class="hlt">wind</span> rather from the boundary between streamers and coronal holes. This would determine the similarities with the fast <span class="hlt">solar</span> <span class="hlt">wind</span> suggesting a major role played by the super-radial expansion responsible for the lower velocity. These new findings have relevant implications for the upcoming <span class="hlt">Solar</span> Orbiter and <span class="hlt">Solar</span> Probe Plus missions, and for turbulence measurements close to the Sun.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JSWSC...6A..30K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JSWSC...6A..30K"><span>Magnitudes and timescales of total <span class="hlt">solar</span> <span class="hlt">irradiance</span> variability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kopp, Greg</p> <p>2016-07-01</p> <p>The Sun's net radiative output varies on timescales of minutes to gigayears. Direct measurements of the total <span class="hlt">solar</span> <span class="hlt">irradiance</span> (TSI) show changes in the spatially- and spectrally-integrated radiant energy on timescales as short as minutes to as long as a <span class="hlt">solar</span> cycle. Variations of ~0.01% over a few minutes are caused by the ever-present superposition of convection and oscillations with very large <span class="hlt">solar</span> flares on rare occasion causing slightly-larger measurable signals. On timescales of days to weeks, changing photospheric magnetic activity affects <span class="hlt">solar</span> brightness at the ~0.1% level. The 11-year <span class="hlt">solar</span> cycle shows variations of comparable magnitude with <span class="hlt">irradiances</span> peaking near <span class="hlt">solar</span> maximum. Secular variations are more difficult to discern, being limited by instrument stability and the relatively short duration of the space-borne record. Historical reconstructions of the Sun's <span class="hlt">irradiance</span> based on indicators of <span class="hlt">solar</span>-surface magnetic activity, such as sunspots, faculae, and cosmogenic isotope records, suggest <span class="hlt">solar</span> brightness changes over decades to millennia, although the magnitudes of these variations have high uncertainties due to the indirect historical records on which they rely. Stellar evolution affects yet longer timescales and is responsible for the greatest <span class="hlt">solar</span> variabilities. In this manuscript I summarize the Sun's variability magnitudes over different temporal regimes and discuss the <span class="hlt">irradiance</span> record's relevance for <span class="hlt">solar</span> and climate studies as well as for detections of exo-<span class="hlt">solar</span> planets transiting Sun-like stars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890045845&hterms=Kock&qs=N%3D0%26Ntk%3DAuthor-Name%26Ntx%3Dmode%2Bmatchall%26Ntt%3DKock%2BM%2BH','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890045845&hterms=Kock&qs=N%3D0%26Ntk%3DAuthor-Name%26Ntx%3Dmode%2Bmatchall%26Ntt%3DKock%2BM%2BH"><span>Absolute, Extreme-Ultraviolet, <span class="hlt">Solar</span> Spectral <span class="hlt">Irradiance</span> Monitor (AESSIM)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Huber, Martin C. E.; Smith, Peter L.; Parkinson, W. H.; Kuehne, M.; Kock, M.</p> <p>1988-01-01</p> <p>AESSIM, the Absolute, Extreme-Ultraviolet, <span class="hlt">Solar</span> Spectral <span class="hlt">Irradiance</span> Monitor, is designed to measure the absolute <span class="hlt">solar</span> spectral <span class="hlt">irradiance</span> at extreme-ultraviolet (EUV) wavelengths. The data are required for studies of the processes that occur in the earth's upper atmosphere and for predictions of atmospheric drag on space vehicles. AESSIM is comprised of sun-pointed spectrometers and newly-developed, secondary standards of spectral <span class="hlt">irradiance</span> for the EUV. Use of the in-orbit standard sources will eliminate the uncertainties caused by changes in spectrometer efficiency that have plagued all previous measurements of the <span class="hlt">solar</span> spectral EUV flux.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19810056379&hterms=isophotes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Disophotes','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19810056379&hterms=isophotes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Disophotes"><span>Coronal streamers in the <span class="hlt">solar</span> <span class="hlt">wind</span> at 1 AU</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gosling, J. T.; Asbridge, J. R.; Bame, S. J.; Feldman, W. C.; Borrini, G.; Hansen, R. T.</p> <p>1981-01-01</p> <p>Virtually all <span class="hlt">solar</span> <span class="hlt">wind</span> observing groups have reported substantial variations in the <span class="hlt">solar</span> <span class="hlt">wind</span> helium-hydrogen abundance ratio (A(He)). A study of Los Alamos Imp <span class="hlt">solar</span> <span class="hlt">wind</span> data has revealed an association between low A(He) and high proton density that occurs at low flow speeds and that is correlated with polarity reversals of the interplanetary magnetic field. The current investigation has the objective to present further examples of the low A(He), high proton density, low speed, magnetic field polarity association, and to document the common occurrence of multiple events lasting approximately 3-7 days. The results are presented of attempts to relate these events directly to maps or isophotes of <span class="hlt">solar</span> coronal brightness at 1.5 <span class="hlt">solar</span> radii. The results of the investigation suggest that a substantial fraction of the low-speed <span class="hlt">solar</span> <span class="hlt">wind</span> originates in coronal streamers, particularly near <span class="hlt">solar</span> minimum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760017036','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760017036"><span>The 3-D <span class="hlt">solar</span> radioastronomy and the structure of the corona and the <span class="hlt">solar</span> <span class="hlt">wind</span>. [<span class="hlt">solar</span> probes of <span class="hlt">solar</span> activity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Steinberg, J. L.; Caroubalos, C.</p> <p>1976-01-01</p> <p>The mechanism causing <span class="hlt">solar</span> radio bursts (1 and 111) is examined. It is proposed that a nonthermal energy source is responsible for the bursts; nonthermal energy is converted into electromagnetic energy. The advantages are examined for an out-of-the-ecliptic <span class="hlt">solar</span> probe mission, which is proposed as a means of stereoscopically viewing <span class="hlt">solar</span> radio bursts, <span class="hlt">solar</span> magnetic fields, coronal structure, and the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840010163&hterms=Temple&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DTemple','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840010163&hterms=Temple&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DTemple"><span>The ISPM <span class="hlt">solar-wind</span> plasma experiment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bame, S. J.; Glore, J. P.; Mccomas, D. J.; Moore, K. R.; Chavez, J. C.; Ellis, T. J.; Peterson, G. R.; Temple, J. H.; Wymer, F. J.</p> <p>1983-01-01</p> <p>The ISPM <span class="hlt">solar</span> <span class="hlt">wind</span> plasma experiment accurately characterizes the bulk flow and internal state conditions of the interplanetary plasma in three dimensions at all heliographic distances and heliographic latitudes reached by the spacecraft. <span class="hlt">Solar</span> <span class="hlt">wind</span> electrons, protons, alpha particles, and heavier ions are measured. Oxygen, silicon, and iron ions at various charge levels are resolved. Electrons and ions are measured simultaneously with independent curved-plate electrostatic analysers equipped with multiple continuous channel electron multipliers arranged so that particle velocity distributions are suitably resolved without gaps in spacecraft polar-angle space. Electrons with energies between 1 and 900 eV are detected at 7 polar angles and various combinations of azimuth angle to cover the unit sphere comprehensively. Ions are detected between 257 eV/Q and 35 keV/Q. Data matrices are obtained every 4 min when the spacecraft is actively transmitting and every 8 min during storage periods. These matrices contain sufficient energy and angle resolution to permit detailed calculations of ion velocity distributions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007NPGeo..14..695M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007NPGeo..14..695M"><span>Multifractality and intermittency in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Macek, W. M.</p> <p>2007-11-01</p> <p>Within the complex dynamics of the <span class="hlt">solar</span> <span class="hlt">wind</span>'s fluctuating plasma parameters, there is a detectable, hidden order described by a chaotic strange attractor which has a multifractal structure. The multifractal spectrum has been investigated using Voyager (magnetic field) data in the outer heliosphere and using Helios (plasma) data in the inner heliosphere. We have also analyzed the spectrum for the <span class="hlt">solar</span> <span class="hlt">wind</span> attractor. The spectrum is found to be consistent with that for the multifractal measure of the self-similar one-scale weighted Cantor set with two parameters describing uniform compression and natural invariant probability measure of the attractor of the system. In order to further quantify the multifractality, we also consider a generalized weighted Cantor set with two different scales describing nonuniform compression. We investigate the resulting multifractal spectrum depending on two scaling parameters and one probability measure parameter, especially for asymmetric scaling. We hope that this generalized model will also be a useful tool for analysis of intermittent turbulence in space plasmas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18596802','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18596802"><span>An asymmetric <span class="hlt">solar</span> <span class="hlt">wind</span> termination shock.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stone, Edward C; Cummings, Alan C; McDonald, Frank B; Heikkila, Bryant C; Lal, Nand; Webber, William R</p> <p>2008-07-03</p> <p>Voyager 2 crossed the <span class="hlt">solar</span> <span class="hlt">wind</span> termination shock at 83.7 au in the southern hemisphere, approximately 10 au closer to the Sun than found by Voyager 1 in the north. This asymmetry could indicate an asymmetric pressure from an interstellar magnetic field, from transient-induced shock motion, or from the <span class="hlt">solar</span> <span class="hlt">wind</span> dynamic pressure. Here we report that the intensity of 4-5 MeV protons accelerated by the shock near Voyager 2 was three times that observed concurrently by Voyager 1, indicating differences in the shock at the two locations. (Companion papers report on the plasma, magnetic field, plasma-wave and lower energy particle observations at the shock.) Voyager 2 did not find the source of anomalous cosmic rays at the shock, suggesting that the source is elsewhere on the shock or in the heliosheath. The small intensity gradient of Galactic cosmic ray helium indicates that either the gradient is further out in the heliosheath or the local interstellar Galactic cosmic ray intensity is lower than expected.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4394683','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4394683"><span>Anisotropy in <span class="hlt">solar</span> <span class="hlt">wind</span> plasma turbulence</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Oughton, S.; Matthaeus, W. H.; Wan, M.; Osman, K. T.</p> <p>2015-01-01</p> <p>A review of spectral anisotropy and variance anisotropy for <span class="hlt">solar</span> <span class="hlt">wind</span> fluctuations is given, with the discussion covering inertial range and dissipation range scales. For the inertial range, theory, simulations and observations are more or less in accord, in that fluctuation energy is found to be primarily in modes with quasi-perpendicular wavevectors (relative to a suitably defined mean magnetic field), and also that most of the fluctuation energy is in the vector components transverse to the mean field. Energy transfer in the parallel direction and the energy levels in the parallel components are both relatively weak. In the dissipation range, observations indicate that variance anisotropy tends to decrease towards isotropic levels as the electron gyroradius is approached; spectral anisotropy results are mixed. Evidence for and against wave interpretations and turbulence interpretations of these features will be discussed. We also present new simulation results concerning evolution of variance anisotropy for different classes of initial conditions, each with typical background <span class="hlt">solar</span> <span class="hlt">wind</span> parameters. PMID:25848082</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=MSFC-6903621&hterms=parking+Solar&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dparking%2BSolar','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=MSFC-6903621&hterms=parking+Solar&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dparking%2BSolar"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Spectrometer on Lunar Surface</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1969-01-01</p> <p>Sitting on the lunar surface, this <span class="hlt">Solar</span> <span class="hlt">Wind</span> Spectrometer is measuring the energies of the particles that make up the <span class="hlt">solar</span> <span class="hlt">wind</span>. This was one of the instruments used during the Apollo 12 mission. The second manned lunar landing mission, Apollo 12 launched from launch pad 39-A at Kennedy Space Center in Florida on November 14, 1969 via a Saturn V launch vehicle. The Saturn V vehicle was developed by the Marshall Space Flight Center (MSFC) under the direction of Dr. Wernher von Braun. Aboard Apollo 12 was a crew of three astronauts: Alan L. Bean, pilot of the Lunar Module (LM), Intrepid; Richard Gordon, pilot of the Command Module (CM), Yankee Clipper; and Spacecraft Commander Charles Conrad. The LM, Intrepid, landed astronauts Conrad and Bean on the lunar surface in what's known as the Ocean of Storms while astronaut Richard Gordon piloted the CM, Yankee Clipper, in a parking orbit around the Moon. Lunar soil activities included the deployment of the Apollo Lunar Surface Experiments Package (ALSEP), finding the unmanned Surveyor 3 that landed on the Moon on April 19, 1967, and collecting 75 pounds (34 kilograms) of rock samples. Apollo 12 safely returned to Earth on November 24, 1969.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhDT........77L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhDT........77L"><span>The structure of the <span class="hlt">solar</span> <span class="hlt">wind</span> in the inner heliosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Christina On-Yee</p> <p>2010-12-01</p> <p>This dissertation is devoted to expanding our understanding of the <span class="hlt">solar</span> <span class="hlt">wind</span> structure in the inner heliosphere and variations therein with <span class="hlt">solar</span> activity. Using spacecraft observations and numerical models, the origins of the large-scale structures and long-term trends of the <span class="hlt">solar</span> <span class="hlt">wind</span> are explored in order to gain insights on how our Sun determines the space environments of the terrestrial planets. I use long term measurements of the <span class="hlt">solar</span> <span class="hlt">wind</span> density, velocity, interplanetary magnetic field, and particles, together with models based on <span class="hlt">solar</span> magnetic field data, to generate time series of these properties that span one <span class="hlt">solar</span> rotation (˜27 days). From these time series, I assemble and obtain the synoptic overviews of the <span class="hlt">solar</span> <span class="hlt">wind</span> properties. The resulting synoptic overviews show that the <span class="hlt">solar</span> <span class="hlt">wind</span> around Mercury, Venus, Earth, and Mars is a complex co-rotating structure with recurring features and occasional transients. During quiet <span class="hlt">solar</span> conditions, the heliospheric current sheet, which separates the positive interplanetary magnetic field from the negative, usually has a remarkably steady two- or four-sector structure that persists for many <span class="hlt">solar</span> rotations. Within the sector boundaries are the slow and fast speed <span class="hlt">solar</span> <span class="hlt">wind</span> streams that originate from the open coronal magnetic field sources that map to the ecliptic. At the sector boundaries, compressed high-density and the related high-dynamic pressure ridges form where streams from different coronal source regions interact. High fluxes of energetic particles also occur at the boundaries, and are seen most prominently during the quiet <span class="hlt">solar</span> period. The existence of these recurring features depends on how long-lived are their source regions. In the last decade, 3D numerical <span class="hlt">solar</span> <span class="hlt">wind</span> models have become more widely available. They provide important scientific tools for obtaining a more global view of the inner heliosphere and of the relationships between conditions at Mercury, Venus, Earth, and Mars. When</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRA..122.2740L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRA..122.2740L"><span>Centennial evolution of monthly <span class="hlt">solar</span> <span class="hlt">wind</span> speeds: Fastest monthly <span class="hlt">solar</span> <span class="hlt">wind</span> speeds from long-duration coronal holes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lukianova, Renata; Holappa, Lauri; Mursula, Kalevi</p> <p>2017-03-01</p> <p>High-speed <span class="hlt">solar</span> <span class="hlt">wind</span> streams (HSSs) are very efficient drivers of geomagnetic activity at high latitudes. In this paper we use a recently developed ΔH parameter of geomagnetic activity, calculated from the nightside hourly magnetic field measurements of the Sodankylä observatory, as a proxy for <span class="hlt">solar</span> <span class="hlt">wind</span> (SW) speed at monthly time resolution in 1914-2014 (<span class="hlt">solar</span> cycles 15-24). The seasonal variation in the relation between monthly ΔH and <span class="hlt">solar</span> <span class="hlt">wind</span> speed is taken into account by calculating separate regressions between ΔH and SW speed for each month. Thereby, we obtain a homogeneous series of proxy values for monthly <span class="hlt">solar</span> <span class="hlt">wind</span> speed for the last 100 years. We find that the strongest HSS-active months of each <span class="hlt">solar</span> cycle occur in the declining phase, in years 1919, 1930, 1941, 1952, 1959, 1973, 1982, 1994, and 2003. Practically all these years are the same or adjacent to the years of annual maximum <span class="hlt">solar</span> <span class="hlt">wind</span> speeds. This implies that the most persistent coronal holes, lasting for several <span class="hlt">solar</span> rotations and leading to the highest annual SW speeds, are also the sources of the highest monthly SW speeds. Accordingly, during the last 100 years, there were no coronal holes of short duration (of about one <span class="hlt">solar</span> rotation) that would produce faster monthly (or <span class="hlt">solar</span> rotation) averaged <span class="hlt">solar</span> <span class="hlt">wind</span> than the most long-living coronal holes in each <span class="hlt">solar</span> cycle produce.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850026753','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850026753"><span>The <span class="hlt">solar</span> <span class="hlt">wind</span> effect on cosmic rays and <span class="hlt">solar</span> activity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fujimoto, K.; Kojima, H.; Murakami, K.</p> <p>1985-01-01</p> <p>The relation of cosmic ray intensity to <span class="hlt">solar</span> <span class="hlt">wind</span> velocity is investigated, using neutron monitor data from Kiel and Deep River. The analysis shows that the regression coefficient of the average intensity for a time interval to the corresponding average velocity is negative and that the absolute effect increases monotonously with the interval of averaging, tau, that is, from -0.5% per 100km/s for tau = 1 day to -1.1% per 100km/s for tau = 27 days. For tau 27 days the coefficient becomes almost constant independently of the value of tau. The analysis also shows that this tau-dependence of the regression coefficiently is varying with the <span class="hlt">solar</span> activity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21163510','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21163510"><span>The <span class="hlt">solar</span> <span class="hlt">wind</span> in the third dimension</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Neugebauer, M.</p> <p>1996-07-20</p> <p>For many years, <span class="hlt">solar-wind</span> physicists have been using plasma and field data acquired near the ecliptic plane together with data on the scintillation of radio sources and remote sensing of structures in the <span class="hlt">solar</span> corona to estimate the properties of the high-latitude <span class="hlt">solar</span> <span class="hlt">wind</span>. Because of the highly successful Ulysses mission, the moment of truth is now here. This paper summarizes the principal agreements and differences between the Ulysses observations and expectations. The speed of the high-latitude <span class="hlt">solar</span> <span class="hlt">wind</span> was even greater than anticipated. The strength of the radial component of the interplanetary magnetic field was found to be independent of latitude. The tilt of the heliospheric current sheet caused reverse corotating shocks to be observed to higher latitudes than forward corotating shocks. The energetic particles accelerated in these shocks were detected well poleward of the latitudes at which Ulysses observed the interaction regions themselves. As anticipated, there was a strong flux of outward propagating Alfven waves throughout the polar flow. Those waves were probably largely responsible for the smaller-than-anticipated increase of galactic cosmic rays with increasing latitude. As expected, the charge state or ionization temperature of heavy ions was lower in the polar flow than in low-latitude interstream flows. What was not anticipated was the correlation of elemental abundances with ionization temperatures; the Ulysses data revealed a connection between the first ionization time in the upper chromosphere and the final ionization state in the corona. As expected, transient events were detected to {approx}60 deg. latitude, but the properties of those high latitude transient flows held some surprises. At high latitudes, the speeds of the transient interplanetary plasma clouds were approximately the same as the speed of the ambient plasma and the expansion of the clouds drove forward and reverse shock pairs that had never been seen at low latitudes. At</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JASS...34..105P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JASS...34..105P"><span>Characteristics of <span class="hlt">Solar</span> <span class="hlt">Wind</span> Density Depletions During <span class="hlt">Solar</span> Cycles 23 and 24</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Park, Keunchan; Lee, Jeongwoo; Yi, Yu; Lee, Jaejin; Sohn, Jongdae</p> <p>2017-06-01</p> <p><span class="hlt">Solar</span> <span class="hlt">wind</span> density depletions are phenomena that <span class="hlt">solar</span> <span class="hlt">wind</span> density is rapidly decreased and keep the state. They are generally believed to be caused by the interplanetary (IP) shocks. However, there are other cases that are hardly associated with IP shocks. We set up a hypothesis for this phenomenon and analyze this study. We have collected the <span class="hlt">solar</span> <span class="hlt">wind</span> parameters such as density, speed and interplanetary magnetic field (IMF) data related to the <span class="hlt">solar</span> <span class="hlt">wind</span> density depletion events during the period from 1996 to 2013 that are obtained with the advanced composition explorer (ACE) and the <span class="hlt">Wind</span> satellite. We also calculate two pressures (magnetic, dynamic) and analyze the relation with density depletion. As a result, we found total 53 events and the most these phenomena’s sources caused by IP shock are interplanetary coronal mass ejection (ICME). We also found that <span class="hlt">solar</span> <span class="hlt">wind</span> density depletions are scarcely related with IP shock’s parameters. The <span class="hlt">solar</span> <span class="hlt">wind</span> density is correlated with <span class="hlt">solar</span> <span class="hlt">wind</span> dynamic pressure within density depletion. However, the <span class="hlt">solar</span> <span class="hlt">wind</span> density has an little anti-correlation with IMF strength during all events of <span class="hlt">solar</span> <span class="hlt">wind</span> density depletion, regardless of the presence of IP shocks. Additionally, In 47 events of IP shocks, we find 6 events that show a feature of blast wave. The quantities of IP shocks are weaker than blast wave from the Sun, they are declined in a short time after increasing rapidly. We thus argue that IMF strength or dynamic pressure are an important factor in understanding the nature of <span class="hlt">solar</span> <span class="hlt">wind</span> density depletion. Since IMF strength and <span class="hlt">solar</span> <span class="hlt">wind</span> speed varies with <span class="hlt">solar</span> cycle, we will also investigate the characteristics of <span class="hlt">solar</span> <span class="hlt">wind</span> density depletion events in different phases of <span class="hlt">solar</span> cycle as an additional clue to their physical nature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JGRA..118.2834Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JGRA..118.2834Z"><span>Association of <span class="hlt">solar</span> <span class="hlt">wind</span> proton flux extremes with pseudostreamers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, L.; Gibson, S. E.; Fisk, L. A.</p> <p>2013-06-01</p> <p>We investigate the characteristics and <span class="hlt">solar</span> origins of a subpopulation of the <span class="hlt">solar</span> <span class="hlt">wind</span> that possesses extreme values of proton flux. Ulysses observations including <span class="hlt">solar</span> <span class="hlt">wind</span> magnetic flux, proton flux, number density and velocity, and ionic composition are examined in this study. We find that the departures of <span class="hlt">solar</span> <span class="hlt">wind</span> proton flux from its constancy occur for time intervals leading up to and encompassing the past two <span class="hlt">solar</span> minima, and the extreme-proton-flux <span class="hlt">wind</span> possesses the following characteristics: (1) it generally originates from sources middle-distant from the Heliospheric Current Sheet (HCS); (2) it is associated with a broad range of velocities and electron temperatures but excludes very fast/cold <span class="hlt">wind</span>; (3) it exhibits anticorrelation between electron temperature and proton velocity, as does the rest of the <span class="hlt">solar</span> <span class="hlt">wind</span>; (4) it has extreme proton density values relative to the rest of the <span class="hlt">solar</span> <span class="hlt">wind</span>; and (5) the extreme-high-proton-flux <span class="hlt">wind</span> has radial component of open magnetic flux (Br) greater than the rest of the <span class="hlt">solar</span> <span class="hlt">wind</span>, and both extreme-high and extreme-low <span class="hlt">wind</span> do not possess the lowest values of Br flux. Comparing with SOHO EIT 195 Å coronal images, we find the observed extreme-proton-flux <span class="hlt">wind</span> has temporal and spatial coincidence with the appearance of low-latitude coronal holes present in the recent two <span class="hlt">solar</span> minima; the magnetic field lines extrapolated by the Potential Field Source Surface model confirm there are coronal pseudostreamer structures involved. So we propose that these extreme-proton-flux <span class="hlt">winds</span> can be associated with mid- to low-latitude coronal holes and "pseudostreamer" structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUSMSH23A..01Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUSMSH23A..01Z"><span>Association of <span class="hlt">Solar</span> <span class="hlt">Wind</span> Proton Flux Extremes with Pseudostreamers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, L.; Gibson, S. E.; Fisk, L. A.</p> <p>2013-05-01</p> <p>We investigate the characteristics and <span class="hlt">solar</span> origins of a sub-population of the <span class="hlt">solar</span> <span class="hlt">wind</span> that possesses extreme values of proton flux. Ulysses observations including <span class="hlt">solar</span> <span class="hlt">wind</span> magnetic flux, proton flux, number density and velocity, and ionic composition are examined in this study. We find the departures of <span class="hlt">solar</span> <span class="hlt">wind</span> proton flux from its constancy occur for time intervals leading up to and encompassing the past two <span class="hlt">solar</span> minima, and the extreme-proton-flux <span class="hlt">wind</span> possesses the following characteristics: 1) it generally originates from sources middle-distant from the Heliospheric Current Sheet (HCS); 2) it is associated with a broad range of velocities and electron temperatures, but excludes very fast/cold <span class="hlt">wind</span>; 3) it exhibits anticorrelation between electron temperature and proton velocity, as does the rest of the <span class="hlt">solar</span> <span class="hlt">wind</span>; 4) it has extreme proton density values relative to the rest of the <span class="hlt">solar</span> <span class="hlt">wind</span>; and 5) the extreme-high-proton-flux <span class="hlt">wind</span> has radial component of open magnetic flux (Br) greater than the rest of the <span class="hlt">solar</span> <span class="hlt">wind</span> and both extreme-high and extreme-low <span class="hlt">wind</span> do not possess the lowest values of Br flux. Comparing with SOHO EIT 195 A coronal images, we find the observed extreme-proton-flux <span class="hlt">wind</span> has temporal and special coincidence with the appearance of low latitude coronal holes present in the recent two <span class="hlt">solar</span> minima; and the magnetic field lines extrapolated by the Potential Field Source Surface (PFSS) model confirm there are coronal pseudostreamer structures involved. So we propose that these extreme-proton-flux <span class="hlt">wind</span> can be associated with mid-to-low-latitude coronal holes and "pseudostreamer" structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.P53C4032D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.P53C4032D"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Interaction with the Martian Upper Atmosphere at Early Mars/Extreme <span class="hlt">Solar</span> Conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dong, C.; Bougher, S. W.; Ma, Y.; Toth, G.; Lee, Y.; Nagy, A. F.; Tenishev, V.; Pawlowski, D. J.; Combi, M. R.</p> <p>2014-12-01</p> <p>The investigation of ion escape fluxes from Mars, resulting from the <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with its upper atmosphere/ionosphere, is important due to its potential impact on the long-term evolution of Mars atmosphere (e.g., loss of water) over its history. In the present work, we adopt the 3-D Mars cold neutral atmosphere profiles (0 ~ 300 km) from the newly developed and validated Mars Global Ionosphere Thermosphere Model (M-GITM) and the 3-D hot oxygen profiles (100 km ~ 5 RM) from the exosphere Monte Carlo model Adaptive Mesh Particle Simulator (AMPS). We apply these 3-D model output fields into the 3-D BATS-R-US Mars multi-fluid MHD (MF-MHD) model (100 km ~ 20 RM) that can simulate the interplay between Mars upper atmosphere and <span class="hlt">solar</span> <span class="hlt">wind</span> by considering the dynamics of individual ion species. The multi-fluid MHD model solves separate continuity, momentum and energy equations for each ion species (H+, O+, O2+, CO2+). The M-GITM model together with the AMPS exosphere model take into account the effects of <span class="hlt">solar</span> cycle and seasonal variations on both cold and hot neutral atmospheres. This feature allows us to investigate the corresponding effects on the Mars upper atmosphere ion escape by using a one-way coupling approach, i.e., both the M-GITM and AMPS model output fields are used as the input for the multi-fluid MHD model and the M-GITM is used as input into the AMPS exosphere model. In this study, we present M-GITM, AMPS, and MF-MHD calculations (1-way coupled) for 2.5 GYA conditions and/or extreme <span class="hlt">solar</span> conditions for present day Mars (high <span class="hlt">solar</span> <span class="hlt">wind</span> velocities, high <span class="hlt">solar</span> <span class="hlt">wind</span> dynamic pressure, and high <span class="hlt">solar</span> <span class="hlt">irradiance</span> conditions, etc.). Present day extreme conditions may result in MF-MHD outputs that are similar to 2.5 GYA cases. The crustal field orientations are also considered in this study. By comparing estimates of past ion escape rates with the current ion loss rates to be returned by the MAVEN spacecraft (2013-2016), we can better constrain the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSH31C2434S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSH31C2434S"><span>The very slow <span class="hlt">solar</span> <span class="hlt">wind</span> in the Inner Heliosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sanchez-Diaz, E.; Segura, K.; Rouillard, A.; Lavraud, B.; Tao, C.; Blelly, P. L.</p> <p>2015-12-01</p> <p>Measurements near 1AU of the bulk and compositional properties of the interplanetary plasma point to the existence of two <span class="hlt">solar</span> <span class="hlt">winds</span> that can be classified by their speeds, V, the fast (V>400 km s-1) and slow <span class="hlt">winds</span> (V<400 km s-1). The slow <span class="hlt">solar</span> <span class="hlt">wind</span> is seldom observed slower than 300 km s-1 at 1 AU. We show that, closer to the Sun, there is a big amount of <span class="hlt">solar</span> <span class="hlt">wind</span> slower than 300 km s-1, hereafter very slow <span class="hlt">solar</span> <span class="hlt">wind</span> (VSSW). It is mostly detected inside 0.7 AU by the HELIOS spacecraft during <span class="hlt">solar</span> maximum (1979-1980). The closer to the Sun the slower it can be observed, reaching velocities of 200 kms-1 near 0.3 AU. This very slow <span class="hlt">wind</span> usually contains the very dense heliospheric plasma sheet as well as the heliospheric current sheet. The very low speeds disappear by 1AU likely due to the interaction with the faster plasma. <span class="hlt">Solar</span> Probe Plus will measure in-situ how low in the inner Heliosphere this interaction starts and whether even lower velocities are observed inside 0.3 AU. The VSSW has higher density and lower temperature than regular slow <span class="hlt">solar</span> <span class="hlt">wind</span>, qualitatively extending the known scaling laws for the <span class="hlt">solar</span> <span class="hlt">wind</span> over 300 km s-1(Lopez & Freeman, 1986) (Hundhausen, Bame, Asbridge, & Sydoriak, 1970). Like the rest of the slow <span class="hlt">solar</span> <span class="hlt">wind</span>, the helium abundance of the VSSW increase with <span class="hlt">solar</span> activity, approaching to the fast <span class="hlt">wind</span> composition at <span class="hlt">solar</span> maximum. Combining a Potential Field Source Surface (PFSS) to a ballistic backmapping, we relate the ins-situ measurements to the <span class="hlt">solar</span> surface. We compute the proton density flux just above the photosphere and find much higher fluxes in the VSSW than in the faster <span class="hlt">winds</span> at <span class="hlt">solar</span> maximum. Based on this, we propose a likely mechanism for the <span class="hlt">solar</span> cycle variability of the helium abundance of the VSSW and slow <span class="hlt">solar</span> <span class="hlt">wind</span>, which will be tested by combining <span class="hlt">Solar</span> Orbiter and <span class="hlt">Solar</span> Probe Plus measurements of the VSSW with high resolution and high cadence Carrington maps. This work was funded by the EU FP7 HELCATS</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820028333&hterms=1087&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%25231087','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820028333&hterms=1087&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%25231087"><span>Correlations between <span class="hlt">solar</span> <span class="hlt">wind</span> parameters and auroral kilometric radiation intensity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gallagher, D. L.; Dangelo, N.</p> <p>1981-01-01</p> <p>The relationship between <span class="hlt">solar</span> <span class="hlt">wind</span> properties and the influx of energy into the nightside auroral region as indicated by the intensity of auroral kilometric radiation is investigated. Smoothed Hawkeye satellite observations of auroral radiation at 178, 100 and 56.2 kHz for days 160 through 365 of 1974 are compared with <span class="hlt">solar</span> <span class="hlt">wind</span> data from the composite <span class="hlt">Solar</span> <span class="hlt">Wind</span> Plasma Data Set, most of which was supplied by the IMP-8 spacecraft. Correlations are made between smoothed daily averages of <span class="hlt">solar</span> <span class="hlt">wind</span> ion density, bulk flow speed, total IMF strength, electric field, <span class="hlt">solar</span> <span class="hlt">wind</span> speed in the southward direction, <span class="hlt">solar</span> <span class="hlt">wind</span> speed multiplied by total IMF strength, the substorm parameter epsilon and the Kp index. The greatest correlation is found between <span class="hlt">solar</span> <span class="hlt">wind</span> bulk flow speed and auroral radiation intensity, with a linear correlation coefficient of 0.78 for the 203 daily averages examined. A possible mechanism for the relationship may be related to the propagation into the nightside magnetosphere of low-frequency long-wavelength electrostatic waves produced in the magnetosheath by the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1226489','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1226489"><span>Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study Phase 3: Technical Overview</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p></p> <p>2015-11-01</p> <p>Technical fact sheet outlining the key findings of Phase 3 of the Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study (WWSIS-3). NREL and GE find that with good system planning, sound engineering practices, and commercially available technologies, the Western grid can maintain reliability and stability during the crucial first minute after grid disturbances with high penetrations of <span class="hlt">wind</span> and <span class="hlt">solar</span> power.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021363&hterms=Properties+wave+function&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DProperties%2Bwave%2Bfunction','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021363&hterms=Properties+wave+function&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DProperties%2Bwave%2Bfunction"><span>Three-fluid <span class="hlt">solar</span> <span class="hlt">wind</span> model with Alfven waves</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Esser, Ruth; Habbal, Shadia R.; Hu, You Q.</p> <p>1995-01-01</p> <p>We present a study of a three-fluid <span class="hlt">solar</span> <span class="hlt">wind</span> model. with continuity, momentum and separate energy equations for protons. alpha particles and electrons. Allowing separate coronal heat sources for all three species, we study the flow properties of the <span class="hlt">solar</span> <span class="hlt">wind</span> as a function of heat input, Alfven wave energy input, and alpha particle abundance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1217837','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1217837"><span><span class="hlt">Solar</span> and <span class="hlt">Wind</span> Technologies for Hydrogen Production Report to Congress</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>None, None</p> <p>2005-12-01</p> <p>DOE's <span class="hlt">Solar</span> and <span class="hlt">Wind</span> Technologies for Hydrogen Production Report to Congress summarizes the technology roadmaps for <span class="hlt">solar</span>- and <span class="hlt">wind</span>-based hydrogen production. Published in December 2005, it fulfills the requirement under section 812 of the Energy Policy Act of 2005.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021292&hterms=solar+wind+power&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dsolar%2Bwind%2Bpower','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021292&hterms=solar+wind+power&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dsolar%2Bwind%2Bpower"><span>Turbulence in the <span class="hlt">solar</span> <span class="hlt">wind</span>: Kinetic effects</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Goldstein, M. L.</p> <p>1995-01-01</p> <p>Although a casual look at the fluctuating magnetic and velocity fields in the <span class="hlt">solar</span> <span class="hlt">wind</span> may be reminiscent of a chaotic and disordered flow, there is, nonetheless. considerable organization and structure in the temporal and spatial evolution of those fluctuations. Much of that evolution is controlled by processes operating on rather large scales for example, in the inner heliosphere, the fluctuations in magnetic and velocity are highly correlated in the sense of outward propagating Alfven waves. This correlation can be destroyed both in time and distance by the velocity gradients present between fast and slow streams and by other nonlinear processes which stir the medium, producing a turbulent cascade of energy from large to small scales. Many aspects of this turbulent evolution can be described using fluid models; however, at some scale the fluid approximation breaks down and a more detailed paradigm is necessary. The breakdown is evident in the power spectrum of magnetic fluctuations at scales approaching the wavelength of ion cyclotron waves. At those scales, as evident in Mariner 10 and other magnetometer data, the spectrum bends over and the fluctuations damp, possibly heating the ambient plasma. Some evidence for heating of the <span class="hlt">solar</span> <span class="hlt">wind</span> is present in the Voyager data. Fluid models can be modified to some extent to incorporate aspects of a kinetic treatment. This is done by modifying the dissipation terms in the fluid equations and by including extra terms, such as the Hall term. As the scale lengths of phenomena shrink further and approach the spatial and temporal scales characteristic of electron phenomena, the fluid description must be abandoned altogether and a fully kinetic treatment is required. One example is the generation of Langmuir solitons produced by the electron beams that generate type 3 <span class="hlt">solar</span> radio bursts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6901074','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6901074"><span>Long-term downward trend in total <span class="hlt">solar</span> <span class="hlt">irradiance</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Willson, R.C.; Hudson, H.S.; Frohlich, C.; Brusa, R.W.</p> <p>1986-11-28</p> <p>The first 5 years (from 1980 to 1985) of total <span class="hlt">solar</span> <span class="hlt">irradiance</span> observations by the first Active Cavity Radiometer <span class="hlt">Irradiance</span> Monitor (ACRIM I) experiment on board the <span class="hlt">Solar</span> Maximum Mission spacecraft show a clearly defined downward trends of -0.019% per year. The existence of this trend has been confirmed by the internal self-calibrations of ACRIM I, by independent measurements from sounding rockets and balloons, and by observations from the Nimbus-7 spacecraft. The trend appears to be due to unpredicted variations of <span class="hlt">solar</span> luminosity on time scales of years, and it may be related to <span class="hlt">solar</span> cycle magnetic activity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1810h0007W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1810h0007W"><span>Direct <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> measurements with a Cryogenic <span class="hlt">Solar</span> Absolute Radiometer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Walter, Benjamin; Winkler, Rainer; Graber, Florian; Finsterle, Wolfgang; Fox, Nigel; Li, Vivian; Schmutz, Werner</p> <p>2017-02-01</p> <p>The World Radiometric Reference (WRR) is an artefact based reference for Direct <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> (DSI) measurements. The WRR is realized by a group of electrical substitution radiometers, the World Standard Group (WSG). In recent years, a relative difference of about -0.3% between the International System of Units (SI) scale and the WRR scale was observed with the SI scale being lower. The Cryogenic <span class="hlt">Solar</span> Absolute Radiometer (CSAR) aims for i) providing direct traceability of DSI measurements to the SI system, ii) reducing the overall uncertainty of DSI measurements towards 0.01% and for iii) replacing the WSG in future. The latest SI-WRR intercomparisons performed with CSAR revealed a relative difference of -0.29% ± 0.064% (k = 1) between the SI and the WRR scale, a result that agrees well with previous findings. The uncertainty of corrections for the window transmittance results currently in the largest contribution to the total uncertainty for the CSAR measurements. The formal transition from the WRR to the SI-scale for DSI measurements is currently being discussed in the WMO/CIMO Task Team on Radiation References.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1215160R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1215160R"><span>The Electrodynamics of the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Interaction with Venus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Russell, C. T.; Ma, Y. J.; Luhman, J. G.</p> <p>2010-05-01</p> <p>Venus has a thick atmosphere whose upper reaches are ionized by <span class="hlt">solar</span> EUV. The temperature and density of this ionosphere provide sufficient pressure that, at <span class="hlt">solar</span> maximum for normal <span class="hlt">solar</span> <span class="hlt">wind</span> pressures, the <span class="hlt">solar</span> <span class="hlt">wind</span> is deflected at altitudes far above the region of significant ion-neutral collisions. Hence when the interplanetary field changes, a current is induced at the ionopause that excludes the magnetic field from the ionosphere. A magnetic barrier of magnetic field draped around the ionosphere builds up and forms the obstacle to the <span class="hlt">solar</span> <span class="hlt">wind</span> flow. Since the size of the Venus obstacle vastly exceeds that of the ion-gyro motion, a bow shock forms that slows, heats, and deflects the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma. This interaction is the epitome of the induced magnetosphere. At times though, the <span class="hlt">solar</span> <span class="hlt">wind</span> pressure is too strong to be stood off by the ionosphere, and the ionopause drops to collisional altitudes. At this point, the ionosphere becomes magnetized throughout. Venus also has an H and O exosphere that extends into the <span class="hlt">solar</span> <span class="hlt">wind</span>. These can lead to the occurrence of cometary processes like mass pickup and deceleration of the flow. In short, the <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with Venus has many facets and is sufficiently complex to continue to fuel new discoveries and a little controversy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA151698','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA151698"><span>A Comparison of FOF2 Baselines for Use in Studying the Effects of <span class="hlt">Solar</span> Ultraviolet <span class="hlt">Irradiance</span> on the F2 Region of the Ionosphere.</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1983-12-01</p> <p>radio wave U)’ traveling at the speed of light, the apparent height of reflection can be calculated. These ionograms are used to deduce electron...including interplanetary mag- netic field sector boundaries, <span class="hlt">solar</span> <span class="hlt">wind</span> , and <span class="hlt">solar</span> 27 day variability in ionizing <span class="hlt">irradiance</span>. The only one that showed...hourly variations in foF2 presumed to be caused by <span class="hlt">solar</span> <span class="hlt">irradiance</span>. 2. Values for foF2 are taken directly from ionograms . The ionogram measurements</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22167597','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22167597"><span>OBSERVATION OF FLUX-TUBE CROSSINGS IN THE <span class="hlt">SOLAR</span> <span class="hlt">WIND</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Arnold, L.; Li, G.; Li, X.; Yan, Y.</p> <p>2013-03-20</p> <p>Current sheets are ubiquitous in the <span class="hlt">solar</span> <span class="hlt">wind</span>. They are a major source of the <span class="hlt">solar</span> <span class="hlt">wind</span> MHD turbulence intermittency. They may result from nonlinear interactions of the <span class="hlt">solar</span> <span class="hlt">wind</span> MHD turbulence or are the boundaries of flux tubes that originate from the <span class="hlt">solar</span> surface. Some current sheets appear in pairs and are the boundaries of transient structures such as magnetic holes and reconnection exhausts or the edges of pulsed Alfven waves. For an individual current sheet, discerning whether it is a flux-tube boundary or due to nonlinear interactions or the boundary of a transient structure is difficult. In this work, using data from the <span class="hlt">Wind</span> spacecraft, we identify two three-current-sheet events. Detailed examination of these two events suggests that they are best explained by the flux-tube-crossing scenario. Our study provides convincing evidence supporting the scenario that the <span class="hlt">solar</span> <span class="hlt">wind</span> consists of flux tubes where distinct plasmas reside.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19810060080&hterms=solar+wind+power&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsolar%2Bwind%2Bpower','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19810060080&hterms=solar+wind+power&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsolar%2Bwind%2Bpower"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> control of auroral zone geomagnetic activity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Clauer, C. R.; Mcpherron, R. L.; Searls, C.; Kivelson, M. G.</p> <p>1981-01-01</p> <p><span class="hlt">Solar</span> <span class="hlt">wind</span> magnetosphere energy coupling functions are analyzed using linear prediction filtering with 2.5 minute data. The relationship of auroral zone geomagnetic activity to <span class="hlt">solar</span> <span class="hlt">wind</span> power input functions are examined, and a least squares prediction filter, or impulse response function is designed from the data. Computed impulse response functions are observed to have characteristics of a low pass filter with time delay. The AL index is found well related to <span class="hlt">solar</span> <span class="hlt">wind</span> energy functions, although the AU index shows a poor relationship. High frequency variations of auroral indices and substorm expansions are not predictable with <span class="hlt">solar</span> <span class="hlt">wind</span> information alone, suggesting influence by internal magnetospheric processes. Finally, the epsilon parameter shows a poorer relationship with auroral geomagnetic activity than a power parameter, having a VBs <span class="hlt">solar</span> <span class="hlt">wind</span> dependency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1095399','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1095399"><span>The Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study Phase 2</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lew, D.; Brinkman, G.; Ibanez, E.; Hodge, B. M.; Hummon, M.; Florita, A.; Heaney, M.</p> <p>2013-09-01</p> <p>The electric grid is a highly complex, interconnected machine, and changing one part of the grid can have consequences elsewhere. Adding <span class="hlt">wind</span> and <span class="hlt">solar</span> affects the operation of the other power plants and adding high penetrations can induce cycling of fossil-fueled generators. Cycling leads to wear-and-tear costs and changes in emissions. Phase 2 of the Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study (WWSIS-2) evaluated these costs and emissions and simulated grid operations for a year to investigate the detailed impact of <span class="hlt">wind</span> and <span class="hlt">solar</span> on the fossil-fueled fleet. This built on Phase 1, one of the largest <span class="hlt">wind</span> and <span class="hlt">solar</span> integration studies ever conducted, which examined operational impacts of high <span class="hlt">wind</span> and <span class="hlt">solar</span> penetrations in the West.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1220243','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1220243"><span>The Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study Phase 2</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lew, Debra; Brinkman, Greg; Ibanez, E.; Florita, A.; Heaney, M.; Hodge, B. -M.; Hummon, M.; Stark, G.; King, J.; Lefton, S. A.; Kumar, N.; Agan, D.; Jordan, G.; Venkataraman, S.</p> <p>2013-09-01</p> <p>The electric grid is a highly complex, interconnected machine, and changing one part of the grid can have consequences elsewhere. Adding <span class="hlt">wind</span> and <span class="hlt">solar</span> affects the operation of the other power plants and adding high penetrations can induce cycling of fossil-fueled generators. Cycling leads to wear-and-tear costs and changes in emissions. Phase 2 of the Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study (WWSIS-2) evaluated these costs and emissions and simulated grid operations for a year to investigate the detailed impact of <span class="hlt">wind</span> and <span class="hlt">solar</span> on the fossil-fueled fleet. This built on Phase 1, one of the largest <span class="hlt">wind</span> and <span class="hlt">solar</span> integration studies ever conducted, which examined operational impacts of high <span class="hlt">wind</span> and <span class="hlt">solar</span> penetrations in the West(GE Energy 2010).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22039422','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22039422"><span>INTERPRETING MAGNETIC VARIANCE ANISOTROPY MEASUREMENTS IN THE <span class="hlt">SOLAR</span> <span class="hlt">WIND</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>TenBarge, J. M.; Klein, K. G.; Howes, G. G.; Podesta, J. J.</p> <p>2012-07-10</p> <p>The magnetic variance anisotropy (A{sub m}) of the <span class="hlt">solar</span> <span class="hlt">wind</span> has been used widely as a method to identify the nature of <span class="hlt">solar</span> <span class="hlt">wind</span> turbulent fluctuations; however, a thorough discussion of the meaning and interpretation of the A{sub m} has not appeared in the literature. This paper explores the implications and limitations of using the A{sub m} as a method for constraining the <span class="hlt">solar</span> <span class="hlt">wind</span> fluctuation mode composition and presents a more informative method for interpreting spacecraft data. The paper also compares predictions of the A{sub m} from linear theory to nonlinear turbulence simulations and <span class="hlt">solar</span> <span class="hlt">wind</span> measurements. In both cases, linear theory compares well and suggests that the <span class="hlt">solar</span> <span class="hlt">wind</span> for the interval studied is dominantly Alfvenic in the inertial and dissipation ranges to scales of k{rho}{sub i} {approx_equal} 5.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSH21B2526J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSH21B2526J"><span>Magnetic Signatures of Nano Dust in the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jia, Y. D.; Lai, H.; Russell, C. T.</p> <p>2016-12-01</p> <p>Nano dust particles become charged and therefore accelerate once they are created and released into the <span class="hlt">solar</span> <span class="hlt">wind</span>. However, it takes hours to accelerate EVEN the lightest dust particles. To study their interaction with the <span class="hlt">solar</span> <span class="hlt">wind</span>, we numerically model the <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with charged dust at several stages in the dust acceleration process: at release; after the dust particles gain 20% of the <span class="hlt">solar</span> <span class="hlt">wind</span> speed; after the dust particles gain 50% of the <span class="hlt">solar</span> <span class="hlt">wind</span> speed; and a subsonic interaction. In addition, we model such interactions on dust particles weighing 3000, 10,000, and 100,000 amu/proton charge. Lastly, we compare such interactions when the dust is released at different heliocentric distances: 0.3 AU, 0.7 AU, and 1 AU. We use these models to predict what a magnetometer will detect at 1 AU when such dust clouds are released upstream.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040037742&hterms=land+size&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dland%2Bsize','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040037742&hterms=land+size&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dland%2Bsize"><span>Atmosphere, Ocean, Land, and <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> Data Sets</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Johnson, James; Ahmad, Suraiya</p> <p>2003-01-01</p> <p>The report present the atmosphere, ocean color, land and <span class="hlt">solar</span> <span class="hlt">irradiation</span> data sets. The data presented: total ozone, aerosol, cloud optical and physical parameters, temperature and humidity profiles, radiances, rain fall, drop size distribution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996AAS...188.4905G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996AAS...188.4905G"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Composition: First Results from SOHO and Future Expectations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Galvin, A. B.; Ipavich, F. M.; Gloeckler, G.; Coplan, M.; Hovestadt, D.; Hilchenbach, M.; Buergi, A.; Klecker, B.; Scholer, M.; Bochsler, P.; Balsiger, H.; Geiss, J.; Kallenbach, R.; Wurz, P.; Gruenwaldt, H.; Axford, W. I.; Livi, S.; Marsch, E.; Wilken, B.; Gliem, F.; Reiche, K.-U.; Lee, M. A.; Moebius, E.; Hsieh, K. C.; Neugebauer, M.; Managadze, G. G.; Verigin, M. I.</p> <p>1996-05-01</p> <p>The SOHO payload includes three experiments designed to make "in situ" particle measurements of the <span class="hlt">solar</span> <span class="hlt">wind</span> and <span class="hlt">solar</span> energetic particles (CELIAS, D. Hovestadt PI; COSTEP, H. Kunow PI; ERNE, J. Torsti PI). The <span class="hlt">solar</span> <span class="hlt">wind</span> measurements that are the focus of this talk are primarily provided by the CELIAS CTOF and MTOF sensors. (CELIAS/STOF and COSTEP-ERNE measure <span class="hlt">solar</span> and interplanetary suprathermal and energetic particle populations.) CELIAS/CTOF measures <span class="hlt">solar</span> <span class="hlt">wind</span> heavy ion elemental and charge state abundances, information which is used (for example) in identifying the type of <span class="hlt">solar</span> <span class="hlt">wind</span> flow and the ionization processes in the corona where the <span class="hlt">solar</span> <span class="hlt">wind</span> charge states become "frozen-in". CELIAS/MTOF provides heavy ion elemental and isotopic abundances that are important (for example) in the study of fractionation factors in coronal abundances (as in the so-called "FIP-effect") for the rarer elements not resolvable in conventional <span class="hlt">solar</span> <span class="hlt">wind</span> composition instruments, and in determining the isotopic make-up of the <span class="hlt">solar</span> corona. MTOF is, by far, the most powerful <span class="hlt">solar</span> <span class="hlt">wind</span> mass spectrometer flown to date, and already has new science to report at the time of this writing. This happenstance is due to a combination of (1) advanced technology in obtaining high mass resolution for ions at <span class="hlt">solar</span> <span class="hlt">wind</span> energies, and (2) increased statistics. The excellent counting statistics are largely due to continuous <span class="hlt">solar</span> <span class="hlt">wind</span> monitoring (with its position at L1, ``the Sun never sets on SOHO''), and the continuous sampling of the <span class="hlt">solar</span> <span class="hlt">wind</span> by the 3-axis stabilized spacecraft further enhanced by MTOF's novel, never previously flown deflection system that encompasses a very large dynamic range. As might be expected, this unique opportunity has allowed MTOF to identify a number of elements for the first time in the <span class="hlt">solar</span> <span class="hlt">wind</span> (e.g., P, Ti, Cr and Ni). A rich assortment of <span class="hlt">solar</span> <span class="hlt">wind</span> isotopes have been identified for the first time, many of which (e.g., Fe 54 and 56; Ni 58,60,62) have</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22342040','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22342040"><span>Short-scale variations of the <span class="hlt">solar</span> <span class="hlt">wind</span> helium abundance</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Šafránková, J.; Němeček, Z.; Cagaš, P.; Přech, L.; Pavlů, J.; Zastenker, G. N.; Riazantseva, M. O.; Koloskova, I. V.</p> <p>2013-11-20</p> <p>Abrupt changes of the relative He abundance in the <span class="hlt">solar</span> <span class="hlt">wind</span> are usually attributed to encounters with boundaries dividing <span class="hlt">solar</span> <span class="hlt">wind</span> streams from different sources in the <span class="hlt">solar</span> corona. This paper presents a systematic study of fast variations of the He abundance that supports the idea that a majority of these variations on short timescales (3-30 s) are generated by in-transit turbulence that is probably driven by the speed difference between the ion species. This turbulence contributes to the <span class="hlt">solar</span> <span class="hlt">wind</span> heating and leads to a correlation of the temperature with He abundance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730002047','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730002047"><span>The large-scale structure of the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wolfe, J. H.</p> <p>1972-01-01</p> <p>The large-scale structure of the <span class="hlt">solar</span> <span class="hlt">wind</span> is reviewed on the basis of experimental space measurements acquired over approximately the last decade. The observations cover the fading portion of the last <span class="hlt">solar</span> cycle up through the maximum of the present cycle. The character of the interplanetary medium is considered from the viewpoint of the temporal behavior of the <span class="hlt">solar</span> <span class="hlt">wind</span> over increasingly longer time intervals, the average properties of the various <span class="hlt">solar</span> <span class="hlt">wind</span> parameters and their interrelationships. Interplanetary-terrestrial relationships and the expected effects of heliographic lattitude and radial distance are briefly discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19780062796&hterms=tritium&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dtritium','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19780062796&hterms=tritium&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dtritium"><span><span class="hlt">Solar-wind</span> tritium limit and nuclear processes in the <span class="hlt">solar</span> atmosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fireman, E. L.; Damico, J.; Defelice, J.</p> <p>1975-01-01</p> <p>Tritium in Surveyor 3 material is measured, and the resulting H-3/H-1 ratio for the <span class="hlt">solar</span> <span class="hlt">wind</span> is applied in a <span class="hlt">solar</span> flare-<span class="hlt">solar</span> <span class="hlt">wind</span> relation to investigate the mixing requirements for the <span class="hlt">solar</span> atmosphere. The flare-<span class="hlt">wind</span> relation is derived. None of the tritium can be attributed to <span class="hlt">solar-wind</span> implantation. The upper limit for the H-3/He ratio in the <span class="hlt">solar</span> <span class="hlt">wind</span> is 4 times 10 to the minus tenth power and corresponds to a H-3/H-1 limit of 2 times 10 to the minus eleventh power. This limit imposes a requirement on the mixing rate in the <span class="hlt">solar</span> atmosphere if the H-3 production rate in <span class="hlt">solar</span>-surface nuclear reactions is greater than 160/sq cm per sec.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMGC11A0678W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMGC11A0678W"><span>The satellite total <span class="hlt">solar</span> <span class="hlt">irradiance</span> database</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Willson, R. C.</p> <p>2009-12-01</p> <p>A precise knowledge of the total <span class="hlt">solar</span> <span class="hlt">irradiance</span> (TSI) over time is essential to understanding the physics of <span class="hlt">solar</span> luminosity variation and its impact on the Earth in the form of climate change. A National Research Council study found that sustained trends as small as 0.25% per century were the most likely forcing for ‘little ice age’ climate minima during the 12th - 19th centuries. Recent phenomenological analyses of TSI observations and proxies indicate that TSI variation is an important climate change forcing on many timescales including the industrial era. The profound sociological and economic implications of understanding the relative climate change contributions of natural and anthropogenic forcings makes it essential that the satellite TSI database be precisely sustained into the foreseeable future. There are currently three satellite TSI monitoring experiments in operation: SOHO/VIRGO, ACRIMSAT/ACRIM3 and SORCE/TIM, in order of deployment (1996, 2000 and 2003, resp.). Results reported on their ‘native scales show the same basic variations in TSI over time, yet some smaller variations detected by ACRIM3 are less well defined or absent in the results of VIRGO and TIM. There is also a scale difference issue: TIM results are 0.35% lower than those of ACRIM3 and VIRGO, outside the ± 0.1% uncertainty bounds predicted for ACRIM3 and VIRGO, and well outside TIM’s ± 0.01% uncertainty design goal. TIM’s failure to achieve 0.01% uncertainty in flight demonstrates that the TSI monitoring paradigm shift of relying on measurement accuracy rather than a redundant/overlap strategy to provide long term traceability cannot be realized with current ‘ambient temperature’ technology. The only viable monitoring approach for the foreseeable future continues to be the redundant/overlap strategy that has provided the 31 year satellite TSI database to date with useful traceability. Intercomparisons of flight experiments at their levels of mutual precision can</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760007453','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760007453"><span>Geomagnetic responses to the <span class="hlt">solar</span> <span class="hlt">wind</span> and the <span class="hlt">solar</span> activity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Svalgaard, L.</p> <p>1975-01-01</p> <p>Following some historical notes, the formation of the magnetosphere and the magnetospheric tail is discussed. The importance of electric fields is stressed and the magnetospheric convection of plasma and magnetic field lines under the influence of large-scale magnetospheric electric fields is outlined. Ionospheric electric fields and currents are intimately related to electric fields and currents in the magnetosphere and the strong coupling between the two regions is discussed. The energy input of the <span class="hlt">solar</span> <span class="hlt">wind</span> to the magnetosphere and upper atmosphere is discussed in terms of the reconnection model where interplanetary magnetic field lines merge or connect with the terrestrial field on the sunward side of the magnetosphere. The merged field lines are then stretched behind earth to form the magnetotail so that kinetic energy from the <span class="hlt">solar</span> <span class="hlt">wind</span> is converted into magnetic energy in the field lines in the tail. Localized collapses of the crosstail current, which is driven by the large-scale dawn/dusk electric field in the magnetosphere, divert part of this current along geomagnetic field lines to the ionosphere, causing substorms with auroral activity and magnetic disturbances. The collapses also inject plasma into the radiation belts and build up a ring current. Frequent collapses in rapid succession constitute the geomagnetic storm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AIPC.1665l0008C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AIPC.1665l0008C"><span>Performance of single crystalline silicon <span class="hlt">solar</span> cell with <span class="hlt">irradiance</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chander, Subhash; Purohit, A.; Nehra, Anshu; Nehra, S. P.; Dhaka, M. S.</p> <p>2015-06-01</p> <p>In this paper, the effect of <span class="hlt">irradiance</span> on the performance parameters of single crystalline silicon <span class="hlt">solar</span> cell is undertaken. The experiment was carried out employing <span class="hlt">solar</span> cell simulator with varying <span class="hlt">irradiance</span> in the range 115-550W/m2 at constant cell temperature 25°C. The results show that the short circuit current is found to be increased linearly with <span class="hlt">irradiance</span> and the open circuit voltage is increased slightly. The fill factor, maximum power and cell efficiency are also found to be increased with <span class="hlt">irradiance</span>. The efficiency is increased linearly at lower <span class="hlt">irradiance</span> while slightly increased at higher. The results revealed that the <span class="hlt">irradiance</span> has a dominant effect on the performance parameters. The results are in good agreement with the available literature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.6607M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.6607M"><span>Open Surface <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> Observations - A Challenge</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Menard, Lionel; Nüst, Daniel; Jirka, Simon; Maso, Joan; Ranchin, Thierry; Wald, Lucien</p> <p>2015-04-01</p> <p>The newly started project ConnectinGEO funded by the European Commission aims at improving the understanding on which environmental observations are currently available in Europe and subsequently providing an informational basis to close gaps in diverse observation networks. The project complements supporting actions and networking activities with practical challenges to test and improve the procedures and methods for identifying observation data gaps, and to ensure viability in real world scenarios. We present a challenge on future concepts for building a data sharing portal for the <span class="hlt">solar</span> energy industry as well as the state of the art in the domain. Decision makers and project developers of <span class="hlt">solar</span> power plants have identified the Surface <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> (SSI) and its components as an important factor for their business development. SSI observations are crucial in the process of selecting suitable locations for building new plants. Since in-situ pyranometric stations form a sparse network, the search for locations starts with global satellite data and is followed by the deployment of in-situ sensors in selected areas for at least one year. To form a convincing picture, answers must be sought in the conjunction of these EO systems, and although companies collecting SSI observations are willing to share this information, the means to exchange in-situ measurements across companies and between stakeholders in the market are still missing. We present a solution for interoperable exchange of SSI data comprising in-situ time-series observations as well as sensor descriptions based on practical experiences from other domains. More concretely, we will apply concepts and implementations of the Sensor Web Enablement (SWE) framework of the Open Geospatial Consortium (OGC). The work is based on an existing spatial data infrastructure (SDI), which currently comprises metadata, maps and coverage data, but no in-situ observations yet. This catalogue is already registered in the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930031964&hterms=1083&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2526%25231083','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930031964&hterms=1083&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2526%25231083"><span>Variations in <span class="hlt">solar</span> Lyman alpha <span class="hlt">irradiance</span> on short time scales</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pap, J. M.</p> <p>1992-01-01</p> <p>Variations in <span class="hlt">solar</span> UV <span class="hlt">irradiance</span> at Lyman alpha are studied on short time scales (from days to months) after removing the long-term changes over the <span class="hlt">solar</span> cycle. The SME/Lyman alpha <span class="hlt">irradiance</span> is estimated from various <span class="hlt">solar</span> indices using linear regression analysis. In order to study the nonlinear effects, Lyman alpha <span class="hlt">irradiance</span> is modeled with a 5th-degree polynomial as well. It is shown that the full-disk equivalent width of the He line at 1083 nm, which is used as a proxy for the plages and active network, can best reproduce the changes observed in Lyman alpha. Approximately 72 percent of the <span class="hlt">solar</span>-activity-related changes in Lyman alpha <span class="hlt">irradiance</span> arise from plages and the network. The network contribution is estimated by the correlation analysis to be about 19 percent. It is shown that significant variability remains in Lyman alpha <span class="hlt">irradiance</span>, with periods around 300, 27, and 13.5d, which is not explained by the <span class="hlt">solar</span> activity indices. It is shown that the nonlinear effects cannot account for a significant part of the unexplained variation in Lyman alpha <span class="hlt">irradiance</span>. Therefore, additional events (e.g., large-scale motions and/or a systematic difference in the area and intensity of the plages and network observed in the lines of Ca-K, He 1083, and Lyman alpha) may explain the discrepancies found between the observed and estimated <span class="hlt">irradiance</span> values.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960017623','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960017623"><span>White Paper on SBUV/2 <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> Measurements</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hilsenrath, Ernest; DeLand, Matthew T.; Cebula, Richard P.</p> <p>1996-01-01</p> <p>The importance of <span class="hlt">solar</span> <span class="hlt">irradiance</span> measurements by the <span class="hlt">Solar</span> Backscatter Ultraviolet, Model 2 (SBUV/2) instruments on NOAA's operational satellites is described. These measurements are necessary accurately monitor the long-term changes in the global column ozone amount, the altitude distribution of ozone in the upper stratosphere, and the degree to which ozone changes are caused by anthropogenic sources. Needed to accomplish these goals are weekly <span class="hlt">solar</span> <span class="hlt">irradiance</span> measurements at the operational ozone wavelengths, daily measurements of the Mg II proxy index, instrument-specific Mg II scale factors, and daily measurements of the <span class="hlt">solar</span> spectral <span class="hlt">irradiance</span> at photochemically important wavelengths. Two <span class="hlt">solar</span> measurement schedules are provided: (1) a baseline schedule for all instruments except the NOAA-14 instrument and (2) a modified schedule for the NOAA-14 SBUV/2 instrument. This latter schedule is needed due to the NOAA-14 grating drive problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1913340P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1913340P"><span>Simulating and cataloguing the background <span class="hlt">solar</span> <span class="hlt">wind</span> conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pinto, Rui; Rouillard, Alexis; Odstrcil, Dusan; Mays, Leila</p> <p>2017-04-01</p> <p>I will present a new series of <span class="hlt">solar</span> <span class="hlt">wind</span> simulations used to build a catalogue of the background <span class="hlt">solar</span> <span class="hlt">wind</span> from the surface of the Sun to 1 AU. We used a new <span class="hlt">solar</span> <span class="hlt">wind</span> model, called MULTI-VP, which takes a coronal magnetic field map as input and calculates the dynamical and thermal properties of the <span class="hlt">solar</span> <span class="hlt">wind</span> from the chromosphere up to about 30 Rsun. MULTI-VP supplies the full set of physical inner boundary conditions required to initiate the model ENLIL, which was then used to calculate the properties of the <span class="hlt">wind</span> flow in the heliosphere (from 21.5 Rsun to 1AU). This combined modelling strategy does not rely on semi-empirical assumptions for the state of the <span class="hlt">solar</span> <span class="hlt">wind</span> at the high corona, and provides new estimates of the state of the background <span class="hlt">wind</span> which are based only on physical principles. MULTI-VP was initiated using Potential Field Source-Surface extrapolations from WSO synoptic maps covering several Carrington rotations both at <span class="hlt">solar</span> minimum and at <span class="hlt">solar</span> maximum (CR 2055 - 2079 and CR 2130 - 2149; see https://stormsweb.irap.omp.eu/doku.php?id=windmaptable). Our solutions were calibrated against in-situ measurements of different spacecrafts, white-light J-Maps and coronal/heliospheric imagery in order to provide better predictions than the classical methods. These <span class="hlt">wind</span> solution will be available as HELCATS catalogues (http://www.helcats-fp7.eu/).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930006343','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930006343"><span>On the variation of the Nimbus 7 total <span class="hlt">solar</span> <span class="hlt">irradiance</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, Robert M.</p> <p>1992-01-01</p> <p>For the interval December 1978 to April 1991, the value of the mean total <span class="hlt">solar</span> <span class="hlt">irradiance</span>, as measured by the Nimbus-7 Earth Radiation Budget Experiment channel 10C, was 1,372.02 Wm(exp -2), having a standard deviation of 0.65 Wm(exp -2), a coefficient of variation (mean divided by the standard deviation) of 0.047 percent, and a normal deviate z (a measure of the randomness of the data) of -8.019 (inferring a highly significant non-random variation in the <span class="hlt">solar</span> <span class="hlt">irradiance</span> measurements, presumably related to the action of the <span class="hlt">solar</span> cycle). Comparison of the 12-month moving average (also called the 13-month running mean) of <span class="hlt">solar</span> <span class="hlt">irradiance</span> to those of the usual descriptors of the <span class="hlt">solar</span> cycle (i.e., sunspot number, 10.7-cm <span class="hlt">solar</span> radio flux, and total corrected sunspot area) suggests possibly significant temporal differences. For example, <span class="hlt">solar</span> <span class="hlt">irradiance</span> is found to have been greatest on or before mid 1979 (leading <span class="hlt">solar</span> maximum for cycle 21), lowest in early 1987 (lagging <span class="hlt">solar</span> minimum for cycle 22), and was rising again through late 1990 (thus, lagging <span class="hlt">solar</span> maximum for cycle 22), having last reported values below those that were seen in 1979 (even though cycles 21 and 22 were of comparable strength). Presuming a genuine correlation between <span class="hlt">solar</span> <span class="hlt">irradiance</span> and the <span class="hlt">solar</span> cycle (in particular, sunspot number) one infers that the correlation is weak (having a coefficient of correlation r less than 0.84) and that major excursions (both as 'excesses' and 'deficits') have occurred (about every 2 to 3 years, perhaps suggesting a pulsating Sun).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005JASTP..67...93T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005JASTP..67...93T"><span>Effects of <span class="hlt">solar</span> UV <span class="hlt">irradiation</span> on dynamics of ozone hole in Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Troshichev, O.; Gabis, I.</p> <p>2005-01-01</p> <p>To study relationship between changes in <span class="hlt">solar</span> ultraviolet (UV) <span class="hlt">irradiance</span> and dynamics of the Antarctic ozone hole during the final breakup of the Antarctic polar vortex the composite Mg II index has been used as a proxy for the <span class="hlt">solar</span> UV <span class="hlt">irradiance</span>. The short-term changes in the UV-<span class="hlt">irradiation</span> have been separated after removing the long- and middle term variations. Examination of maps of the total ozone distribution above Antarctica showed that the ozone hole collapse succeeds displacement of the hole center from the South Pole, where the absolute minimum of total ozone is usually located. Comparison with variations of the UV <span class="hlt">irradiation</span> reveals that phase of the quick decay of the ozone hole is preceded by the maximal <span class="hlt">solar</span> UV <span class="hlt">irradiation</span> in course of the regular 27-days variation. Analysis of the vertical profiles of ozone density, temperature, <span class="hlt">wind</span> speed and total column ozone above station Amundsen Scott showed that ozone hole is filled up in spring typically in two phases. During the first gradual phase the ozone filling occurs very slowly, whereas the second phase is characterized by sudden and sharp increase of the ozone content (about 50 100 Dobson units in few days). In this period the strong <span class="hlt">wind</span> disturbances are observed in the higher stratosphere as well. Conclusion is made that rate of the ozone hole filling during the Antarctic later spring depends on the intensity of <span class="hlt">solar</span> UV, and high level of the UV <span class="hlt">irradiation</span> turns out to be sufficient to initiate the dynamical processes leading to the collapse of the winter circumpolar vortex.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43.4089K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43.4089K"><span>Implications of L1 observations for slow <span class="hlt">solar</span> <span class="hlt">wind</span> formation by <span class="hlt">solar</span> reconnection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kepko, L.; Viall, N. M.; Antiochos, S. K.; Lepri, S. T.; Kasper, J. C.; Weberg, M.</p> <p>2016-05-01</p> <p>While the source of the fast <span class="hlt">solar</span> <span class="hlt">wind</span> is known to be coronal holes, the source of the slow <span class="hlt">solar</span> <span class="hlt">wind</span> has remained a mystery. Long time scale trends in the composition and charge states show strong correlations between <span class="hlt">solar</span> <span class="hlt">wind</span> velocity and plasma parameters, yet these correlations have proved ineffective in determining the slow <span class="hlt">wind</span> source. We take advantage of new high time resolution (12 min) measurements of <span class="hlt">solar</span> <span class="hlt">wind</span> composition and charge state abundances at L1 and previously identified 90 min quasiperiodic structures to probe the fundamental timescales of slow <span class="hlt">wind</span> variability. The combination of new high temporal resolution composition measurements and the clearly identified boundaries of the periodic structures allows us to utilize these distinct <span class="hlt">solar</span> <span class="hlt">wind</span> parcels as tracers of slow <span class="hlt">wind</span> origin and acceleration. We find that each 90 min (2000 Mm) parcel of slow <span class="hlt">wind</span> has near-constant speed yet exhibits repeatable, systematic charge state and composition variations that span the entire range of statistically determined slow <span class="hlt">solar</span> <span class="hlt">wind</span> values. The classic composition-velocity correlations do not hold on short, approximately hourlong, time scales. Furthermore, the data demonstrate that these structures were created by magnetic reconnection. Our results impose severe new constraints on slow <span class="hlt">solar</span> <span class="hlt">wind</span> origin and provide new, compelling evidence that the slow <span class="hlt">wind</span> results from the sporadic release of closed field plasma via magnetic reconnection at the boundary between open and closed flux in the Sun's atmosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021367&hterms=Structural+Equation+Modeling&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DStructural%2BEquation%2BModeling','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021367&hterms=Structural+Equation+Modeling&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DStructural%2BEquation%2BModeling"><span>Coronal roots of <span class="hlt">solar</span> <span class="hlt">wind</span> streams: 3-D MHD modeling</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pisanko, Yu. V.</p> <p>1995-01-01</p> <p>Weak (discontinuous) solutions of the 3-D MHD equations look like a promising tool to model the transonic <span class="hlt">solar</span> <span class="hlt">wind</span> with structural elements: current sheets, coronal plumes etc. Using the observational information about various coronal emissions one can include these structural elements into the 3-D MHD <span class="hlt">solar</span> <span class="hlt">wind</span> model by embedding the discontinuities of given type. Such 3-D MHD structured <span class="hlt">solar</span> <span class="hlt">wind</span> is calculated self-consistently: variants are examined via numerical experiments. In particular, the behavior of coronal plumes in the transonic <span class="hlt">solar</span> <span class="hlt">wind</span> flow, is modeled. The input information for numerical modeling (for example, the magnetic field map at the very base of the <span class="hlt">solar</span> corona) can be adjusted so that fast stream arises over the center of the coronal hole, over the coronal hole boundaries and, even, over the region with closed magnetic topology. 3-D MHD equations have the analytical solution which can serve as a model of supersonic trans-alfvenic <span class="hlt">solar</span> <span class="hlt">wind</span> in the (5-20) <span class="hlt">solar</span> radii heliocentric distance interval. The transverse, nonradial total (gas + magnetic field) pressure balance in the flow is the corner-stone of this solution. The solution describes the filamentation (ray-like structure of the <span class="hlt">solar</span> corona) and streaming (formation of high-speed streams with velocities up to 800 km/sec) as a consequence of the magnetic field spatial inhomogeneous structure and trans-alfvenic character of the flow. The magnetic field works in the model as a 'controller' for the <span class="hlt">solar</span> <span class="hlt">wind</span> streaming and filamentation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMPA24A..05R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMPA24A..05R"><span>Identifying "Carrington Events" in <span class="hlt">Solar</span>, <span class="hlt">Solar</span> <span class="hlt">Wind</span>, and Magnetospheric Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Russell, C. T.; Riley, P.; Luhmann, J. G.; Lai, H.</p> <p>2016-12-01</p> <p>Extreme space weather begins when extraordinary levels of stored magnetic energy in the photosphere rapidly destabilizes. This destabilization generally releases a rapidly expelled plasma and magnetic flux rope. Large fluxes of highly relativistic particles signal the event and at Earth precede the expelled flux rope. The most recent such <span class="hlt">solar</span> event did not encounter the Earth, but was recorded by STEREO A on July 23, 2012. The energy density in the relativistic particles that preceded the rapidly expanding magnetic cloud was so intense that the compression front expanded with a sub fast mode speed (i.e. `subsonically') and the compression front became a slow mode wave. The peak magnetic field in the rope was 109 nT, larger than any previously reported field at 1 AU in the <span class="hlt">solar</span> <span class="hlt">wind</span>. An equally fast disturbance left the Sun on September 1, 1859, and caused intense induced currents when it reached the Earth. It is likely that at least some of the magnetospheric currents were caused by the accompanying magnetic cloud, but magnetospheric diagnostics were scarce during this event. This first space weather event became the defining occurrence of extreme space weather. A second modern event not generally recognized as "Carrington" class, but arguably super-Carrington, arrived on August 4, 1972. Between the Apollo 16 and 17 missions. It was a strong producer of geomagnetic induced currents, but produced only a weak ring current, possibly because the part of the magnetic cloud in contact with the Earth had a polarity that did not couple the <span class="hlt">solar</span> <span class="hlt">wind</span> momentum flux to the magnetosphere. The pressure wave reached 1 AU in the shortest time of any recorded <span class="hlt">solar</span> event and brought an energetic particle flux that would have harmed the astronauts had they been in space. To identify which <span class="hlt">solar</span> events are capable of producing the most extreme space weather events, we must identify those that are expelled toward the Earth at the highest speeds. How these events manifest their</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910048815&hterms=causes+PTH&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcauses%2BPTH','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910048815&hterms=causes+PTH&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcauses%2BPTH"><span>Intermittent turbulence in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burlaga, L. F.</p> <p>1991-01-01</p> <p>This paper demonstrates the existence of intermittent turbulence in the <span class="hlt">solar</span> <span class="hlt">wind</span> at 8.5 AU. The pth-order velocity structure functions show scaling behavior in the range of periods from 0.85 hour to 13.6 hours for p of less than 20. The exponent of the scaling law s(p) is a quadratic function of p. These observations of s(p) for compressible MHD turbulence on a scale of the order of about 1 AU are consistent with laboratory measurements of s(p) for gasdynamic turbulence on a scale of the order of 1 m, indicating the universal character of intermittent turbulence. The observations are not described by the 'constant beta' model of intermittent turbulence. They are marginally consistent with the lognormal model. The observations are consistent with a random beta model prediction which assumes that the turbulence is a mixture of sheets and space-filling eddies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/924986','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/924986"><span>Innovations in <span class="hlt">Wind</span> and <span class="hlt">Solar</span> PV Financing</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cory, K.; Coughlin, J.; Jenkin, T.; Pater, J.; Swezey, B.</p> <p>2008-02-01</p> <p>There is growing national interest in renewable energy development based on the economic, environmental, and security benefits that these resources provide. Historically, greater development of our domestic renewable energy resources has faced a number of hurdles, primarily related to cost, regulation, and financing. With the recent sustained increase in the costs and associated volatility of fossil fuels, the economics of renewable energy technologies have become increasingly attractive to investors, both large and small. As a result, new entrants are investing in renewable energy and new business models are emerging. This study surveys some of the current issues related to <span class="hlt">wind</span> and <span class="hlt">solar</span> photovoltaic (PV) energy project financing in the electric power industry, and identifies both barriers to and opportunities for increased investment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22365612','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22365612"><span>RELAXATION PROCESSES IN <span class="hlt">SOLAR</span> <span class="hlt">WIND</span> TURBULENCE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Servidio, S.; Carbone, V.; Gurgiolo, C.; Goldstein, M. L.</p> <p>2014-07-10</p> <p>Based on global conservation principles, magnetohydrodynamic (MHD) relaxation theory predicts the existence of several equilibria, such as the Taylor state or global dynamic alignment. These states are generally viewed as very long-time and large-scale equilibria, which emerge only after the termination of the turbulent cascade. As suggested by hydrodynamics and by recent MHD numerical simulations, relaxation processes can occur during the turbulent cascade that will manifest themselves as local patches of equilibrium-like configurations. Using multi-spacecraft analysis techniques in conjunction with Cluster data, we compute the current density and flow vorticity and for the first time demonstrate that these localized relaxation events are observed in the <span class="hlt">solar</span> <span class="hlt">wind</span>. Such events have important consequences for the statistics of plasma turbulence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21929247','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21929247"><span>Nonaxisymmetric anisotropy of <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Turner, A J; Gogoberidze, G; Chapman, S C; Hnat, B; Müller, W-C</p> <p>2011-08-26</p> <p>A key prediction of turbulence theories is frame-invariance, and in magnetohydrodynamic (MHD) turbulence, axisymmetry of fluctuations with respect to the background magnetic field. Paradoxically the power in fluctuations in the turbulent <span class="hlt">solar</span> <span class="hlt">wind</span> are observed to be ordered with respect to the bulk macroscopic flow as well as the background magnetic field. Here, nonaxisymmetry across the inertial and dissipation ranges is quantified using in situ observations from Cluster. The observed inertial range nonaxisymmetry is reproduced by a "fly through" sampling of a direct numerical simulation of MHD turbulence. Furthermore, fly through sampling of a linear superposition of transverse waves with axisymmetric fluctuations generates the trend in nonaxisymmetry with power spectral exponent. The observed nonaxisymmetric anisotropy may thus simply arise as a sampling effect related to Taylor's hypothesis and is not related to the plasma dynamics itself.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19800013734','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800013734"><span>Magnetic clouds in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burlaga, L. F.; Klein, L.</p> <p>1980-01-01</p> <p>Two interplanetary magnetic clouds, characterized by anomalous magnetic field directions and unusually high magnetic field strengths with a scale of the order of 0.25 AU, are identified and described. As the clouds moved past a spacecraft located in the <span class="hlt">solar</span> <span class="hlt">wind</span> near Earth, the magnetic field direction changed by rotating approximately 180 deg nearly parallel to a plane which was essentially perpendicular to the ecliptic. The configuration of the magnetic field in the clouds might be that of a tightly wound cylindrical helix or a series of closed circular loops. One of the magnetic clouds was in a cold stream preceded by a shock, and it caused both a geomagnetic storm and a depression in the galactic cosmic ray intensity. No stream, geomagnetic storm, or large cosmic ray decrease was associated with the other magnetic cloud.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20000073293&hterms=Ulysses&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DUlysses','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20000073293&hterms=Ulysses&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DUlysses"><span>Microstructures in the Polar <span class="hlt">Solar</span> <span class="hlt">Wind</span>: Ulysses</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tsuruyani, Bruce T.; Arballo, J. K.; Galvan, C.; Goldstein, B. E.; Lakhina, G. S.; Sakurai, R.; Smith, E. J.; Neugebauer, M.</p> <p>1999-01-01</p> <p>We find that small (10-200 rP) magnetic decreases comprise a dominant part of the polar <span class="hlt">solar</span> <span class="hlt">wind</span> microstructure at Ulysses distances (2.2 AU). These magnetic field dips are almost always bounded by tangential discontinuities, a feature which is not well understood at this time. Hundreds of these events have been examined in detail and a variety of types have been found. These will be described. It is speculated that these structures have been generated by perpendicular heating of ions closer to the Sun and have then been convected to distances of Ulysses. Such structures may be very important for the rapid cross- field diffusion of ions in the polar regions of the heliosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090006949','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090006949"><span>Genesis <span class="hlt">Solar</span> <span class="hlt">Wind</span> Array Collector Cataloging Status</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burkett, P.J.; Rodriguez, M.C.; Calaway, M.C.; Allton, J.H.</p> <p>2009-01-01</p> <p>Genesis <span class="hlt">solar</span> <span class="hlt">wind</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22215435','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22215435"><span>ASYMMETRIC ELECTRON DISTRIBUTIONS IN THE <span class="hlt">SOLAR</span> <span class="hlt">WIND</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rha, Kicheol; Ryu, Chang-Mo; Yoon, Peter H.</p> <p>2013-09-20</p> <p>A plausible mechanism responsible for producing asymmetric electron velocity distribution functions in the <span class="hlt">solar</span> <span class="hlt">wind</span> is investigated by means of one-dimensional electrostatic particle-in-cell (PIC) simulation. A recent paper suggests that the variation in the ion-to-electron temperature ratio influences the nonlinear wave-particle dynamics such that it results in the formation of asymmetric distributions. The present PIC code simulation largely confirms this finding, but quantitative differences between the weak turbulence formalism and the present PIC simulation are also found, suggesting the limitation of the analytical method. The inter-relationship between the asymmetric electron distribution and the ion-to-electron temperature ratio may be a new useful concept for the observation.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhRvE..89e2812M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhRvE..89e2812M"><span>Stationarity of extreme bursts in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moloney, N. R.; Davidsen, J.</p> <p>2014-05-01</p> <p>Recent results have suggested that the statistics of bursts in the <span class="hlt">solar</span> <span class="hlt">wind</span> vary with <span class="hlt">solar</span> cycle. Here, we show that this variation is basically absent if one considers extreme bursts. These are defined as threshold-exceeding events over the range of high thresholds for which their number decays as a power law. In particular, we find that the distribution of duration times and energies of extreme bursts in the <span class="hlt">solar</span> <span class="hlt">wind</span> ɛ parameter and similar observables are independent of the <span class="hlt">solar</span> cycle and in this sense stationary, and show robust asymptotic power laws with exponents that are independent of the specific threshold. This is consistent with what has been observed for <span class="hlt">solar</span> flares and, thus, provides evidence in favor of a link between <span class="hlt">solar</span> flares and extreme bursts in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25353849','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25353849"><span>Stationarity of extreme bursts in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Moloney, N R; Davidsen, J</p> <p>2014-05-01</p> <p>Recent results have suggested that the statistics of bursts in the <span class="hlt">solar</span> <span class="hlt">wind</span> vary with <span class="hlt">solar</span> cycle. Here, we show that this variation is basically absent if one considers extreme bursts. These are defined as threshold-exceeding events over the range of high thresholds for which their number decays as a power law. In particular, we find that the distribution of duration times and energies of extreme bursts in the <span class="hlt">solar</span> <span class="hlt">wind</span> ε parameter and similar observables are independent of the <span class="hlt">solar</span> cycle and in this sense stationary, and show robust asymptotic power laws with exponents that are independent of the specific threshold. This is consistent with what has been observed for <span class="hlt">solar</span> flares and, thus, provides evidence in favor of a link between <span class="hlt">solar</span> flares and extreme bursts in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22365426','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22365426"><span><span class="hlt">Solar</span> energetic particle events in different types of <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kahler, S. W.; Vourlidas, A.</p> <p>2014-08-10</p> <p>We examine statistically some properties of 96 20 MeV gradual <span class="hlt">solar</span> energetic proton (SEP) events as a function of three different types of <span class="hlt">solar</span> <span class="hlt">wind</span> (SW) as classified by Richardson and Cane. Gradual SEP (E > 10 MeV) events are produced in shocks driven by fast (V ≳ 900 km s{sup –1}) and wide (W > 60°) coronal mass ejections (CMEs). We find no differences among the transient, fast, and slow SW streams for SEP 20 MeV proton event timescales. It has recently been found that the peak intensities Ip of these SEP events scale with the ∼2 MeV proton background intensities, which may be a proxy for the near-Sun shock seed particles. Both the intensities Ip and their 2 MeV backgrounds are significantly enhanced in transient SW compared to those of fast and slow SW streams, and the values of Ip normalized to the 2 MeV backgrounds only weakly correlate with CME V for all SW types. This result implies that forecasts of SEP events could be improved by monitoring both the Sun and the local SW stream properties and that the well known power-law size distributions of Ip may differ between transient and long-lived SW streams. We interpret an observed correlation between CME V and the 2 MeV background for SEP events in transient SW as a manifestation of enhanced <span class="hlt">solar</span> activity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JApA...36..185D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JApA...36..185D"><span><span class="hlt">Solar</span> Coronal Plumes and the Fast <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dwivedi, Bhola N.; Wilhelm, Klaus</p> <p>2015-03-01</p> <p>The spectral profiles of the coronal Ne viii line at 77 nm have different shapes in quiet-Sun regions and Coronal Holes (CHs). A single Gaussian fit of the line profile provides an adequate approximation in quiet-Sun areas, whereas, a strong shoulder on the long-wavelength side is a systematic feature in CHs. Although this has been noticed since 1999, no physical reason for the peculiar shape could be given. In an attempt to identify the cause of this peculiarity, we address three problems that could not be conclusively resolved, in a review article by a study team of the International Space Science Institute (ISSI) (Wilhelm et al. 2011): (1) The physical processes operating at the base and inside of plumes, as well as their interaction with the <span class="hlt">Solar</span> <span class="hlt">Wind</span> (SW). (2) The possible contribution of plume plasma to the fast SW streams. (3) The signature of the First-Ionization Potential (FIP) effect between plumes and inter-plume regions (IPRs). Before the spectroscopic peculiarities in IPRs and plumes in Polar Coronal Holes (PCHs) can be further investigated with the instrument <span class="hlt">Solar</span> Ultraviolet Measurements of Emitted Radiation (SUMER) aboard the <span class="hlt">Solar</span> and Heliospheric Observatory (SOHO), it is mandatory to summarize the results of the review to place the spectroscopic observations into context. Finally, a plume model is proposed that satisfactorily explains the plasma flows up and down the plume field lines and leads to the shape of the neon line in PCHs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSH51D4191P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSH51D4191P"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> compressible structures at ion scales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Perrone, D.; Alexandrova, O.; Rocoto, V.; Pantellini, F. G. E.; Zaslavsky, A.; Maksimovic, M.; Issautier, K.; Mangeney, A.</p> <p>2014-12-01</p> <p>In the <span class="hlt">solar</span> <span class="hlt">wind</span> turbulent cascade, the energy partition between fluid and kinetic degrees of freedom, in the vicinity of plasma characteristic scales, i.e. ion and electron Larmor radius and inertial lengths, is still under debate. In a neighborhood of the ion scales, it has been observed that the spectral shape changes and fluctuations become more compressible. Nowadays, a huge scientific effort is directed to the comprehension of the link between macroscopic and microscopic scales and to disclose the nature of compressive fluctuations, meaning that if space plasma turbulence is a mixture of quasi-linear waves (as whistler or kinetic Alfvèn waves) or if turbulence is strong with formation of coherent structures responsible for dissipation. Here we present an automatic method to identify compressible coherent structures around the ion spectral break, using Morlet wavelet decomposition of magnetic signal from Cluster spacecraft and reconstruction of magnetic fluctuations in a selected scale range. Different kind of coherent structures have been detected: from soliton-like one-dimensional structures to current sheet- or wave-like two-dimensional structures. Using a multi-satellite analysis, in order to characterize 3D geometry and propagation in plasma rest frame, we recover that these structures propagate quasi-perpendicular to the mean magnetic field, with finite velocity. Moreover, without using the Taylor hypothesis, the spatial scales of coherent structures have been estimated. Our observations in the <span class="hlt">solar</span> <span class="hlt">wind</span> can provide constraints on theoretical modeling of small scale turbulence and dissipation in collisionless magnetized plasmas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1814950V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1814950V"><span>Evolution of <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence and intermittency over the <span class="hlt">solar</span> cycle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Väisänen, Pauli; Virtanen, Ilpo; Echim, Marius; Munteanu, Costel; Mursula, Kalevi</p> <p>2016-04-01</p> <p><span class="hlt">Solar</span> <span class="hlt">wind</span> is a natural, near-by plasma physics laboratory, which offers possibilities to study plasma physical phenomena over a wide range of parameter values that are difficult to reach in ground-based laboratories. Accordingly, the <span class="hlt">solar</span> <span class="hlt">wind</span> is subject of many studies of, e.g., intermittency, turbulence and other nonlinear space plasma phenomena. Turbulence is an important feature of the <span class="hlt">solar</span> <span class="hlt">wind</span> dynamics, e.g., for the energy transfer mechanisms and their scale invariance, the <span class="hlt">solar</span> <span class="hlt">wind</span> evolution, the structure of the heliospheric magnetic field (HMF), the particle energization and heating, and for phenomena related to <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with the planetary plasma systems. Here we analyse high resolution measurements of the <span class="hlt">solar</span> <span class="hlt">wind</span> and the heliospheric magnetic field provided by several ESA and NASA satellites, including ACE, STEREO, Ulysses and Cluster. This collection of satellites allows us to compile and study nearly 20 years of high-resolution <span class="hlt">solar</span> <span class="hlt">wind</span> and HMF measurements from the start of <span class="hlt">solar</span> cycle 23 to the current declining phase of <span class="hlt">solar</span> cycle 24. Long-term studies require homogeneity and, therefore, we pay great attention to the reliability and consistency of the data, in particular to instrumental defects like spin harmonics, the purity of the <span class="hlt">solar</span> <span class="hlt">wind</span> and its possible contamination in the foreshock by magnetospheric ions. We study how the different key-descriptors of turbulence like the slope of the power law of power spectral density and the kurtosis of the fluctuations of the heliospheric magnetic field vary over the <span class="hlt">solar</span> cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28949585','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28949585"><span><span class="hlt">Solar</span> <span class="hlt">Irradiance</span> Variability is Caused by the Magnetic Activity on the <span class="hlt">Solar</span> Surface.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yeo, Kok Leng; Solanki, Sami K; Norris, Charlotte M; Beeck, Benjamin; Unruh, Yvonne C; Krivova, Natalie A</p> <p>2017-09-01</p> <p>The variation in the radiative output of the Sun, described in terms of <span class="hlt">solar</span> <span class="hlt">irradiance</span>, is important to climatology. A common assumption is that <span class="hlt">solar</span> <span class="hlt">irradiance</span> variability is driven by its surface magnetism. Verifying this assumption has, however, been hampered by the fact that models of <span class="hlt">solar</span> <span class="hlt">irradiance</span> variability based on <span class="hlt">solar</span> surface magnetism have to be calibrated to observed variability. Making use of realistic three-dimensional magnetohydrodynamic simulations of the <span class="hlt">solar</span> atmosphere and state-of-the-art <span class="hlt">solar</span> magnetograms from the <span class="hlt">Solar</span> Dynamics Observatory, we present a model of total <span class="hlt">solar</span> <span class="hlt">irradiance</span> (TSI) that does not require any such calibration. In doing so, the modeled <span class="hlt">irradiance</span> variability is entirely independent of the observational record. (The absolute level is calibrated to the TSI record from the Total <span class="hlt">Irradiance</span> Monitor.) The model replicates 95% of the observed variability between April 2010 and July 2016, leaving little scope for alternative drivers of <span class="hlt">solar</span> <span class="hlt">irradiance</span> variability at least over the time scales examined (days to years).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvL.119i1102Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvL.119i1102Y"><span><span class="hlt">Solar</span> <span class="hlt">Irradiance</span> Variability is Caused by the Magnetic Activity on the <span class="hlt">Solar</span> Surface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yeo, K. L.; Solanki, S. K.; Norris, C. M.; Beeck, B.; Unruh, Y. C.; Krivova, N. A.</p> <p>2017-09-01</p> <p>The variation in the radiative output of the Sun, described in terms of <span class="hlt">solar</span> <span class="hlt">irradiance</span>, is important to climatology. A common assumption is that <span class="hlt">solar</span> <span class="hlt">irradiance</span> variability is driven by its surface magnetism. Verifying this assumption has, however, been hampered by the fact that models of <span class="hlt">solar</span> <span class="hlt">irradiance</span> variability based on <span class="hlt">solar</span> surface magnetism have to be calibrated to observed variability. Making use of realistic three-dimensional magnetohydrodynamic simulations of the <span class="hlt">solar</span> atmosphere and state-of-the-art <span class="hlt">solar</span> magnetograms from the <span class="hlt">Solar</span> Dynamics Observatory, we present a model of total <span class="hlt">solar</span> <span class="hlt">irradiance</span> (TSI) that does not require any such calibration. In doing so, the modeled <span class="hlt">irradiance</span> variability is entirely independent of the observational record. (The absolute level is calibrated to the TSI record from the Total <span class="hlt">Irradiance</span> Monitor.) The model replicates 95% of the observed variability between April 2010 and July 2016, leaving little scope for alternative drivers of <span class="hlt">solar</span> <span class="hlt">irradiance</span> variability at least over the time scales examined (days to years).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/86287','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/86287"><span><span class="hlt">Solar</span> semidiurnal tidal <span class="hlt">wind</span> oscillations above the CART site</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Whiteman, C.D.; Bian, X.</p> <p>1995-03-01</p> <p>Harmonic analysis of wintertime data from 915- and 404-MHz radar <span class="hlt">wind</span> profilers at four sites in North America has identified coherent semidiurnal <span class="hlt">wind</span> oscillations through the entire depth of the troposphere. These <span class="hlt">winds</span> are readily apparent above the CART site, as evidenced from analyses of data from the Haviland, KS, radar profiler. The characteristics of this <span class="hlt">wind</span> system match the characteristics of <span class="hlt">solar</span> semidiurnal atmospheric tides, as predicted by a simple dynamic model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995arm..meet...20W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995arm..meet...20W"><span><span class="hlt">Solar</span> semidiurnal tidal <span class="hlt">wind</span> oscillations above the CART site</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Whiteman, C. D.; Bian, X.</p> <p>1995-03-01</p> <p>Harmonic analysis of wintertime data from 915- and 404-MHz radar <span class="hlt">wind</span> profilers at four sites in North America has identified coherent semidiurnal <span class="hlt">wind</span> oscillations through the entire depth of the troposphere. These <span class="hlt">winds</span> are readily apparent above the CART site, as evidenced from analyses of data from the Haviland, KS, radar profiler. The characteristics of this <span class="hlt">wind</span> system match the characteristics of <span class="hlt">solar</span> semidiurnal atmospheric tides, as predicted by a simple dynamic model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E1664K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E1664K"><span>Reconstructions of <span class="hlt">solar</span> <span class="hlt">irradiance</span> on centennial time scales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krivova, Natalie; Solanki, Sami K.; Dasi Espuig, Maria; Kok Leng, Yeo</p> <p></p> <p><span class="hlt">Solar</span> <span class="hlt">irradiance</span> is the main external source of energy to Earth's climate system. The record of direct measurements covering less than 40 years is too short to study <span class="hlt">solar</span> influence on Earth's climate, which calls for reconstructions of <span class="hlt">solar</span> <span class="hlt">irradiance</span> into the past with the help of appropriate models. An obvious requirement to a competitive model is its ability to reproduce observed <span class="hlt">irradiance</span> changes, and a successful example of such a model is presented by the SATIRE family of models. As most state-of-the-art models, SATIRE assumes that <span class="hlt">irradiance</span> changes on time scales longer than approximately a day are caused by the evolving distribution of dark and bright magnetic features on the <span class="hlt">solar</span> surface. The surface coverage by such features as a function of time is derived from <span class="hlt">solar</span> observations. The choice of these depends on the time scale in question. Most accurate is the version of the model that employs full-disc spatially-resolved <span class="hlt">solar</span> magnetograms and reproduces over 90% of the measured <span class="hlt">irradiance</span> variation, including the overall decreasing trend in the total <span class="hlt">solar</span> <span class="hlt">irradiance</span> over the last four cycles. Since such magnetograms are only available for about four decades, reconstructions on time scales of centuries have to rely on disc-integrated proxies of <span class="hlt">solar</span> magnetic activity, such as sunspot areas and numbers. Employing a surface flux transport model and sunspot observations as input, we have being able to produce synthetic magnetograms since 1700. This improves the temporal resolution of the <span class="hlt">irradiance</span> reconstructions on centennial time scales. The most critical aspect of such reconstructions remains the uncertainty in the magnitude of the secular change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005ApJS..157..147W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005ApJS..157..147W"><span>A <span class="hlt">Solar</span> Minimum <span class="hlt">Irradiance</span> Spectrum for Wavelengths below 1200 Å</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Warren, Harry P.</p> <p>2005-03-01</p> <p>NRLEUV represents an independent approach to modeling the Sun's EUV <span class="hlt">irradiance</span> and its variability. Our model utilizes differential emission measure distributions derived from spatially and spectrally resolved <span class="hlt">solar</span> observations, full-disk <span class="hlt">solar</span> images, and a database of atomic physics parameters to calculate the <span class="hlt">solar</span> EUV <span class="hlt">irradiance</span>. In this paper we present a new <span class="hlt">solar</span> minimum <span class="hlt">irradiance</span> spectrum for wavelengths below 1200 Å. This spectrum is based on extensive observations of the quiet Sun taken with the CDS and SUMER spectrometers on the <span class="hlt">Solar</span> and Heliospheric Observatory (SOHO) and the most recent version of the CHIANTI atomic physics database. In general, we find excellent agreement between this new <span class="hlt">irradiance</span> spectrum and our previous quiet-Sun reference spectrum derived primarily from Harvard Skylab observations. Our analysis does show that the quiet-Sun emission measure above about 1 MK declines more rapidly than in our earlier emission measure distribution and that the intensities of the EUV free-bound continua at some wavelengths are somewhat smaller than indicated by the Harvard observations. Our new reference spectrum is also generally consistent with recent <span class="hlt">irradiance</span> observations taken near <span class="hlt">solar</span> minimum. There are, however, two areas of persistent disagreement. Our <span class="hlt">solar</span> spectrum indicates that the <span class="hlt">irradiance</span> measurements overestimate the contribution of the EUV free-bound continua at some wavelengths by as much as a factor of 10. Our model also cannot reproduce the observed <span class="hlt">irradiances</span> at wavelengths below about 150 Å. Comparisons with spectrally resolved <span class="hlt">solar</span> and stellar observations indicate that only a small fraction of the emission lines in the 60-120 Å wavelength range are accounted for in CHIANTI.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22127065','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22127065"><span>RESIDUAL ENERGY SPECTRUM OF <span class="hlt">SOLAR</span> <span class="hlt">WIND</span> TURBULENCE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chen, C. H. K.; Bale, S. D.; Salem, C. S.; Maruca, B. A.</p> <p>2013-06-20</p> <p>It has long been known that the energy in velocity and magnetic field fluctuations in the <span class="hlt">solar</span> <span class="hlt">wind</span> is not in equipartition. In this paper, we present an analysis of 5 yr of <span class="hlt">Wind</span> data at 1 AU to investigate the reason for this. The residual energy (difference between energy in velocity and magnetic field fluctuations) was calculated using both the standard magnetohydrodynamic (MHD) normalization for the magnetic field and a kinetic version, which includes temperature anisotropies and drifts between particle species. It was found that with the kinetic normalization, the fluctuations are closer to equipartition, with a mean normalized residual energy of {sigma}{sub r} = -0.19 and mean Alfven ratio of r{sub A} = 0.71. The spectrum of residual energy, in the kinetic normalization, was found to be steeper than both the velocity and magnetic field spectra, consistent with some recent MHD turbulence predictions and numerical simulations, having a spectral index close to -1.9. The local properties of residual energy and cross helicity were also investigated, showing that globally balanced intervals with small residual energy contain local patches of larger imbalance and larger residual energy at all scales, as expected for nonlinear turbulent interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1215270T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1215270T"><span>The Paleoarchean geodynamo, <span class="hlt">solar</span> <span class="hlt">wind</span> and magnetopause</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tarduno, John A.; Cottrell, R. D.; Watkeys, M. K.; Hofmann, A.; Doubrovine, P. V.; Mamajek, E.; Liu, D.; Sibeck, D. G.; Neukirch, L. P.; Usui, Y.</p> <p>2010-05-01</p> <p>The standoff of stellar <span class="hlt">winds</span> by a planetary magnetic field prevents atmospheric erosion and water loss important for the evolution of a habitable planet. But little is known about early magnetic field strength and whether intense radiation from the young, rapidly rotating Sun modified Earth's atmosphere. New paleointensity results from single silicate crystals bearing magnetic inclusions indicate the presence of a geodynamo between 3.4 and 3.45 billion years ago. The field measured is ~30-50% weaker than that of present-day and when combined with a greater <span class="hlt">solar</span> <span class="hlt">wind</span> pressure suggests steady-state Paleoarchean magnetopause standoff distances ≤ 5 Earth radii, similar to values observed during recent coronal mass ejection events. Aurora would have been at lower latitudes and polar cap area is predicted to have been up to 3 times greater than today. Heating, expansion and volatile loss from the exosphere is implied, affecting long-term atmospheric composition. Efforts to examine even older Paleoarchean-Hadean magnetic mineral carriers for geomagnetic paleointensity signatures will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5094645','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5094645"><span>Vacuum-ultraviolet instrumentation for <span class="hlt">solar</span> <span class="hlt">irradiance</span> and thermospheric airglow</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Woods, T.N.; Rottman, G.J. . High Altitude Observatory); Bailey, S.M.; Solomon, S.C. . Lab. for Atmospheric and Space Physics)</p> <p>1994-02-01</p> <p>A NASA sounding rocket experiment was developed to study the <span class="hlt">solar</span> extreme-ultraviolet (EUV) spectral <span class="hlt">irradiance</span> and its effect on the upper atmosphere. Both the <span class="hlt">solar</span> flux and the terrestrial molecular nitrogen via the Lyman-Birge-Hopfield bands in the far-ultraviolet (FUV) region were measured remotely from a sounding rocket on October 27, 1992. The rocket experiments also includes EUV instruments from Boston University, but only the National Center for Atmospheric Research's (NCAR)/University of Colorado's (CU) four <span class="hlt">solar</span> instruments and one airglow instrument are discussed. The primary <span class="hlt">solar</span> EUV instrument is a 0.25-m Rowland circle EUV spectrograph that has flown on three rockets since 1988 measuring the <span class="hlt">solar</span> spectral <span class="hlt">irradiance</span> from 30 to 110 nm with 0.2-nm resolution. Another <span class="hlt">solar</span> <span class="hlt">irradiance</span> instrument is an array of six silicon soft x-ray (XUV) photodiodes, each having different metallic filters coated directly on the photodiodes. The other <span class="hlt">solar</span> <span class="hlt">irradiance</span> instrument is a silicon avalanche photodiode coupled with pulse height analyzer electronics. The fourth <span class="hlt">solar</span> instrument is a XUV imager that images the sun at 17.5 nm with a spatial resolution of 20 arc sec. The airglow spectrograph measures the terrestrial FUV airglow emissions along the horizon from 125 to 160 nm with 0.2-nm spectral resolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSH14B..07V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSH14B..07V"><span>Flux tubes embedded into reconnection outflows in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Voros, Z.; Zaqarashvili, T.; Sasunov, Y.; Narita, Y.</p> <p>2015-12-01</p> <p>Reconnection exhausts in the <span class="hlt">solar</span> <span class="hlt">wind</span> are usually interpreted in terms of a quasi-stationary Petschek-type reconnection model. Accordingly, within a region of magnetic field reversal, the wedge-shaped, Alfvenic accelerated plasma outflow is bounded by layers containing (anti-) correlated components of speed and magnetic field fluctuations. However, time-dependent impulsive reconnection can generate flux ropes embedded into accelerated outflows. Reconnection associated moving flux ropes or plasmoids are frequently observed in the Earth's magnetotail, while similar observations are missing in the <span class="hlt">solar</span> <span class="hlt">wind</span>. We present the first observations of small-scale magnetic flux ropes associated with reconnection exhausts in the <span class="hlt">solar</span> <span class="hlt">wind</span>, using the data from the <span class="hlt">WIND</span> probe. We argue that the interaction of moving flux ropes with the background plasma can generate turbulence leading finally to the local heating of the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPD....4830106H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPD....4830106H"><span>Slow <span class="hlt">Solar</span> <span class="hlt">Wind</span> from S-Web Arcs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Higginson, Aleida K.; Antiochos, Spiro K.; DeVore, C. Richard; Wyper, Peter; Zurbuchen, Thomas H.</p> <p>2017-08-01</p> <p>A long-standing mystery posed by in-situ heliospheric observations is the large angular extent of slow <span class="hlt">solar</span> <span class="hlt">wind</span> about the heliospheric current sheet (HCS). Measurements of plasma composition strongly imply that much of the slow <span class="hlt">wind</span> consists of plasma from the closed corona that escapes onto open field lines, presumably by field-line opening or by interchange reconnection. Both of these processes are expected to release closed-field plasma into the <span class="hlt">solar</span> <span class="hlt">wind</span> within and immediately adjacent to the HCS. The recently proposed Separatrix-Web (S-Web) Theory postulates that the observations of slow <span class="hlt">wind</span> far from the HCS can be explained by the dynamical interaction of open and closed flux in regions of complex coronal-hole topology. We present the first high-resolution, three-dimensional numerical simulations of the dynamic S-Web. These simulations suggest that photospheric motions at coronal-hole boundaries are responsible for the release of slow <span class="hlt">solar</span> <span class="hlt">wind</span> plasma from the magnetically closed <span class="hlt">solar</span> corona, specifically through prolific interchange magnetic reconnection. The location of this plasma once it is released into the <span class="hlt">solar</span> <span class="hlt">wind</span> depends strongly on the geometry of the coronal-hole flux. We demonstrate how the dynamics at the boundaries of narrow corridors of open flux (coronal hole corridors) can create giant S-Web arcs of slow <span class="hlt">solar</span> <span class="hlt">wind</span> at high latitudes in the heliosphere, far from the HCS, accounting for the long-puzzling slow-<span class="hlt">wind</span> observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001IAUS..203..495H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001IAUS..203..495H"><span>Coronal Heating and the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Acceleration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hirayama, T.</p> <p></p> <p>The twisting magnetic field as the DC energy injection will produce charge separation and consequently an electric field parallel to the magnetic field. Accelerated beam electrons (a few times thermal velocity) due to this electric filed will be stopped by classical collisions with ambient electrons and ions. The beam electrons, 10-3 of the bulk electrons, do not create electric currents due to the back streaming bulk electrons. Hence it is not the normal or anomalous Joule heating, but a co-spatial frictional heating, and yet bulk heating. The heating rate is the kinetic energy density of beams multiplied by the classical collision frequency, and is about 10-4 erg cm-3 s-1. It successfully reproduces observations of quiet and active regions, including the RTV scaling law. In the open field, the damping length of this Alfvénic twist is 0.4 <span class="hlt">solar</span> radii. This is appropriate to produce slow and high-speed <span class="hlt">solar</span> <span class="hlt">winds</span>. Ion-cyclotron waves may be excited due to supra-thermal beams.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011APS..MARV31015P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011APS..MARV31015P"><span>Analysis of <span class="hlt">Wind</span> Forces on Roof-Top <span class="hlt">Solar</span> Panel</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Panta, Yogendra; Kudav, Ganesh</p> <p>2011-03-01</p> <p>Structural loads on <span class="hlt">solar</span> panels include forces due to high <span class="hlt">wind</span>, gravity, thermal expansion, and earthquakes. International Building Code (IBC) and the American Society of Civil Engineers are two commonly used approaches in <span class="hlt">solar</span> industries to address <span class="hlt">wind</span> loads. Minimum Design Loads for Buildings and Other Structures (ASCE 7-02) can be used to calculate <span class="hlt">wind</span> uplift loads on roof-mounted <span class="hlt">solar</span> panels. The present study is primarily focused on 2D and 3D modeling with steady, and turbulent flow over an inclined <span class="hlt">solar</span> panel on the flat based roof to predict the <span class="hlt">wind</span> forces for designing <span class="hlt">wind</span> management system. For the numerical simulation, 3-D incompressible flow with the standard k- ɛ was adopted and commercial CFD software ANSYS FLUENT was used. Results were then validated with <span class="hlt">wind</span> tunnel experiments with a good agreement. <span class="hlt">Solar</span> panels with various aspect ratios for various high <span class="hlt">wind</span> speeds and angle of attacks were modeled and simulated in order to predict the <span class="hlt">wind</span> loads in various scenarios. The present study concluded to reduce the strong <span class="hlt">wind</span> uplift by designing a guide plate or a deflector before the panel. Acknowledgments to Northern States Metal Inc., OH (GK & YP) and School of Graduate Studies of YSU for RP & URC 2009-2010 (YP).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1326077','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1326077"><span>Modeling <span class="hlt">solar</span> <span class="hlt">wind</span> with boundary conditions from interplanetary scintillations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Manoharan, P.; Kim, T.; Pogorelov, N. V.; Arge, C. N.</p> <p>2015-09-30</p> <p>Interplanetary scintillations make it possible to create three-dimensional, time- dependent distributions of the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity. Combined with the magnetic field observations in the <span class="hlt">solar</span> photosphere, they help perform <span class="hlt">solar</span> <span class="hlt">wind</span> simulations in a genuinely time-dependent way. Interplanetary scintillation measurements from the Ooty Radio Astronomical Observatory in India provide directions to multiple stars and may assure better resolution of transient processes in the <span class="hlt">solar</span> <span class="hlt">wind</span>. In this paper, we present velocity distributions derived from Ooty observations and compare them with those obtained with the Wang-Sheeley-Arge (WSA) model. We also present our simulations of the <span class="hlt">solar</span> <span class="hlt">wind</span> flow from 0.1 AU to 1 AU with the boundary conditions based on both Ooty and WSA data.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1326077-modeling-solar-wind-boundary-conditions-from-interplanetary-scintillations','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1326077-modeling-solar-wind-boundary-conditions-from-interplanetary-scintillations"><span>Modeling <span class="hlt">solar</span> <span class="hlt">wind</span> with boundary conditions from interplanetary scintillations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Manoharan, P.; Kim, T.; Pogorelov, N. V.; ...</p> <p>2015-09-30</p> <p>Interplanetary scintillations make it possible to create three-dimensional, time- dependent distributions of the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity. Combined with the magnetic field observations in the <span class="hlt">solar</span> photosphere, they help perform <span class="hlt">solar</span> <span class="hlt">wind</span> simulations in a genuinely time-dependent way. Interplanetary scintillation measurements from the Ooty Radio Astronomical Observatory in India provide directions to multiple stars and may assure better resolution of transient processes in the <span class="hlt">solar</span> <span class="hlt">wind</span>. In this paper, we present velocity distributions derived from Ooty observations and compare them with those obtained with the Wang-Sheeley-Arge (WSA) model. We also present our simulations of the <span class="hlt">solar</span> <span class="hlt">wind</span> flow from 0.1 AUmore » to 1 AU with the boundary conditions based on both Ooty and WSA data.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820012230','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820012230"><span>Evidence for <span class="hlt">solar</span> <span class="hlt">wind</span> control of Saturn radio emission</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Desch, M. D.</p> <p>1982-01-01</p> <p>Using data collected by the Voyager 1 and 2 spacecraft in 1980 and 1981, strong evidence is presented for a direct correlation between variations in the <span class="hlt">solar</span> <span class="hlt">wind</span> at Saturn and the level of activity of Saturn's nonthermal radio emission. Correlation coefficients of 57 to 58% are reached at lag times of 0 to 1 days between the arrival at Saturn of high pressure <span class="hlt">solar</span> <span class="hlt">wind</span> streams and the onset of increased radio emission. The radio emission exhibits a long-term periodicity of 25 days, identical to the periodicity seen in the <span class="hlt">solar</span> <span class="hlt">wind</span> at this time and consistent with the <span class="hlt">solar</span> rotation period. The energy coupling efficiency between the <span class="hlt">solar</span> <span class="hlt">wind</span> with the Saturn radio emission is estimated and compared with that for Earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820061261&hterms=data+collection+techniques&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Ddata%2Bcollection%2Btechniques','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820061261&hterms=data+collection+techniques&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Ddata%2Bcollection%2Btechniques"><span>A technique for determining <span class="hlt">solar</span> <span class="hlt">irradiance</span> deficits. [photovoltaic arrays design</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gonzalez, C. C.; Ross, R. G., Jr.</p> <p>1982-01-01</p> <p>An analytic technique which determines the variation of <span class="hlt">solar</span> <span class="hlt">irradiance</span> from long term averages is presented. The technique involves computer-assisted data reduction techniques, and was designed to improve system reliability by determining the amount of storage capability required to supplement a baseline system. Variations in time intervals of up to 60 days can be determined, and 10 years of data collection are reviewed. The technique involves first calculating average monthly <span class="hlt">irradiance</span> values, then examining the average <span class="hlt">irradiance</span> deviation over time intervals. The calculation procedure is clarified by determining <span class="hlt">solar</span> energy level probabilities and the long term <span class="hlt">solar</span> energy deviation (achieved by repeatedly integrating actual <span class="hlt">irradiance</span> figures). It is found that a 15% increase in collector area and the addition of energy storage or backup are essential contributions to achieving cost-effectiveness. In addition, one to seven no-sun day storage capacities are required to accommodate weather caused deficits.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170003051&hterms=Winds&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DWinds','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170003051&hterms=Winds&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DWinds"><span>Implications of L1 Observations for Slow <span class="hlt">Solar</span> <span class="hlt">Wind</span> Formation by <span class="hlt">Solar</span> Reconnection</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kepko, L.; Viall, N. M.; Antiochos, S. K.; Lepri, S. T.; Kasper, J. C.; Weberg, M.</p> <p>2016-01-01</p> <p>While the source of the fast <span class="hlt">solar</span> <span class="hlt">wind</span> is known to be coronal holes, the source of the slow <span class="hlt">solar</span> <span class="hlt">wind</span> has remained a mystery. Long time scale trends in the composition and charge states show strong correlations between <span class="hlt">solar</span> <span class="hlt">wind</span> velocity and plasma parameters, yet these correlations have proved ineffective in determining the slow <span class="hlt">wind</span> source. We take advantage of new high time resolution (12 min) measurements of <span class="hlt">solar</span> <span class="hlt">wind</span> composition and charge state abundances at L1 and previously identified 90 min quasi periodic structures to probe the fundamental timescales of slow <span class="hlt">wind</span> variability. The combination of new high temporal resolution composition measurements and the clearly identified boundaries of the periodic structures allows us to utilize these distinct <span class="hlt">solar</span> <span class="hlt">wind</span> parcels as tracers of slowwind origin and acceleration. We find that each 90 min (2000 Mm) parcel of slow <span class="hlt">wind</span> has near-constant speed yet exhibits repeatable, systematic charge state and composition variations that span the entire range of statistically determined slow <span class="hlt">solar</span> <span class="hlt">wind</span> values. The classic composition-velocity correlations do not hold on short, approximately hour long, time scales. Furthermore, the data demonstrate that these structures were created by magnetic reconnection. Our results impose severe new constraints on slow <span class="hlt">solar</span> <span class="hlt">wind</span> origin and provide new, compelling evidence that the slow <span class="hlt">wind</span> results from the sporadic release of closed field plasma via magnetic reconnection at the boundary between open and closed flux in the Sun's atmosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940020778','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940020778"><span>The <span class="hlt">solar</span> spectral <span class="hlt">irradiances</span> from x ray to radio wavelengths</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>White, O. R.</p> <p>1993-01-01</p> <p>Sources of new measurements of the <span class="hlt">solar</span> EUV, UV, and visible spectrum are presented together with discussion of formation of the <span class="hlt">solar</span> spectrum as a problem in stellar atmospheres. Agreement between the data and a modern synthetic spectrum shows that observed radiative variability is a minor perturbation on a photosphere in radiative equilibrium and local thermodynamic equilibrium (LTE). Newly observed <span class="hlt">solar</span> variability in 1992 defines a magnetic episode on the Sun closely associated with changes in both spectral <span class="hlt">irradiances</span> and the total <span class="hlt">irradiance</span>. This episode offers the opportunity to track the relationship between radiation and magnetic flux evolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1209352','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1209352"><span>Computation of glint, glare, and <span class="hlt">solar</span> <span class="hlt">irradiance</span> distribution</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Ho, Clifford Kuofei; Khalsa, Siri Sahib Singh</p> <p>2015-08-11</p> <p>Described herein are technologies pertaining to computing the <span class="hlt">solar</span> <span class="hlt">irradiance</span> distribution on a surface of a receiver in a concentrating <span class="hlt">solar</span> power system or glint/glare emitted from a reflective entity. At least one camera captures images of the Sun and the entity of interest, wherein the images have pluralities of pixels having respective pluralities of intensity values. Based upon the intensity values of the pixels in the respective images, the <span class="hlt">solar</span> <span class="hlt">irradiance</span> distribution on the surface of the entity or glint/glare corresponding to the entity is computed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1373397','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1373397"><span>Computation of glint, glare, and <span class="hlt">solar</span> <span class="hlt">irradiance</span> distribution</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Ho, Clifford Kuofei; Khalsa, Siri Sahib Singh</p> <p>2017-08-01</p> <p>Described herein are technologies pertaining to computing the <span class="hlt">solar</span> <span class="hlt">irradiance</span> distribution on a surface of a receiver in a concentrating <span class="hlt">solar</span> power system or glint/glare emitted from a reflective entity. At least one camera captures images of the Sun and the entity of interest, wherein the images have pluralities of pixels having respective pluralities of intensity values. Based upon the intensity values of the pixels in the respective images, the <span class="hlt">solar</span> <span class="hlt">irradiance</span> distribution on the surface of the entity or glint/glare corresponding to the entity is computed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20020015528&hterms=solar+construct&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsolar%2Bconstruct','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20020015528&hterms=solar+construct&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsolar%2Bconstruct"><span>Ground-Based Correlates of <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> Variation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jones, Harrison P.</p> <p>2001-01-01</p> <p>Ground-based instruments cannot directly measure <span class="hlt">solar</span> <span class="hlt">irradiance</span> variability at the 0.1% level at which it occurs because of the earth's atmosphere. However, many forms of ground-based <span class="hlt">solar</span> observations correlate well with <span class="hlt">solar</span> <span class="hlt">irradiance</span> variations, and this fact has been used to construct facular-sunspot models which can explain about 90% of the variance of total <span class="hlt">solar</span> <span class="hlt">irradiance</span> as observed by spacecraft radiometers. It is not yet clear whether remaining discrepancies are observational or require additional sources in the model. This paper is a selective review of the current status of the use of ground-based data to understand spacecraft observations of <span class="hlt">solar</span> <span class="hlt">irradiance</span> and to apply this understanding to periods before space-based measurements were available. New results from the extension of the histogram analysis of NASA/NSO spectromagnetograph observations (Jones et al., 2000, ApJ529, 1070) to the period from Nov. 1992 to Sep. 2000 are reported which confirm that strong mixed polarity magnetic regions (quiet network) are not significantly correlated with total <span class="hlt">solar</span> <span class="hlt">irradiance</span> and which show an unexplained linear trend in the residuals of a multiple regression.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18046399','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18046399"><span>Little or no <span class="hlt">solar</span> <span class="hlt">wind</span> enters Venus' atmosphere at <span class="hlt">solar</span> minimum.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, T L; Delva, M; Baumjohann, W; Auster, H-U; Carr, C; Russell, C T; Barabash, S; Balikhin, M; Kudela, K; Berghofer, G; Biernat, H K; Lammer, H; Lichtenegger, H; Magnes, W; Nakamura, R; Schwingenschuh, K; Volwerk, M; Vörös, Z; Zambelli, W; Fornacon, K-H; Glassmeier, K-H; Richter, I; Balogh, A; Schwarzl, H; Pope, S A; Shi, J K; Wang, C; Motschmann, U; Lebreton, J-P</p> <p>2007-11-29</p> <p>Venus has no significant internal magnetic field, which allows the <span class="hlt">solar</span> <span class="hlt">wind</span> to interact directly with its atmosphere. A field is induced in this interaction, which partially shields the atmosphere, but we have no knowledge of how effective that shield is at <span class="hlt">solar</span> minimum. (Our current knowledge of the <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with Venus is derived from measurements at <span class="hlt">solar</span> maximum.) The bow shock is close to the planet, meaning that it is possible that some <span class="hlt">solar</span> <span class="hlt">wind</span> could be absorbed by the atmosphere and contribute to the evolution of the atmosphere. Here we report magnetic field measurements from the Venus Express spacecraft in the plasma environment surrounding Venus. The bow shock under low <span class="hlt">solar</span> activity conditions seems to be in the position that would be expected from a complete deflection by a magnetized ionosphere. Therefore little <span class="hlt">solar</span> <span class="hlt">wind</span> enters the Venus ionosphere even at <span class="hlt">solar</span> minimum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021391&hterms=balsiger&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbalsiger','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021391&hterms=balsiger&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbalsiger"><span>Iron charge states in the <span class="hlt">solar</span> <span class="hlt">wind</span> as measured by SMS on <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Galvin, A. B.; Cohen, C. M. S.; Ipavich, F. M.; Gloeckler, G.; Hamilton, D. C.; Chotoo, K.; Balsiger, H.; Sheldon, R.</p> <p>1995-01-01</p> <p>The <span class="hlt">Wind</span> spacecraft was launched in November 1994. In the first half of 1995 it was in the interplanetary medium upstream of the Earth. The <span class="hlt">Solar</span> <span class="hlt">Wind</span> and Suprathermal Ion Composition Experiment (SMS) on <span class="hlt">Wind</span> consists of three sensors, the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Ion Composition Spectrometer (SWICS), the Suprathermal Ion Composition Spectrometer (STICS), and the high mass resolution spectrometer (MASS). All three instruments utilize electrostatic deflection combined with time-of-flight measurement. The data from these three sensors allows the determination of the ionic composition of the <span class="hlt">solar</span> <span class="hlt">wind</span> in a variety of <span class="hlt">solar</span> <span class="hlt">wind</span> conditions over a large energy/charge range (0.5 to 230 keV/e). We have examined the <span class="hlt">Wind</span> database for time periods conducive to observing <span class="hlt">solar</span> <span class="hlt">wind</span> iron. With the high mass resolution of the MASS spectrometer (M/Delta-M greater than 100) iron is easily identified while the electrostatic deflection provides information concerning the mass/charge distribution. We present here the relative abundance of iron charge states in the <span class="hlt">solar</span> <span class="hlt">wind</span> near 1 AU.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021391&hterms=Bern&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DBern','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021391&hterms=Bern&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DBern"><span>Iron charge states in the <span class="hlt">solar</span> <span class="hlt">wind</span> as measured by SMS on <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Galvin, A. B.; Cohen, C. M. S.; Ipavich, F. M.; Gloeckler, G.; Hamilton, D. C.; Chotoo, K.; Balsiger, H.; Sheldon, R.</p> <p>1995-01-01</p> <p>The <span class="hlt">Wind</span> spacecraft was launched in November 1994. In the first half of 1995 it was in the interplanetary medium upstream of the Earth. The <span class="hlt">Solar</span> <span class="hlt">Wind</span> and Suprathermal Ion Composition Experiment (SMS) on <span class="hlt">Wind</span> consists of three sensors, the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Ion Composition Spectrometer (SWICS), the Suprathermal Ion Composition Spectrometer (STICS), and the high mass resolution spectrometer (MASS). All three instruments utilize electrostatic deflection combined with time-of-flight measurement. The data from these three sensors allows the determination of the ionic composition of the <span class="hlt">solar</span> <span class="hlt">wind</span> in a variety of <span class="hlt">solar</span> <span class="hlt">wind</span> conditions over a large energy/charge range (0.5 to 230 keV/e). We have examined the <span class="hlt">Wind</span> database for time periods conducive to observing <span class="hlt">solar</span> <span class="hlt">wind</span> iron. With the high mass resolution of the MASS spectrometer (M/Delta-M greater than 100) iron is easily identified while the electrostatic deflection provides information concerning the mass/charge distribution. We present here the relative abundance of iron charge states in the <span class="hlt">solar</span> <span class="hlt">wind</span> near 1 AU.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRA..122.2973B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRA..122.2973B"><span>Substorm occurrence rates, substorm recurrence times, and <span class="hlt">solar</span> <span class="hlt">wind</span> structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Borovsky, Joseph E.; Yakymenko, Kateryna</p> <p>2017-03-01</p> <p>Two collections of substorms are created: 28,464 substorms identified with jumps in the SuperMAG AL index in the years 1979-2015 and 16,025 substorms identified with electron injections into geosynchronous orbit in the years 1989-2007. Substorm occurrence rates and substorm recurrence-time distributions are examined as functions of the phase of the <span class="hlt">solar</span> cycle, the season of the year, the Russell-McPherron favorability, the type of <span class="hlt">solar</span> <span class="hlt">wind</span> plasma at Earth, the geomagnetic-activity level, and as functions of various <span class="hlt">solar</span> and <span class="hlt">solar</span> <span class="hlt">wind</span> properties. Three populations of substorm occurrences are seen: (1) quasiperiodically occurring substorms with recurrence times (waiting times) of 2-4 h, (2) randomly occurring substorms with recurrence times of about 6-15 h, and (3) long intervals wherein no substorms occur. A working model is suggested wherein (1) the period of periodic substorms is set by the magnetosphere with variations in the actual recurrence times caused by the need for a <span class="hlt">solar</span> <span class="hlt">wind</span> driving interval to occur, (2) the mesoscale structure of the <span class="hlt">solar</span> <span class="hlt">wind</span> magnetic field triggers the occurrence of the random substorms, and (3) the large-scale structure of the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma is responsible for the long intervals wherein no substorms occur. Statistically, the recurrence period of periodically occurring substorms is slightly shorter when the ram pressure of the <span class="hlt">solar</span> <span class="hlt">wind</span> is high, when the magnetic field strength of the <span class="hlt">solar</span> <span class="hlt">wind</span> is strong, when the Mach number of the <span class="hlt">solar</span> <span class="hlt">wind</span> is low, and when the polar-cap potential saturation parameter is high.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.3488D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.3488D"><span>Analysis of satellite-derived <span class="hlt">solar</span> <span class="hlt">irradiance</span> over the Netherlands</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dirksen, Marieke; Fokke Meirink, Jan; Sluiter, Raymond</p> <p>2017-04-01</p> <p>Measurements from geostationary satellites allow the retrieval of surface <span class="hlt">solar</span> <span class="hlt">irradiance</span> homogeneously over large areas, thereby providing essential information for the <span class="hlt">solar</span> energy sector. In this paper, the SICCS <span class="hlt">solar</span> <span class="hlt">irradiance</span> data record derived from 12 years of Meteosat Second Generation satellite measurements is analysed with a focus on the Netherlands, where the spatial resolution is about 6 by 3 km2. Extensive validation of the SICCS data with pyranometer observations is performed, indicating a bias of approximately 3 W/m2 and RMSE of 11 W/m2 for daily data. Long term averages and seasonal variations of <span class="hlt">solar</span> <span class="hlt">irradiance</span> show regional patterns related to the surface type (e.g., coastal waters, forests, cities). The inter-annual variability over the time frame of the data record is quantified. Methods to merge satellite and surface observations into an optimized data record are explored.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IAUS..320..333T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IAUS..320..333T"><span>Temporal <span class="hlt">solar</span> <span class="hlt">irradiance</span> variability analysis using neural networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tebabal, Ambelu; Damtie, Baylie; Nigussie, Melessew</p> <p></p> <p>A feed-forward neural network which can account for nonlinear relationship was used to model total <span class="hlt">solar</span> <span class="hlt">irradiance</span> (TSI). A single layer feed-forward neural network with Levenberg-marquardt back-propagation algorithm have been implemented for modeling daily total <span class="hlt">solar</span> <span class="hlt">irradiance</span> from daily photometric sunspot index, and core-to-wing ratio of Mg II index data. In order to obtain the optimum neural network for TSI modeling, the root mean square error (RMSE) and mean absolute error (MAE) have been taken into account. The modeled and measured TSI have the correlation coefficient of about R=0.97. The neural networks (NNs) model output indicates that reconstructed TSI from <span class="hlt">solar</span> proxies (photometric sunspot index and Mg II) can explain 94% of the variance of TSI. This modeled TSI using NNs further strengthens the view that surface magnetism indeed plays a dominant role in modulating <span class="hlt">solar</span> <span class="hlt">irradiance</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996KosIs..34..451M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996KosIs..34..451M"><span>Multifractal properties of <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence: theory and observations.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Milovanov, A. V.; Avanov, L. A.; Zastenker, G. N.; Zelenyj, L. M.</p> <p>1996-10-01</p> <p>A fractal model of the <span class="hlt">solar</span> <span class="hlt">wind</span> is presented. This model treats fluctuations of the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity from the viewpoint of nonlinear processes originating in the convective region and photosphere of the Sun. The multifractal structure of proton velocity fluctuations in a region of heliocentric distances from 0.2 to 0.8 AU is a result of these processes. Continuous measurements of <span class="hlt">solar</span> <span class="hlt">wind</span> velocity aboard the ISEE-3 spacecraft during one month were used to compare the theoretical and experimental results. It is shown that fluctuations of proton velocity have a multifractal structure in a frequency range of 10-5 - 10-3Hz.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920048629&hterms=tutorial&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dtutorial','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920048629&hterms=tutorial&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dtutorial"><span>The <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with unmagnetized planets - A tutorial</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Luhmann, J. G.</p> <p>1990-01-01</p> <p>The interaction of the <span class="hlt">solar</span> <span class="hlt">wind</span> with the Venus ionosphere induces currents which can substantially exclude the <span class="hlt">solar</span> <span class="hlt">wind</span> and IMF from the dayside ionosphere beneath the 'ionopause', where ionosphere thermal pressure equals incident <span class="hlt">solar</span> <span class="hlt">wind</span> dynamic pressure. The field then diffuses through the ionopause with increasing speed at decreasing altitudes, and is weakest in the subpolar region. Once within the ionopause, the magnetic field is redistributed by ionospheric convection, and then decays at low altitudes via collisional dissipation of the associated currents. The maximum ionospheric field magnitudes observed, of about 150 nT, furnish magnetic pressures exceeding the ionospheric thermal pressure by a factor of about 3.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.1715M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.1715M"><span><span class="hlt">Solar</span> <span class="hlt">wind</span>, radiation belt electrons and atmospheric vorticity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mironova, Irina; Tinsley, Brian; Zhou, Limin</p> <p></p> <p>The association of atmospheric vorticity changes with <span class="hlt">solar</span> <span class="hlt">wind</span> sector structure explored by John Wilcox and Walter Orr Roberts in the 1970s is examined in terms of the sector related minima in <span class="hlt">solar</span> <span class="hlt">wind</span> speed, and associated minima in relativistic electron precipitation from the outer radiation belt. Stronger correlations of atmospheric vorticity with the relativistic electron flux are found than with either <span class="hlt">solar</span> <span class="hlt">wind</span> speed or the passage of magnetic sector boundaries over the Earth. This is consistent with changes in the ionosphere-earth current density affecting cloud microphysics, with the ionization from the Bremsstrahlung X-rays from the relativistic electron precipitation increasing the conductivity of the stratosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19830016174','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830016174"><span>The relationship between Saturn kilometric radiation and the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Desch, M. D.; Rucker, H. O.</p> <p>1983-01-01</p> <p>Voyager spacecraft radio, interplanetary plasma, and interplanetary magnetic field data are used to show that large amplitude fluctuations in the power generated by the Saturn kilometric radio emission are best correlated with <span class="hlt">solar</span> <span class="hlt">wind</span> ram pressure variation. In all, thirteen <span class="hlt">solar</span> <span class="hlt">wind</span> quantities previously found important in driving terrestrial magnetospheric substorms and other auroral processes were examined for evidence of correlations with the Saturn radio emission. The results are consistent with hydromagnetic wave or eddy diffusion processes driven by large scale <span class="hlt">solar</span> <span class="hlt">wind</span> pressure changes at Saturn's dayside magnetopause.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890052693&hterms=Hom&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DHom','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890052693&hterms=Hom&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DHom"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> control of Jupiter's hectometric radio emission</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Barrow, C. H.; Desch, M. D.</p> <p>1989-01-01</p> <p>Radio, plasma, and magnetic field data obtained by Voyager 1 and Voyager 2 were used to examine the manner in which the Jovian hectometric radio emission (HOM) is controlled by the <span class="hlt">solar</span> <span class="hlt">wind</span>. Using the method of superposed epochs, it was found that the higher energy HOM is correlated with the IMF as well as with the <span class="hlt">solar</span> <span class="hlt">wind</span> density and pressure. However, unlike the Io-independent decametric radio emission (Non-Io DAM), the HOM displayed no correlation with the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity, although this radio component appear to be also influenced by the IMF. The results suggest separate HOM amd Non-Io DAM sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21394380','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21394380"><span>MEASUREMENTS OF RAPID DENSITY FLUCTUATIONS IN THE <span class="hlt">SOLAR</span> <span class="hlt">WIND</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Malaspina, D. M.; Ergun, R. E.; Kellogg, P. J.; Bale, S. D.</p> <p>2010-03-01</p> <p>The power spectrum of density fluctuations in the <span class="hlt">solar</span> <span class="hlt">wind</span> is inferred by tracking small timescale changes in the electron plasma frequency during periods of strong Langmuir wave activity. STEREO electric field waveform data are used to produce time profiles of plasma density from which the density power spectrum is derived. The power spectra obtained by this method extend the observed frequency range by an order of magnitude while remaining consistent with previous results near a few Hertz. Density power spectral indices are found to be organized by the angle between the local magnetic field and the <span class="hlt">solar</span> <span class="hlt">wind</span> direction, indicating significant anisotropy in <span class="hlt">solar</span> <span class="hlt">wind</span> high-frequency density turbulence.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008EOSTr..89..212C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008EOSTr..89..212C"><span>Mars: A Richly Complicated Obstacle to the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Crider, Dana H.; Brain, David A.; Lundin, Rickard</p> <p>2008-06-01</p> <p>Chapman Conference on the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Interaction With Mars; San Diego, California, 22-25 January 2008; Although studies of the <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with Mars (SWIM) date back to the mid-1960s, whether Mars possessed a global magnetic field remained uncertain until 1997. We now know that Mars lacks a measurable dynamo; however, it has intense, localized regions of magnetization tied to its crust. With this patchy magnetic field, the <span class="hlt">solar</span> <span class="hlt">wind</span> interacts directly with the upper atmosphere of Mars, driving structural and compositional variations and providing energy for atmospheric escape to space. These processes may have played an important role in the long-term evolution of the Martian climate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1914825O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1914825O"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> parameteres and disturbances in STEREO view</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Opitz, Andrea</p> <p>2017-04-01</p> <p>The twin STEREO spacecraft provided two vantage point <span class="hlt">solar</span> <span class="hlt">wind</span> observations between 2007 and 2014. Instrumentation of the STEREO A and B spacecraft is very nearly identical, hence their measurements are easily comparable. These measurements are visualised and treated with different methods in order to obtain a global view of the in-ecliptic background <span class="hlt">solar</span> <span class="hlt">wind</span> and the disturbances such as CIRs and CMEs. Comparison of the two datasets and exclusion of spatial effects provides information on the in-ecliptic <span class="hlt">solar</span> <span class="hlt">wind</span> structure in the inner heliosphere. These methods and results will be revised in this paper.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920063558&hterms=born+out&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dborn%2Bout','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920063558&hterms=born+out&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dborn%2Bout"><span>Charge-exchange born He(+) ions in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gruntman, Michael A.</p> <p>1992-01-01</p> <p>The effect of charge transfer between <span class="hlt">solar</span> <span class="hlt">wind</span> alpha-particles and hydrogen atoms of interstellar origin is revisited. Singly-charged helium ions born in the charge transfer carry important information on processes in the <span class="hlt">solar</span> <span class="hlt">wind</span> and the heliosphere. The velocity distribution of such He(+) ions is substantially different from that of He(+) pick-up ions due to ionization of the interstellar helium atoms. Estimates of the expected abundances of the charge-exchange born He(+) in the <span class="hlt">solar</span> <span class="hlt">wind</span> are presented, and the possibility of measuring this plasma component on deep space missions is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6517833','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6517833"><span><span class="hlt">Wind</span> loading on <span class="hlt">solar</span> concentrators: some general considerations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Roschke, E. J.</p> <p>1984-05-01</p> <p>A survey has been completed to examine the problems and complications arising from <span class="hlt">wind</span> loading on <span class="hlt">solar</span> concentrators. <span class="hlt">Wind</span> loading is site specific and has an important bearing on the design, cost, performance, operation and maintenance, safety, survival, and replacement of <span class="hlt">solar</span> collecting systems. Emphasis herein is on paraboloidal, two-axis tracking systems. Thermal receiver problems also are discussed. <span class="hlt">Wind</span> characteristics are discussed from a general point of view; current methods for determining design <span class="hlt">wind</span> speed are reviewed. Aerodynamic coefficients are defined and illustrative examples are presented. <span class="hlt">Wind</span> tunnel testing is discussed, and environmental <span class="hlt">wind</span> tunnels are reviewed; recent results on heliostat arrays are reviewed as well. Aeroelasticity in relation to structural design is discussed briefly. <span class="hlt">Wind</span> loads, i.e., forces and moments, are proportional to the square of the mean <span class="hlt">wind</span> velocity. Forces are proportional to the square of concentrator diameter, and moments are proportional to the cube of diameter. Thus, <span class="hlt">wind</span> loads have an important bearing on size selection from both cost and performance standpoints. It is concluded that sufficient information exists so that reasonably accurate predictions of <span class="hlt">wind</span> loading are possible for a given paraboloidal concentrator configuration, provided that reliable and relevant <span class="hlt">wind</span> conditions are specified. Such predictions will be useful to the design engineer and to the systems engineer as well. Information is lacking, however, on <span class="hlt">wind</span> effects in field arrays of paraboloidal concentrators. <span class="hlt">Wind</span> tunnel tests have been performed on model heliostat arrays, but there are important aerodynamic differences between heliostats and paraboloidal dishes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MS%26E...78a2042T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MS%26E...78a2042T"><span>The Feasibility of <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Energy Application for Oil and Gas Offshore Platform</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tiong, Y. K.; Zahari, M. A.; Wong, S. F.; Dol, S. S.</p> <p>2015-04-01</p> <p>Renewable energy is an energy which is freely available in nature such as <span class="hlt">winds</span> and <span class="hlt">solar</span> energy. It plays a critical role in greening the energy sector as these sources of energy produce little or no pollution to environment. This paper will focus on capability of renewable energy (<span class="hlt">wind</span> and <span class="hlt">solar</span>) in generating power for offshore application. Data of <span class="hlt">wind</span> speeds and <span class="hlt">solar</span> <span class="hlt">irradiation</span> that are available around SHELL Sabah Water Platform for every 10 minutes, 24 hours a day, for a period of one year are provided by SHELL Sarawak Sdn. Bhd. The suitable <span class="hlt">wind</span> turbine and photovoltaic panel that are able to give a high output and higher reliability during operation period are selected by using the tabulated data. The highest power output generated using single <span class="hlt">wind</span> energy application is equal to 492 kW while for <span class="hlt">solar</span> energy application is equal to 20 kW. Using the calculated data, the feasibility of renewable energy is then determined based on the platform energy demand.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AIPC.1539...94Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AIPC.1539...94Z"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> proton flux extremes and their association with pseudostreamers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, Liang; Gibson, Sarah E.; Fisk, Lennard A.</p> <p>2013-06-01</p> <p>Proton flux, as defined by the product of proton number density and proton speed, while exhibiting remarkable constancy across heliographic latitudes from pole to equator as measured by the Ulysses spacecraft, nevertheless showed obvious departure from this constancy for some mid-latitude <span class="hlt">wind</span> and extended to high heliomagnetic latitudes during the recent two <span class="hlt">solar</span> minima. We examine the <span class="hlt">solar</span> <span class="hlt">wind</span> exclusive of ICMEs from Ulysses and ACE observations, to analyze the <span class="hlt">solar</span> <span class="hlt">wind</span> in-situ data exhibiting extremes in proton flux. We first find these extreme-proton-flux <span class="hlt">winds</span> generally originate in latitudes middle-distant from the heliospheric current sheet (HCS), and they have relatively slower speed than the bulk of the <span class="hlt">solar</span> <span class="hlt">wind</span>. Then we map the in-situ ACE observations in Carrington rotation (CR) 1997 back to the <span class="hlt">solar</span> surface by using the Potential-Field-Source-Surface (PFSS) model, in order to consider the coronal properties at the extreme-proton-flux <span class="hlt">wind</span> sources. We find there is a clear association between these extreme-proton-flux <span class="hlt">solar</span> <span class="hlt">wind</span> and the mid-latitude coronal holes and "pseudostreamer" structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSM41D2461N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSM41D2461N"><span>Diamagnetic effect in the foremoon <span class="hlt">solar</span> <span class="hlt">wind</span> observed by Kaguya</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nishino, M. N.; Saito, Y.; Tsunakawa, H.; Miyake, Y.; Harada, Y.; Yokota, S.; Takahashi, F.; Matsushima, M.; Shibuya, H.; Shimizu, H.</p> <p>2016-12-01</p> <p>Interaction between the lunar surface and incident <span class="hlt">solar</span> <span class="hlt">wind</span> is one of the crucial phenomena of the lunar plasma sciences. Recent observations by lunar orbiters revealed that strength of the interplanetary magnetic field (IMF) at spacecraft altitude increases over crustal magnetic fields on the dayside. In addition, variations of the IMF on the lunar night side have been reported in the viewpoint of diamagnetic effect around the lunar wake. However, few studies have been performed for the IMF over non-magnetized regions on the dayside. Here we show an event where strength of the IMF decreases at 100 km altitude on the lunar dayside (i.e. in the foremoon <span class="hlt">solar</span> <span class="hlt">wind</span>) when the IMF is almost parallel to the incident <span class="hlt">solar</span> <span class="hlt">wind</span> flow, comparing the upstream <span class="hlt">solar</span> <span class="hlt">wind</span> data from ACE and <span class="hlt">WIND</span> with Kaguya magnetometer data. The lunar surface below the Kaguya orbit is not magnetized (or very weakly magnetized), and the sunward-travelling protons show signatures of those back-scattered at the lunar surface. We find that the decrease in the magnetic pressure is compensated by the thermal pressure of the back-scattered protons. In other words, the IMF strength in the foremoon <span class="hlt">solar</span> <span class="hlt">wind</span> decreases by diamagnetic effect of sunward-travelling protons back-scattered at the lunar dayside surface. Such diamagnetic effect would be prominent in the high-beta <span class="hlt">solar</span> <span class="hlt">wind</span> environment, and may be ubiquitous in the environment where planetary surface directly interacts with surrounding space plasma.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1510078M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1510078M"><span>Ionospheric mid-latitude response to <span class="hlt">solar</span> <span class="hlt">wind</span> discontinuities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Munteanu, Costel; Mosna, Zbysek; Kouba, Daniel; Echim, Marius</p> <p>2013-04-01</p> <p>We have compiled a database of 356 discontinuities detected by both the Advanced Composition Explorer ACE) and Cluster satellites in the <span class="hlt">solar</span> <span class="hlt">wind</span> between 2001-2012 and analyzed their ionospheric response. Each discontinuity of the data base is defined by a change of at least 5 nT in less than 5 min in one or more components of the interplanetary magnetic field (IMF). The discontinuities are observed in January-April every year, when Cluster enters the <span class="hlt">solar</span> <span class="hlt">wind</span>. The ionospheric effects of <span class="hlt">solar</span> <span class="hlt">wind</span> discontinuities are investigated by checking the variations of critical frequencies foF2, the heights of the F layer and the ionospheric plasma dynamics recorded using ground measurement with a time resolution of 15 minutes from mid-latitude digisondes located in Czech Republic. The time delay between <span class="hlt">solar</span> <span class="hlt">wind</span> input and the ionospheric response is analyzed using the characteristics and the shape of the ionograms. The geoeffectiveness of the <span class="hlt">solar</span> <span class="hlt">wind</span> discontinuities is expressed as correlation between key plasma parameters (e,g, the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity, magnetic jump across the discontinuity) and the ionospheric variations. <span class="hlt">Solar</span> cycle effects are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSA13D..08C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSA13D..08C"><span>Predicting Inner Heliospheric <span class="hlt">Solar</span> <span class="hlt">Wind</span> Conditions in Advance of <span class="hlt">Solar</span> Probe Plus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Case, A. W.; Kasper, J. C.; Korreck, K. E.; Stevens, M. L.; Cohen, O.; Salem, C. S.; Halekas, J. S.; Larson, D. E.; Maruca, B. A.</p> <p>2012-12-01</p> <p>In advance of the upcoming inner heliospheric missions (<span class="hlt">Solar</span> Orbiter and <span class="hlt">Solar</span> Probe Plus) it is vital to have an accurate prediction of the range of <span class="hlt">solar</span> <span class="hlt">wind</span> conditions that occur between 9.5Rs and 0.7AU. These conditions will place constraints on instrument design and the operational modes that are used. In this paper, we discuss and compare different methods of predicting the <span class="hlt">solar</span> <span class="hlt">wind</span> bulk plasma parameters. One method uses observed 1AU conditions observed with the <span class="hlt">Wind</span> spacecraft combined with scaling laws derived from Helios observations. We extend this simple model by using a more realistic <span class="hlt">solar</span> <span class="hlt">wind</span> velocity profile in addition to the <span class="hlt">Wind</span> and Helios observations. Another method uses 3D MHD simulations from which <span class="hlt">solar</span> <span class="hlt">wind</span> conditions along a spacecraft trajectory can be extracted. We discuss some implications of these models in the design of the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Electrons Alphas and Protons investigation, a suite of <span class="hlt">solar</span> <span class="hlt">wind</span> instruments being designed to fly on <span class="hlt">Solar</span> Probe Plus.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19830002737','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830002737"><span>Stationarity of magnetohydrodynamic fluctuations in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Matthaeus, W. H.; Goldstein, M. L.</p> <p>1982-01-01</p> <p><span class="hlt">Solar</span> <span class="hlt">wind</span> research and studies of charged particle propagation often assume that the interplanetary magnetic field represents a stationary random process. The extent to which ensemble averages of the <span class="hlt">solar</span> <span class="hlt">wind</span> magnetic fields follow the asymptotic behavior predicted by the ergodic theorem was investigated. Several time periods, including a span of nearly two years, are analyzed. Data intervals which span many <span class="hlt">solar</span> rotations satisfy the conditions of weak stationarity if the effects of <span class="hlt">solar</span> rotation are included in the asymptotic analysis. Shorter intervals which include a small integral number of interplanetary sectors also satisfy weak stationarity. The results are illustrated using magnetometer data from the ISEE-3, Voyager and IMP spacecraft.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMIN12A..08W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMIN12A..08W"><span>LISIRD: Where to go for <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wilson, A.; Pankratz, C. K.; Lindholm, D. M.; Snow, M.; Knapp, B.; Woodraska, D.; Templeman, B.; Woods, T.; Eparvier, F.; Fontenla, J.; Harder, J.; Bill, M.</p> <p>2008-12-01</p> <p>LASP, the Laboratory for Atmospheric and Space Physics, has been providing web access to <span class="hlt">solar</span> <span class="hlt">irradiance</span> measurements, reference spectra, composites and model data covering the <span class="hlt">solar</span> spectrum from .1 to 2400 nm through LISIRD, the LASP Interactive <span class="hlt">Solar</span> <span class="hlt">IRradiance</span> Datacenter. No single instrument can measure the <span class="hlt">solar</span> spectral <span class="hlt">irradiance</span> from X-rays to the IR, but the ensemble of LASP instruments can. LISIRD uses a single interface to provide easy, logical access to a variety of mission data, merged in time and wavelength. Daily space weather measurements are available, including total <span class="hlt">solar</span> <span class="hlt">irradiance</span> (TSI), Lyman Alpha (121 nm), Magnesium II Index (280 nm), He II (30.4 nm), FE XVI (33.5 nm), and the FUV continuum (145 to 165 nm). More recently, LISIRD has recently added the Whole Heliosphere Interval (WHI) <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> time series, which provides a quiet sun reference spectra for the period of April 10-16 of 2008. LISIRD also recently added a composite <span class="hlt">solar</span> spectral <span class="hlt">irradiance</span> product over the range of 120 to 400 nm for the time period from November 8, 1978 to August 1, 2005. This product, created by Mathew Deland at SSAI, merges data from six different satellites into a single SSI product. And, we are currently adding a time series for daily <span class="hlt">solar</span> spectral <span class="hlt">irradiance</span> from 1950 to 2006, created by Judith Lean of the Naval Research Lab. This product adjusts observed <span class="hlt">irradiance</span> for a given wavelength with parameters that represent known sources of variability at that wavelength. LISIRD remains committed to improving data access in a variety of ways. We are planning and developing a means for the broader community of scientists to easily determine data availability for a particular date range without having to know mission or instrument details. Improved data subsetting will allow users to request only the time range or spectra that users need, making data management generally easier. We expect to continue to enhance our data offerings. Future vision for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010089646&hterms=Principal&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DPrincipal','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010089646&hterms=Principal&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DPrincipal"><span>Principal Component Analysis of Arctic <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> Spectra</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rabbette, Maura; Pilewskie, Peter; Gore, Warren J. (Technical Monitor)</p> <p>2000-01-01</p> <p>During the FIRE (First ISCPP Regional Experiment) Arctic Cloud Experiment and coincident SHEBA (Surface Heat Budget of the Arctic Ocean) campaign, detailed moderate resolution <span class="hlt">solar</span> spectral measurements were made to study the radiative energy budget of the coupled Arctic Ocean - Atmosphere system. The NASA Ames <span class="hlt">Solar</span> Spectral Flux Radiometers (SSFRs) were deployed on the NASA ER-2 and at the SHEBA ice camp. Using the SSFRs we acquired continuous <span class="hlt">solar</span> spectral <span class="hlt">irradiance</span> (380-2200 nm) throughout the atmospheric column. Principal Component Analysis (PCA) was used to characterize the several tens of thousands of retrieved SSFR spectra and to determine the number of independent pieces of information that exist in the visible to near-infrared <span class="hlt">solar</span> <span class="hlt">irradiance</span> spectra. It was found in both the upwelling and downwelling cases that almost 100% of the spectral information (<span class="hlt">irradiance</span> retrieved from 1820 wavelength channels) was contained in the first six extracted principal components. The majority of the variability in the Arctic downwelling <span class="hlt">solar</span> <span class="hlt">irradiance</span> spectra was explained by a few fundamental components including infrared absorption, scattering, water vapor and ozone. PCA analysis of the SSFR upwelling Arctic <span class="hlt">irradiance</span> spectra successfully separated surface ice and snow reflection from overlying cloud into distinct components.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010089646&hterms=arctic+ocean&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Darctic%2Bocean','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010089646&hterms=arctic+ocean&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Darctic%2Bocean"><span>Principal Component Analysis of Arctic <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> Spectra</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rabbette, Maura; Pilewskie, Peter; Gore, Warren J. (Technical Monitor)</p> <p>2000-01-01</p> <p>During the FIRE (First ISCPP Regional Experiment) Arctic Cloud Experiment and coincident SHEBA (Surface Heat Budget of the Arctic Ocean) campaign, detailed moderate resolution <span class="hlt">solar</span> spectral measurements were made to study the radiative energy budget of the coupled Arctic Ocean - Atmosphere system. The NASA Ames <span class="hlt">Solar</span> Spectral Flux Radiometers (SSFRs) were deployed on the NASA ER-2 and at the SHEBA ice camp. Using the SSFRs we acquired continuous <span class="hlt">solar</span> spectral <span class="hlt">irradiance</span> (380-2200 nm) throughout the atmospheric column. Principal Component Analysis (PCA) was used to characterize the several tens of thousands of retrieved SSFR spectra and to determine the number of independent pieces of information that exist in the visible to near-infrared <span class="hlt">solar</span> <span class="hlt">irradiance</span> spectra. It was found in both the upwelling and downwelling cases that almost 100% of the spectral information (<span class="hlt">irradiance</span> retrieved from 1820 wavelength channels) was contained in the first six extracted principal components. The majority of the variability in the Arctic downwelling <span class="hlt">solar</span> <span class="hlt">irradiance</span> spectra was explained by a few fundamental components including infrared absorption, scattering, water vapor and ozone. PCA analysis of the SSFR upwelling Arctic <span class="hlt">irradiance</span> spectra successfully separated surface ice and snow reflection from overlying cloud into distinct components.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870007250&hterms=technologie&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dtechnologie','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870007250&hterms=technologie&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dtechnologie"><span><span class="hlt">Solar</span> <span class="hlt">wind</span>-plasma interaction: The AMPTE <span class="hlt">solar</span> <span class="hlt">wind</span> plasma releases</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1986-01-01</p> <p>In situ measurements during AMPTE <span class="hlt">solar</span> <span class="hlt">wind</span> ion releases are described. The creation of a diamagnetic cavity, compression and draping of magnetic field lines, recoil of the entire artificial comet, and ion beam and tail formation are discussed. The wave measurements were used to determine the time variation of the plasma density from the measurement of the electron plasma frequency and to determine the state of cloud expansion and cavity formation. Features found include absence of strong turbulence and anomalous diffusion in the cavity boundary, and the appearance of very intense shock-like emission in front of the plasma clouds. The first effect suggests partially unknowm processes leading to magnetic field penetration into the region of the clouds. The direct observation of the interaction processes between the fast streaming <span class="hlt">solar</span> <span class="hlt">wind</span> plasma and the expanding cloud plasma of the Li and artificial comet releases may have relevance to astrophysical situations as, for instance, encountered in <span class="hlt">solar</span> flares, interstellar clouds, or during accretion of matter onto compact objects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/112936','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/112936"><span>He abundance variations in the <span class="hlt">solar</span> <span class="hlt">wind</span>: Observations from Ulysses</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Barraclough, B.L.; Gosling, J.T.; Phillips, J.L.; McComas, D.J.; Feldman, W.C.; Goldstein, B.E.</p> <p>1995-09-01</p> <p>The Ulysses mission is providing the first opportunity to observe variations in <span class="hlt">solar</span> <span class="hlt">wind</span> plasma parameters at heliographic latitudes far removed from the ecliptic plane. We present an overview of the <span class="hlt">solar</span> <span class="hlt">wind</span> speed and the variability in helium abundance, [He] data on [He] in six high latitude coronal mass ejections (CMEs), and a superposed epoch analysis of [He] variations at the seven heliospheric current sheet (HCS) crossings made during the rapid-latitude-scan portion of the mission. The differences in the variability of the <span class="hlt">solar</span> <span class="hlt">wind</span> speed and [He] in high latitude and equatorial regions are quite striking. <span class="hlt">Solar</span> <span class="hlt">wind</span> speed is generally low but highly variable near the <span class="hlt">solar</span> equator, while at higher latitudes the average speed is quite high with little variability. [He] can vary over nearly two decades at low <span class="hlt">solar</span> latitudes, while at high latitudes it varies only slightly. In contrast to the high [He] that is commonly associated with CMEs observed in the ecliptic, none of the six high-speed CMEs encountered at high southern heliographic latitudes showed any significant variation in helium content. A superposed epoch analysis of the [He] during all seven HCS crossings made as Ulysses passed from the southern to northern <span class="hlt">solar</span> hemisphere shows the expected [He] minimum near the crossing and a broad region of low [He] around the crossing time. We discuss how our <span class="hlt">solar</span> <span class="hlt">wind</span> [He] observations may provide an accurate measure of the helium composition for the entire convective zone of the Sun.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1914406T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1914406T"><span>Alfvénic <span class="hlt">solar</span> <span class="hlt">wind</span> powers substorms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tanskanen, Eija; Hynönen, Reko; Mursula, Kalevi</p> <p>2017-04-01</p> <p>Alfvenic <span class="hlt">solar</span> <span class="hlt">wind</span> fluctuations (ALFs) are known to modulate geomagnetic activity. We have examined high-latitude geomagnetic activity over the <span class="hlt">solar</span> cycle 23 and found out that increase of <span class="hlt">solar</span> <span class="hlt">wind</span> Alfvenicity enhance both auroral substorm intensity and substorm frequency. Alfvénic <span class="hlt">solar</span> <span class="hlt">wind</span> fluctuations are found throughout the <span class="hlt">solar</span> cycle, but they are fastest, most frequent and geo-effective in the declining phase of the cycle, when the number of high-speed streams at the Earth's vicinity increases rapidly. We find a rapid transition from the predominance of slow (< 400 km/s) ALFs in 2002 to fast (> 600 km/s) ALFs in 2003, in coincidence with the rapid increase of substorm activity from late 2002 to early 2003. The Alfvénicity of <span class="hlt">solar</span> <span class="hlt">wind</span> increased by 40% from 2002 to 2003. After the transition the fast ALFs occur twice per <span class="hlt">solar</span> rotation while in previous year only four fast ALF intervals were detected. Increase of <span class="hlt">solar</span> <span class="hlt">wind</span> Alfvénicity by 40% from 2002 to 2003, and transition from slow to fast Alfvén fluctuations coincide with the increase of auroral substorm intensity by 28% and substorm frequency by 43%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM23A2231O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM23A2231O"><span>Effects of the Dayside Ionospheric Conductance on <span class="hlt">Solar</span> <span class="hlt">Wind</span>-Magnetosphere-Ionosphere Coupling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ohtani, S.; Wing, S.; Merkin, V. G.; Higuchi, T.</p> <p>2013-12-01</p> <p>In the present study we seek to observationally address the role of ionospheric conductance in the <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere coupling in terms of global field-aligned currents (FACs). <span class="hlt">Solar</span> EUV <span class="hlt">irradiance</span> changes during a <span class="hlt">solar</span> cycle, and so does its contribution to the ionospheric conductance. We statistically examine how, for fixed ranges of external driver, the intensities of the R1 and R2 currents and their demarcation latitude depend on <span class="hlt">solar</span> activity (F10.7). An emphasis is placed on night-side FACs in the dark hemisphere. The result shows that under fixed external conditions, the night-side FACs are more intense for higher <span class="hlt">solar</span> activity irrespective of their polarities or local time. It is also found that the overall FAC system, therefore the auroral oval, moves equatorward as the <span class="hlt">solar</span> activity increases. For both current intensity and latitude, the dependence on <span class="hlt">solar</span> activity is more sensitive for smaller values of F10.7 and it becomes more gradual with increasing F10.7. The intensities of dayside FACs reveal similar F10.7 dependence as expected from the enhancement of the local ionospheric conductance. Interestingly, they also move equatorward with increasing <span class="hlt">solar</span> activity. We suggest that as the dayside R1 current becomes more intense with increasing <span class="hlt">solar</span> activity, the magnetosphere shrinks on the day side and expands on the night side. This configurational change of the magnetosphere is considered to affect the energy transport from the <span class="hlt">solar</span> <span class="hlt">wind</span> to the magnetosphere, although the details still remain to be understood. We conclude that the ionospheric conductance actively affects the <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere-ionosphere coupling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1094889','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1094889"><span>Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study Phase 2 (Fact Sheet)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Not Available</p> <p>2013-09-01</p> <p>This is one-page, two-sided fact sheet presents high-level summary results of the Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study Phase 2, which examined operational impacts of high penetrations of variable renewable generation in the West.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060041718&hterms=ubiquitous&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dubiquitous','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060041718&hterms=ubiquitous&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dubiquitous"><span>Origins of the Slow and the Ubiquitous Fast <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Korendyke, Noci C.; Habbal, S. R.</p> <p>1997-01-01</p> <p>We present in this letter the first coordinated radio occultation measurements and ultraviolet observations of the inner corona below 5.5 Rs, obtained during the Galileo <span class="hlt">solar</span> conjunction in January 1997, to establish the origin of the slow <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA19719.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA19719.html"><span>Artist Concept of the Interaction of the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2015-07-17</p> <p>Artist concept of the interaction of the <span class="hlt">solar</span> <span class="hlt">wind</span> the supersonic outflow of electrically charged particles from the Sun with Pluto predominantly nitrogen atmosphere based on NASA New Horizons SWAP instrument.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890054328&hterms=electrodynamics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Delectrodynamics','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890054328&hterms=electrodynamics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Delectrodynamics"><span>Electrodynamics of <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere-ionosphere interactions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kan, Joseph R.; Akasofu, Syun-Ichi</p> <p>1989-01-01</p> <p>The paper presents a coherent picture of fundamental physical processes in three basic elements of the <span class="hlt">solar-wind</span>/magnetosphere/ionosphere coupling system: (1) the field-aligned potential structure which leads to the formation of auroral arcs, (2) the magnetosphere-ionosphere coupling which leads to the onset of magnetospheric substorms, and (3) the <span class="hlt">solar-wind</span>/magnetosphere dynamo which supplies the power driving various magnetospheric processes. Process (1) is forced into existence by the loss-cone constriction effect when the upward field-aligned current density exceeds the loss-cone thermal flux limit. Substorm onset occurs when the ionosphere responds fully to the enhanced magnetospheric convection driven by the <span class="hlt">solar</span> <span class="hlt">wind</span>. Energy is transferred from the <span class="hlt">solar</span> <span class="hlt">wind</span> to the magnetosphere by a dynamo process, primarily on open field lines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMSM13B1604C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMSM13B1604C"><span>Relationship between the sawtooth period and <span class="hlt">solar</span> <span class="hlt">wind</span> drivers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cai, X.; Clauer, C. R.; Weimer, D. R.</p> <p>2009-12-01</p> <p>Cai and Clauer [2009] shows the mean period of sawtooth events has a large variability from 2 to 4 hours, with a mean period around 3 hours. What controls the period, whether by <span class="hlt">solar</span> <span class="hlt">wind</span> drivers or internal magnetospheric parameters, is unknown. In this presentation, we examine the relationship between the <span class="hlt">solar</span> <span class="hlt">wind</span> drivers and the period for each individual tooth. No clear linear trends are found so we conclude that the period of sawtooth events does not depend on any single <span class="hlt">solar</span> <span class="hlt">wind</span> driver exclusively. However sawtooth events driven by stream interaction events have a longer period (~ 180 minutes) than those driven by interplanetary coronal mass ejections (~ 150 minutes). This might suggest the <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere system has different coupling efficiencies during these two types of sawtooth events. We also propose an idea to explain why sawtooth events occur periodically and why the Earth has different response modes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AGUFM.P32A1066D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AGUFM.P32A1066D"><span>Mass dragged from Mars's atmosphere by the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Durand-Manterola, H. J.</p> <p>2003-12-01</p> <p>In the past Mars had a denser atmosphere, but it lacks a magnetic field to protect the ionosphere and exosphere from the <span class="hlt">solar</span> <span class="hlt">wind</span>. A model describing the loss of atmosphere by the erosion of the <span class="hlt">solar</span> <span class="hlt">wind</span> in geologic time is presented. Recent results shows that the Martian dynamo existed in Early and Middle Noachian. Then <span class="hlt">solar</span> <span class="hlt">wind</span> erosion would have started at the end of Middle Noachian or the beginning of Late Noachian. With this assumption the amount of volatiles dragged by the <span class="hlt">solar</span> <span class="hlt">wind</span>, if the chronology developed by Neukum and Wise is correct, is in the range of 0.472 to 1.89 Terrestrial Atmospheric Masses (TAM). If the chronology developed by Hartmann et al. is correct, the loss remains in the range of 0.0624 to 0.25 TAM.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SpWea..14..973C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SpWea..14..973C"><span>Quantitative evaluation of <span class="hlt">solar</span> <span class="hlt">wind</span> time-shifting methods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cameron, Taylor; Jackel, Brian</p> <p>2016-11-01</p> <p>Nine years of <span class="hlt">solar</span> <span class="hlt">wind</span> dynamic pressure and geosynchronous magnetic field data are used for a large-scale statistical comparison of uncertainties associated with several different algorithms for propagating <span class="hlt">solar</span> <span class="hlt">wind</span> measurements. The MVAB-0 scheme is best overall, performing on average a minute more accurately than a flat time-shift. We also evaluate the accuracy of these time-shifting methods as a function of <span class="hlt">solar</span> <span class="hlt">wind</span> magnetic field orientation. We find that all time-shifting algorithms perform significantly worse (>5 min) due to geometric effects when the <span class="hlt">solar</span> <span class="hlt">wind</span> magnetic field is radial (parallel or antiparallel to the Earth-Sun line). Finally, we present an empirical scheme that performs almost as well as MVAB-0 on average and slightly better than MVAB-0 for intervals with nonradial B.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19740042885&hterms=planet+mars+jupiter&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dplanet%2Bmars%2Bjupiter','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19740042885&hterms=planet+mars+jupiter&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dplanet%2Bmars%2Bjupiter"><span>Magnetic fields of Mars and Venus - <span class="hlt">Solar</span> <span class="hlt">wind</span> interactions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ness, N. F.</p> <p>1974-01-01</p> <p>Recent USSR studies of the magnetic field and <span class="hlt">solar</span> <span class="hlt">wind</span> flow in the vicinity of Mars and Venus confirm earlier U.S. reports of a bow shock wave developed as the <span class="hlt">solar</span> <span class="hlt">wind</span> interacts with these planets. Mars 2 and 3 magnetometer experiments report the existence of an intrinsic planetary magnetic field, sufficiently strong to form a magnetopause, deflecting the <span class="hlt">solar</span> <span class="hlt">wind</span> around the planet and its ionosphere. This is in contrast to the case for Venus, where it is assumed to be the ionosphere and processes therein which are responsible for the <span class="hlt">solar</span> <span class="hlt">wind</span> deflection. An empirical relationship appears to exist between planetary dipole magnetic moments and their angular momentum for the Moon, Mars, Venus, Earth, and Jupiter. Implications for the magnetic fields of Mercury and Saturn are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870027492&hterms=css&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcss','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870027492&hterms=css&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcss"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> flow upstream of the coronal slow shock</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Whang, Y. C.</p> <p>1986-01-01</p> <p>Slow shocks have been predicted to exist embedded in large coronal holes at low altitude. Two or more curved slow shocks may link together to form a composite discontinuity surface around the sun which may be called the coronal slow shock (CSS). Here a <span class="hlt">solar-wind</span> model is studied under the assumption that a standing CSS exists and cororates with the sun at a constant angular velocity. A steady, axisymmetrical one-fluid model is introduced to study the expansion of <span class="hlt">solar</span> <span class="hlt">wind</span> in the open-field region upstream of the CSS. The model requires that the conditions downstream of the CSS near the equatorial plane can produce a <span class="hlt">solar</span> <span class="hlt">wind</span> agreeable with the observations made near the earth's orbit. The paper presents an illustrative calculation in which the polar caps within 60 deg of the polar angle are assumed to be the source region of the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1094881','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1094881"><span>Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study: Phase 2 (Presentation)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lew, D.; Brinkman, G.; Ibanez, E.; Lefton, S.; Kumar, N.; Venkataraman, S.; Jordan, G.</p> <p>2013-09-01</p> <p>This presentation summarizes the scope and results of the Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study Phase 2, which examined operational impacts of high penetrations of variable renewable generation in the West.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSH41F..05K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSH41F..05K"><span>Integrating Multiple Approaches to Solving <span class="hlt">Solar</span> <span class="hlt">Wind</span> Turbulence Problems (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Karimabadi, H.; Roytershteyn, V.</p> <p>2013-12-01</p> <p>The ultimate understanding of the <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence must explain the physical process and their connection at all scales ranging from the largest down to electron kinetic scales. This is a daunting task and as a result a more piecemeal approach to the problem has been followed. For example, the role of each wave has been explored in isolation and in simulations with scales limited to those of the underlying waves. In this talk, we present several issues with this approach and offer an alternative with an eye towards more realistic simulations of <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence. The main simulation techniques used have been MHD, Hall MHD, hybrid, fully kinetic, and gyrokinetic. We examine the limitations of each approach and their viability for studies of <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence. Finally, the effect of initial conditions on the resulting turbulence and their comparison with <span class="hlt">solar</span> <span class="hlt">wind</span> are demonstrated through several kinetic simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080026012','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080026012"><span>Genesis <span class="hlt">Solar</span> <span class="hlt">Wind</span> Sample Curation: A Progress Report</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Allton, Judith H.; Calaway, M. J.; Rodriquez, M. C.; Hittle, J. D.; Wentworth, S. J.; Stansbery, E. K.; McNamara, K. M.</p> <p>2006-01-01</p> <p>In the year since the Genesis <span class="hlt">solar</span> <span class="hlt">wind</span> collector fragments were returned, early science samples, specimens for cleaning experiments, and science allocations have been distributed. <span class="hlt">Solar</span> <span class="hlt">wind</span> 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 <span class="hlt">solar</span> <span class="hlt">wind</span> 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 <span class="hlt">solar</span> <span class="hlt">wind</span> for fragments greater than 2 cm are available. Removal of contaminant particles using flowing ultrapure water (UPW) energized megasonically is provided as requested.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19830052897&hterms=accounts+charge&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Daccounts%2Bcharge','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19830052897&hterms=accounts+charge&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Daccounts%2Bcharge"><span>Charge exchange in <span class="hlt">solar</span> <span class="hlt">wind</span>-cometary interactions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gombosi, T. I.; Horanyi, M.; Kecskemety, K.; Cravens, T. E.; Nagy, A. F.</p> <p>1983-01-01</p> <p>A simple model of a cometary spherically symmetrical atmosphere and ionosphere is considered. An analytic solution of the governing equations describing the radial distribution of the neutral and ion densities is found. The new solution is compared to the well-known solution of the equations containing only ionization terms. Neglecting recombination causes a significant overestimate of the ion density in the vicinity of the comet. An axisymmetric model of the <span class="hlt">solar</span> <span class="hlt">wind</span>-cometary interaction is considered, taking into account the loss of <span class="hlt">solar</span> <span class="hlt">wind</span> ions due to charge exchange. The calculations predict that for active comets, <span class="hlt">solar</span> <span class="hlt">wind</span> absorption due to charge exchange becomes important at a few thousand kilometers from the nucleus, and a surface separating the shocked <span class="hlt">solar</span> <span class="hlt">wind</span> from the cometary ionosphere develops in this region. These calculations are in reasonable agreement with the few observations available for the ionopause location at comets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E3124S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E3124S"><span>Transient flows of the <span class="hlt">solar</span> <span class="hlt">wind</span> associated with small-scale <span class="hlt">solar</span> activity in <span class="hlt">solar</span> minimum</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Slemzin, Vladimir; Veselovsky, Igor; Kuzin, Sergey; Gburek, Szymon; Ulyanov, Artyom; Kirichenko, Alexey; Shugay, Yulia; Goryaev, Farid</p> <p></p> <p>The data obtained by the modern high sensitive EUV-XUV telescopes and photometers such as CORONAS-Photon/TESIS and SPHINX, STEREO/EUVI, PROBA2/SWAP, SDO/AIA provide good possibilities for studying small-scale <span class="hlt">solar</span> activity (SSA), which is supposed to play an important role in heating of the corona and producing transient flows of the <span class="hlt">solar</span> <span class="hlt">wind</span>. During the recent unusually weak <span class="hlt">solar</span> minimum, a large number of SSA events, such as week <span class="hlt">solar</span> flares, small CMEs and CME-like flows were observed and recorded in the databases of flares (STEREO, SWAP, SPHINX) and CMEs (LASCO, CACTUS). On the other hand, the <span class="hlt">solar</span> <span class="hlt">wind</span> data obtained in this period by ACE, <span class="hlt">Wind</span>, STEREO contain signatures of transient ICME-like structures which have shorter duration (<10h), weaker magnetic field strength (<10 nT) and lower proton temperature than usual ICMEs. To verify the assumption that ICME-like transients may be associated with the SSA events we investigated the number of weak flares of C-class and lower detected by SPHINX in 2009 and STEREO/EUVI in 2010. The flares were classified on temperature and emission measure using the diagnostic means of SPHINX and Hinode/EIS and were confronted with the parameters of the <span class="hlt">solar</span> <span class="hlt">wind</span> (velocity, density, ion composition and temperature, magnetic field, pitch angle distribution of the suprathermal electrons). The outflows of plasma associated with the flares were identified by their coronal signatures - CMEs (only in few cases) and dimmings. It was found that the mean parameters of the <span class="hlt">solar</span> <span class="hlt">wind</span> projected to the source surface for the times of the studied flares were typical for the ICME-like transients. The results support the suggestion that weak flares can be indicators of sources of transient plasma flows contributing to the slow <span class="hlt">solar</span> <span class="hlt">wind</span> at <span class="hlt">solar</span> minimum, although these flows may be too weak to be considered as separate CMEs and ICMEs. The research leading to these results has received funding from the European Union’s Seventh Programme</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.6992J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.6992J"><span><span class="hlt">Solar</span> <span class="hlt">irradiance</span> over Earth's surface and relations with temperature rise</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jimenez, Marta; Cony, Marco, ,, Dr; Fernández, Irene; Weisenberg, Ralf, ,, Dr</p> <p>2017-04-01</p> <p>The present study analyzes if exist a relation between Temperature and <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> Components during a large time period, and how it affects to <span class="hlt">Solar</span> Energy production. The study was made in three different places over the planet since 2000 to 2013, and methodology used is based on choosing one monthly data, corresponding to highest Temperature day of each month, for to determine its respective differences. In first approximation, a proportional relation between variables is observed both GHI component and DNI component regarding T, considering that all of them have similar trends. Keeping in mind <span class="hlt">solar</span> energy flux definition in function of <span class="hlt">solar</span> radiation, <span class="hlt">solar</span> energy production haves the same trends than temperature. This result gives cause for future studies about exact relation which connect temperature with <span class="hlt">solar</span> radiation, which can be useful in terms of <span class="hlt">solar</span> forecast.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19790030552&hterms=three+field+view&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dthree%2Bfield%2Bof%2Bview','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19790030552&hterms=three+field+view&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dthree%2Bfield%2Bof%2Bview"><span>A view of <span class="hlt">solar</span> magnetic fields, the <span class="hlt">solar</span> corona, and the <span class="hlt">solar</span> <span class="hlt">wind</span> in three dimensions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Svalgaard, L.; Wilcox, J. M.</p> <p>1978-01-01</p> <p>In the last few years it has been recognized that the <span class="hlt">solar</span> corona and the <span class="hlt">solar</span> <span class="hlt">wind</span> are three-dimensional. The deviations from spherical or even cylindrical symmetry are first-order effects, which are important for a basic description and physical understanding of the coronal expansion. Models of coronal magnetic fields are considered along with the characteristics of large-scale <span class="hlt">solar</span> structure, the interplanetary magnetic field, coronal holes, geomagnetic activity, cosmic rays, and polar fields of the sun. It is pointed out that the present understanding of coronal and interplanetary morphology is based on data acquired during the descending part and the minimum of the considered sunspot cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890005692','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890005692"><span>Analysis of ISEE-3/ICE <span class="hlt">solar</span> <span class="hlt">wind</span> data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Coplan, Michael A.</p> <p>1989-01-01</p> <p>Under the grant that ended November 11, 1988 work was accomplished in a number of areas, as follows: (1) Analysis of <span class="hlt">solar</span> <span class="hlt">wind</span> data; (2) Analysis of Giacobini/Zinner encounter data; (3) Investigation of <span class="hlt">solar</span> <span class="hlt">wind</span> and magnetospheric electron velocity distributions; and (4) Experimental investigation of the electronic structure of clusters. Reprints and preprints of publications resulting from this work are included in the appendices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820024368','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820024368"><span>Calculation of <span class="hlt">solar</span> <span class="hlt">wind</span> flows about terrestrial planets</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stahara, S. S.; Spreiter, J. R.</p> <p>1982-01-01</p> <p>A computational model was developed for the determination of the plasma and magnetic field properties of the global interaction of the <span class="hlt">solar</span> <span class="hlt">wind</span> with terrestrial planetary magneto/ionospheres. The theoretical method is based on an established single fluid, steady, dissipationless, magnetohydrodynamic continuum model, and is appropriate for the calculation of supersonic, super Alfvenic <span class="hlt">solar</span> <span class="hlt">wind</span> flow past terrestrial planets. A summary is provided of the important research results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JGRA..118...45B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JGRA..118...45B"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> forcing at Mercury: WSA-ENLIL model results</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baker, Daniel N.; Poh, Gangkai; Odstrcil, Dusan; Arge, C. Nick; Benna, Mehdi; Johnson, Catherine L.; Korth, Haje; Gershman, Daniel J.; Ho, George C.; McClintock, William E.; Cassidy, Timothy A.; Merkel, Aimee; Raines, Jim M.; Schriver, David; Slavin, James A.; Solomon, Sean C.; TráVníčEk, Pavel M.; Winslow, Reka M.; Zurbuchen, Thomas H.</p> <p>2013-01-01</p> <p>Analysis and interpretation of observations from the MESSENGER spacecraft in orbit about Mercury require knowledge of <span class="hlt">solar</span> <span class="hlt">wind</span> "forcing" parameters. We have utilized the Wang-Sheeley-Arge (WSA)-ENLIL <span class="hlt">solar</span> <span class="hlt">wind</span> modeling tool in order to calculate the values of interplanetary magnetic field (IMF) strength (B), <span class="hlt">solar</span> <span class="hlt">wind</span> velocity (V) and density (n), ram pressure (~nV2), cross-magnetosphere electric field (V × B), Alfvén Mach number (MA), and other derived quantities of relevance for <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere interactions. We have compared upstream MESSENGER IMF and <span class="hlt">solar</span> <span class="hlt">wind</span> measurements to see how well the ENLIL model results compare. Such parameters as <span class="hlt">solar</span> <span class="hlt">wind</span> dynamic pressure are key for determining the Mercury magnetopause standoff distance, for example. We also use the relatively high-time-resolution B-field data from MESSENGER to estimate the strength of the product of the <span class="hlt">solar</span> <span class="hlt">wind</span> speed and southward IMF strength (Bs) at Mercury. This product VBs is the electric field that drives many magnetospheric dynamical processes and can be compared with the occurrence of energetic particle bursts within the Mercury magnetosphere. This quantity also serves as input to the global magnetohydrodynamic and kinetic magnetosphere models that are being used to explore magnetospheric and exospheric processes at Mercury. Moreover, this modeling can help assess near-real-time magnetospheric behavior for MESSENGER or other mission analysis and/or ground-based observational campaigns. We demonstrate that this <span class="hlt">solar</span> <span class="hlt">wind</span> forcing tool is a crucial step toward bringing heliospheric science expertise to bear on planetary exploration programs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170002772&hterms=Winds&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DWinds','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170002772&hterms=Winds&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DWinds"><span>On Electron-Scale Whistler Turbulence in the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Narita, Y.; Nakamura, R.; Baumjohann, W.; Glassmeier, K.-H.; Motschmann, U.; Giles, B.; Magnes, W.; Fischer, D.; Torbert, R. B.; Russell, C. T.</p> <p>2016-01-01</p> <p>For the first time, the dispersion relation for turbulence magnetic field fluctuations in the <span class="hlt">solar</span> <span class="hlt">wind</span> is determined directly on small scales of the order of the electron inertial length, using four-point magnetometer observations from the Magnetospheric Multiscale mission. The data are analyzed using the high-resolution adaptive wave telescope technique. Small-scale <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence is primarily composed of highly obliquely propagating waves, with dispersion consistent with that of the whistler mode.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750011027','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750011027"><span>Interplanetary stream magnetism: Kinematic effects. [<span class="hlt">solar</span> magnetic fields and <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burlaga, L. F.; Barouch, E.</p> <p>1974-01-01</p> <p>The particle density, and the magnetic field intensity and direction are calculated in corotating streams of the <span class="hlt">solar</span> <span class="hlt">wind</span>, assuming that the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity is constant and radial and that its azimuthal variations are not two rapid. The effects of the radial velocity profile in corotating streams on the magnetic fields were examined using kinematic approximation and a variety of field configurations on the inner boundary. Kinematic and dynamic effects are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991AcGSn..34..272Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991AcGSn..34..272Z"><span>System identification of geomagnetic disturbances initiated by the <span class="hlt">solar</span> <span class="hlt">wind</span>.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, Xiaoyan; Tschu, Kangkun</p> <p>1991-05-01</p> <p>On the basis of linear and time-invariant supposition, the geomagnetic disturbances initiated by the <span class="hlt">solar</span> <span class="hlt">wind</span> have been studied in terms of least square non-parametric identification method. The macro-external description of the response of the magnetosphere to the <span class="hlt">solar</span> <span class="hlt">wind</span> is given by the impulse response function. The predicted geomagnetic disturbances are compared with the observations; they are found to agree quite well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170002772&hterms=solar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsolar','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170002772&hterms=solar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsolar"><span>On Electron-Scale Whistler Turbulence in the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Narita, Y.; Nakamura, R.; Baumjohann, W.; Glassmeier, K.-H.; Motschmann, U.; Giles, B.; Magnes, W.; Fischer, D.; Torbert, R. B.; Russell, C. T.</p> <p>2016-01-01</p> <p>For the first time, the dispersion relation for turbulence magnetic field fluctuations in the <span class="hlt">solar</span> <span class="hlt">wind</span> is determined directly on small scales of the order of the electron inertial length, using four-point magnetometer observations from the Magnetospheric Multiscale mission. The data are analyzed using the high-resolution adaptive wave telescope technique. Small-scale <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence is primarily composed of highly obliquely propagating waves, with dispersion consistent with that of the whistler mode.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840065464&hterms=lithium+ions&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dlithium%2Bions','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840065464&hterms=lithium+ions&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dlithium%2Bions"><span>Collective capture of released lithium ions in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Winske, D.; Wu, C. S.; Li, Y. Y.; Zhou, G. C.</p> <p>1984-01-01</p> <p>The capture of newly ionized lithium ions in the <span class="hlt">solar</span> <span class="hlt">wind</span> by means of electromagnetic instabilities is investigated through linear analysis and computer simulation. Three instabilities, driven by a lithium velocity ring perpendicular to and drifting along the magnetic field, are considered. The capture time of the lithium by the <span class="hlt">solar</span> <span class="hlt">wind</span> is roughly 10 linear growth times, regardless of whether resonant or nonresonant modes dominate initially. Possible implications of the results for the Active Magnetosphere Particle Tracer Explorer (AMPTE) mission are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840005046','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840005046"><span>Mixed <span class="hlt">solar</span> <span class="hlt">wind</span> originating from coronal regions of different temperatures</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bochsler, P.</p> <p>1983-01-01</p> <p>Ionization states of elements in the <span class="hlt">solar</span> <span class="hlt">wind</span> are often used to determine thermal gradients in the lower corona. This method is based on the assumption, that in the beginning, <span class="hlt">solar</span> <span class="hlt">wind</span> material has a homogeneous temperature determining the original charge state of elements. Features in M/Q-spectra which might appear if the above assumption is violated are investigated and compared with observational evidence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.9271J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.9271J"><span>STEREO Observations of <span class="hlt">Solar</span> <span class="hlt">Wind</span> in 2007-2014</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jian, Lan; Luhmann, Janet; Russell, Christopher; Blanco-Cano, Xochitl; Kilpua, Emilia; Li, Yan</p> <p>2016-04-01</p> <p>Since the launch of twin STEREO spacecraft, we have been monitoring the <span class="hlt">solar</span> <span class="hlt">wind</span> and providing the Level 3 event lists of large-scale <span class="hlt">solar</span> <span class="hlt">wind</span> and particle events to public (http://www-ssc.igpp.ucla.edu/forms/stereo/stereo_level_3.html). The interplanetary coronal mass ejections (ICMEs), stream interaction regions (SIRs), interplanetary shocks, and <span class="hlt">solar</span> energetic particles (based on high energy telescope data) have been surveyed for 2007-2014 before STEREO A went to the superior <span class="hlt">solar</span> conjunction and STEREO B was lost in contact. In conjunction with our previous observations of same <span class="hlt">solar</span> <span class="hlt">wind</span> structures in 1995-2009 using <span class="hlt">Wind</span>/ACE data and the same identification criteria, we study the <span class="hlt">solar</span> cycle variations of these structures, especially compare the same phase of <span class="hlt">solar</span> cycles 23 and 24. Although the sunspot number at <span class="hlt">solar</span> maximum 24 is only 60% of the level at last <span class="hlt">solar</span> maximum, Gopalswamy et al. (2015a, b) found there were more halo CMEs in cycle 24 and the number of magnetic clouds did not decline either. We examine if the two vantage points of STEREO provide a consistent view with the above finding. In addition, because the twin STEREO spacecraft have experienced the full-range longitudinal separation of 0-360 degree, they have provided us numerous opportunities for multipoint observations. We will report the findings on the spatial scope of ICMEs including their driven shocks, and the stability of SIRs from the large event base.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..4310586V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..4310586V"><span>Transport of <span class="hlt">solar</span> <span class="hlt">wind</span> plasma onto the lunar nightside surface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vorburger, A.; Wurz, P.; Barabash, S.; Futaana, Y.; Wieser, M.; Bhardwaj, A.; Dhanya, M. B.; Asamura, K.</p> <p>2016-10-01</p> <p>We present first measurements of energetic neutral atoms that originate from <span class="hlt">solar</span> <span class="hlt">wind</span> plasma having interacted with the lunar nightside surface. We observe two distinct energetic neutral atom (ENA) distributions parallel to the terminator, the spectral shape, and the intensity of both of which indicate that the particles originate from the bulk <span class="hlt">solar</span> <span class="hlt">wind</span> flow. The first distribution modifies the dayside ENA flux to reach ˜6° into the nightside and is well explained by the kinetic temperature of the <span class="hlt">solar</span> <span class="hlt">wind</span> protons. The second distribution, which was not predicted, reaches from the terminator to up to 30° beyond the terminator, with a maximum at ˜102° in <span class="hlt">solar</span> zenith angle. As most likely wake transport processes for this second distribution we identify acceleration by the ambipolar electric field and by the negatively charged lunar nightside surface. In addition, our data provide the first observation indicative of a global <span class="hlt">solar</span> zenith angle dependence of positive dayside surface potentials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110013339','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110013339"><span>The Character of the <span class="hlt">Solar</span> <span class="hlt">Wind</span>, Surface Interactions, and Water</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Farrell, William M.</p> <p>2011-01-01</p> <p>We discuss the key characteristics of the proton-rich <span class="hlt">solar</span> <span class="hlt">wind</span> and describe how it may interact with the lunar surface. We suggest that <span class="hlt">solar</span> <span class="hlt">wind</span> can be both a source and loss of water/OH related volatiles, and review models showing both possibilities. Energy from the Sun in the form of radiation and <span class="hlt">solar</span> <span class="hlt">wind</span> plasma are in constant interaction with the lunar surface. As such, there is a <span class="hlt">solar</span>-lunar energy connection, where <span class="hlt">solar</span> energy and matter are continually bombarding the lunar surface, acting at the largest scale to erode the surface at 0.2 Angstroms per year via ion sputtering [1]. Figure 1 illustrates this dynamically Sun-Moon system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730002067','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730002067"><span>Interplanetary shock waves and the structure of <span class="hlt">solar</span> <span class="hlt">wind</span> disturbances</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hundhausen, A. J.</p> <p>1972-01-01</p> <p>Observations and theoretical models of interplanetary shock waves are reviewed, with emphasis on the large-scale characteristics of the associated <span class="hlt">solar</span> <span class="hlt">wind</span> disturbances and on the relationship of these disturbances to <span class="hlt">solar</span> activity. The sum of observational knowledge indicates that shock waves propagate through the <span class="hlt">solar</span> <span class="hlt">wind</span> along a broad, roughly spherical front, ahead of plasma and magnetic field ejected from <span class="hlt">solar</span> flares. Typically, the shock front reaches 1 AU about two days after its flare origin, and is of intermediate strength. Not all large flares produce observable interplanetary shock waves; the best indicator of shock production appears to be the generation of both type 2 and type 4 radio bursts by a flare. Theoretical models of shock propagation in the <span class="hlt">solar</span> <span class="hlt">wind</span> can account for the typically observed shock strength, transit time, and shape.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/964607','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/964607"><span>Potential for Development of <span class="hlt">Solar</span> and <span class="hlt">Wind</span> Resource in Bhutan</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gilman, P.; Cowlin, S.; Heimiller, D.</p> <p>2009-09-01</p> <p>With support from the U.S. Agency for International Development (USAID), the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) produced maps and data of the <span class="hlt">wind</span> and <span class="hlt">solar</span> resources in Bhutan. The <span class="hlt">solar</span> resource data show that Bhutan has an adequate resource for flat-plate collectors, with annual average values of global horizontal <span class="hlt">solar</span> radiation ranging from 4.0 to 5.5 kWh/m2-day (4.0 to 5.5 peak sun hours per day). The information provided in this report may be of use to energy planners in Bhutan involved in developing energy policy or planning <span class="hlt">wind</span> and <span class="hlt">solar</span> projects, and to energy analysts around the world interested in gaining an understanding of Bhutan's <span class="hlt">wind</span> and <span class="hlt">solar</span> energy potential.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840024844','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840024844"><span><span class="hlt">Wind</span> loading on <span class="hlt">solar</span> concentrators: Some general considerations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Roschke, E. J.</p> <p>1984-01-01</p> <p>A survey was completed to examine the problems and complications arising from <span class="hlt">wind</span> loading on <span class="hlt">solar</span> concentrators. <span class="hlt">Wind</span> loading is site specific and has an important bearing on the design, cost, performance, operation and maintenance, safety, survival, and replacement of <span class="hlt">solar</span> collecting systems. Emphasis herein is on paraboloidal, two-axis tracking systems. Thermal receiver problems also are discussed. <span class="hlt">Wind</span> characteristics are discussed from a general point of view. Current methods for determining design <span class="hlt">wind</span> speed are reviewed. Aerodynamic coefficients are defined and illustrative examples are presented. <span class="hlt">Wind</span> tunnel testing is discussed, and environmental <span class="hlt">wind</span> tunnels are reviewed. Recent results on heliostat arrays are reviewed as well. Aeroelasticity in relation to structural design is discussed briefly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1984STIN...8432915R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1984STIN...8432915R"><span><span class="hlt">Wind</span> loading on <span class="hlt">solar</span> concentrators: Some general considerations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roschke, E. J.</p> <p>1984-05-01</p> <p>A survey was completed to examine the problems and complications arising from <span class="hlt">wind</span> loading on <span class="hlt">solar</span> concentrators. <span class="hlt">Wind</span> loading is site specific and has an important bearing on the design, cost, performance, operation and maintenance, safety, survival, and replacement of <span class="hlt">solar</span> collecting systems. Emphasis herein is on paraboloidal, two-axis tracking systems. Thermal receiver problems also are discussed. <span class="hlt">Wind</span> characteristics are discussed from a general point of view. Current methods for determining design <span class="hlt">wind</span> speed are reviewed. Aerodynamic coefficients are defined and illustrative examples are presented. <span class="hlt">Wind</span> tunnel testing is discussed, and environmental <span class="hlt">wind</span> tunnels are reviewed. Recent results on heliostat arrays are reviewed as well. Aeroelasticity in relation to structural design is discussed briefly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020086296','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020086296"><span>Investigation of <span class="hlt">Solar</span> <span class="hlt">Wind</span> Correlations and <span class="hlt">Solar</span> <span class="hlt">Wind</span> Modifications Near Earth by Multi-Spacecraft Observations: IMP 8, <span class="hlt">WIND</span> and INTERBALL-1</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Paularena, Karolen I.; Richardson, John D.; Zastenker, Georgy N.</p> <p>2002-01-01</p> <p>The foundation of this Project is use of the opportunity available during the ISTP (International <span class="hlt">Solar</span>-Terrestrial Physics) era to compare <span class="hlt">solar</span> <span class="hlt">wind</span> measurements obtained simultaneously by three spacecraft - IMP 8, <span class="hlt">WIND</span> and INTERBALL-1 at wide-separated points. Using these data allows us to study three important topics: (1) the size and dynamics of near-Earth mid-scale (with dimension about 1-10 million km) and small-scale (with dimension about 10-100 thousand km) <span class="hlt">solar</span> <span class="hlt">wind</span> structures; (2) the reliability of the common assumption that <span class="hlt">solar</span> <span class="hlt">wind</span> conditions at the upstream Lagrangian (L1) point accurately predict the conditions affecting Earth's magnetosphere; (3) modification of the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma and magnetic field in the regions near the Earth magnetosphere, the foreshock and the magnetosheath. Our Project was dedicated to these problems. Our research has made substantial contributions to the field and has lead others to undertake similar work.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004A%26G....45d..38H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004A%26G....45d..38H"><span><span class="hlt">Solar</span> <span class="hlt">wind</span>: The <span class="hlt">solar</span> <span class="hlt">wind</span> and the Sun-Earth link</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Habbal, Shadia Rifia; Woo, Richard</p> <p>2004-08-01</p> <p>The <span class="hlt">solar</span> <span class="hlt">wind</span> fills the space between the Sun and its planets, shapes the planetary environments and the heliosphere, and comes to a screeching halt at the heliopause, the boundary with the interstellar medium. This tenuous medium is a fertile environment for exotic plasma processes, most of which are not fully understood. It also holds the intimate secrets of the mechanisms heating the corona that continue to elude us. As the only accessible space plasma laboratory, we must continue its exploration in search of the processes that impact the Earth's environment and govern the evolution of stars and their planetary systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110005629','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110005629"><span>Dissipation of Turbulence in the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Goldstein, Melvyn L.</p> <p>2010-01-01</p> <p>I will describe the first three-dimensional (3-D) dispersion relations and wavenumber spectra of magnetic turbulence in the <span class="hlt">solar</span> <span class="hlt">wind</span> at sub-proton scales. The analysis takes advantage of the short separations of the Cluster spacecraft (d/sim approx.200 km) to apply the {it k}-filtering technique to the frequency range where the transition to sub-proton scales occurs. The dispersion diagrams show unambiguously that the cascade is carried by highly oblique Kinetic Alfven Wave with \\omega\\leq 0.1\\omega_{ci} in the plasma rest frame down to k_\\perp\\rho_i \\sim 2. The wavenumber spectra in the direction perpendicular to the mean magnetic field consists of two ranges of scales separated by a breakpoint in the interval [0.4,1] k_\\perp \\rho_i. Above the breakpoint, the spectra follow the Kolmogorov scaling k_\\perp^{-1.7}, consistent with existing theoretical predictions. Below the breakpoint, the spectra steepen to \\sim k_\\perp^{-4.5}. We conjecture that the turbulence undergoes a {\\it transition-range}, where part of energy is dissipated into proton heating via Landau damping, and the remaining energy cascades down to electron scales where electron Landau damping may predominate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040000671&hterms=sorting&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dsorting','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040000671&hterms=sorting&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dsorting"><span>Interaction of Comets and the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wagner, William (Technical Monitor); Raymond, John C.</p> <p>2003-01-01</p> <p>We had originally planned to analyze UVCS observations of Comet Machholz, but we obtained higher quality observations of Comet Kudo-Fujikawa in January 2003 at its 0.19 AU perihelion. Besides a large and rapidly increasing water outgassing rate, we detected a bright tail in doubly ionized carbon. The amount of carbon was greater than could be accounted for by GO photodissociation, and we attribute the carbon to evaporation of organics from dust. A spectacular disconnection event was apparent in the C III tail, and it coincides within the uncertainties with the position of the heliospheric current sheet. A paper is in press in Science, and it will be the subject of a press release. We are also analyzing two sungrazing comets. Comet C/2001 C2 shows evidence for sub-fragments and for a very long lasting source of neutrals, which we tentatively identify as evaporation of pyroxene dust grains. Comet C/2002 S2 shows a sudden 2 magnitude drop in optical brightness and an equally sudden recovery. UVCS observations during that time show a steadily increasing outgassing rate. We have derived <span class="hlt">solar</span> <span class="hlt">wind</span> densities for both comets, but we are still sorting out the ambiguities involving the fragmentation and optical behavior. We are collaborating with Philippe Lamy on the LASCO measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040182379','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040182379"><span>Interaction of Comets and the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wagner, William (Technical Monitor); Raymond, John C.</p> <p>2004-01-01</p> <p>The analysis of Comet Kudo-Fujikawa at perihelion was published and picked up by Der Spiegel. Besides a large and rapidly increasing water outgassing rate, we detected a bright tail in doubly ionized carbon. The amount of carbon was greater than could be accounted for by CO photodissociation, and we attribute it to evaporation of organics from dust. A spectacular disconnection event was apparent in the C III tail, and it coincides within the uncertainties to the position of the heliospheric current sheet. The analysis of the sungrazing comet C2001 C2 is in press. It showed evidence for subfragments and for a very long lasting source of neutrals, which we identify as evaporation of pyroxene dust grains. Results were also presented at COSPAR. We are working on observations of another sungrazer, comet C2002 S2, which shows a sudden 2 magnitude drop in optical brightness and an equally sudden recovery. UVCS observations during that time show a steadily increasing outgassing rate. We have derived <span class="hlt">solar</span> <span class="hlt">wind</span> densities for both comets, but we are still sorting out the ambiguities involving the fragmentation and optical behavior.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040000671&hterms=Williams+Raymond&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D40%26Ntt%3DWilliams%252C%2BRaymond','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040000671&hterms=Williams+Raymond&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D40%26Ntt%3DWilliams%252C%2BRaymond"><span>Interaction of Comets and the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wagner, William (Technical Monitor); Raymond, John C.</p> <p>2003-01-01</p> <p>We had originally planned to analyze UVCS observations of Comet Machholz, but we obtained higher quality observations of Comet Kudo-Fujikawa in January 2003 at its 0.19 AU perihelion. Besides a large and rapidly increasing water outgassing rate, we detected a bright tail in doubly ionized carbon. The amount of carbon was greater than could be accounted for by GO photodissociation, and we attribute the carbon to evaporation of organics from dust. A spectacular disconnection event was apparent in the C III tail, and it coincides within the uncertainties with the position of the heliospheric current sheet. A paper is in press in Science, and it will be the subject of a press release. We are also analyzing two sungrazing comets. Comet C/2001 C2 shows evidence for sub-fragments and for a very long lasting source of neutrals, which we tentatively identify as evaporation of pyroxene dust grains. Comet C/2002 S2 shows a sudden 2 magnitude drop in optical brightness and an equally sudden recovery. UVCS observations during that time show a steadily increasing outgassing rate. We have derived <span class="hlt">solar</span> <span class="hlt">wind</span> densities for both comets, but we are still sorting out the ambiguities involving the fragmentation and optical behavior. We are collaborating with Philippe Lamy on the LASCO measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1918255P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1918255P"><span>Intermittent structures at ion scales in the turbulent <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Perrone, Denise; Alexandrova, Olga; Lion, Sonny; Roberts, Owen W.; Maksimovic, Milan; Escoubet, Philippe C.; Zouganelis, Yannis</p> <p>2017-04-01</p> <p>Understanding the physical mechanisms of dissipation, and the related heating, in turbulent collisionless plasmas (such as the <span class="hlt">solar</span> <span class="hlt">wind</span>) represents nowadays one of the key issues of plasma physics. Although the complex behavior of the <span class="hlt">solar</span> <span class="hlt">wind</span> has been matter of investigation of many years, some of the primary problems still remain a puzzle for the scientific community. Here, we study coherent structures responsible for <span class="hlt">solar</span> <span class="hlt">wind</span> intermittency around ion characteristic scales. We find that, in fast <span class="hlt">solar</span> <span class="hlt">wind</span>, intermittency is due to current sheets and Alfvén vortex-like structures. In slow <span class="hlt">solar</span> <span class="hlt">wind</span>, we observe as well compressive structures like magnetic solitons, holes and shocks. By using high-time resolution magnetic field data of multi-point measurements of Cluster spacecraft, we characterize the observed coherent structures in terms of topology and propagation speed. We show that all structures, both in fast and slow <span class="hlt">solar</span> <span class="hlt">wind</span>, are characterized by a strong wave-vector anisotropy in the perpendicular direction with respect to the local magnetic field and typical scales around ion characteristic scales. Moreover, some of them propagate in the plasma rest frame. Moreover, a further analysis on the ion velocity distribution shows a high variability; in particular, close to coherent structures the proton distribution function appears strongly deformed and far from the thermodynamic equilibrium. We discuss possible interpretation of the observed structures and their role in the heating process of the plasma.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1051165','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1051165"><span>Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study Phase 2: Preprint</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lew, D.; Brinkman, G.; Ibanez, E.; Hodge, B.-M.; King, J.</p> <p>2012-09-01</p> <p>The Western <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Integration Study (WWSIS) investigates the impacts of high penetrations of <span class="hlt">wind</span> and <span class="hlt">solar</span> power into the Western Interconnection of the United States. WWSIS2 builds on the Phase 1 study but with far greater refinement in the level of data inputs and production simulation. It considers the differences between <span class="hlt">wind</span> and <span class="hlt">solar</span> power on systems operations. It considers mitigation options to accommodate <span class="hlt">wind</span> and <span class="hlt">solar</span> when full costs of wear-and-tear and full impacts of emissions rates are taken into account. It determines wear-and-tear costs and emissions impacts. New data sets were created for WWSIS2, and WWSIS1 data sets were refined to improve realism of plant output and forecasts. Four scenarios were defined for WWSIS2 that examine the differences between <span class="hlt">wind</span> and <span class="hlt">solar</span> and penetration level. Transmission was built out to bring resources to load. Statistical analysis was conducted to investigate <span class="hlt">wind</span> and <span class="hlt">solar</span> impacts at timescales ranging from seasonal down to 5 minutes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110015175','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110015175"><span>Sputtering by the <span class="hlt">Solar</span> <span class="hlt">Wind</span>: Effects of Variable Composition</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Killen, R. M.; Arrell, W. M.; Sarantos, M.; Delory, G. T.</p> <p>2011-01-01</p> <p>It has long been recognized that <span class="hlt">solar</span> <span class="hlt">wind</span> bombardment onto exposed surfaces in the <span class="hlt">solar</span> system will produce an energetic component to the exospheres about those bodies. Laboratory experiments have shown that there is no increase in the sputtering yield caused by highly charged heavy ions for metallic and for semiconducting surfaces, but the sputter yield can be noticeably increased in the case of a good insulating surface. Recently measurements of the <span class="hlt">solar</span> <span class="hlt">wind</span> composition have become available. It is now known that the <span class="hlt">solar</span> <span class="hlt">wind</span> composition is highly dependent on the origin of the particular plasma. Using the measured composition of the slow <span class="hlt">wind</span>, fast <span class="hlt">wind</span>, <span class="hlt">solar</span> energetic particle (SEP) population, and coronal mass ejection (CME), broken down into its various components, we have estimated the total sputter yield for each type of <span class="hlt">solar</span> <span class="hlt">wind</span>. Whereas many previous calculations of sputtering were limited to the effects of proton bombardment. we show that the heavy ion component. especially the He++ component. can greatly enhance the total sputter yield during times when the heavy ion population is enhanced. We will discuss sputtering of both neutrals and ions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1712421S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1712421S"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> precipitation - a comparison between Mars and Venus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stenberg Wieser, Gabriella; Nilsson, Hans; Futaana, Yoshifumi; Holmström, Mats; Barabash, Stas</p> <p>2015-04-01</p> <p>Mars and Venus both have atmospheres but both lack a substantial intrinsic magnetic field. Hence, their interaction with the <span class="hlt">solar</span> <span class="hlt">wind</span> is similar. Due to currents set up in the ionospheres the interplanetary magnetic field embedded in the <span class="hlt">solar</span> <span class="hlt">wind</span> drapes around the planets forming induced magnetospheres. The plasma instrument packages ASPERA-3 and ASPERA-4 on the two spacecraft Mars Express and Venus Express are very similar and invite to a comparison between the two plasma environments. In this study we used the Ion Mass Analyser (IMA) on both spacecraft to investigate the <span class="hlt">solar</span> <span class="hlt">wind</span> precipitation onto the upper atmospheres. We focus on the differences between the two planets. We conclude that on Mars we regularly observe precipitating <span class="hlt">solar</span> <span class="hlt">wind</span> ions (H+ and He2+) inside the induced magnetosphere boundary (IMB). The precipitation is clearly guided by the <span class="hlt">solar</span> <span class="hlt">wind</span> convection electric field and He2+ and H+ are seen independently of each other. On Venus precipitation of He2+ is only observed close to the IMB and always together with H+. The precipitation events on Venus have no clear correlation with the <span class="hlt">solar</span> <span class="hlt">wind</span> electric field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17842428','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17842428"><span>Spectrum line intensity as a surrogate for <span class="hlt">solar</span> <span class="hlt">irradiance</span> variations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Livingston, W C; Wallace, L; White, O R</p> <p>1988-06-24</p> <p>Active Cavity Radiometer <span class="hlt">Irradiance</span> Monitor (ACRIM) <span class="hlt">solar</span> constant measurements from 1980 to 1986 are compared with ground-based, <span class="hlt">irradiance</span> spectrophotometry of selected Fraunhofer lines. Both data sets were identically sampled and smoothed with an 85-day running mean, and the ACRIM total <span class="hlt">solar</span> <span class="hlt">irradiance</span> (S) values were corrected for sunspot blocking (S(c)). The strength of the mid-photospheric manganese 539.4-nanometer line tracks almost perfectly with ACRIM S(e), Other spectral features formed high in the photosphere and chromosphere also track well. These comparisons independently confirm the variability in the ACRIM S(e), signal, indicate that the source of <span class="hlt">irradiance</span> is faculae, and indicate that ACRIM S(e), follows the 11-year activity cycle.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4604519','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4604519"><span>Impacts of <span class="hlt">wind</span> stilling on <span class="hlt">solar</span> radiation variability in China</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lin, Changgui; Yang, Kun; Huang, Jianping; Tang, Wenjun; Qin, Jun; Niu, Xiaolei; Chen, Yingying; Chen, Deliang; Lu, Ning; Fu, Rong</p> <p>2015-01-01</p> <p><span class="hlt">Solar</span> dimming and <span class="hlt">wind</span> stilling (slowdown) are two outstanding climate changes occurred in China over the last four decades. The <span class="hlt">wind</span> stilling may have suppressed the dispersion of aerosols and amplified the impact of aerosol emission on <span class="hlt">solar</span> dimming. However, there is a lack of long-term aerosol monitoring and associated study in China to confirm this hypothesis. Here, long-term meteorological data at weather stations combined with short-term aerosol data were used to assess this hypothesis. It was found that surface <span class="hlt">solar</span> radiation (SSR) decreased considerably with <span class="hlt">wind</span> stilling in heavily polluted regions at a daily scale, indicating that <span class="hlt">wind</span> stilling can considerably amplify the aerosol extinction effect on SSR. A threshold value of 3.5 m/s for <span class="hlt">wind</span> speed is required to effectively reduce aerosols concentration. From this SSR dependence on <span class="hlt">wind</span> speed, we further derived proxies to quantify aerosol emission and <span class="hlt">wind</span> stilling amplification effects on SSR variations at a decadal scale. The results show that aerosol emission accounted for approximately 20% of the typical <span class="hlt">solar</span> dimming in China, which was amplified by approximately 20% by <span class="hlt">wind</span> stilling. PMID:26463748</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMSH11A1502A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMSH11A1502A"><span>Implications of the Deep Minimum for Slow <span class="hlt">Solar</span> <span class="hlt">Wind</span> Origin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Antiochos, S. K.; Mikic, Z.; Lionello, R.; Titov, V. S.; Linker, J. A.</p> <p>2009-12-01</p> <p>The origin of the slow <span class="hlt">solar</span> <span class="hlt">wind</span> has long been one of the most important problems in <span class="hlt">solar</span>/heliospheric physics. Two observational constraints make this problem especially challenging. First, the slow <span class="hlt">wind</span> has the composition of the closed-field corona, unlike the fast <span class="hlt">wind</span> that originates on open field lines. Second, the slow <span class="hlt">wind</span> has substantial angular extent, of order 30 degrees, which is much larger than the widths observed for streamer stalks or the widths expected theoretically for a dynamic heliospheric current sheet. We propose that the slow <span class="hlt">wind</span> originates from an intricate network of narrow (possibly singular) open-field corridors that emanate from the polar coronal hole regions. Using topological arguments, we show that these corridors must be ubiquitous in the <span class="hlt">solar</span> corona. The total <span class="hlt">solar</span> eclipse in August 2008, near the lowest point of the Deep Minimum, affords an ideal opportunity to test this theory by using the ultra-high resolution Predictive Science's (PSI) eclipse model for the corona and <span class="hlt">wind</span>. Analysis of the PSI eclipse model demonstrates that the extent and scales of the open-field corridors can account for both the angular width of the slow <span class="hlt">wind</span> and its closed-field composition. We discuss the implications of our slow <span class="hlt">wind</span> theory for the structure of the corona and heliosphere at the Deep Minimum and describe further observational and theoretical tests. This work has been supported by the NASA HTP, SR&T, and LWS programs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26463748','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26463748"><span>Impacts of <span class="hlt">wind</span> stilling on <span class="hlt">solar</span> radiation variability in China.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lin, Changgui; Yang, Kun; Huang, Jianping; Tang, Wenjun; Qin, Jun; Niu, Xiaolei; Chen, Yingying; Chen, Deliang; Lu, Ning; Fu, Rong</p> <p>2015-10-14</p> <p><span class="hlt">Solar</span> dimming and <span class="hlt">wind</span> stilling (slowdown) are two outstanding climate changes occurred in China over the last four decades. The <span class="hlt">wind</span> stilling may have suppressed the dispersion of aerosols and amplified the impact of aerosol emission on <span class="hlt">solar</span> dimming. However, there is a lack of long-term aerosol monitoring and associated study in China to confirm this hypothesis. Here, long-term meteorological data at weather stations combined with short-term aerosol data were used to assess this hypothesis. It was found that surface <span class="hlt">solar</span> radiation (SSR) decreased considerably with <span class="hlt">wind</span> stilling in heavily polluted regions at a daily scale, indicating that <span class="hlt">wind</span> stilling can considerably amplify the aerosol extinction effect on SSR. A threshold value of 3.5 m/s for <span class="hlt">wind</span> speed is required to effectively reduce aerosols concentration. From this SSR dependence on <span class="hlt">wind</span> speed, we further derived proxies to quantify aerosol emission and <span class="hlt">wind</span> stilling amplification effects on SSR variations at a decadal scale. The results show that aerosol emission accounted for approximately 20% of the typical <span class="hlt">solar</span> dimming in China, which was amplified by approximately 20% by <span class="hlt">wind</span> stilling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSA42A..07B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSA42A..07B"><span>Influence of <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> on Polar Ionospheric Convection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Burrell, A. G.; Yeoman, T. K.; Stephen, M.; Lester, M.</p> <p>2016-12-01</p> <p>Plasma convection over the poles shows the result of direct interactions between the terrestrial atmosphere, magnetosphere, and the sun. The paths that the ionospheric plasma takes in the polar cap form a variety of patterns, which have been shown to depend strongly on the direction of the Interplanetary Magnetic Field (IMF) and the reconnection rate. While the IMF and level of geomagnetic activity clearly alter the plasma convection patterns, the influence of changing <span class="hlt">solar</span> <span class="hlt">irradiance</span> is also important. The <span class="hlt">solar</span> <span class="hlt">irradiance</span> and magnetospheric particle precipitation regulate the rate of plasma production, and thus the ionospheric conductivity. Previous work has demonstrated how season alters the convection patterns observed over the poles, demonstrating the importance that <span class="hlt">solar</span> photoionisation has on plasma convection. This study investigates the role of <span class="hlt">solar</span> photoionisation on convection more directly, using measurements of ionospheric convection made by the Super Dual Auroral Radar Network (SuperDARN) and <span class="hlt">solar</span> <span class="hlt">irradiance</span> observations made by the <span class="hlt">Solar</span> EUV Experiment (SEE) to explore the influence of the <span class="hlt">solar</span> cycle on ionospheric convection, and the implications this may have on magnetosphere-ionosphere coupling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015TESS....110802K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015TESS....110802K"><span>Using the fingerprints of <span class="hlt">solar</span> magnetic reconnection to identify the elemental building blocks of the slow <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kepko, Larry; Viall, Nicholeen M.; Kasper, Justin; Lepri, Sue</p> <p>2015-04-01</p> <p>While the source of the fast <span class="hlt">solar</span> <span class="hlt">wind</span> is well understood to be linked to coronal holes, the source of the slow <span class="hlt">solar</span> <span class="hlt">wind</span> has remained elusive. Many previous studies of the slow <span class="hlt">solar</span> <span class="hlt">wind</span> have examined trends in the composition and charge states over long time scales and found strong relationships between the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity and these plasma parameters. These relationships have been used to constrain models of <span class="hlt">solar</span> <span class="hlt">wind</span> source and acceleration. In this study, we take advantage of high time resolution (12 min) measurements of <span class="hlt">solar</span> <span class="hlt">wind</span> composition and charge-state abundances recently reprocessed by the ACE <span class="hlt">Solar</span> <span class="hlt">Wind</span> Ion Composition Spectrometer (SWICS) science team to probe the timescales of <span class="hlt">solar</span> <span class="hlt">wind</span> variability at relatively small scales. We study an interval of slow <span class="hlt">solar</span> <span class="hlt">wind</span> containing quasi-periodic 90 minute structures and show that they are remnants of <span class="hlt">solar</span> magnetic reconnection. Each 90-minute parcel of slow <span class="hlt">solar</span> <span class="hlt">wind</span>, though the speed remains steady, exhibits the complete range of charge state and composition variations expected for the entire range of slow <span class="hlt">solar</span> <span class="hlt">wind</span>, which is repeated again in the next 90-minute interval. These observations show that previous statistical results break down on these shorter timescales, and impose new and important constraints on models of slow <span class="hlt">solar</span> <span class="hlt">wind</span> creation. We conclude by suggesting these structures were created through interchange magnetic reconnection and form elemental building blocks of the slow <span class="hlt">solar</span> <span class="hlt">wind</span>. We also discuss the necessity of decoupling separately the process(es) responsible for the release and acceleration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19790009952&hterms=history+Silver&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dhistory%2BSilver','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19790009952&hterms=history+Silver&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dhistory%2BSilver"><span>Prediction of <span class="hlt">solar</span> energetic particle event histories using real-time particle and <span class="hlt">solar</span> <span class="hlt">wind</span> measurements</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Roelof, E. C.; Gold, R. E.</p> <p>1978-01-01</p> <p>The comparatively well-ordered magnetic structure in the <span class="hlt">solar</span> corona during the decline of <span class="hlt">Solar</span> Cycle 20 revealed a characteristic dependence of <span class="hlt">solar</span> energetic particle injection upon heliographic longitude. When analyzed using <span class="hlt">solar</span> <span class="hlt">wind</span> mapping of the large scale interplanetary magnetic field line connection from the corona to the Earth, particle fluxes display an approximately exponential dependence on heliographic longitude. Since variations in the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity (and hence the coronal connection longitude) can severely distort the simple coronal injection profile, the use of real-time <span class="hlt">solar</span> <span class="hlt">wind</span> velocity measurements can be of great aid in predicting the decay of <span class="hlt">solar</span> particle events. Although such exponential injection profiles are commonplace during 1973-1975, they have also been identified earlier in <span class="hlt">Solar</span> Cycle 20, and hence this structure may be present during the rise and maximum of the cycle, but somewhat obscured by greater temporal variations in particle injection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1176751','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1176751"><span>Measuring Broadband IR <span class="hlt">Irradiance</span> in the Direct <span class="hlt">Solar</span> Beam (Presentation)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Reda, I.</p> <p>2015-03-01</p> <p><span class="hlt">Solar</span> and atmospheric science radiometers, e.g. pyranometers, pyrheliometers, and photovoltaic cells are calibrated with traceability to a consensus reference, which is maintained by Absolute Cavity Radiometers (ACRs). The ACR is an open cavity with no window, developed to measure extended broadband direct <span class="hlt">solar</span> <span class="hlt">irradiance</span> beyond the ultraviolet and infrared bands below and above 0.2 um and 50 um, respectively. On the other hand, pyranometers and pyrheliometers are developed to measure broadband shortwave <span class="hlt">irradiance</span> from approximately 0.3 um to 3 um, while the present photovoltaic cells are limited to approximately 0.3 um to 1 um. The broadband mismatch of ACR versus such radiometers causes discrepancy in radiometers' calibration methods that has not been discussed or addressed in the <span class="hlt">solar</span> and atmospheric science literature. Pyrgeometers are also used for <span class="hlt">solar</span> and atmospheric science applications and are calibrated with traceability to consensus reference, yet are calibrated during nighttime only, because no consensus reference has yet been established for the daytime longwave <span class="hlt">irradiance</span>. This poster shows a method to measure the broadband IR <span class="hlt">irradiance</span> in the direct <span class="hlt">solar</span> beam from 3 um to 50 um, as a first step that might be used to help develop calibration methods to address the mismatch between broadband ACR and shortwave radiometers, and the lack of a daytime reference for pyrgeometers. The <span class="hlt">irradiance</span> was measured from sunrise to sunset for 5 days when the sun disk was cloudless; the <span class="hlt">irradiance</span> varied from approximately 1 Wm-2 to 16 Wm-2 for <span class="hlt">solar</span> zenith angle from 80 degrees to 16 degrees respectively; estimated uncertainty is 1.5 Wm-2.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1172945','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1172945"><span>Measuring Broadband IR <span class="hlt">Irradiance</span> in the Direct <span class="hlt">Solar</span> Beam (Poster)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Reda, I.; Konings, J.; Xie, Y.; Dooraghi, M.; Sengupta, M.</p> <p>2015-03-01</p> <p><span class="hlt">Solar</span> and atmospheric science radiometers, e.g. pyranometers, pyrheliometers, and photovoltaic cells are calibrated with traceability to a consensus reference, which is maintained by Absolute Cavity Radiometers (ACRs). The ACR is an open cavity with no window, developed to measure extended broadband direct <span class="hlt">solar</span> <span class="hlt">irradiance</span> beyond the ultraviolet and infrared bands below and above 0.2 micrometers and 50 micrometers, respectively. On the other hand, pyranometers and pyrheliometers are developed to measure broadband shortwave <span class="hlt">irradiance</span> from approximately 0.3 micrometers to 3 micrcometers, while the present photovoltaic cells are limited to approximately 0.3 micrometers to 1 micrometers. The broadband mismatch of ACR versus such radiometers causes discrepancy in radiometers' calibration methods that has not been discussed or addressed in the <span class="hlt">solar</span> and atmospheric science literature. Pyrgeometers are also used for <span class="hlt">solar</span> and atmospheric science applications and calibrated with traceability to consensus reference, yet calibrated during nighttime only, because no consensus reference has yet been established for the daytime longwave <span class="hlt">irradiance</span>. This poster shows a method to measure the broadband IR <span class="hlt">irradiance</span> in the direct <span class="hlt">solar</span> beam from 3 micrometers to 50 micrometers, as first step that might be used to help develop calibration methods to address the mismatch between broadband ACR and shortwave radiometers, and the lack of a daytime reference for pyrgeometers. The <span class="hlt">irradiance</span> was measured from sunrise to sunset for 5 days when the sun disk was cloudless; the <span class="hlt">irradiance</span> varied from approximately 1 Wm-2 to 16 Wm-2 for <span class="hlt">solar</span> zenith angle from 80 degres to 16 degrees respectively; estimated uncertainty is 1.5 Wm-2.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960021284&hterms=solar+energy+you&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsolar%2Benergy%2Byou','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960021284&hterms=solar+energy+you&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsolar%2Benergy%2Byou"><span>Electron energy transport in the <span class="hlt">solar</span> <span class="hlt">wind</span>: Ulysses observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Scime, Earl; Gary, S. Peter; Phillips, J. L.; Corniileau-Wehrlin, N.; Solomon, J.</p> <p>1995-01-01</p> <p>The electron heat flux in the <span class="hlt">solar</span> <span class="hlt">wind</span> has been measured by the Ulysses <span class="hlt">solar</span> <span class="hlt">wind</span> plasma experiment in the ecliptic from 1 to 5 AU and out of the ecliptic during the recently completed pass over the <span class="hlt">solar</span> south pole and the ongoing pass over the <span class="hlt">solar</span> north pole. Although the electron heat flux contains only a fraction of the kinetic energy of the <span class="hlt">solar</span> <span class="hlt">wind</span>. the available energy is sufficient to account for the non-adiabatic expansion of the <span class="hlt">solar</span> <span class="hlt">wind</span> electrons. The Ulysses measurements indicate that the electron heat flux is actively dissipated in the <span class="hlt">solar</span> <span class="hlt">wind</span>. The exact mechanism or mechanisms is unknown. but a model based on the whistler heat flux instability predicts radial gradients for the electron heat flux in good agreement with the data. We will present measurements of the correlation between wave activity measured by the unified radio and plasma experiment (URAP) and the electron heat flux throughout the Ulysses mission. The goal is to determine if whistler waves are a good candidate for the observed electron heat flux dissipation. The latitudinal gradients of the electron heat flux. wave activity. and electron pressure will be discussed in light of the changes in the magnetic field geometry from equator to poles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17947578','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17947578"><span>Constraints on neon and argon isotopic fractionation in <span class="hlt">solar</span> <span class="hlt">wind</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Meshik, Alex; Mabry, Jennifer; Hohenberg, Charles; Marrocchi, Yves; Pravdivtseva, Olga; Burnett, Donald; Olinger, Chad; Wiens, Roger; Reisenfeld, Dan; Allton, Judith; McNamara, Karen; Stansbery, Eileen; Jurewicz, Amy J G</p> <p>2007-10-19</p> <p>To evaluate the isotopic composition of the <span class="hlt">solar</span> nebula from which the planets formed, the relation between isotopes measured in the <span class="hlt">solar</span> <span class="hlt">wind</span> and on the Sun's surface needs to be known. The Genesis Discovery mission returned independent samples of three types of <span class="hlt">solar</span> <span class="hlt">wind</span> produced by different <span class="hlt">solar</span> processes that provide a check on possible isotopic variations, or fractionation, between the <span class="hlt">solar-wind</span> and <span class="hlt">solar</span>-surface material. At a high level of precision, we observed no significant inter-regime differences in 20Ne/22Ne or 36Ar/38Ar values. For 20Ne/22Ne, the difference between low- and high-speed <span class="hlt">wind</span> components is 0.24 +/- 0.37%; for 36Ar/38Ar, it is 0.11 +/- 0.26%. Our measured 36Ar/38Ar ratio in the <span class="hlt">solar</span> <span class="hlt">wind</span> of 5.501 +/- 0.005 is 3.42 +/- 0.09% higher than that of the terrestrial atmosphere, which may reflect atmospheric losses early in Earth's history.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950063967&hterms=current+sheet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dcurrent%2Bsheet','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950063967&hterms=current+sheet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dcurrent%2Bsheet"><span><span class="hlt">Solar</span> <span class="hlt">wind</span> eddies and the heliospheric current sheet</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Suess, S. T.; Mccomas, D. J.; Bame, S. J.; Goldstein, B. E.</p> <p>1995-01-01</p> <p>Ulysses has collected data between 1 and 5 AU during, and just following <span class="hlt">solar</span> maximum, when the heliospheric current sheet (HCS) can be thought of as reaching its maximum tilt and being subject to the maximum amount of turbulence in the <span class="hlt">solar</span> <span class="hlt">wind</span>. The Ulysses <span class="hlt">solar</span> <span class="hlt">wind</span> plasma instrument measures the vector velocity and can be used to estimate the flow speed and direction in turbulent 'eddies' in the <span class="hlt">solar</span> <span class="hlt">wind</span> that are a fraction of an astronomical unit in size and last (have either a turnover or dynamical interaction time of) several hours to more than a day. Here, in a simple exercise, these <span class="hlt">solar</span> <span class="hlt">wind</span> eddies at the HCS are characterized using Ulysses data. This character is then used to define a model flow field with eddies that is imposed on an ideal HCS to estimate how the HCS will be deformed by the flow. This model inherently results in the complexity of the HCS increasing with heliocentric distance, but the result is a measure of the degree to which the observed change in complexity is a measure of the importance of <span class="hlt">solar</span> <span class="hlt">wind</span> flows in deforming the HCS. By comparison with randomly selected intervals not located on the HCS, it appears that eddies on the HCS are similar to those elsewhere at this time during the <span class="hlt">solar</span> cycle, as is the resultant deformation of the interplanetary magnetic field (IMF). The IMF deformation is analogous to what is often termed the 'random walk' of interplanetary magnetic field lines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19720038776&hterms=solar+plant&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dsolar%2Bplant','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720038776&hterms=solar+plant&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dsolar%2Bplant"><span>Penetration of <span class="hlt">solar</span> <span class="hlt">irradiances</span> through the atmosphere and plant canopies.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weinman, J. A.; Guetter, P. J.</p> <p>1972-01-01</p> <p>The equation of radiative transfer is applied to an analysis of <span class="hlt">solar</span> <span class="hlt">irradiances</span> penetrating into a plant canopy covered by a turbid atmosphere. The method of discrete coordinates is applied to vertically inhomogeneous atmospheres and plant canopies. It is shown that four-point quadrature yields results with an accuracy that is consistent with <span class="hlt">irradiance</span> measurements. It is believed that the presented computational scheme may have considerable agricultural applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E.207B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E.207B"><span>Chandrayaan-1 results on the <span class="hlt">solar</span> <span class="hlt">wind</span> ion - regolith interaction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barabash, Stas</p> <p></p> <p>Recently several missions (Kaguya, Chandrayaan-1, IBEX) revealed for the first time the complexity of the <span class="hlt">solar</span> <span class="hlt">wind</span> ions interaction with the lunar regolith. In this review we focus on the observations performed by the Chandrayaan-1 mission at the Moon but similar interaction processes take place on all airless bodies covered by regolith. Contrary to early assumptions the <span class="hlt">solar</span> <span class="hlt">wind</span> ions are not fully absorbed by the regolith but experience strong (10-20% of the impinging flux) backscattering. Only hydrogen was firmly identified. Helium for the helium enriched <span class="hlt">solar</span> <span class="hlt">wind</span> was detected only tentatively. The charge - state of the backscattered particles is mainly neutral. The fraction of H (+) varies strongly with the impinging <span class="hlt">solar</span> <span class="hlt">wind</span> velocity and constitutes 0.01 - 10% of the total backscattered flux. No H (-) ions were detected. The spectrum of the backscattered hydrogen is best-fitted by a Maxwellian distribution with a temperature of 40 - 160 eV linearly proportional to the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity. The spectrum of the backscattered protons is also Maxwellian although shifted to a velocity some what smaller than the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity. The scattering function of the neutrals is close to isotropic at large impinging angles (small <span class="hlt">solar</span> zenith angles) and becomes backward peaked at shallow impinging angles. The scattering function and energy spectra of the backscatters indicate that the <span class="hlt">solar</span> <span class="hlt">wind</span> protons experience multiple collisions with surfaces of individual grain when traveling in the inter-grain space. Why the reflection efficiency is so high in this case is a puzzle. The <span class="hlt">solar</span> <span class="hlt">wind</span> also causes sputtering of elements composing the regolith minerals. Only sputtered oxygen was identified although at levels lower than expected. Chandrayaan-1 results on the <span class="hlt">solar</span> <span class="hlt">wind</span> ion - regolith interaction still remain to be explained. The orbital measurements should be complemented by measurements from landers revealing the “ground true”. Further studies of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23092623','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23092623"><span>Analyzing UV-B narrowband <span class="hlt">solar</span> <span class="hlt">irradiance</span>: comparison with erythemal and vitamin D production <span class="hlt">irradiances</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sola, Yolanda; Lorente, Jerónimo; Ossó, Albert</p> <p>2012-12-05</p> <p>The heliotherapy and the phototherapy are mainly focused on taking benefit of the therapeutic effects of the ultraviolet (UV) <span class="hlt">irradiance</span> on different skin diseases. The use of UV-B narrowband lamps, with emissions centered at 311 nm, has spread out among the dermatologist community because of its high therapeutic effect in comparison with its low erythema dose. For cloudless sun exposure, the balance of <span class="hlt">solar</span> erythemal and <span class="hlt">solar</span> narrowband (NB)-equivalent <span class="hlt">irradiances</span> depends on several factors such as the <span class="hlt">solar</span> zenith angle (SZA), the total ozone column (TOC) and the altitude. For SZA below 55°, the ratio of <span class="hlt">solar</span> UV-B narrowband and erythemal <span class="hlt">irradiances</span> increases with the SZA whereas the ratio of vitamin D production and erythemal <span class="hlt">irradiances</span> decreases with the SZA with the maximum around midday. Furthermore, the <span class="hlt">solar</span> NB ratio also increases with the TOC because the shorter wavelengths of the erythemal action spectrum are more affected by the ozone absorption processes. Considering the daily variations of the ratio between narrowband and erythemal <span class="hlt">irradiance</span>, sun exposures avoiding midday hours are recommended in order to prevent negative side-effects. However to accumulate great NB doses and sufficient vitamin D in winter months is difficult because the time exposures may be longer than the day duration. Copyright © 2012 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950058980&hterms=climate+change+solar+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dclimate%2Bchange%2Bsolar%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950058980&hterms=climate+change+solar+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dclimate%2Bchange%2Bsolar%2Benergy"><span>A discussion of plausible <span class="hlt">solar</span> <span class="hlt">irradiance</span> variations, 1700-1992</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hoyt, Douglas V.; Schatten, Kenneth H.</p> <p>1993-01-01</p> <p>From satellite observations the <span class="hlt">solar</span> total <span class="hlt">irradiance</span> is known to vary. Sunspot blocking, facular emission, and network emission are three identified causes for the variations. In this paper we examine several different <span class="hlt">solar</span> indices measured over the past century that are potential proxy measures for the Sun's <span class="hlt">irradiance</span>. These indices are (1) the equatorial <span class="hlt">solar</span> rotation rate, (2) the sunspot structure, the decay rate of individual sunspots, and the number of sunspots without umbrae, and (3) the length and decay rate of the sunspot cycle. Each index can be used to develop a model for the Sun's total <span class="hlt">irradiance</span> as seen at the Earth. Three <span class="hlt">solar</span> indices allow the <span class="hlt">irradiance</span> to be modeled back to the mid-1700s. The indices are (1) the length of the <span class="hlt">solar</span> cycle, (2) the normalized decay rate of the <span class="hlt">solar</span> cycle, and (3) the mean level of <span class="hlt">solar</span> activity. All the indices are well correlated, and one possible explanation for their nearly simultaneous variations is changes in the Sun's convective energy transport. Although changes in the Sun's convective energy transport are outside the realm of normal stellar structure theory (e.g., mixing length theory), one can imagine variations arising from even the simplest view of sunspots as vertical tubes of magnetic flux, which would serve as rigid pillas affecting the energy flow patterns by ensuring larger-scale eddies. A composite <span class="hlt">solar</span> <span class="hlt">irradiance</span> model, based upon these proxies, is compared to the northern hemisphere temperature depatures for 1700-1992. Approximately 71% of the decadal variance in the last century can be modeled with these <span class="hlt">solar</span> indices, although this analysis does not include anthropogenic or other variations which would affect the results. Over the entire three centuries, approx. 50% of the variance is modeled. Both this analysis and previous similar analyses have correlations of model <span class="hlt">solar</span> <span class="hlt">irradiances</span> and measured Earth surface temperatures that are significant at better than the 95% confidence level</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080022945','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080022945"><span>On the Relationship Between <span class="hlt">Solar</span> <span class="hlt">Wind</span> Speed, Geomagnetic Activity, and the <span class="hlt">Solar</span> Cycle Using Annual Values</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, Robert M.; Hathaway, David H.</p> <p>2008-01-01</p> <p>The aa index can be decomposed into two separate components: the leading sporadic component due to <span class="hlt">solar</span> activity as measured by sunspot number and the residual or recurrent component due to interplanetary disturbances, such as coronal holes. For the interval 1964-2006, a highly statistically important correlation (r = 0.749) is found between annual averages of the aa index and the <span class="hlt">solar</span> <span class="hlt">wind</span> speed (especially between the residual component of aa and the <span class="hlt">solar</span> <span class="hlt">wind</span> speed, r = 0.865). Because cyclic averages of aa (and the residual component) have trended upward during cycles 11-23, cyclic averages of <span class="hlt">solar</span> <span class="hlt">wind</span> speed are inferred to have also trended upward.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17790539','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17790539"><span><span class="hlt">Solar</span> flare acceleration of <span class="hlt">solar</span> <span class="hlt">wind</span>: influence of active region magnetic field.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lundstedt, H; Wilcox, J M; Scherrer, P H</p> <p>1981-06-26</p> <p>The direction of the photospheric magnetic field at the site of a <span class="hlt">solar</span> flare is a good predictor of whether the flare will accelerate <span class="hlt">solar</span> <span class="hlt">wind</span> plasma. If the field has a southward component, high-speed <span class="hlt">solar</span> <span class="hlt">wind</span> plasma is usually observed near the earth about 4 days later. If the field has a northward component, such high-speed <span class="hlt">solar</span> <span class="hlt">wind</span> is almost never observed. Southward-field flares may then be expected to have much larger terrestrial effects than northward flares.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.3347T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.3347T"><span><span class="hlt">Solar</span> cycle dependence of the distribution of <span class="hlt">solar</span> <span class="hlt">wind</span> in-situ plasma parameters, and how this drives <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere coupling parameters.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tindale, Elizabeth; Chapman, Sandra</p> <p>2017-04-01</p> <p>Climate is the statistical distribution of observed weather and we thus expect the climate of space weather to vary with the <span class="hlt">solar</span> cycle of activity. The 11-year <span class="hlt">solar</span> cycle is irregular, with each cycle exhibiting a unique duration and peak activity. The distinct activity of each cycle is then coupled from the Sun to the Earth's magnetosphere via the <span class="hlt">solar</span> <span class="hlt">wind</span>, leading to long-term trends in the statistics of space weather. Here, we introduce the data quantile-quantile (DQQ) plot as a model-independent method for tracing <span class="hlt">solar</span> cycle changes in the likelihood of observing a given energy flow in the <span class="hlt">solar</span> <span class="hlt">wind</span>. We apply the method to 1-minute resolution <span class="hlt">Wind</span> data spanning the minima and maxima of cycles 23 and 24 [1]. We consider in-situ <span class="hlt">solar</span> <span class="hlt">wind</span> plasma parameters in fast and slow <span class="hlt">solar</span> <span class="hlt">wind</span> such as the magnetic energy density and the Poynting flux and how these influence commonly used <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere coupling functions such as Akasofu's ɛ parameter. The core of the plasma parameter distributions retains a log-normal functional form simply varying in amplitude with the <span class="hlt">solar</span> cycles, in agreement with previous work [e.g. 2] and suggestive of a multiplicative underlying physical process consistent with turbulence. The DQQ method also identifies the threshold energy flux at which <span class="hlt">solar</span> <span class="hlt">wind</span> plasma parameters depart from the lognormal regime; this 'extremal' component exhibits its own dependence on the <span class="hlt">solar</span> cycle which is distinct between fast and slow <span class="hlt">wind</span>. How the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma parameter distributions vary, and how this variation is reflected in that of the <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere coupling functions, is different between fast and slow <span class="hlt">solar</span> <span class="hlt">wind</span>. We can use this approach to compare different <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere coupling parameters to determine which, and under what conditions, are most sensitive to these <span class="hlt">solar</span> cycle <span class="hlt">solar</span> <span class="hlt">wind</span> changes. [1] Tindale, E., and S.C. Chapman (2016), Geophys. Res. Lett., 43(11), doi: 10.1002/2016GL068920. [2] Burlaga</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007coma.book..161W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007coma.book..161W"><span><span class="hlt">Solar</span> and <span class="hlt">Solar-Wind</span> Composition Results from the Genesis Mission</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wiens, R. C.; Burnett, D. S.; Hohenberg, C. M.; Meshik, A.; Heber, V.; Grimberg, A.; Wieler, R.; Reisenfeld, D. B.</p> <p></p> <p>The Genesis mission returned samples of <span class="hlt">solar</span> <span class="hlt">wind</span> to Earth in September 2004 for ground-based analyses of <span class="hlt">solar-wind</span> composition, particularly for isotope ratios. Substrates, consisting mostly of high-purity semiconductor materials, were exposed to the <span class="hlt">solar</span> <span class="hlt">wind</span> at L1 from December 2001 to April 2004. In addition to a bulk sample of the <span class="hlt">solar</span> <span class="hlt">wind</span>, 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 <span class="hlt">solar</span> <span class="hlt">wind</span> and in different <span class="hlt">solar-wind</span> 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 <span class="hlt">solar</span> <span class="hlt">wind</span> and separate <span class="hlt">solar-wind</span> 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 <span class="hlt">solar-wind</span> 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 <span class="hlt">solar</span> <span class="hlt">wind</span> trapped in lunar grains and meteorites. Isotope ratios of the heavy noble gases, nitrogen, and oxygen are in the process of being measured.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007SSRv..130..161W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007SSRv..130..161W"><span><span class="hlt">Solar</span> and <span class="hlt">Solar-Wind</span> Composition Results from the Genesis Mission</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wiens, R. C.; Burnett, D. S.; Hohenberg, C. M.; Meshik, A.; Heber, V.; Grimberg, A.; Wieler, R.; Reisenfeld, D. B.</p> <p>2007-06-01</p> <p>The Genesis mission returned samples of <span class="hlt">solar</span> <span class="hlt">wind</span> to Earth in September 2004 for ground-based analyses of <span class="hlt">solar-wind</span> composition, particularly for isotope ratios. Substrates, consisting mostly of high-purity semiconductor materials, were exposed to the <span class="hlt">solar</span> <span class="hlt">wind</span> at L1 from December 2001 to April 2004. In addition to a bulk sample of the <span class="hlt">solar</span> <span class="hlt">wind</span>, 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 <span class="hlt">solar</span> <span class="hlt">wind</span> and in different <span class="hlt">solar-wind</span> 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 <span class="hlt">solar</span> <span class="hlt">wind</span> and separate <span class="hlt">solar-wind</span> 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 <span class="hlt">solar-wind</span> 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 <span class="hlt">solar</span> <span class="hlt">wind</span> trapped in lunar grains and meteorites. Isotope ratios of the heavy noble gases, nitrogen, and oxygen are in the process of being measured.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.1126V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.1126V"><span>Modeling the spectral <span class="hlt">solar</span> <span class="hlt">irradiance</span> in the SOTERIA Project Framework</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vieira, Luis Eduardo; Dudok de Wit, Thierry; Kretzschmar, Matthieu; Cessateur, Gaël</p> <p></p> <p>The evolution of the radiative energy input is a key element to understand the variability of the Earth's neutral and ionized atmospheric components. However, reliable observations are limited to the last decades, when observations realized above the Earth's atmosphere became possible. These observations have provide insights about the variability of the spectral <span class="hlt">solar</span> <span class="hlt">irradiance</span> on time scales from days to years, but there is still large uncertainties on the evolu-tion on time scales from decades to centuries. Here we discuss the physics-based modeling of the ultraviolet <span class="hlt">solar</span> <span class="hlt">irradiance</span> under development in the <span class="hlt">Solar</span>-Terrestrial Investigations and Archives (SOTERIA) project framework. In addition, we compare the modeled <span class="hlt">solar</span> emission with variability observed by LYRA instrument onboard of Proba2 spacecraft.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSH13B2256R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSH13B2256R"><span>Comparing <span class="hlt">Solar</span> <span class="hlt">Wind</span> Velocity Measurements Derived from Sun-grazing Comet Lovejoy (C/2011 W3) with <span class="hlt">Solar</span> <span class="hlt">Wind</span> Models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ramanjooloo, Y.; Jones, G. H.; Coates, A. J.; Owens, M. J.; Battams, K.</p> <p>2012-12-01</p> <p>Comets' plasma (type I) tails have been studied as natural probes of the <span class="hlt">solar</span> <span class="hlt">wind</span> since the mid-20th century. Local <span class="hlt">solar</span> <span class="hlt">wind</span> conditions directly control the morphology and dynamics of a comet's plasma tail. During ideal observing geometries, the orientation and structure of the plasma tail can reveal large-scale and small-scale variations in the local <span class="hlt">solar</span> <span class="hlt">wind</span> structure. We present <span class="hlt">solar</span> <span class="hlt">wind</span> velocity measurements derived from multiple observing locations of comet Lovejoy (C/2011 W3) from the 14th - 19th December 2011 using recent images from the SECCHI and LASCO heliospheric imagers and coronagraphs aboard STEREO A and B, and SOHO. Overlapping observation sessions from the three spacecraft provided the perfect opportunity to use comet Lovejoy as a diagnostic tool to understand <span class="hlt">solar</span> <span class="hlt">wind</span> variability close to the Sun. Our unique analysis technique [submitted] allows us to determine the latitudinal variations of the <span class="hlt">solar</span> <span class="hlt">wind</span>, heliospheric current sheet sector boundaries and the boundaries of transient features as comet Lovejoy probes the Sun's atmosphere. We plan to compare our observations to results of suitable simulations of plasma conditions in the corona and inner heliosphere during the time of Lovejoy's perihelion passage.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015TESS....140902M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015TESS....140902M"><span>Plasma Properties of Pseudostreamers and Their <span class="hlt">Solar</span> <span class="hlt">Wind</span> Streams</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miralles, Mari Paz; Allen, Lorraine A.</p> <p>2015-04-01</p> <p>We study pseudostreamers (i.e., open-field extensions of plasma from unipolar footpoints in the corona; distinct from classical helmet streamers that have opposite-polarity footpoints) that are believed to be sources of slow to intermediate speed <span class="hlt">wind</span> streams. We make use of multi-spacecraft and ground-based observations that extend from the <span class="hlt">solar</span> corona to the <span class="hlt">solar</span> <span class="hlt">wind</span> at 1 AU. We compare the physical properties of selected pseudostreamers and helmet streamers to characterize how the differences in magnetic topology affect the plasma properties of the coronal structures and their <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21371703','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21371703"><span>Velocity Distributions and Proton Beam Production in the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pierrard, Viviane; Voitenko, Yuriy</p> <p>2010-03-25</p> <p>Helios, Ulysses, and <span class="hlt">Wind</span> spacecraft have observed the velocity distribution functions (VDFs) of <span class="hlt">solar</span> <span class="hlt">wind</span> particles deviating significantly from Maxwellians. We review recent models using different approximations and mechanisms that determine various observed characteristics of the VDFs for the electrons, protons and minor ions. A new generation mechanism is proposed for super-Alfvenic proton beams and tails that are often observed in the fast <span class="hlt">solar</span> <span class="hlt">wind</span>. The mechanism is based on the proton trapping and acceleration by kinetic Alfven waves (KAWs), which carry a field-aligned potential well propagating with super-Alfven velocities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840019583&hterms=lazy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dlazy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840019583&hterms=lazy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dlazy"><span>Modelling <span class="hlt">Solar</span> Spectral <span class="hlt">Irradiance</span> Variations at Ultraviolet Wavelengths</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lean, J. L.; Livingston, W. C.; White, O. R.; Skumanich, A.</p> <p>1984-01-01</p> <p><span class="hlt">Solar</span> UV <span class="hlt">irradiance</span> variations with <span class="hlt">solar</span> activity are examined using a three component model of the CaII K chromospheric emission. This model, developed from ground based observations of the location, area and relative intensity of CaII K plage, in conjunction with measurements throughout <span class="hlt">solar</span> cycle 21 of the full disc CaII K emission, includes the contributions to the ultraviolet flux from both plage and active network emission. The model successfully replicates changes in the Lyman alpha flux related to the 27 day rotation of <span class="hlt">solar</span> plage, outbreaks (or rounds) of activity over periods of a year or more, and the growth and accumulation of active regions over the eleven year <span class="hlt">solar</span> activity cycles. Estimates of the magnitude of the <span class="hlt">solar</span> cycle variability of the UV emission between 200 and 300 nm are presented but cannot currently be verified by available observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.3071S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.3071S"><span>Lyman alpha <span class="hlt">solar</span> spectral <span class="hlt">irradiance</span> line profile observations and models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Snow, Martin; Machol, Janet; Quemerais, Eric; Curdt, Werner; Kretschmar, Matthieu; Haberreiter, Margit</p> <p>2016-04-01</p> <p><span class="hlt">Solar</span> lyman alpha <span class="hlt">solar</span> spectral <span class="hlt">irradiance</span> measurements are available on a daily basis, but only the 1-nm integrated flux is typically published. The International Space Science Institute (ISSI) in Bern, Switzerland has sponsored a team to make higher spectral resolution data available to the community. Using a combination of SORCE/SOLSTICE and SOHO/SUMER observations plus empirical and semi-empirical modeling, we will produce a dataset of the line profile. Our poster will describe progress towards this goal.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19830014039','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830014039"><span><span class="hlt">Solar</span> ultraviolet spectral <span class="hlt">irradiance</span> monitor experiment on OSS-1</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Vanhossier, M. E.</p> <p>1983-01-01</p> <p>The need to improve the accuracy of measurement of the absolute <span class="hlt">solar</span> flux within the wavelength range 120 nm to 400 nm requires an extensive effort in contamination control and in tracking the instruments' stability. The techniques used in the <span class="hlt">solar</span> ultraviolet <span class="hlt">irradiance</span> monitor are described. These methods resulted in very high calibration stability as proved by preflight and postflight calibration. In-flight calibrating and the pointing accuracy provided by the shuttle attitude control system are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SoPh..291.3777L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SoPh..291.3777L"><span>A Possible Cause of the Diminished <span class="hlt">Solar</span> <span class="hlt">Wind</span> During the <span class="hlt">Solar</span> Cycle 23 - 24 Minimum</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liou, Kan; Wu, Chin-Chun</p> <p>2016-12-01</p> <p>Interplanetary magnetic field and <span class="hlt">solar</span> <span class="hlt">wind</span> plasma density observed at 1 AU during <span class="hlt">Solar</span> Cycle 23 - 24 (SC-23/24) minimum were significantly smaller than those during its previous <span class="hlt">solar</span> cycle (SC-22/23) minimum. Because the Earth's orbit is embedded in the slow <span class="hlt">wind</span> during <span class="hlt">solar</span> minimum, changes in the geometry and/or content of the slow <span class="hlt">wind</span> region (SWR) can have a direct influence on the <span class="hlt">solar</span> <span class="hlt">wind</span> parameters near the Earth. In this study, we analyze <span class="hlt">solar</span> <span class="hlt">wind</span> plasma and magnetic field data of hourly values acquired by Ulysses. It is found that the <span class="hlt">solar</span> <span class="hlt">wind</span>, when averaging over the first (1995.6 - 1995.8) and third (2006.9 - 2008.2) Ulysses' perihelion ({˜} 1.4 AU) crossings, was about the same speed, but significantly less dense ({˜} 34 %) and cooler ({˜} 20 %), and the total magnetic field was {˜} 30 % weaker during the third compared to the first crossing. It is also found that the SWR was {˜} 50 % wider in the third ({˜} 68.5^deg; in heliographic latitude) than in the first ({˜} 44.8°) <span class="hlt">solar</span> orbit. The observed latitudinal increase in the SWR is sufficient to explain the excessive decline in the near-Earth <span class="hlt">solar</span> <span class="hlt">wind</span> density during the recent <span class="hlt">solar</span> minimum without speculating that the total <span class="hlt">solar</span> output may have been decreasing. The observed SWR inflation is also consistent with a cooler <span class="hlt">solar</span> <span class="hlt">wind</span> in the SC-23/24 than in the SC-22/23 minimum. Furthermore, the ratio of the high-to-low latitude photospheric magnetic field (or equatorward magnetic pressure force), as observed by the Mountain Wilson Observatory, is smaller during the third than the first Ulysses' perihelion orbit. These findings suggest that the smaller equatorward magnetic pressure at the Sun may have led to the latitudinally-wider SRW observed by Ulysses in SC-23/24 minimum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1616241V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1616241V"><span>Possible external sources of terrestrial cloud cover variability: the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Voiculescu, Mirela; Usoskin, Ilya; Condurache-Bota, Simona</p> <p>2014-05-01</p> <p>Cloud cover plays an important role in the terrestrial radiation budget. The possible influence of the <span class="hlt">solar</span> activity on cloud cover is still an open question with contradictory answers. An extraterrestrial factor potentially affecting the cloud cover is related to fields associated with <span class="hlt">solar</span> <span class="hlt">wind</span>. We focus here on a derived quantity, the interplanetary electric field (IEF), defined as the product between the <span class="hlt">solar</span> <span class="hlt">wind</span> speed and the meridional component, Bz, of the interplanetary magnetic field (IMF) in the Geocentric <span class="hlt">Solar</span> Magnetospheric (GSM) system. We show that cloud cover at mid-high latitudes systematically correlates with positive IEF, which has a clear energetic input into the atmosphere, but not with negative IEF, in general agreement with predictions of the global electric circuit (GEC)-related mechanism. Since the IEF responds differently to <span class="hlt">solar</span> activity than, for instance, cosmic ray flux or <span class="hlt">solar</span> <span class="hlt">irradiance</span>, we also show that such a study allows distinguishing one <span class="hlt">solar</span>-driven mechanism of cloud evolution, via the GEC, from others. We also present results showing that the link between cloud cover and IMF varies depending on composition and altitude of clouds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18764383','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18764383"><span>Eigenmode structure in <span class="hlt">solar-wind</span> Langmuir waves.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ergun, R E; Malaspina, D M; Cairns, Iver H; Goldman, M V; Newman, D L; Robinson, P A; Eriksson, S; Bougeret, J L; Briand, C; Bale, S D; Cattell, C A; Kellogg, P J; Kaiser, M L</p> <p>2008-08-01</p> <p>We show that observed spatial- and frequency-domain signatures of intense <span class="hlt">solar-wind</span> Langmuir waves can be described as eigenmodes trapped in a parabolic density well. Measured <span class="hlt">solar-wind</span> electric field spectra and waveforms are compared with 1D linear solutions and, in many cases, can be represented by 1-3 low-order eigenstates. To our knowledge, this report is the first observational confirmation of Langmuir eigenmodes in space. These results suggest that linear eigenmodes may be the starting point of the nonlinear evolution, critical for producing <span class="hlt">solar</span> type II and type III radio bursts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22304144','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22304144"><span>Scale-free texture of the fast <span class="hlt">solar</span> <span class="hlt">wind</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hnat, B; Chapman, S C; Gogoberidze, G; Wicks, R T</p> <p>2011-12-01</p> <p>The higher-order statistics of magnetic field magnitude fluctuations in the fast quiet <span class="hlt">solar</span> <span class="hlt">wind</span> are quantified systematically, scale by scale. We find a single global non-Gaussian scale-free behavior from minutes to over 5 h. This spans the signature of an inertial range of magnetohydrodynamic turbulence and a ~1/f range in magnetic field components. This global scaling in field magnitude fluctuations is an intrinsic component of the underlying texture of the <span class="hlt">solar</span> <span class="hlt">wind</span> and puts a strong constraint on any theory of <span class="hlt">solar</span> corona and the heliosphere. Intriguingly, the magnetic field and velocity components show scale-dependent dynamic alignment outside of the inertial range.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080022193&hterms=INTERFACE+INTERACTION&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DINTERFACE%2BINTERACTION','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080022193&hterms=INTERFACE+INTERACTION&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DINTERFACE%2BINTERACTION"><span><span class="hlt">Solar</span> <span class="hlt">Wind</span> Stream Interaction Regions without Sector Boundaries</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Neugebauer, M.; Liewer, P. C.; Goldstein, B. E.; Zhou., X.; Steinberg, J. T.</p> <p>2004-01-01</p> <p>During periods of high <span class="hlt">solar</span> activity when there are many sources of <span class="hlt">solar</span> <span class="hlt">wind</span> on the <span class="hlt">solar</span> disk, a spacecraft occasionally encounters consecutive <span class="hlt">solar</span> <span class="hlt">wind</span> streams with the same magnetic polarity. The low-speed <span class="hlt">wind</span> in the region of interaction between the two streams exhibits many of the same features as, but has some differences from, the low-speed <span class="hlt">wind</span> that includes crossings of the heliospheric current sheet (HCS) where the direction of the heliospheric magnetic field reverses. The non-HCS slow <span class="hlt">wind</span> exhibits many of the same small-scale structures usually associated with the slow <span class="hlt">wind</span> around the HCS; these include discontinuous stream interfaces and other discontinuities, magnetic holes, and low-entropy structures. These entropy holes do not appear to have the same origin as the plasma sheets observed near the HCS, however. The helium abundances and heavy ion charge states in the non-HCS regions are not significantly different from those in HCS-associated regions. Some of the dynamical properties of the non-HCS regions differ from those found near the HCS; the regions between leading and trailing stream interfaces have a shorter duration or scale size, greater minimum speed, and lower peak and average densities. No correlation could be found between the non-HCS slow <span class="hlt">wind</span> and visible coronal streamers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22342072','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22342072"><span>The Yaglom law in the expanding <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gogoberidze, G.; Perri, S.; Carbone, V.</p> <p>2013-06-01</p> <p>We study the Yaglom law, which relates the mixed third-order structure function to the average dissipation rate of turbulence, in a uniformly expanding <span class="hlt">solar</span> <span class="hlt">wind</span> by using the two-scale expansion model of magnetohydrodynamic (MHD) turbulence. We show that due to the expansion of the <span class="hlt">solar</span> <span class="hlt">wind</span>, two new terms appear in the Yaglom law. The first term is related to the decay of the turbulent energy by nonlinear interactions, whereas the second term is related to the non-zero cross-correlation of the Elsässer fields. Using magnetic field and plasma data from <span class="hlt">WIND</span> and Helios 2 spacecrafts, we show that at lower frequencies in the inertial range of MHD turbulence the new terms become comparable to Yaglom's third-order mixed moment, and therefore they cannot be neglected in the evaluation of the energy cascade rate in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSH53A2268M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSH53A2268M"><span>Coronal Streamers and Their Associated <span class="hlt">Solar</span> <span class="hlt">Wind</span> Streams</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miralles, M. P.; Landi, E.; Cranmer, S. R.; Cohen, O.; Raymond, J. C.</p> <p>2012-12-01</p> <p>We use the EUV spectrometers aboard SOHO and Hinode and white-light coronagraphs to characterize the physical properties of coronal streamers during Earth/Ulysses quadrature configurations for the previous two <span class="hlt">solar</span> minimum periods. In addition, comparisons between coronal observations and in situ measurements of <span class="hlt">solar</span> <span class="hlt">wind</span> plasma properties are being used to further characterize the origins of slow <span class="hlt">wind</span> streams. In order to investigate slow <span class="hlt">solar</span> <span class="hlt">wind</span> heating and acceleration, we also compare with predictions from three-dimensional MHD models. We aim to use the empirical measurements to distinguish between different proposed physical processes for slow <span class="hlt">wind</span> acceleration (e.g., waves/turbulence versus reconnection). This work is supported by NASA grant NNX10AQ58G to the Smithsonian Astrophysical Observatory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/582279','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/582279"><span>Shear flow induced wave couplings in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Poedts, S.; Rogava, A.D. |; Mahajan, S.M. |</p> <p>1998-01-01</p> <p>A sheared background flow in a plasma induces coupling between different MHD wave modes, resulting in their mutual transformations with corresponding energy redistributing between the modes. In this way, the energy can be transfered from one wave mode to the other, but energy can also be added to or extracted from the background flow. In the present paper it is investigated whether the wave coupling and energy transfer mechanisms can operate under <span class="hlt">solar</span> <span class="hlt">wind</span> conditions. It is shown that this is indeed the case. Hence, the long-period waves observed in the <span class="hlt">solar</span> <span class="hlt">wind</span> at r > 0.3 AU might be generated by much faster periodic oscillations in the photosphere of the Sun. Other possible consequences for observable beat phenomena in the <span class="hlt">wind</span> and the acceleration of the <span class="hlt">solar</span> <span class="hlt">wind</span> particles are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.A11I0133R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.A11I0133R"><span>Continuing the <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> Data Record with TSIS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Richard, E. C.; Pilewskie, P.; Kopp, G.; Coddington, O.; Woods, T. N.; Wu, D. L.</p> <p>2016-12-01</p> <p>The Total and Spectral <span class="hlt">Solar</span> <span class="hlt">Irradiance</span> Sensor (TSIS), first selected in 1998 for the National Polar-orbiting Operational Environmental Satellite System (NPOESS), re-manifested in 2010 on the NOAA-NASA Joint Polar Satellite System (JPSS), then the NOAA Polar Free Flyer, is now scheduled for deployment in 2017 on the International Space Station. The TSIS will acquire measurements of total and spectral <span class="hlt">solar</span> <span class="hlt">irradiance</span> (TSI and SSI, respectively). TSIS provides continuation of the Total <span class="hlt">Irradiance</span> Monitor (TIM) and the Spectral <span class="hlt">Irradiance</span> Monitor (SIM), currently flying on the NASA