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1

Pioneer Venus and IMP 8 observations of the latitude dependence of the solar wind  

NASA Technical Reports Server (NTRS)

Solar wind speeds and magnetic field data from the Pioneer Venus Orbiter (0.7 AU) and IMP 8 (1 AU) have been compared to infer the latitudinal structure of the solar wind in the inner heliosphere between 1984 and 1987. The solar wind in the inner heliosphere was found to exhibit an unusual structure during the last solar minimum (1986-1987). High-speed streams were excluded from the vicinity of the solar equator, and the solar wind at low heliographic latitudes (less than 3 deg) was characterized by low-speed solar wind with irregular fluctuations in velocity. At higher latitudes the solar wind had a conventional stream structure with two high-speed streams per solar rotation. While the velocities of these high-speed streams did not appear to vary significantly with latitude, the latitudinal gradients at the equatorward boundaries of high-speed streams were high.

Gazis, P. R.

1993-01-01

2

Time and latitude dependence of the solar wind mass flux derived from the SOHO/SWAN data analysis  

NASA Astrophysics Data System (ADS)

We present an updated analysis of the complete SOHO/SWAN Lyman-? dataset spanning from 1996 to 2011. We calculate the total interstellar hydrogen ionization rates as a function of latitude and time by fitting a hot model to the calibrated SWAN maps. The ionization is produced mainly by charge exchange with the solar wind ions. We normalize the derived rates to the ecliptic measured values of solar wind charge exchange rates from in-situ data, combined with photoionization rates derived by EUV data. We derive the solar wind mass flux distribution and discuss the results.

Koutroumpa, D.; Quemerais, E.; Lallement, R.; Ferron, S.; Bertaux, J.

2012-12-01

3

Latitude-Dependent Temperature Variations at the Solar Limb  

NASA Astrophysics Data System (ADS)

We use observations from the solar aspect sensor of RHESSI to characterize the latitude dependence of the temperature of the photosphere at the solar limb. Previous observations have suggested the presence of a polar temperature excess as large as 1.5 K. The RHESSI observations, made with a rotating telescope in space, have great advantages in the rejection of systematic errors in the very precise photometry required for such an observation. This photometry is differential, i.e. relative to a mean limb-darkening function. The data base consists of about 1,000 images per day from linear CCDs with 1.73 arc sec square pixels, observing a narrow band (12nm FWHM) at 670 nm. Each image shows a chord crossing the disk at a different location as the spacecraft rotates and precesses around its average solar pointing. We fit an average limb-darkening function and reassemble the residuals into synoptic maps of differential intensity variations as function of position angle. We further mask these images against SOHO/EIT 284A images in order to eliminate magnetic regions. The analysis establishes a limit on the quadrupole dependence of temperature (brightness) on position angle of 0.04 +/- 0.02 K. This results in a possible correction of our precise measurement of the solar oblateness which is smaller than its rms error of 0.14 mas.

Fivian, M. D.; Hudson, H. S.; Lin, R. P.; Zahid, H. J.

2009-12-01

4

Depth and latitude dependence of the solar internal angular velocity  

NASA Technical Reports Server (NTRS)

One of the design goals for the dedicated helioseismology observing state located at Mount Wilson Observatory was the measurement of the internal solar rotation using solar p-mode oscillations. In this paper, the first p-mode splittings obtained from Mount Wilson are reported and compared with those from several previously published studies. It is demonstrated that the present splittings agree quite well with composite frequency splittings obtained from the comparisons. The splittings suggest that the angular velocity in the solar equatorial plane is a function of depth below the photosphere. The latitudinal differential rotation pattern visible at the surface appears to persist at least throughout the solar convection zone.

Rhodes, Edward J., Jr.; Cacciani, Alessandro; Korzennik, Sylvain; Tomczyk, Steven; Ulrich, Roger K.; Woodard, Martin F.

1990-01-01

5

Solar modulation of galactic cosmic rays 4: Latitude dependent modulation  

NASA Technical Reports Server (NTRS)

A numerical method is outlined for solving the equation which describes the solar modulation of cosmic rays in models where interplanetary conditions can vary with heliocentric latitude. As an illustration of the use of this method, it is shown how variations in the modulation with latitude could produce the small radial gradients in the intensity that were observed from the Pioneers 10 and 11 spacecraft.

Fisk, L. A.

1976-01-01

6

Time trends and latitude dependence of uveal and cutaneous malignant melanoma induced by solar radiation  

SciTech Connect

In order to evaluate the role of solar radiation in uveal melanoma etiology, the time and latitude dependency of the incidence rates of this melanoma type were studied in comparison with those of cutaneous malignant melanoma (CMM). Norway and several other countries with Caucasian populations were included. There is a marked north - south gradient of the incidence rates of CMM in Norway, with three times higher rates in the south than in the north. No such gradient is found for uveal melanoma. Similar findings have been published for CMM in other Caucasian populations, with the exception of Europe as a whole. In most populations the ratios of uveal melanoma incidence rates to those of CMM tend to decrease with increasing CMM rates. This is also true for Europe, in spite of the fact that in this region there is an inverse latitude gradient of CMM, with higher rates in the north than in the south. In Norway the incidence rates of CMM have increased until about 1990 but have been constant, or even decreased (for young people) after that time, indicating constant or decreasing sun exposure. The uveal melanoma rates have been increasing after 1990. In most other populations the incidence rates of CMM have been increasing until recently while those of uveal melanoma have been decreasing. These data generally support the assumption that uveal melanomas are not generated by ultraviolet (UV) radiation and that solar UV, via its role in vitamin D photosynthesis, may have a protective effect.

Moan, J.; Setlow, R.; Cicarma, E.; Porojnicu, A. C.; Grant, W. B.; Juzeniene, A.

2010-01-01

7

Time trends and latitude dependence of uveal and cutaneous malignant melanoma induced by solar radiation  

PubMed Central

In order to evaluate the role of solar radiation in uveal melanoma etiology, the time and latitude dependency of the incidence rates of this melanoma type were studied in comparison with those of cutaneous malignant melanoma (CMM). Norway and several other countries with Caucasian populations were included. there is a marked north-south gradient of the incidence rates of CMM in Norway, with three times higher rates in the south than in the north. No such gradient is found for uveal melanoma. Similar findings have been published for CMM in other Caucasian populations, with the exception of Europe as a whole. In most populations the ratios of uveal melanoma incidence rates to those of CMM tend to decrease with increasing CMM rates. This is also true for Europe, in spite of the fact that in this region there is an inverse latitude gradient of CMM, with higher rates in the north than in the south. In Norway the incidence rates of CMM have increased until about 1990 but have been constant or even decreased (for young people) after that time, indicating constant or decreasing sun exposure. The uveal melanoma rates have been increasing after 1990. In most other populations the incidence rates of CMM have been increasing until recently while those of uveal melanoma have been decreasing. These data generally support the assumption that uveal melanomas are not generated by ultraviolet (UV) radiation and that solar UV, via its role in vitamin D photosynthesis, may have a protective effect.

Moan, Johan; Cicarma, Emanuela; Setlow, Richard; Porojnicu, Alina C; Grant, William B

2010-01-01

8

Latitude-Dependent Effects in the Stellar Wind of Eta Carinae  

NASA Technical Reports Server (NTRS)

The Homunculus reflection nebula around eta Carinae provides the rare opportunity to observe the spectrum of a star from more than one direction. In the case of eta Car, the nebula's geometry is known well enough to infer how wind profiles vary with latitude. We present STIS spectra of several positions in the Homunculus, showing directly that eta Car has an aspherical and axisymmetric stellar wind. P Cygni absorption in Balmer lines depends on latitude, with relatively high velocities and strong absorption near the polar axis. Stronger absorption at high latitudes is surprising, and it suggests higher mass flux toward the poles, perhaps resulting from equatorial gravity darkening on a rotating star. Reflected profiles of He I lines are more puzzling, and offer clues to eta Car's wind geometry and ionization structure. During eta Car's high-excitation state in March 2000, the wind had a fast, dense polar wind, with higher ionization at low latitudes. Older STIS data obtained since 1998 reveal that this global stellar-wind geometry changes during eta Car's 5.5 year cycle, and may suggest that this star s spectroscopic events are shell ejections. Whether or not a companion star triggers these outbursts remains ambiguous. The most dramatic changes in the wind occur at low latitudes, while the dense polar wind remains relatively undisturbed during an event. The apparent stability of the polar wind also supports the inferred bipolar geometry. The wind geometry and its variability have critical implications for understanding the 5.5 year cycle and long-term variability, but do not provide a clear alternative to the binary hypothesis for generating eta Car s X-rays.

Smith, Nathan; Davidson, Kris; Gull, Theodore R.; Ishibashi, Kazunori; Hillier, D. John

2002-01-01

9

A COMPANION AS THE CAUSE OF LATITUDE-DEPENDENT EFFECTS IN THE WIND OF ETA CARINAE  

SciTech Connect

We analyze spatially resolved spectroscopic observations of the Eta Carinae binary system obtained with the Hubble Space Telescope/STIS. Eta Car is enshrouded by the dusty Homunculus nebula, which scatters light emitted by the central binary and provides a unique opportunity to study a massive binary system from different vantage points. We investigate the latitudinal and azimuthal dependence of H{alpha} line profiles caused by the presence of a wind-wind collision (WWC) cavity created by the companion star. Using two-dimensional radiative transfer models, we find that the wind cavity can qualitatively explain the observed line profiles around apastron. Regions of the Homunculus which scatter light that propagated through the WWC cavity show weaker or no H{alpha} absorption. Regions scattering light that propagated through a significant portion of the primary wind show stronger P Cygni absorption. Our models overestimate the H{alpha} absorption formed in the primary wind, which we attribute to photoionization by the companion, not presently included in the models. We can qualitatively explain the latitudinal changes that occur during periastron, shedding light on the nature of Eta Car's spectroscopic events. Our models support the idea that during the brief period of time around periastron when the primary wind flows unimpeded toward the observer, H{alpha} absorption occurs in directions toward the central object and Homunculus SE pole, but not toward equatorial regions close to the Weigelt blobs. We suggest that observed latitudinal and azimuthal variations are dominated by the companion star via the WWC cavity, rather than by rapid rotation of the primary star.

Groh, J. H. [Geneva Observatory, Geneva University, Chemin des Maillettes 51, CH-1290 Sauverny (Switzerland); Madura, T. I.; Weigelt, G. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany); Hillier, D. J. [Department of Physics and Astronomy, University of Pittsburgh, 3941 O'Hara Street, Pittsburgh, PA 15260 (United States); Kruip, C. J. H., E-mail: jose.groh@unige.ch [Leiden Observatory, Leiden University, Postbus 9513, NL-2300 RA Leiden (Netherlands)

2012-11-01

10

Latitude-Dependent Effects in the Stellar Wind of ETA Carinae.  

National Technical Information Service (NTIS)

The Homunculus reflection nebula around 77 Carinae provides the rare Opportunity to observe the spectrum of a star from more than one direction. In the case of eta Car, the nebula's geometry is known well enough to infer how wind profiles vary with latitu...

N. Smith K. Davidson T. R. Gull K. Ishibashi D. J. Hiller

2003-01-01

11

Solar Wind Five  

NASA Technical Reports Server (NTRS)

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.

Neugebauer, M. (editor)

1983-01-01

12

The Solar Wind  

NSDL National Science Digital Library

This site describes the nature of the solar winds and the relationships between its speed and solar features. The effect of the variations in the speed of the solar wind on the magnetosphere of the Earth is also discussed, along with the research results of the Ulysses spacecraft and the Advanced Composition Explorer (ACE) satellite. The site also provides links to solar wind conditions for the last seven days and the last 24 hours.

Hathaway, David

13

Warming: mechanism and latitude dependence  

NASA Astrophysics Data System (ADS)

Introduction. In the work it is shown, that in present warming of climate of the Earth and in style of its display a fundamental role the mechanism of the forced swing and relative oscillations of eccentric core of the Earth and its mantle plays. Relative displacements of the centers of mass of the core and the mantle are dictated by the features of orbital motions of bodies of solar system and nonineriality of the Earth reference frame (or ot the mantle) at the motion of the Earth with respect to a baricenter of solar system and at rotation of the planet. As a result in relative translational displacements of the core and the mantle the frequencies characteristic for orbital motion of all bodies of solar system, and also their combination are shown. Methods of a space geodesy, gravimetry, geophysics, etc. unequivocally and clearly confirm phenomenon of drift of the center of mass of the Earth in define northern direction. This drift is characterized by the significant velocity in about 5 mm/yr. The unique opportunity of its explanation consists in the natural assumption of existence of the unidirectional relative displacement (drift) the center of mass of the core and the center of mass of the mantle of the Earth. And this displacement (at superfluous mass of the core in 16.7 % from the mass of full the Earth) is characterized still more significant velocity in 2.6 cm/yr and occurs on our geodynamic studies in a direction to Taimyr peninsula. The dynamic explanation to century drift for today does not exist. It is possible to note, however, that data of observations of last years, indirectly testifying that similar drifts of the centers of mass in present epoch occur on other bodies of Solar system have been obtain: the Sun, Mars, the Titan, Enceladus, the Neptune, etc. We connect with mentioned phenomena the observed secular variations of natural processes on this celestial bodies. I.e. it is possible to assume, that observable eccentric positions of the centers of mass of some bodies of solar system and attributes of secular displacements of their centers of mass are universal and testify to relative translational displacements of shells of these bodies (such as the core, the mantle and others). And it means, that there is a highly effective mechanism of an active life of planets and satellites [1, 2]. This mechanism is distinct from the tidal mechanism of gravitational interaction of deformable celestial bodies. Its action is shown, for example, even in case if the core and the mantle are considered as absolutely rigid gravitating bodies, but separated by a is viscous-elastic layer. Classics of celestial mechanics did not consider gravitational interaction and relative translational displacement of the core and the mantle of the Earth. As our studies have shown the specified new mechanism is high energetic and allows to explain many of the phenomena earlier inaccessible to understanding in various geosciences, including climatology [1] - [5]. It has been shown, that secular changes in activity of all planetary processes on the Earth are connected with a secular drift of the core of the Earth, and are controlled by the core and are reflections and displays of the core drift [5]. It is naturally, that slow climatic changes are connected with drift of the core, with induced by this drift inversion changes in an atmosphere, ocean, with thermodynamic variations of state of layer D ', with changes and variations in mantle convection and in plume activity of the Earth. The drift of the core controls a transmission of heat in the top layers of the mantle and on a surface of the Earth, organizes volcanic and seismic activity of the Earth in planetary scale. The mechanism of a warming up of layers of the mantle and cyclic inversion changes of a climate. According to a developed geodynamic model all layers of the mantle at oscillations and motions of the core under action of its gravitational attraction test wide class of inversion deformations [1]. Thus the part of energy of deformations passes in heat by virtue of dissipation

Barkin, Yury

2010-05-01

14

Solar cycle and latitude dependence of high-beta suprathermal plasma conditions in interplanetary space between 1.3 and 5.4 AU  

NASA Astrophysics Data System (ADS)

The analysis of energetic particles and magnetic field measurements from the Ulysses spacecraft has shown that in a series of events, the energy density contained in the suprathermal tail particle distribution is comparable to or larger than that of the magnetic field, creating conditions of high-beta plasma. In this work we analyze periods of high-beta suprathermal plasma occurrences (?ep > 1) in interplanetary space, using the ratio (?ep) of the energetic particle (20 keV to ˜5 MeV) and magnetic field energy densities from measurements covering the entire Ulysses mission lifetime (1990-2009) in order to reveal new or to reconfirm some recently defined interesting characteristics. The main key-results of the work are summarized as follows: (i) we verify that high-beta events are detected within well identified regions corresponding mainly to the vicinity of shock surfaces and magnetic structures, and associated with energetic particle intensity enhancements due to (a) reacceleration at shock-fronts and (b) unusually large magnetic field depressions. (ii) We define three considerable features for the high-beta events, concentrated on the next points: (a) there is an appreciable solar-activity influence on the high-beta events, during the maximum and middle solar-cycle phase, (b) the annual peak magnitude and the number of occurrences of high events are well correlated with the sunspot number, (c) the high-beta suprathermal plasma events present a spatial distribution in heliographic latitudes (HL) up to ˜±80°, and a specific important concentration on the low (-25° ? HL < -6°, 6° < HL ? 25°) and median (-45° ? HL < -25°, 25° < HL ? 45°) latitudes. We also reconfirm by a statistical analysis the results of Marhavilas and Sarris (2011), that the high-beta suprathermal plasma (?ep > 1) events are characterized by a very large parameter ?ep (up to 1732.5), a great total duration (406 days) and a large percentage of the Ulysses-mission lifetime (which is equal to 6.34% of the total duration with usable measurements, and 11.3% of the duration in presence of suprathermal particles events).

Marhavilas, Panagiotis K.

2012-05-01

15

Solar Wind Magnetic Fields  

NASA Technical Reports Server (NTRS)

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.

Smith, E. J.

1995-01-01

16

Solar wind composition  

NASA Technical Reports Server (NTRS)

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

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

1995-01-01

17

Solar Wind Complexity  

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

18

Flank solar wind interaction  

NASA Technical Reports Server (NTRS)

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.

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

1994-01-01

19

Accelerating the Solar Wind  

NASA Astrophysics Data System (ADS)

At 1 AU the fast solar wind reaches speeds that are 2-3 times greater than can be accounted for by the pressure gradient due to the high coronal temperatures. This paper introduces a mechanism that may account for this shortfall, namely, the force due to the gradient of the magnetic pressure of an azimuthal magnetic field, B?, generated by a current jr flowing along the open-ended flux tube guiding the wind. The electromotive force (EMF) driving this current is due to the difference between the thermoelectric force acting on the electron gas within a flux tube and that in the ambient plasma. Using observed values of the magnetic field, we show that this mechanism is capable of accelerating the solar wind up to speeds of 800 km s-1 and higher. It also produces a profile of the radial wind speed v(r) that is nearly flat beyond about 0.15 AU, as is observed.

Ashbourn, J. M. A.; Woods, L. C.

2005-04-01

20

Flank solar wind interaction  

NASA Technical Reports Server (NTRS)

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.

Moses, Stewart L.; Greenstadt, Eugene W.

1992-01-01

21

Solar wind stream interfaces  

Microsoft Academic Search

Measurements aboard Imp 6, 7, and 8 reveal that approximately one third of all high-speed solar wind streams observed at 1 AU contain a sharp boundary (of thickness less than approx.4 x 10⁴ km) near their leading edge, called a stream interface, which separates plasma of distinctly different properties and origins. Identified as discontinuities across which the density drops abruptly,

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

1978-01-01

22

Solar Wind Electrons  

Microsoft Academic Search

Average characteristics of solar wind electron velocity distributions as well as the range and nature of their variations are presented. The measured distributions are generally symmetric about the heat flux direction and are adequately parameterized by the superposition of a nearly bi-Maxwellian function which characterizes the low-energy electrons and a bi-Maxwellian function which characterizes a distinct, ubiquitous component of higher-energy

W. C. Feldman; J. R. Asbridge; S. J. Bame; M. D. Montgomery; S. P. Gary

1975-01-01

23

Discontinuities in the solar wind  

Microsoft Academic Search

The nonuniform emission of the solar wind from the sun means that conditions are established which favor the development of discontinuities in the plasma parameters. Since the solar wind is in rapid proper motion with respect to the sun and the earth, examination of these discontinuities requires that the wind velocity be transformed away. Then it is found that they

D. S. Colburn; C. P. Sonett

1966-01-01

24

Wind and solar powered turbine  

Microsoft Academic Search

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

I. D. Wells; J. L. Koh; M. Holmes

1984-01-01

25

Personal overview of solar wind 6  

SciTech Connect

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)

Gosling, J.T.

1987-01-01

26

Heliographic latitude dependence of the IMF dominant polarity in 1972--1973 using Pioneer 10 data  

Microsoft Academic Search

The heliographic latitude dependence of the interplanetary magnetic ; field (IMF) was studied by using Pioneer 10 data taken from March 1972 through ; June 1973 over Bartels solar rotation (SR) periods 1896--1913. The daily IMF ; sector polarities were plotted for each of these SR periods. Then the number of ; days of positive polarity (''away'' directed fields) per

Ronald L. Rosenberg

1975-01-01

27

Solar wind stagnation near comets  

Microsoft Academic Search

The nature of the solar wind flow near comets is examined analytically in this paper. In particular, typical values for the stagnation pressure and magnetic barrier strength are estimated, taking into account magnetic field line tension and change-exchange cooling of the mass-loaded solar wind. A knowledge of the strength of the magnetic barrier is required in order to determine the

A. A. Galeev; T. E. Cravens; T. I. Gombosi

1985-01-01

28

Venus: Interaction with Solar Wind  

NASA Astrophysics Data System (ADS)

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 ...

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

2002-07-01

29

Study of Solar Wind Interactions.  

National Technical Information Service (NTIS)

The report is divided into two parts: Part I - Solar Wind Phenomena, and Part II - Magnetospheric Phenomena. The papers in Part I contain discussions of phenomena in which the solar wind itself is involved in a primary way. The papers grouped into Part II...

A. J. Dessler

1966-01-01

30

Solar wind and magnetosphere interactions  

NASA Technical Reports Server (NTRS)

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

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

1979-01-01

31

Solar wind photoplate study  

NASA Technical Reports Server (NTRS)

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.

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

1972-01-01

32

Solar wind latitudinal variations deduced from Mariner 10 interplanetary H /1216 A/ observations  

NASA Technical Reports Server (NTRS)

The Mariner 10 H (1216-A) interplanetary observations are examined by using models that consider anisotropies in the solar fluxes. It is verified that the dominant contribution to asymmetric structure in the Mariner 10 H (1216-A) data is a latitudinal variation of the solar-wind flux and of the solar wind velocity, leading to a hydrogen atom lifetime that is latitude dependent. The average lifetime at 1 AU is found to increase from the solar equator to the solar poles by about 25%. This allows interstellar hydrogen to penetrate closer to the solar poles than to the equator. A general analytic model is constructed for evaluating the neutral hydrogen density distribution in interplanetary space. This model takes into account the latitude-dependent ionization rate. When this model is applied to the Mariner 10 H (1216-A) data, it is shown to be capable of matching the observations with a statistical accuracy of 5%. The effect of this latitudinal variation on H (1216-A) sky background maps is to produce a latitudinal shift in the maximum toward the north ecliptic pole.

Witt, N.; Blum, P. W.; Ajello, J. M.

1979-01-01

33

Wind and solar powered turbine  

NASA Technical Reports Server (NTRS)

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.

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

1984-01-01

34

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

...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...

2012-10-10

35

Solar wind stagnation near comets  

NASA Technical Reports Server (NTRS)

The nature of the solar wind flow near comets is examined analytically in this paper. In particular, typical values for the stagnation pressure and magnetic barrier strength are estimated, taking into account magnetic field line tension and change-exchange cooling of the mass-loaded solar wind. A knowledge of the strength of the magnetic barrier is required in order to determine the location of the ionopause surface which separates the contaminated solar wind plasma from the outflowing plasma of the cometary ionosphere.

Galeev, A. A.; Cravens, T. E.; Gombosi, T. I.

1985-01-01

36

Magnetospheric feedback in solar wind energy transfer  

Microsoft Academic Search

The solar wind kinetic energy fueling all dynamical processes within the near-Earth space is extracted in a dynamo process at the magnetopause. This direct energy transfer from the solar wind into the magnetosphere depends on the orientation of the interplanetary magnetic field (IMF) as well as other solar wind parameters, such as the IMF magnitude and solar wind velocity. Using

M. Palmroth; H. E. J. Koskinen; T. I. Pulkkinen; P. K. Toivanen; P. Janhunen; S. E. Milan; M. Lester

2010-01-01

37

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

NASA Astrophysics Data System (ADS)

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.

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

2004-12-01

38

Solar wind acceleration in the solar corona  

NASA Technical Reports Server (NTRS)

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.

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

1997-01-01

39

Highly Alfvenic Slow Solar Wind  

NASA Technical Reports Server (NTRS)

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.

Roberts, D. Aaron

2010-01-01

40

Wind in the Solar System  

ERIC Educational Resources Information Center

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

McIntosh, Gordon

2010-01-01

41

Periodic solar wind density structures  

NASA Astrophysics Data System (ADS)

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: coronal activity creates coherent structures in the solar wind at smaller size scales than previously thought; corona-formed coherent structures persist to 1 AU largely intact; finally, a significant amount of discrete frequency wave power in Earth's magnetosphere is directly driven by these structures once they reach Earth.

Viall, Nicholeen Mary

2010-01-01

42

Atomic oxygen profiles (80 to 115 km) derived from Wind Imaging Interferometer/Upper Atmospheric Research Satellite measurements of the hydroxyl and greenline airglow: Local time-latitude dependence  

NASA Astrophysics Data System (ADS)

Hydroxyl and oxygen greenline nightglow observations from the Wind Imaging Interferometer (WINDII) are used to examine the local time-latitude variation of atomic oxygen in the mesopause region. Individual hydroxyl and greenline emission profiles from over 5 years of data are converted to oxygen mixing ratio (or concentration) profiles and then binned into local times, latitudes, and seasons. The two derived oxygen profiles from each emission are then combined into a single profile that spans a significant portion of the mesopause region (80 to 115 km). A technique developed earlier that addresses the altitude variability of the emission profiles is used. This level of agreement indicates a high degree of consistency in the radiance observations and in the photochemistry used to convert the emission rates to oxygen profiles. We demonstrate that the atomic oxygen concentration or mixing ratio profiles are very sensitive to local nighttime, and we display the manner in which they vary. The local time variation is primarily due to the tidal dynamics in the atmosphere. Comparisons between our atomic oxygen data set, a simple tidal model, and the TIME-GCM show good agreement; however, the local time tidal structure of atomic oxygen from MSISE-90 shows a 180° phase inconsistency. The measured local time oxygen variations vary with season and latitude, and we show that these oscillations are stronger under equinox conditions.

Russell, Jason P.; Ward, W. E.; Lowe, R. P.; Roble, R. G.; Shepherd, G. G.; Solheim, B.

2005-08-01

43

ASYMMETRIC SOLAR WIND ELECTRON DISTRIBUTIONS  

SciTech Connect

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.

Yoon, Peter H.; Kim, Sunjung; Lee, Junggi; Lee, Junhyun; Park, Jongsun; Park, Kyungsun; Seough, Jungjoon [School of Space Research, Kyung Hee University, Yongin-Si, Gyeonggi-Do 446-701 (Korea, Republic of); Hong, Jinhy [Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of)

2012-08-20

44

Western Wind and Solar Integration Study  

Microsoft Academic Search

The Western Wind and Solar Integration Study (WWSIS) is one of the largest regional wind and solar integration studies to date. It was initiated in 2007 to examine the operational impact of up to 35% energy penetration of wind, photovoltaics (PV), and concentrating solar power (CSP) on the power system operated by the WestConnect group of utilities in Arizona, Colorado,

D. Lew; R. Piwko; G. Jordan; N. Miller; K. Clark; L. Freeman; M. Milligan

2011-01-01

45

Radial Evolution of Solar Wind Speeds (Postprint).  

National Technical Information Service (NTIS)

The WSA ENLIL model predicts significant evolution of the solar wind speed. Along a flux tube the solar wind speed at 1.0 AU and beyond is found to be significantly altered from the solar wind speed in the outer corona at 0.1 AU, with most of the change o...

C. N. Arge D. Odstreil N. A. Schwadron S. L. McGregor W. J. Hughes

2012-01-01

46

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

National Technical Information Service (NTIS)

It took the solar polar passage of Ulysses in the early 1990s to establish the global structure of the solar wind speed during solar minimum. However, it remains unclear if the solar wind is composed of two distinct populations of solar wind from differen...

C. N. Arge D. Odstreil M. J. Owens S. L. McGregor W. J. Hughes

2012-01-01

47

Coronal holes as sources of solar wind  

Microsoft Academic Search

We investigate the association of high-speed solar wind with coronal holes during the Skylab mission by: (1) direct comparison of solar wind and coronal X-ray data; (2) comparison of near-equatorial coronal hole area with maximum solar wind velocity in the associated streams; and (3) examination of the correlation between solar and interplanetary magnetic polarities. We find that all large near-equatorial

J. T. Nolte; A. S. Krieger; A. F. Timothy; R. E. Gold; E. C. Roelof; G. Vaiana; A. J. Lazarus; J. D. Sullivan; P. S. McIntosh

1976-01-01

48

Solar wind ion precipitation on Mars  

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

49

Latitudinal dependence of solar wind speed  

NASA Technical Reports Server (NTRS)

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

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

1987-01-01

50

Magnetic Flux Transfer by the Solar Wind  

Microsoft Academic Search

We calculated the change of the magnetic flux through the surface encircled by the Earth's orbit. This change is associated with the magnetic flux transfer by the solar wind flow and exhibits clear 22-year periodicity. The magnetic flux transferred by the solar wind is of the same order of magnitude as the flux of the main solar magnetic field through

P. L. Israelevich; A. I. Ershkovich; T. I. Gombosi

2001-01-01

51

Does the solar wind affect the solar cycle?  

Microsoft Academic Search

We calculated the change of the magnetic flux through the surface encircled by the Earth's orbit. This change is associated with the magnetic flux transfer by the solar wind flow and exhibits clear 22-year periodicity. The magnetic flux transferred by the solar wind is of the same order of magnitude as the flux of the main solar magnetic field through

P. L. Israelevich; A. I. Ershkovich; T. I. Gombosi

2000-01-01

52

S olar Orbiter Neutral Solar Wind Detector  

NASA Astrophysics Data System (ADS)

Neutral hydrogen atoms, which give rise to the prominent so lar Ly-? corona, are closely coup led to the emerging solar-wind plasma. The density ratio of neutral hydrogen to protons is minute, ~10-6; therefore, the neutral atoms are tracers in the solar wind. In-situ observations of the neutral atoms, their flight paths (imag ing), density, and velocity distribu tions are a new tool to the understanding of the Ly-? corona, i.e. setting limits on the plasma velocity distribution along the solar magnetic field lines. The other goal of the neutral solar- wind instrumentation is the in-situ observation of the interactions between solar wind plasma and dust grains near the Sun. We will discuss the science objectives and the potential "zero charge" solar-wind instrument envelope onboard Solar Orbiter .

Hilchenbach, M.; Orsini, S.; Hsieh, K. C.; Antonucci, E.; Barabash, S.; Bamert, K.; Bruno, R.; Collier, M. R.; Czechowski, A.; D'Amicis, R.; De Angelis, E.; Dandouras, I.; Di Lellis, A. M.; Esser, R.; Giacalone, J.; Gruntman, M.; Habbal, S. R.; Jokipii, J. R.; Kallio, E.; Kota, J.; Kucharek, H.; Leoni, R.; Livi, S.; Mann, I.; Marsch, E.; Massetti, S.; Milillo, A.; Möbius, E.; Mura, A.; Sheldon, R. B.; Schmidt, W.; Selci, S.; Szego, K.; Woch, J.; Wurz, P.; Zanza, V.; Zurbuchen, T. H.

2007-01-01

53

Solar wind and interstellar medium coupling  

Microsoft Academic Search

An overview is given of the current state of theory and modelling for the interaction between the solar wind and the interstellar\\u000a medium (ISM). The final frontiers of the solar wind, as it pushes itself into the ISM, have been an object of speculation\\u000a and analysis for many years. Observational evidence from the solar wind and heliospheric energetic particles, and

David Burgess

1997-01-01

54

Solar wind pressure on interplanetary dust  

Microsoft Academic Search

The pseudo-Poynting-Robertson effect on an interplanetary grain due to solar wind bombardments is examined with careful consideration for sputtering of a grain and for the velocity dispersion of the solar wind particles. It is found that for water-ice and obsidian grains with radii in the range 0.01-100 micrometers, the retarding force due to solar wind is stronger than, and of

T. Mukai; T. Yamamoto

1982-01-01

55

Comet Borrelly Slows Solar Wind  

NASA Technical Reports Server (NTRS)

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.

2001-01-01

56

Role of solar wind turbulence in the coupling of the solar wind to the Earth's magnetosphere  

Microsoft Academic Search

The correlation between the amplitude of the MHD turbulence in the upstream solar wind and the amplitude of the Earth's geomagnetic activity indices AE, AU, AL, Kp, ap, Dst, and PCI is explored. The amplitude of the MHD turbulence is determined by the fluctuation amplitude of the solar wind magnetic field. This “turbulence effect” in solar wind\\/magnetosphere coupling is more

Joseph E. Borovsky; Herbert O. Funsten

2003-01-01

57

Integrated wind and solar powered desalination facility  

SciTech Connect

This design concept for a solar desalination plant couples a state of the art solar power generation system with a reverse osmosis membrane filtration system. An average throughput of 6000 m/sup 3//d is realized through operation totally independent of interconnection with the utility grid. Alternating current electric power is generated by an integrated wind and solar energy conversion system. The optimal wind/solar ratio is very dependent upon site conditions. 7 refs.

Szostak, R.M.; Agarwal, D.; Callahan, J.T.; Mohn, J.V. III

1981-01-01

58

Wind loading on solar collectors  

SciTech Connect

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

Bhaduri, S.; Murphy, L.M.

1985-06-01

59

Spectroscopic mapping of solar wind velocities  

NASA Technical Reports Server (NTRS)

During the total solar eclipse of 1970, measurements of resonantly scattered Lyman-alpha radiation from the solar corona revealed a means to determine temperatures and densities in the solar corona beyond 1.5 R solar radii. A natural extension of this work is to use the Solar Probe to measure the spectral line profile of Lyman-alpha radiation backscattered toward the Sun from coronal regions between 4 R solar radii and 10 R solar radii. The backscattered profile would provide unique and quantitative determinations of the outlaw velocities of coronal material into the solar wind. Such information is of critical importance for understanding solar-wind formation and solar-terrestrial effects on the earth's climate. There is no known way to obtain this information without a Solar Probe-type mission.

Kohl, J. L.

1978-01-01

60

Coronal Heating And Solar Wind Acceleration  

NASA Astrophysics Data System (ADS)

The energy transport in the electron-proton solar wind will be examined. An overview of the fundamental problems of solar wind heating and acceleration will be given. It will be followed by a detailed analysis of the solar wind energy budget, from the mid-chromosphere to the earth's orbit. Emphasis will be placed on the transition region and corona where most of the heating and acceleration takes place. Energy losses and energy input necessary to drive the solar wind will be discussed. Observations leading to constraints on heating and acceleration requirements will be reviewed. Observations in transition region and corona pertain mostly to ions heavier than helium. The question whether and how these observations also constrain the background solar wind, can only be answered using model calculations investigating the coupling between these ions and the bulk of the solar wind flow. Therefore, examples of heavy ion expansion and energy considerations will be included, even though the heavy ions contribute only about 1% to the total solar wind ions. To study the expansion behavior of heavy ions is also important since more general conclusions about possible solar wind heating mechanisms are often drawn from their observed parameters.

Esser, R.

2009-04-01

61

The abundances of elements and isotopes in the solar wind  

NASA Technical Reports Server (NTRS)

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.

Gloeckler, George; Geiss, Johannes

1988-01-01

62

Expansion effects on solar wind hybrid simulations  

SciTech Connect

Ion kinetic simulations of the solar wind using hybrid codes can model local wave input, heating and instabilities, but generally do not include long term evolution effects in the expanding solar wind. We further develop the expanding box model used in earlier studies to include the mirror force effects and study their role in the evolution of the proton distribution functions in the outer corona and inner heliosphere. The mirror force, significant in the acceleration region of the solar wind, is required for consistency with the conservation of magnetic moment of particles in the expanding wind. We present preliminary results from the modified 1D expanding box hybrid (EBHM) simulations.

Parashar, Tulasi N.; Velli, Marco; Goldstein, Bruce E. [NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

2013-06-13

63

Expansion effects on solar wind hybrid simulations  

NASA Astrophysics Data System (ADS)

Ion kinetic simulations of the solar wind using hybrid codes can model local wave input, heating and instabilities, but generally do not include long term evolution effects in the expanding solar wind. We further develop the expanding box model used in earlier studies to include the mirror force effects and study their role in the evolution of the proton distribution functions in the outer corona and inner heliosphere. The mirror force, significant in the acceleration region of the solar wind, is required for consistency with the conservation of magnetic moment of particles in the expanding wind. We present preliminary results from the modified 1D expanding box hybrid (EBHM) simulations.

Parashar, Tulasi N.; Velli, Marco; Goldstein, Bruce E.

2013-06-01

64

The solar wind-magnetosphere-ionosphere system  

PubMed

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. PMID:10856203

Lyon

2000-06-16

65

The quiescent corona and slow solar wind  

NASA Technical Reports Server (NTRS)

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.

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

66

Solar cycle changes in the high latitude solar wind  

NASA Technical Reports Server (NTRS)

Measurements of the solar wind velocity during the period 1971-79 using the technique of interplanetary scintillation are discussed. The average wind speed was faster than 500 km/s at latitudes above 30 deg for most of 1973-77. The fast polar stream, observed to become much narrower in 1978-79 is examined. The narrowing of the polar streams coincided with the emergence of sunspots at midlatitudes, with the start of the new solar cycle, and with a corresponding contraction of the polar coronal holes. The theory that the solar magnetic field controls the large scale structure of the solar wind is discussed in relation to the results.

Rickett, B. J.; Coles, W. A.

1980-01-01

67

Integrated wind and solar powered desalination facility  

Microsoft Academic Search

This design concept for a solar desalination plant couples a state of the art solar power generation system with a reverse osmosis membrane filtration system. An average throughput of 6000 m³\\/d is realized through operation totally independent of interconnection with the utility grid. Alternating current electric power is generated by an integrated wind and solar energy conversion system. The optimal

R. M. Szostak; D. Agarwal; J. T. Callahan; J. V. Mohn

1981-01-01

68

Contact discontinuities in solar wind  

NASA Astrophysics Data System (ADS)

Contact discontinuities (CD) are discontinuities that have magnetic fields linked between two sides but no plasma flows across its surface. Due to the lack of demonstrations of CD in observation, their stable existence is still under debate. Contact discontinuities are not expected to be observed in the solar wind because of the rapid diffusion of plasma along the magnetic fields across their surfaces. Nevertheless, hybrid simulations had demonstrated that stable CD can exist with a finite ratio of the electron temperature to ion temperature; but full particle simulations predicted that CD cannot persist in collisionless plasma as a result of electron thermal transport. On the other hand, electrostatic Vlasov simulations show that the structure of a contact discontinuity can be stable under a condition of out-of-phase profiles of the ion and electron temperatures. According to theoretical considerations, CD can survive in magnetodynamics plasma with constant total thermal pressure across the surface of CD, in ion-electron two-fluid plasma further with out-of-phase variations of the ion and electron thermal pressures, and in Vlasov theory with additionally out-of-phase variations of the ion and electron temperatures. In this study, we define the criteria for the selection of a CD event in observation, in accord with the jump conditions. CD events in the solar wind, with a constant total thermal pressure but different performances on the variations of thermal pressure and temperatures of ions and electrons will be demonstrated. The practical behavior of ion and electron temperature will be discussed in follow.

Hsieh, Wen-Chieh; Shue, Jih-Hong; Chao, Jih-Kwin; Tsai, Tsung-Che; Nemecek, Zdenek; Safrankova, Jana; Kruparova, Oksana

2014-05-01

69

Global Network of Slow Solar Wind  

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

70

Electric Solar Wind Sail in tailwind  

NASA Astrophysics Data System (ADS)

The Electric Solar Wind Sail (E-sail) is a novel propulsion concept that enables faster space travel to many solar system targets. E-sail uses charged solar wind particles as the source of its propulsion. This is achieved by deploying long, conducting and charged tethers, which get pushed by the solar wind by Coulomb drag [1]. E-sail technology is being developed to technical readiness level (TRL) 4-5 by the European Union's Seventh Framework Programme for Research and Technological Development, EU FP7, in a project named ESAIL (http://www.electric-sailing.fi/fp7). Prototypes of the key parts are to be produced. The design will be scalable so that a real solar wind demonstration mission could be scaled up from them. We review here the latest results of the constantly evolving E-sail project.

Janhunen, P.; Merikallio, S.; Toivanen, P.; Polkko, J.; Haeggström, E.; Seppänen, H.; Kurppa, R.; Ukkonen, J.; Ylitalo, T.; Kiprich, S.; Koivisto, H.; Kalvas, T.; Tarvainen, O.; Kauppinen, J.; Thornell, G.; Kratz, H.; Sundqvist, J.; Grönland, T.-A.; Johansson, H.; Rangsten, P.; Vinterhav, E.; Noorma, M.; Envall, J.; Lätt, S.; Allik, V.; Voormansik, K.; Kvell, U.; Lebreton, J.-P.; Hallikainen, M.; Praks, J.; Krömer, O.; Rosta, R.; Salminen, P.; Mengali, G.; Quarta, A.; Aliasi, G.; Marcuccio, S.; Pergola, P.; Giusti, N.

2011-10-01

71

Solar wind pressure on interplanetary dust  

NASA Astrophysics Data System (ADS)

The pseudo-Poynting-Robertson effect on an interplanetary grain due to solar wind bombardments is examined with careful consideration for sputtering of a grain and for the velocity dispersion of the solar wind particles. It is found that for water-ice and obsidian grains with radii in the range 0.01-100 micrometers, the retarding force due to solar wind is stronger than, and of the same order as, respectively, that due to solar radiation. On the other hand, for magnetite this drag force is always less than that due to solar radiation. In addition, since the wind flow generally comes from the east of the sun, a grain in a prograde orbit suffers a larger retarding force compared with a grain in a retrograde orbit.

Mukai, T.; Yamamoto, T.

1982-03-01

72

Preferred solar longitudes with signatures in the solar wind  

NASA Astrophysics Data System (ADS)

Using spacecraft data collected over three solar cycles, Neugebauer et al. [2000] found a persistent dependence of the solar wind speed and the radial component of the interplanetary magnetic field on solar longitude, defined in a coordinate system with a rotation period of 27.03 days. Here we investigate the solar source of this period using observations of the photospheric magnetic field. We study the lowest-order nonaxisymmetric modes of the solar field extracted from synoptic charts of the Wilcox Solar Observatory. We find there is a robust magnetic structure on the Sun, which rotates with the period found by Neugebauer et al. [2000] in the solar wind. This rotation is more rapid than the solar equatorial and core rotations. We discuss the association of this nonaxisymmetric mode with the magnetic field generated by the solar mean field dynamo.

Ruzmaikin, A.; Feynman, J.; Neugebauer, M.; Smith, E. J.

2001-05-01

73

Multifractal Solar Wind Turbulence at High Latitudes  

NASA Astrophysics Data System (ADS)

We study the inhomogeneous rate of the transfer of the energy flux indicating multifractal and intermittent behavior of solar wind turbulence out of the ecliptic plane. In particular, we analyze time series of the velocities of the solar wind during solar minimum (1994 -1997, 2006 -2007) at various heliographic latitudes measured in situ by Ulysses, which is the only mission that has investigated parameters of the solar wind out of the ecliptic plane also in the polar regions of the Sun. By using our weighted two-scale Cantor set model [1], in comparison with the simple one scale multifractal spectrum, we show that the degree of multifractality for fluctuations at high latitudes during solar minimum for the fast solar wind exhibit latitudinal dependence with some symmetry with respect to the ecliptic plane. In particular, the minimum of intermittency is observed at mid-latitudes possibly related to the transition from the region where the interaction of the fast and slow streams takes place to a more homogeneous region of the pure fast solar wind [2]. It is worth noting that degree of multifractality of the fast solar wind at high latitudes is somewhat smaller as compared with those at the ecliptic and we observe roughly symmetric multifractal singularity spectra. [1] W. M. Macek and A. Szczepaniak (2008), Generalized two-scale weighted Cantor set model for solar wind turbulence, Geophys. Res. Lett., 35, L02108, doi:10.1029/2007GL032263. [2] A. Wawrzaszek and W. M. Macek (2010), Observation of multifractal spectrum in solar wind turbulence by Ulysses at high latitudes, J. Geophys. Res., doi:10.1029/2009ja015176.

Wawrzaszek, Anna; Macek, Wies?aw M.

74

Solar Wind Structure at Solar Minimum: 3D MHD Solar Wind Model Results Compared with STEREO and ACE Observations  

Microsoft Academic Search

During the present period of low solar activity, STEREO-A and -B have been observing solar wind structure where quasi-steady corotating interaction regions (CIRs) are prevalent. We recently used several models developed by CISM (Center for Integrated Space weather Modeling), now available at the Community Coordinated Modeling Center (CCMC), to analyze the solar control of the declining phase solar wind observed

C. O. Lee; J. G. Luhmann; I. de Pater; D. Odstrcil; P. MacNeice; C. N. Arge; P. Riley; P. Schroeder; R. A. Leske; L. K. Jian; C. T. Russell; G. M. Mason; A. B. Galvin; K. D. Simunac; S. McGregor

2007-01-01

75

Anisotropic turbulence in the solar wind  

NASA Technical Reports Server (NTRS)

Solar wind turbulence has been viewed traditionally as composed of parallel propagating ('slab' fluctuations) or otherwise as isotropic turbulence. A variety of recent investigations, reviewed here, indicate that the spectrum may contain a significant admixture of two dimensional fluctuations, having variations mainly perpendicular to the local magnetic field. These indications come from simulations, from the theory of nearly incompressible MHD, from cosmic ray transport studies and from transport theory for solar wind turbulence, as well as from interpretations of direct observations. Thus, solar wind turbulence may be more like bundles of spaghetti than like parallel phase fronts.

Matthaeus, W. H.; Bieber, J. W.; Zank, G. P.

1995-01-01

76

DSCOVR High Time Resolution Solar Wind Measurements  

NASA Technical Reports Server (NTRS)

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.

Szabo, Adam

2012-01-01

77

DSCOVR High Time Resolution Solar Wind Measurements  

NASA Astrophysics Data System (ADS)

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.

Szabo, A.

2012-12-01

78

Prospects for future solar-wind missions  

NASA Technical Reports Server (NTRS)

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.

Bochsler, P.; Moebius, E.

1993-01-01

79

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

NASA Technical Reports Server (NTRS)

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.

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

2013-01-01

80

The solar wind interaction with Venus  

NASA Technical Reports Server (NTRS)

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 obstacle is a dipole magnetic field, but there are two important distinctions. In the wake of the Venus obstacle one finds an induced magnetic tail composed of varying interplanetary fields rather than the constant fields of intrinsic origin. This magnetotail is further seen to be populated by Heavy (0+) ions that are evidently escaping from the planet at significant (approximately 10(exp -25) s(exp -1)) rates. These heavy ions are also observed in the dayside magnetosheath. The interpretation is that ions are produced by both photoionization and solar wind electron impact ionization of the upper neutral atmosphere that extends into the magnetosheath.

Luthmann, J. G.

1992-01-01

81

Pluto's interaction with the solar wind  

SciTech Connect

If Pluto's atmospheric escape rate is significantly greater than 1.5 x 10{sup 27} molecules s{sup {minus}1} then the interaction with the tenuous solar wind at 30 A.U. will be like that of a comet: there will be extensive ion pick-up upstream and the size of the interaction region will vary directly with variations in the solar wind flux. If the escape flux is much less, then one expects that the solar wind will be deflected around Pluto's ionosphere in a Venus-like interaction. In either case, the weak interplanetary magnetic field at 30 A.U. results in very large gyroradii for the picked up ions and a thick bow shock, necessitating a kinetic treatment of the interaction. Strong variations in the size of the interaction region are expected on time scales of days due to changes in the solar wind.

Bagenal, F. (Univ. of Colorado, Boulder (USA)); McNutt, R.L. Jr. (Massachusetts Institute of Technology, Cambridge (USA))

1989-11-01

82

Magnetic energy flow in the solar wind.  

NASA Technical Reports Server (NTRS)

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.

Modisette, J. L.

1972-01-01

83

Pluto's Interaction with the Solar Wind  

Microsoft Academic Search

If Pluto's atmospheric escape rate is significantly greater than 1.5 x 10 to the 27th molecules\\/s then the interaction with the tenuous solar wind at 30 A.U. will be like that of a comet. There will be extensive ion pick-up upstream and the size of the interaction region will vary directly with variations in the solar wind flux. If the

Fran Bagenal; Ralph L. McNutt Jr.

1989-01-01

84

Topological Origins of the Slow Solar Wind  

Microsoft Academic Search

Although the slow solar wind has been studied for decades with both in situ and remote sensing observations, its origin is still a matter of intense debate. In the standard quasi-steady model, the slow wind is postulated to originate near coronal hole boundaries that define topologically well-behaved separatrices between open and closed field regions. In the interchange model, on the

S. Antiochos

2008-01-01

85

THREE-DIMENSIONAL NUMERICAL SIMULATIONS OF MAGNETIZED WINDS OF SOLAR-LIKE STARS  

SciTech Connect

By means of self-consistent three-dimensional magnetohydrodynamics (MHD) numerical simulations, we analyze magnetized solar-like stellar winds and their dependence on the plasma-{beta} parameter (the ratio between thermal and magnetic energy densities). This is the first study to perform such analysis solving the fully ideal three-dimensional MHD equations. We adopt in our simulations a heating parameter described by {gamma}, which is responsible for the thermal acceleration of the wind. We analyze winds with polar magnetic field intensities ranging from 1 to 20 G. We show that the wind structure presents characteristics that are similar to the solar coronal wind. The steady-state magnetic field topology for all cases is similar, presenting a configuration of helmet streamer-type, with zones of closed field lines and open field lines coexisting. Higher magnetic field intensities lead to faster and hotter winds. For the maximum magnetic intensity simulated of 20 G and solar coronal base density, the wind velocity reaches values of {approx}1000 km s{sup -1} at r {approx} 20r {sub 0} and a maximum temperature of {approx}6 x 10{sup 6} K at r {approx} 6r {sub 0}. The increase of the field intensity generates a larger 'dead zone' in the wind, i.e., the closed loops that inhibit matter to escape from latitudes lower than {approx}45 deg. extend farther away from the star. The Lorentz force leads naturally to a latitude-dependent wind. We show that by increasing the density and maintaining B {sub 0} = 20 G the system recover back to slower and cooler winds. For a fixed {gamma}, we show that the key parameter in determining the wind velocity profile is the {beta}-parameter at the coronal base. Therefore, there is a group of magnetized flows that would present the same terminal velocity despite its thermal and magnetic energy densities, as long as the plasma-{beta} parameter is the same. This degeneracy, however, can be removed if we compare other physical parameters of the wind, such as the mass-loss rate. We analyze the influence of {gamma} in our results and we show that it is also important in determining the wind structure.

Vidotto, A. A.; Jatenco-Pereira, V. [University of Sao Paulo, Rua do Matao 1226, Sao Paulo, SP 05508-090 (Brazil); Opher, M. [George Mason University, 4400 University Drive, Fairfax, VA 22030-4444 (United States); Gombosi, T. I. [University of Michigan, 1517 Space Research Building, Ann Arbor, MI 48109-2143 (United States)], E-mail: aline@astro.iag.usp.br

2009-07-01

86

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

NASA Technical Reports Server (NTRS)

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.

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

87

The Genesis Solar Wind Sample Return Mission  

NASA Technical Reports Server (NTRS)

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.

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

1990-01-01

88

Prospects for Future Solar-Wind Missions.  

National Technical Information Service (NTIS)

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...

P. Bochsler E. Moebius

1993-01-01

89

OMNIWeb: The Ionosphere and Solar Wind  

NSDL National Science Digital Library

This educational brief provides an overview of the layers of the atmosphere, the effects of the solar wind upon them, and how these effects are mitigated by Earth's magnetic field. It also describes OMNIWeb, an internet-based data retrieval interface for obtaining datasets on solar energetic particles.

90

Solar wind electrons and Langmuir turbulence  

NASA Astrophysics Data System (ADS)

Typical in situ spacecraft measurements made in the solar wind show that charged particle velocity distribution function (VDF) contains energetic component with quasi scale-free power-law velocity dependence, f ~ ?-?. This paper proposes a theory for quiet-time solar-wind electrons that are in dynamical equilibrium with plasma turbulence. The theory predicts f ~ ?-6.5 for high electron velocities, while observations by WIND and STEREO spacecraft reveal ?-5.0 to ?-8.0 dependence. This shows that theory falls within the observed range.

Yoon, P. H.; Lin, R. P.; Larson, D. E.; Bale, S. D.

2012-05-01

91

Solar Wind control in Gas Giant Ionospheres  

NASA Astrophysics Data System (ADS)

The influences that the Solar Wind and Gas Giant magnetospheres have upon the upper atmospheres and ionospheres of these planets is largely controlled by currents closing along magnetic field lines into the polar regions. These currents in turn result in significant currents across the ionosphere that can be observed from ground-based observations. Here, we will present a discussion of the current understanding of how the Solar Wind controls the auroral regions of the Gas Giants, as has been measured in the past. We will also present new ion wind measurements from the past year, with observations from VLT of Jupiter, Saturn and Uranus.

Stallard, T.; Melin, H.; Miller, S.; Blake, J.; O'Donoghue, J.

2013-09-01

92

Solar wind origin in coronal funnels.  

PubMed

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. PMID:15845846

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

2005-04-22

93

Solar wind and its interaction with the magnetosphere - Measured parameters  

Microsoft Academic Search

The sun and the solar wind are considered in terms of the 'ballerina' model first proposed by Alfven (1977), taking into account high speed streams, the slow solar wind, stream-stream interactions, the relation of streams and magnetic structure, and transients caused by solar activity. The main features of the solar wind behavior are illustrated with the aid of data, covering

R. Schwenn

1981-01-01

94

Solar wind proton deposition into the Martian atmosphere  

Microsoft Academic Search

The direct impact of solar wind H + with the planet Mars is calculated using a three- dimensional hybrid particle code. The simulation results show a strong dependence on solar wind velocity and interplanetary magnetic field angle with the solar wind velocity vector. The energy fluxes calculated approach the solar EUV heating rates fxom photoelectrons and are found to be

Stephen H. Brecht

1997-01-01

95

The Interaction of the Solar Wind With Mars  

Microsoft Academic Search

The interaction of the solar wind with Mars is unique in the solar system because it combines many aspects of the solar wind interaction with other unmagnetized bodies. Like Venus, the Martian atmosphere is primarily responsible for diverting the solar wind around the planet since it lacks a significant global dipole field. Like comets, the neutral atmosphere extends into the

D. A. Brain

2005-01-01

96

Structure of Slow Solar Wind during Solar Activity Minimum  

NASA Astrophysics Data System (ADS)

We investigate the structure of the slow solar wind using the observations by the STEREO and Wind spacecraft during two Carrington rotations (2054 and 2055) that occurred at the time of the present solar activity minimum. At solar minimum distinct interplanetary coronal mass ejections (ICMEs) are rare, but we found that the signatures of transients with small scale-sizes and/or low magnetic field strength (comparable with the typical solar wind value) are frequently found in the slow solar wind at these times. Source mapping using models based on GONG magnetograms suggests that these transients come from the vicinity of coronal source surface sector boundaries and in-situ they are correspondingly observed near high density structures where the dominant electron heat flux reverses its flow polarity. We will discuss the properties of the identified transients and the extent the slow solar wind may be considered transient in nature. We will also discuss their connection to dynamical changes at the coronal hole boundaries where magnetic reconnection has been suggested to open up the magnetic field lines allowing the material to escape from the closed loops.

Kilpua, E. K. J.; Luhmann, J. G.; Gosling, J. T.

2009-04-01

97

The Solar Wind Ion Analyzer for MAVEN  

NASA Astrophysics Data System (ADS)

The Solar Wind Ion Analyzer (SWIA) on the MAVEN mission will measure the solar wind ion flows around Mars, both in the upstream solar wind and in the magneto-sheath and tail regions inside the bow shock. The solar wind flux provides one of the key energy inputs that can drive atmospheric escape from the Martian system, as well as in part controlling the structure of the magnetosphere through which non-thermal ion escape must take place. SWIA measurements contribute to the top level MAVEN goals of characterizing the upper atmosphere and the processes that operate there, and parameterizing the escape of atmospheric gases to extrapolate the total loss to space throughout Mars' history. To accomplish these goals, SWIA utilizes a toroidal energy analyzer with electrostatic deflectors to provide a broad 360?×90? field of view on a 3-axis spacecraft, with a mechanical attenuator to enable a very high dynamic range. SWIA provides high cadence measurements of ion velocity distributions with high energy resolution (14.5 %) and angular resolution (3.75?×4.5? in the sunward direction, 22.5?×22.5? elsewhere), and a broad energy range of 5 eV to 25 keV. Onboard computation of bulk moments and energy spectra enable measurements of the basic properties of the solar wind at 0.25 Hz.

Halekas, J. S.; Taylor, E. R.; Dalton, G.; Johnson, G.; Curtis, D. W.; McFadden, J. P.; Mitchell, D. L.; Lin, R. P.; Jakosky, B. M.

2013-11-01

98

Solar-wind minor ions: recent observations  

SciTech Connect

During the years following the Solar Wind Four Conference at Burghausen our knowledge of the solar wind ion composition and dynamics has grown. There have been some surprises, and our understanding of the evolution of the solar wind has been improved. Systematic studies have shown that the minor ions generally travel with a common bulk speed and have temperatures roughly proportional to their masses. It has been determined that the /sup 3/He/sup + +/ content varies greatly; /sup 3/He/sup + +///sup 4/He/sup + +/ ranges from as high as 10/sup 2/ values to below 2 x 10/sup -4/. In some solar wind flows which can be related to energetic coronal events, the minor ions are found in unusual ionization states containing Fe/sup 16 +/ as a prominent ion, showing that the states were formed at unusually high temperatures. Unexpectedly, in a few flows substantial quantities of /sup 4/He/sup +/ have been detected, sometimes with ions identifiable as O/sup 2 +/ and O/sup 3 +/. Surprisingly, in some of these examples the ionization state is mixed showing that part of the plasma escaped the corona without attaining the usual million-degree temperatures while other parts were heated more nearly in the normal manner. Additionally, detailed studies of the minor ions have increased our understanding of the coronal expansion. For example, such studies have contributed to identifying near equatorial coronal streamers as the source of solar wind flows between high speed streams.

Bame, S.J.

1982-01-01

99

Solar system plasma physics. Volume 1 - Solar and solar wind plasma physics  

Microsoft Academic Search

The paper covers such aspects of solar physics as the mechanisms which drive solar phenomena (such as heating of the corona, the acceleration of particles in flares, the dissipation of magnetic energy in current sheets, and the generation of the solar wind), the structure and energetics of the quiet solar atmosphere, the structure of the corona, the solar composition, and

E. N. Parker; C. F. Kennel; L. J. Lanzerotti

1979-01-01

100

Evidence for solar wind modulation of lightning  

NASA Astrophysics Data System (ADS)

The response of lightning rates over Europe to arrival of high speed solar wind streams at Earth is investigated using a superposed epoch analysis. Fast solar wind stream arrival is determined from modulation of the solar wind V y component, measured by the Advanced Composition Explorer spacecraft. Lightning rate changes around these event times are determined from the very low frequency arrival time difference (ATD) system of the UK Met Office. Arrival of high speed streams at Earth is found to be preceded by a decrease in total solar irradiance and an increase in sunspot number and Mg II emissions. These are consistent with the high speed stream’s source being co-located with an active region appearing on the Eastern solar limb and rotating at the 27 d period of the Sun. Arrival of the high speed stream at Earth also coincides with a small (?1%) but rapid decrease in galactic cosmic ray flux, a moderate (?6%) increase in lower energy solar energetic protons (SEPs), and a substantial, statistically significant increase in lightning rates. These changes persist for around 40 d in all three quantities. The lightning rate increase is corroborated by an increase in the total number of thunder days observed by UK Met stations, again persisting for around 40 d after the arrival of a high speed solar wind stream. This result appears to contradict earlier studies that found an anti-correlation between sunspot number and thunder days over solar cycle timescales. The increase in lightning rates and thunder days that we observe coincides with an increased flux of SEPs which, while not being detected at ground level, nevertheless penetrate the atmosphere to tropospheric altitudes. This effect could be further amplified by an increase in mean lightning stroke intensity that brings more strokes above the detection threshold of the ATD system. In order to remove any potential seasonal bias the analysis was repeated for daily solar wind triggers occurring during the summer months (June to August). Though this reduced the number of solar wind triggers to 32, the response in both lightning and thunder day data remained statistically significant. This modulation of lightning by regular and predictable solar wind events may be beneficial to medium range forecasting of hazardous weather.

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

2014-05-01

101

Solar wind modulation of UK lightning  

NASA Astrophysics Data System (ADS)

The response of lightning rates in the UK to arrival of high speed solar wind streams at Earth is investigated using a superposed epoch analysis. The fast solar wind streams' arrivals are determined from modulation of the solar wind Vy component, measured by the Advanced Composition Explorer (ACE) spacecraft. Lightning rate changes around these event times are then determined from the very low frequency Arrival Time Difference (ATD) system of the UK Met Office. Arrival of high speed streams at Earth is found to be preceded by a decrease in total solar irradiance and an increase in sunspot number and Mg II emissions. These are consistent with the high speed stream's source being co-located with an active region appearing on the Eastern solar limb and rotating at the 27 day rate of the Sun. Arrival of the high speed stream at Earth also coincides with a rapid decrease in cosmic ray flux and an increase in lightning rates over the UK, persisting for around 40 days. The lightning rate increase is corroborated by an increase in the total number of thunder days observed by UK Met stations, again for around 40 days after the arrival of a high speed solar wind stream. This increase in lightning may be beneficial to medium range forecasting of hazardous weather.

Davis, Chris; Harrison, Giles; Lockwood, Mike; Owens, Mathew; Barnard, Luke

2013-04-01

102

Solar wind ion composition and charge states  

NASA Technical Reports Server (NTRS)

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.

vonSteiger, R.

1995-01-01

103

Studies of Quiet Solar Wind Conditions with Data from the Wind and GEOTAIL Satellites  

Microsoft Academic Search

Solar activity levels with less than one energetic event per day are referred to as quiet solar wind condition. Magnetic data from the WIND and GEOTAIL satellites which are at apogees of 240RE and 25RE respectively were considered for the already identified quiet solar wind condition which extends from 8 March to 10 March 1997. A plot of the WIND

Emmanuel Ariyibi

2008-01-01

104

Magnetofluid Turbulence in the Solar Wind  

NASA Technical Reports Server (NTRS)

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.

Goldstein, Melvyn L.

2008-01-01

105

Ion cyclotron damping in the solar corona and solar wind  

NASA Astrophysics Data System (ADS)

The solar corona is the hot, ionized outer atmosphere of the Sun. Coronal plasma expands into interplanetary space as a supersonic bulk outflow known as the solar wind. This tenuous and unbounded medium is a unique laboratory for the study of kinetic theory in a nearly collisionless plasma, as well as magnetohydrodynamic waves, shocks, and jets. Particle velocity distributions in the solar wind have been probed directly by spacecraft (outside the orbit of Mercury), and indirectly by ultraviolet spectroscopy (close to the Sun). Fluctuations in the plasma properties and in electromagnetic fields have been measured on time scales ranging from seconds to years. Despite more than a half-century of study, though, the basic physical processes responsible for heating the million-degree corona and accelerating the solar wind past the Sun's escape velocity are still not known with certainty. Understanding the basic physics of the solar wind is necessary to predict the Sun's impact on the Earth's climate and local space environment. This presentation will review the kinetic origins of several physical processes that are currently believed to be important in depositing energy and momentum in coronal particle velocity distributions. Because ions in the solar wind are heated and accelerated more than would be expected in either thermodynamic equilibrium or via a mass-proportional process, an ion cyclotron resonance has been suggested as a likely mechanism. Other evidence for gyroresonant wave dissipation in the corona will be presented, and possible generation mechanisms for the (as yet unobserved) high-frequency cyclotron waves will be reviewed. The mean state of the coronal and heliospheric plasma is intimately coupled with kinetic fluctuations about that mean, and theories of turbulence, wave dissipation, and instabilities must continue to be developed along with steady state descriptions of the solar wind. .

Cranmer, Steven R.

2001-10-01

106

Solar Wind Properties During the Current Solar Minimum: Ulysses Observations  

NASA Astrophysics Data System (ADS)

During its nearly 19 year mission, Ulysses pioneered novel measurements of the three-dimensional heliosphere and particularly first in situ observations of solar wind from polar coronal holes (PCHs). It is thus possible to compare observations in the current, peculiar solar minimum with those obtained in 1994-95. It has been reported earlier that, during the current minimum, there is a ~ 15% reduction of the heliospheric magnetic field (Smith and Balogh, 2008), and ~ 17% and ~ 14% reduction in density and temperature, respectively (McComas et al., 2008), as compared to the previous minimum. But the PCH-associated solar wind streams show long-term variability not only in dynamic, but also in compositional signatures. From 1995 to 2008, the C and O freeze-in temperatures measured in high-latitude solar wind have decreased by ~ 15% and are now around 0.86 MK and 1.0 MK, respectively. Si and Fe ionization states also exhibit a substantial cooling with a reduction of 0.2 and 0.3 charge states, respectively. Thus it appears that the PCH of cycle 23 are cooler overall than those of cycle 22. It is more difficult to assess whether there are significant changes of the elemental composition of the solar wind, as exhibited through the First Ionization Potential fractionation effect, which seems to have remained at f = 1.8 ± 0.3 during both sets of polar passages, i.e., enhanced to the photospheric composition (f = 1). If this can be confirmed the streams from PCH would truly be the 'ground state' of the solar wind. These observations provide a unique test for theories of the solar wind and its composition. We will present results from this data analysis and also provide a discussion of their scientific implications.

von Steiger, Rudolf; Zurbuchen, Thomas H.

2010-05-01

107

Quiet and Disturbed Solar Wind in the New Solar Cycle  

NASA Astrophysics Data System (ADS)

Observations of the solar wind since the beginning of the STEREO mission in 2007 show the notably weak solar wind and interplanetary field described in the literature persists even in the face of the increasing activity of solar cycle 24. These conditions have produced on average low values of geoeffective parameters such as solar wind dynamic pressure and the southward component of the interplanetary field -Bz. In addition, the magnetic disturbances associated with interplanetary coronal mass ejections (ICMEs) have been primarily northward in their leading edges where their fields are compressed by their ambient solar wind interaction. This combination has generally reduced the strengths of storms produced by the ICMEs and stream interaction regions. Interestingly, the rate of CMEs in coronal images has been similar to the previous cycle which had a significantly higher sunspot number and related solar surface field. We summarize how recent conditions on the Sun have modified those that affect the Earth and planets, and the likely trends we may expect.

Luhmann, Janet G.; Jian, Lan; Galvin, Antoinette; Simunac, Kristin; Kilpua, Emilia; Russell, Christopher; Ellenburg, Michael

2012-07-01

108

Solar cycle evolution of the solar wind in three dimensions  

NASA Technical Reports Server (NTRS)

Measurements of the solar wind speed both in and out of the ecliptic are presented for 1971-82. The speed estimates, which were made with the interplanetary scintillation system at UC San Diego, have been compared to in situ for large, slowly evolving structures, and thus such structures can be studied up to 60 degrees north and south heliographic latitude. Annual average wind speeds are presented versus latitude for an entire solar cycle. Fast wind streams from the poles persisted through declining and low solar activity, but were closed off during four years of high activity. This evolution follows that of the polar coronal holes, as displayed by comparing averaged speed and coronal density over latitude and longitude. The most recent data (1982) show the reestablishment of large tilted polar holes and associated fast streams. Coronal magnetic field data show that the neutral sheet is confined to low latitudes at solar minimum and extends to high latitudes at solar maximum; thus the slow solar wind comes from the same latitude range as that of the neutral sheet.

Rickett, B. J.; Coles, W. A.

1983-01-01

109

Magnetosphere II: The Solar Wind Strikes Back!  

NSDL National Science Digital Library

A view of a computer-generated model of the Earth's magnetosphere. Semi-transparent surfaces represent particle density (red is high, blue is low), the silvery tube represent magnetic field lines and the yellow ribbons represent the paths of charged solar wind particles. In this particular model, the solar wind has an ambient density of 8.35 particles-cm^3. The isosurfaces are then red (>17 particles-cm^3), yellow (>12 particles-cm^3), green (>8.6 particles-cm^3) and blue (<1.0 particle-cm^3).

Bridgman, Tom; Mitchell, Horace; Sokolowsky, Eric; Spicer, Dan

2002-03-01

110

Solar Wind Change Exchange from the Magnetosheath  

NASA Technical Reports Server (NTRS)

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.

Snowden, Steve

2008-01-01

111

Magnetohydrodynamic turbulence in the solar wind  

NASA Technical Reports Server (NTRS)

The fluctuations in magnetic field and plasma velocity in solar wind, which possess many features of fully developed magnetohydrodynamic (MHD) turbulence, are discussed. Direct spacecraft observations from 0.3 to over 20 AU, remote sensing radio scintillation observations, numerical simulations, and various models provide complementary methods that show that the fluctuations in the wind parameters undergo significant dynamical evolution independent of whatever turbulence might exist in the solar photosphere and corona. The Cluster mission, with high time resolution particle and field measurements and its variable separation strategies, should be able to provide data for answering many questions on MHD turbulence.

Goldstein, Melvyn L.

1995-01-01

112

Geomagnetic activity: Dependence on solar wind parameters  

NASA Technical Reports Server (NTRS)

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

Svalgaard, L.

1977-01-01

113

Solar Wind Dynamic Pressure Variations: Quantifying the Statistical Magnetospheric Response.  

National Technical Information Service (NTIS)

Solar wind dynamic pressure variations are common and have large amplitudes. Existing models for the transient magnetospheric and ionospheric response to the solar wind dynamic pressure variation are quantified. The variations drive large amplitude (appro...

D. G. Sibeck

1990-01-01

114

The Large Scale Structure of the Solar Wind.  

National Technical Information Service (NTIS)

The solar wind 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 solar wind over increasi...

J. H. Wolfe

1971-01-01

115

Electric solar wind sail mass budget model  

NASA Astrophysics Data System (ADS)

The electric solar wind sail (E-sail) is a new type of propellantless propulsion system for Solar System transportation, which uses the natural solar wind for producing spacecraft propulsion. This paper discusses a mass breakdown and a performance model for an E-sail spacecraft that hosts a scientific payload of prescribed mass. In particular, the model is able to estimate the total spacecraft mass and its propulsive acceleration as a function of various design parameters such as the tethers number and their length. A number of subsystem masses are calculated assuming existing or near-term E-sail technology. In light of the obtained performance estimates, an E-sail represents a promising propulsion system for a variety of transportation needs in the Solar System.

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

2012-07-01

116

Solar wind composition from the Moon;  

NASA Astrophysics Data System (ADS)

The lunar regolith contains the best accessible record of the solar wind 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 solar wind, 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 solar wind composition by means of long-duration exposure experiments with various techniques as baseline for investigation of the historic and ancient solar wind. (2) A multidisciplinary program, involving an experimental investigation of implantation-, storage- and loss-processes of solar 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.

Bochsler, P.

1994-06-01

117

Solar Wind Forecasting with Coronal Holes  

Microsoft Academic Search

An empirical model for forecasting solar wind speed related geomagnetic events is presented here. The model is based on the\\u000a estimated location and size of solar coronal holes. This method differs from models that are based on photospheric magnetograms\\u000a (e.g., Wang–Sheeley model) to estimate the open field line configuration. Rather than requiring the use of a full magnetic\\u000a synoptic map,

S. Robbins; C. J. Henney; J. W. Harvey

2006-01-01

118

The driving of the plasma sheet by the solar wind  

Microsoft Academic Search

The coupling of the plasma sheet to the solar wind is studied statistically using measurements from various satellite pairs: one satellite in the solar wind and one in either the magnetotail central plasma sheet or the near-Earth plasma sheet. It is found that the properties of the plasma sheet are highly correlated with the properties of the solar wind: specifically

Joseph E. Borovsky; Michelle F. Thomsen; Richard C. Elphic

1998-01-01

119

Latitudinal Extent of Large Scale Solar Wind Structures  

Microsoft Academic Search

In this study we examine solar wind observations from two spacecraft widely separated in helocentric latitude in order to determine the latitudinal exent of large scale solar wind structures. In particular, we compare solar wind plasma observations obtained from ACE near 1 AU to those of Ulysses between 2 and 5.5 AU from the start of 1998 through day 200

H. A. Elliott; D. J. McComas; P. Riley

2001-01-01

120

Coronal Plumes in the Fast Solar Wind  

NASA Technical Reports Server (NTRS)

The expansion of a coronal hole filled with a discrete number of higher density coronal plumes is simulated using a time-dependent two-dimensional code. A solar wind model including an exponential coronal heating function and a flux of Alfven waves propagating both inside and outside the structures is taken as a basic state. Different plasma plume profiles are obtained by using different scale heights for the heating rates. Remote sensing and solar wind in situ observations are used to constrain the parameter range of the study. Time dependence due to plume ignition and disappearance is also discussed. Velocity differences of the order of approximately 50 km/s, such as those found in microstreams in the high-speed solar wind, may be easily explained by slightly different heat deposition profiles in different plumes. Statistical pressure balance in the fast wind data may be masked by the large variety of body and surface waves which the higher density filaments may carry, so the absence of pressure balance in the microstreams should not rule out their interpretation as the extension of coronal plumes into interplanetary space. Mixing of plume-interplume material via the Kelvin-Helmholtz instability seems to be possible within the parameter ranges of the models defined here, only at large di stances from the Sun, beyond 0.2-0.3 AU. Plasma and composition measurements in the inner heliosphere, such as those which will become available with Solar Orbiter and Solar Probe Plus, should therefore definitely be able to identify plume remnants in the solar wind.

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

2011-01-01

121

How did the solar wind structure change around the solar maximum? From interplanetary scintillation observation  

Microsoft Academic Search

Observations from the second Ulysses fast latitude scan show that the global structure of solar wind near solar maximum is much more complex than at solar minimum. Soon after solar maximum, Ulysses observed a polar coronal hole (high speed) plasma with magnetic polarity of the new solar cycle in the Northern Hemisphere. We analyze the solar wind structure at and

K. Fujiki; M. Kojima; M. Tokumaru; T. Ohmi; A. Yokobe; K. Hayashi; D. J. McComas; H. A. Elliott

2003-01-01

122

Substorm occurrence during quiet solar wind driving  

NASA Astrophysics Data System (ADS)

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 solar driving periods, especially during the solar 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 solar wind 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 solar wind electric field, the electrojet intensity is smaller (by few tens of nT), and the electrojet resides farther poleward (by over 1°) during extended quiet solar driving in 2009 than during average solar activity conditions. During the solar 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 solar wind driving conditions is about 5-8 h, which is almost double that of the average solar activity conditions.

Pulkkinen, T. I.; Partamies, N.; Kilpua, E. K. J.

2014-04-01

123

Combination wind turbine generator and solar hot water system  

Microsoft Academic Search

This demonstration combined two renewable sources of energy, wind and solar, to meet the needs for a hot water system and electrical generation. A new and unique wind blade design called a Helical Wind Turbine was used. The solar hot water system used was commercially produced. The project has demonstrated that wind generators are feasible in Harford County, Maryland.

J. L. Jr

1983-01-01

124

Solar Wind Heating by Pickup Protons  

NASA Astrophysics Data System (ADS)

We review observations of solar wind heating in the outer heliosphere as measured by the Voyager and Pioneer spacecraft and described previously by a theory of pickup ion wave excitation and turbulent transport. That theory was most recently applied to observations by Smith et al. [2001] and with significant revision of the pickup proton component by Isenberg et al. [2003]. We extend the application of the theory to include time variation of solar wind parameters as recorded by the Omnitape dataset of 1 AU measurements. By averaging Omnitape observations over several solar rotations and using the resulting values as input to the theory, we are able to reproduce the variability of the thermal proton temperatures observed in the outer heliosphere. This is seen to be a direct result of the dependence of energy injection by pickup protons upon bulk solar wind parameters such as Alfven speed and wind speed and the fact that these parameters persist in a predictable manner from 1 AU to the outer heliosphere. Smith et al., JGR, A106, 8253-8272 [2001] Isenberg et al., ApJ, 592, 564-573 [2003

Smith, C. W.; Isenberg, P. A.; Matthaeus, W. H.; Richardson, J. D.

2004-05-01

125

Magnetopause location under extreme solar wind conditions  

Microsoft Academic Search

During the solar wind dynamic pressure enhancement, around 0200 UT on January 11, 1997, at the end of the January 6-11 magnetic cloud event, the magnetopause was pushed inside geosynchronous orbit. The LANL 1994-084 and GMS 4 geosynchronous satellites crossed the magnetopause and moved into the magnetosheath. Also, the Geotail satellite was in the magnetosheath while the Interball 1 satellite

J.-H. Shue; P. Song; J. T. Steinberg; J. K. Chao; G. Zastenker; O. L. Vaisberg; S. Kokubun; H. J. Singer; T. R. Detman; H. Kawano

1998-01-01

126

Triggering of substorms by solar wind discontinuities  

Microsoft Academic Search

In order to study the relationship between substorm occurrence and magnetospheric compression caused by solar wind discontinuities, 125 storm sudden commencements (ssc's) observed during the 4 years 1967-1970 were examined by using ground magnetograms, AE indices, and magnetic field data obtained by Explorer 33, 34, and 35 and OGO 5. Statistical and case studies confirm that geogmagnetic activity and interplanetary

S. Kokubun; R. L. McPherron; C.T. Russell

1977-01-01

127

Double ion streams in the solar wind  

Microsoft Academic Search

Distinct interpenetrating ion streams have been identified in the solar wind for the first time. They are shown to be interplanetary in origin and to be associated with the filling in of regions of density rarefactions accompanying high-velocity streams. With few excep- tions, the ion stream with the lower-energy density flux has higher energy. Furthermore, nonradial magnetic field directions seem

W. C. Feldman; J. R. Asbridge; S. J. Bame; M. D. Montgomery

1973-01-01

128

The Solar Wind as a Turbulence Laboratory  

NASA Astrophysics Data System (ADS)

In this review we will focus on a topic of fundamental importance for both astrophysics and plasma physics, namely the occurrence of large-amplitude low-frequency fluctuations of the fields that describe the plasma state. This subject will be treated within the context of the expanding solar wind and the most meaningful advances in this research field will be reported emphasizing the results obtained in the past decade or so. As a matter of fact, Helios inner heliosphere and Ulysses' high latitude observations, recent multi-spacecrafts measurements in the solar wind (Cluster four satellites) and new numerical approaches to the problem, based on the dynamics of complex systems, brought new important insights which helped to better understand how turbulent fluctuations behave in the solar wind. In particular, numerical simulations within the realm of magnetohydrodynamic (MHD) turbulence theory unraveled what kind of physical mechanisms are at the basis of turbulence generation and energy transfer across the spectral domain of the fluctuations. In other words, the advances reached in these past years in the investigation of solar wind turbulence now offer a rather complete picture of the phenomenological aspect of the problem to be tentatively presented in a rather organic way.

Bruno, Roberto; Carbone, Vincenzo

2013-05-01

129

Combined Solar and Wind Energy Systems  

NASA Astrophysics Data System (ADS)

In this paper we present the new concept of combined solar and wind energy systems for buildings applications. Photovoltaics (PV) and small wind turbines (WTs) can be install on buildings, in case of sufficient wind potential, providing the building with electricity. PVs can be combined with thermal collectors to form the hybrid photovoltaic/thermal (PV/T) systems. The PVs (or the PV/Ts) and WT subsystems can supplement each other to cover building electrical load. In case of using PV/T collectors, the surplus of electricity, if not used or stored in batteries, can increase the temperature of the thermal storage tank of the solar thermal unit. The description of the experimental set-up of the suggested PV/T/WT system and experimental results are presented. In PV/T/WT systems the output from the solar part depends on the sunshine time and the output of the wind turbine part depends on the wind speed and is obtained any time of day or night. The use of the three subsystems can cover a great part of building energy load, contributing to conventional energy saving and environment protection. The PV/T/WT systems are considered suitable in rural and remote areas with electricity supply from stand-alone units or mini-grid connection. PV/T/WT systems can also be used in typical grid connected applications.

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

2010-01-01

130

Material Interactions with Solar Wind Ion Environments  

NASA Technical Reports Server (NTRS)

Solar wind composition is dominated by hydrogen (approx.96%) and helium (approx.3 to 4%) with a minor fraction (less than or equal to 1%) of heavy ions. Hydrogen (helium) ions impact spacecraft surfaces with energies from 0.5 to 5 keV (1.8 to 21 keV) due to variations in solar wind velocity from 300 km/s to 1000 km/sec with extremes of a few 10 s keV during periods of extremely high solar wind velocity exceeding 1000 km/sec. Mean impact energies are typically on the order of approximately 1 keV and 4 keV for hydrogen ions and helium ions, respectively. These energies are typically of the peak of the energy dependent light ion sputter yields for hydrogen and helium on many metals. In addition, light ions with kilovolt energies have been shown to produce blister (or exfoliation) damage to metal surfaces due to formation of high pressure gas bubbles within the materials when exposed to ion fluences on the order of 10(exp 16 to (10(exp 17 ions/sq cm. A number of spacecraft designs for current and future missions include gossamer polymer structures with thin metallic reflection coatings to shield instruments from the Sun or solar sail propulsion systems for use in a variety of locations in the inner solar system from 0.5 to 1 AU. In addition, there is interest in designing spacecraft for solar physics missions requiring operations as close to the Sun as 0.16 to 0.2 AU. Integrity of the metallic coatings is critical in many of these applications since degradation will result in modification of material thermal properties or exposure of polymers to solar UV photons which can compromise mission requirements. This paper will evaluate the relative contributions of sputtering and blister formation to material degradation in solar wind environments over a range of radial distances from the Sun to demonstrate where solar wind environments become important for materials selection. We will first review the physics and results from laboratory measurements of light ion sputtering, blistering, and exfoliation of metallic surfaces to establish the order of magnitude ion fluence required for significant surface damage. Solar wind ion fluence environments will then be evaluated due to variations in solar wind conditions as a function of solar cycle for varying distances from the Sun using models for radial variations in solar wind ion number density, temperature, and velocity to determine where sputtering and blistering is most likely to be an issue. Finally, ion fluence statistics for varying radial distances from the Sun will be shown to establish the mission duration and radial distances from the Sun where missions will encounter sufficient ion fluence to exhibit damage to metallic surfaces.

Minow, Joseph I.; McWilliams, Brett

2006-01-01

131

Solar Wind Properties During the Current Solar Minimum: Ulysses Observations  

NASA Astrophysics Data System (ADS)

Using Ulysses solar wind composition data it is possible to compare observations in the current, unusual solar minimum with those obtained during the minimum in 1994-95. It has been re-ported earlier that, during the current minimum, there is a ˜ 15% reduction of the heliospheric magnetic field (Smith and Balogh, 2008), and ˜ 17% and ˜ 14% reduction in density and temperature, respectively (McComas et al., 2008), as compared to the previous minimum. But the polar coronal hole (PCH)-associated solar wind streams show long-term variability not only in dynamic, but also in compositional properties. The observed trends provide powerful tools to investigate the properties of the underlying corona during this time. From 1995 to 2008, the C and O freeze-in temperatures measured in high-latitude solar wind have steadily decreased by ˜ 15% and are now around 0.86 MK and 1.0 MK, respectively. Si and Fe ionization states also exhibit a substantial cooling with a reduction of 0.2 and 0.3 charge states, respectively. Thus it appears that all observed PCHs of cycle 23 are cooler overall than those of cycle 22. It is more difficult to assess whether there are significant changes of the elemental composition of the solar wind, as exhibited through the First Ionization Potential fractionation effect, which seems to have remained at f = 1.8 ± 0.3 during all polar passages. These observations provide a unique test for theories of the solar wind and its composition. Furthermore, the comparative analysis of the corona with these data provides important insights about the physical processes that link the Sun and its heliosphere.

von Steiger, Rudolf; Zurbuchen, Thomas H.

132

Numerical simulations to study solar wind turbulence  

SciTech Connect

Numerical simulation of coupled equations of kinetic Alfven wave (KAW) and ion acoustic wave is presented in the solar wind. The nonlinear dynamical equations satisfy the modified Zakharov system of equations by taking the nonadiabatic response of the background density. The ponderomotive nonlinearity is incorporated in the wave dynamics. The effect of Landau damping of KAW is taken into account. Localization of magnetic field intensity and the wavenumber spectra (perpendicular and parallel) of magnetic fluctuations are studied in solar plasmas around 1 a.u. Our results reveal the formation of damped localized structures and the steeper spectra that are in good agreement with the observations. These damped structures and steeper turbulent spectra can be responsible for plasma heating and particle acceleration in solar wind.

Sharma, R. P.; Sharma, Nidhi; Kumar, Sanjay [Centre for Energy Studies, Indian Institute of Technology Delhi, Delhi 110016 (India); Kumar, Sachin [Department of Applied Sciences and Humanities, Ajay Kumar Garg Engineering College, Ghaziabad 201009 (India); Singh, H. D. [Department of Physical Sciences, School of Physical and Chemical Sciences, Sikkim University, Sikkim 737102 (India)

2011-02-15

133

Coronal magnetic fields and the solar wind  

NASA Technical Reports Server (NTRS)

Current information is presented on coronal magnetic fields as they bear on problems of the solar wind. Both steady state fields and coronal transient events are considered. A brief critique is given of the methods of calculating coronal magnetic fields including the potential (current free) models, exact solutions for the solar wind and field interaction, and source surface models. These solutions are compared with the meager quantitative observations which are available at this time. Qualitative comparisons between the shapes of calculated magnetic field lines and the forms visible in the solar corona at several recent eclipses are displayed. These suggest that: (1) coronal streamers develop above extended magnetic arcades which connect unipolar regions of opposite polarity; and (2) loops, arches, and rays in the corona correspond to preferentially filled magnetic tubes in the approximately potential field.

Newkirk, G., Jr.

1972-01-01

134

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

Microsoft Academic Search

The measurement of the solar wind electron temperature radial profile in the unexplored region between 1 and 45 R_s is of prime importance for understanding the solar wind acceleration. Solar Orbiter's location, combined with its ability to observe the corona in co-rotation, will furnish strong observational constraints on solar wind models. We discuss the implementation of the plasma thermal noise

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

2004-01-01

135

Prediction of Solar Energetic Particle Event Histories Using Real-Time Particle and Solar Wind Measurements.  

National Technical Information Service (NTIS)

The comparatively well-ordered magnetic structure in the solar corona during the decline of Solar Cycle 20 has revealed a characteristic dependence of solar energetic particle injection upon heliographic longitude. When analyzed using solar wind mapping o...

E. C. Roelof R. E. Gold

1976-01-01

136

Wind and IMP 8 Solar Wind, Magnetosheath and Shock Data  

NASA Technical Reports Server (NTRS)

The purpose of this project was to provide the community access to magnetosheath data near Earth. We provided 27 years of IMP 8 magnetosheath proton velocities, densities, and temperatures with our best (usually 1-min.) time resolution. IMP 8 crosses the magnetosheath twice each 125 day orbit, and we provided magnetosheath data for the roughly 27 years of data for which magnetometer data are also available (which are needed to reliably pick boundaries). We provided this 27 years of IMP 8 magnetosheath data to the NSSDC; this data is now integrated with the IMP 8 solar wind data with flags indicating whether each data point is in the solar wind, magnetosheath, or at the boundary between the two regions. The plasma speed, density, and temperature are provided for each magnetosheath point. These data are also available on the MIT web site ftp://space .mit.edu/pub/plasma/imp/www/imp.html. We provide ASCII time-ordered rows of data giving the observation time, the spacecraft position in GSE, the velocity is GSE, the density and temperature for protons. We also have analyzed and archived on our web site the Wind magnetosheath plasma parameters. These consist of ascii files of the proton and alpha densities, speeds, and thermal speeds. These data are available at ftp://space.mit.edu/pub/plasma/wind/sheath These are the two products promised in the work statement and they have been completed in full.

2004-01-01

137

On Solar-Wind Electron Heating at Large Solar Distances  

NASA Astrophysics Data System (ADS)

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

Chashei, Igor V.; Fahr, Hans J.

2014-04-01

138

Solar sources of the interplanetary magnetic field and solar wind  

NASA Technical Reports Server (NTRS)

Open magnetic field lines, those which extend from the solar photosphere to interplanetary space, are traced in the current-free (potential field) approximation using measured photospheric fields as a boundary condition. It is found that (1) only a relatively small fraction of the photospheric area connects via open field lines to the interplanetary magnetic field; (2) those photospheric areas which do contribute open field lines lie beneath coronal holes and within the boundaries of the holes as projected onto the photosphere or else between loop systems of an active region; (3) the interplanetary magnetic field in the plane of the sun's equator, essentially the field in the ecliptic plane, may connect to photospheric regions of high latitude; and (4) the fastest solar wind streams are correlated with those magnetic flux tubes which expand least in cross-sectional area over the distance between the photosphere and the coronal height where the solar wind begins.

Levine, R. H.; Altschuler, M. D.; Harvey, J. W.

1977-01-01

139

Laboratory experiments simulating solar wind driven magnetospheres  

SciTech Connect

Magnetosphere-solar wind interactions are simulated in a laboratory setting with a small permanent magnet driven by two types of supersonic plasma wind sources. The first higher speed, shorter duration plasma wind is from a laser blow-off plasma while the second longer duration, lower speed plasma wind is produced with a capacitor discharge driven coaxial electrode creating plasma jets. The stand off distance of the solar wind from the magnetosphere was measured to be 1.7{+-}0.3 cm for the laser-produced plasma experiment and 0.87{+-}0.03 cm for the coaxial electrode plasma experiment. The stand off distance of the plasma was calculated using data from HYADES[J. T. Larsen and S. M. Lane, J. Quant. Spectrosc. Radiat. Transf. 51, 179 (1994)] as 1.46{+-}0.02 cm for the laser-produced plasma, and estimated for the coaxial plasma jet as r{sub mp}=0.72{+-}0.07 cm. Plasma build up on the poles of the magnets, consistent with magnetosphere systems, was also observed.

Brady, P.; Ditmire, T. [Fusion Research Center, The University of Texas at Austin, Austin, Texas 78712 (United States); Horton, W.; Mays, M. L. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States); Zakharov, Y. [Institute of Laser Physics, Russian Academy of Sciences, Novosibirsk 630090, Av. Lavrentyeva 13/3 (Russian Federation)

2009-04-15

140

Properties of Minor Ions in the Solar Wind and Implications for the Background Solar Wind Plasma  

NASA Technical Reports Server (NTRS)

Ion charge states measured in situ in interplanetary space are formed in the inner coronal regions below 5 solar radii, hence they carry information on the properties of the solar wind 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. The goal of the proposal is to make use of ion fractions observed in situ in the solar wind to learn about both, the plasma conditions in the inner corona and the expansion and ion formation itself. This study is carried out using solar wind models, coronal observations, and ion fraction calculations in conjunction with the in situ observations.

Esser, Ruth; Wagner, William (Technical Monitor)

2003-01-01

141

Interpreting the solar wind ionization state  

NASA Technical Reports Server (NTRS)

The ionization state of the solar coronal expansion is frozen within a few solar radii of the solar photosphere, and spacecraft measurements of the solar wind heavy ion charge state can therefore yield information about coronal conditions (e.g., electron temperature). Previous interpretations of the frozen-in ionization state have always assumed that in the coronal freezing-in region, (1) all heavy ions flow at the same bulk speed as protons, (2) the electron velocity distribution function is Maxwellian, and (3) conditions vary in space but not in time. The consequences of relaxing these assumptions for the interpretation of solar wind charge state measurements are examined. It is found that: (1) the temperature inferred by traditional interpretation of the interplanetary ionization state overestimates (underestimate) the actual coronal electron temperature if higher ion charge stages flow systematically faster (slower) than lower stages at the coronal freezing radius; (2) temperatures inferred from relative abundance measurements of ion-charge-stages with high ionization potentials moderately overestimate the actual coronal electron temperature if the high-energy tail of the coronal electron velocity distribution is enhanced relative to a Maxwellian distribution; (3) the propagation of a disturbance, e.g., a shock wave, through the corona can strongly affect the frozen-in charge state, but only over a time (a few times ten minutes) corresponding to the coronal transit time for the disturbance.

Owocki, S. P.

1983-01-01

142

Global Solar Wind Structure from Solar Minimum to Solar Maximum: Sources and Evolution  

Microsoft Academic Search

During the past few years, significant progress has been made in identifying the coronal sources of structures observed in\\u000a the solar wind. This recent work has been facilitated by the relative simplicity and stability of structures during solar\\u000a minimum. The challenge now is to continue to use coordinated coronal\\/solar wind observations to study the far more complicated\\u000a and time-evolving structures

S. E. Gibson

2001-01-01

143

The Solar Wind and the Sun in the Past  

NASA Astrophysics Data System (ADS)

Exposure to the solar wind can have significant long term consequences for planetary atmospheres, especially for planets such as Mars that are not protected by global magnetospheres. Estimating the effects of solar wind exposure requires knowledge of the history of the solar wind. Much of what we know about the Sun’s past behavior is based on inferences from observations of young solar-like stars. Stellar analogs of the weak solar wind cannot be detected directly, but the interaction regions between these winds and the interstellar medium have been detected and used to estimate wind properties. I here review these observations, with emphasis on what they suggest about the history of the solar wind.

Wood, Brian E.

2006-10-01

144

Solar Wind Thermally Induced Magnetic Fluctuations  

NASA Astrophysics Data System (ADS)

A kinetic description of Alfvén-cyclotron magnetic fluctuations for anisotropic electron-proton quasistable plasmas is studied. An analytical treatment, based on the fluctuation-dissipation theorem, consistently shows that spontaneous fluctuations in plasmas with stable distributions significantly contribute to the observed magnetic fluctuations in the solar wind, as seen, for example, in [S. D. Bale et al., Phys. Rev. Lett. 103, 211101 (2009)], even far below from the instability thresholds. Furthermore, these results, which do not require any adjustable parameters or wave excitations, are consistent with the results provided by hybrid simulations. It is expected that this analysis contributes to our understanding of the nature of magnetic fluctuations in the solar wind.

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

2014-06-01

145

The solar wind and magnetospheric dynamics  

NASA Technical Reports Server (NTRS)

The dynamic processes involved in the interaction between the solar wind and the earth's magnetosphere are reviewed. The evolution of models of the magnetosphere is first surveyed. The existence of the auroral substorm and the cyclical polar magnetic substorm is evidence that the magnetosphere is a dynamic system. The dynamic changes occurring in the magnetosphere, including erosion of the magnetopause, changes in the size of the polar cap, variations in the flaring angle of the tail, neutral point formation, plasma sheet motions, and the inward collapse of the midnight magnetosphere, are discussed. The cyclical variations of geomagnetic activity are explained in terms of the control of the solar wind-magnetosphere interaction by the north-south component of the interplanetary magnetic field. Present phenomenological models allow prediction of geomagnetic activity from interplanetary measurements, but modeling of detailed magnetospheric processes is still in its infancy.

Russell, C. T.

1974-01-01

146

Latitudinal Variation of Solar Wind Velocity  

NASA Astrophysics Data System (ADS)

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

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

1995-04-01

147

A statistical study of the interdependence of solar wind parameters  

NASA Astrophysics Data System (ADS)

Correlation analysis of solar wind parameters, namely solar wind velocity, proton density, proton temperature and mean interplanetary magnetic field (IMF) from the ACE spacecraft data near Earth, was done. To our best knowledge, this study is a novel one since we consider here only the parameters inside the solar wind, including the mean IMF and, hence, the solar wind is a self consistent system. We have proposed a Multiple Linear Regression (MLR) model for the prediction of the response variable (solar wind velocity) using the parameters proton density, proton temperature and mean IMF measured as daily averages. About 60% of the observed value can be predicted using this model. It is shown that, in general, the correlation between solar wind parameters is significant. A deviation from the prediction at the solar maximum is interpreted. These results are verified by a graphical method.

John, Shollykutty; Kurian, P. J.

2009-04-01

148

Bidirectional solar wind electron heat flux events  

Microsoft Academic Search

Normally the approx. >80-eV electrons which carry the solar wind electron heat flux are collimated along the interplanetary magnetic field (IMF) in the direction pointing outward away from the sun. Occasionally, however, collimated fluxes of approx. >80-eV electrons are observed traveling both parallel and antiparallel to the IMF. Here we present the results of a survey of such bidirectional electron

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

1987-01-01

149

Turbulence and waves in the solar wind  

SciTech Connect

Studies of turbulence and waves in the solar wind is discussed. Consideration is given to the observations and theory concerning the origin and evolution of interplanetary MHD fluctuations and to the observations, theory, and simulations of compressive fluctuations. Particular attention is given to extrapolations to near-sun and polar fields regions. Results obtained on turbulence at comets and magnetic turbulence of low-frequency waves excited by unstable distributions of ions are discussed. 230 refs.

Roberts, D.A.; Goldstein, M.L. (USAF, Geophysics Laboratory, Hanscom AFB, MA (United States))

1991-01-01

150

The Nascent Solar Wind: Origin and Acceleration  

Microsoft Academic Search

High-speed solar wind is known to originate in polar coronal holes, which, however, are made up of two components: bright, high-density regions known as ``plumes'' and dark, weakly emitting low-density regions known as ``interplumes.'' Recent space observations have shown that the width of UV lines is larger in interplume regions, while observations of the ratio of the O VI doublet

Luca Teriaca; Giannina Poletto; Marco Romoli; Doug A. Biesecker

2003-01-01

151

Microscale fluctuations in the solar wind  

NASA Technical Reports Server (NTRS)

Theoretical constraints on the interpretation of fluctuations (either propagating or stationary) in the interplanetary medium are reviewed, with emphasis on the important differences between the properties of hydromagnetic waves (and stationary structures) in collisionless and in collision-dominated plasmas, and on the possible roles of Landau damping and nonlinear effects in determining the interplanetary fluctuation spectrum. Hypotheses about the origins of the fluctuations and their influence on the large-scale properties of the solar wind are reviewed.

Barnes, A. A., Jr.

1972-01-01

152

The Genesis Solar-Wind Collector Materials  

Microsoft Academic Search

Genesis (NASA Discovery Mission #5) is a sample return mission. Collectors comprised of ultra-high purity materials will be\\u000a exposed to the solar wind and then returned to Earth for laboratory analysis. There is a suite of fifteen types of ultra-pure\\u000a materials distributed among several locations. Most of the materials are mounted on deployable panels (‘collector arrays’),\\u000a with some as targets

A. J. G. Jurewicz; D. S. Burnett; R. C. Wiens; T. A. Friedmann; C. C. Hays; R. J. Hohlfelder; K. Nishiizumi; J. A. Stone; D. S. Woolum; R. Becker; A. L. Butterworth; A. J. Campbell; M. Ebihara; I. A. Franchi; V. Heber; C. M. Hohenberg; M. Humayun; K. D. McKeegan; K. McNamara; A. Meshik; R. O. Pepin; D. Schlutter; R. Wieler

2003-01-01

153

Solar wind thermally induced magnetic fluctuations.  

PubMed

A kinetic description of Alfvén-cyclotron magnetic fluctuations for anisotropic electron-proton quasistable plasmas is studied. An analytical treatment, based on the fluctuation-dissipation theorem, consistently shows that spontaneous fluctuations in plasmas with stable distributions significantly contribute to the observed magnetic fluctuations in the solar wind, as seen, for example, in [S.?D. Bale et al., Phys. Rev. Lett. 103, 211101 (2009). PMID:24996092

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

2014-06-20

154

Quasi-steady solar wind dynamics  

NASA Technical Reports Server (NTRS)

Progress in understanding the large scale dynamics of quasisteady, corotating solar wind structure was reviewed. The nature of the solar wind at large heliocentric distances preliminary calculations from a 2-D MHD model are used to demonstrate theoretical expectations of corotating structure out to 30 AU. It is found that the forward and reverse shocks from adjacent CIR's begin to interact at about 10 AU, producing new shock pairs flanking secondary CIR's. These sawtooth secondary CIR's interact again at about 20 AU and survive as visible entities to 30 AU. The model predicts the velocity jumps at the leading edge of the secondary CIR's at 30 AU should be very small but there should still be sizable variations in the thermodynamic and magnetic parameters. The driving dynamic mechanism in the distant solar wind is the relaxation of pressure gradients. The second topic is the influence of weak, nonimpulsive time dependence in quasisteady dynamics. It is suggested that modest large scale variations in the coronal flow speed on periods of several hours to a day may be responsible for many of the remaining discrepancies between theory and observation. Effects offer a ready explanation for the apparent rounding of stream fronts between 0.3 and 1.0 AU discovered by Helios.

Pizzo, V. J.

1983-01-01

155

Equatorwards Expansion of Unperturbed, High-Latitude Fast Solar Wind  

NASA Astrophysics Data System (ADS)

We use dual-site radio observations of interplanetary scintillation (IPS) with extremely long baselines (ELB) to examine meridional flow characteristics of the ambient fast solar wind at plane-of-sky heliocentric distances of 24 - 85 solar radii ( R ?). Our results demonstrate an equatorwards deviation of 3 - 4? in the bulk fast solar wind flow direction over both northern and southern solar hemispheres during different times in the declining phase of Solar Cycle 23.

Dorrian, G. D.; Breen, A. R.; Fallows, R. A.; Bisi, M. M.

2013-07-01

156

Solar wind and its interaction with the magnetosphere - Measured parameters  

NASA Astrophysics Data System (ADS)

The sun and the solar wind are considered in terms of the 'ballerina' model first proposed by Alfven (1977), taking into account high speed streams, the slow solar wind, stream-stream interactions, the relation of streams and magnetic structure, and transients caused by solar activity. The main features of the solar wind behavior are illustrated with the aid of data, covering one complete solar rotation in 1974/1975, which were obtained with instruments aboard the Helios-1 solar probe. It is pointed out that the solar wind acts like a huge buffer pushing onto the earth's magnetosphere with a highly variable pressure. Of the energy in the highly variable solar wind reservoir only a tiny fraction is absorbed by the magnetosphere in an obviously very nonstationary way.

Schwenn, R.

157

Coronal roots of solar wind streams: 3-D MHD modeling  

Microsoft Academic Search

Weak (discontinuous) solutions of the 3-D MHD equations look like a promising tool to model the transonic solar wind 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 solar wind model by embedding the discontinuities of given type. Such 3-D MHD structured solar

Yu. V. Pisanko

1995-01-01

158

Genesis capturing the sun: Solar wind irradiation at Lagrange 1  

Microsoft Academic Search

Genesis, a member of NASAs Discovery Mission program, is the world's first sample return mission since the Apollo program to bring home solar matter in ultra-pure materials. Outside the protection of Earth's magnetosphere at the Earth-Sun Lagrange 1 point, the deployed sample collectors were directly exposed to solar wind irradiation. The natural process of solar wind ion implantation into a

Michael J. Calaway; Eileen K. Stansbery; Lindsay P. Keller

2009-01-01

159

Origin of the solar wind from composition data  

Microsoft Academic Search

The ESA\\/NASA spacecraft Ulysses is making, for the first time, direct measurements in the solar wind originating from virtually all places where the corona expands. Since the initial two polar passes of Ulysses occur during relatively quiet solar conditions, we discuss here the three main regimes of quasi-stationary solar wind flow: the high speed streams (HSSTs) coming out of the

J. Geiss; G. Gloeckler; R. VON STEIGER

1995-01-01

160

Simulation of period doubling of recurrent solar wind structures  

Microsoft Academic Search

In 1974, IMP, Pioneer 11 and Pioneer 10 observed a recurrent solar wind structure over five consecutive solar rotations at three different trajectories between 1 and 6 AU. Using MHD simulations and input functions generated from plasma and magnetic field data observed from Pioneer 11. The authors study the continuing evolution of this solar wind structure between 5 and 20

Y. C. Whang; L. F. Burlaga

1990-01-01

161

The Solar Origins of Solar Wind Interstream Flows: Near-Equatorial Coronal Streamers  

Microsoft Academic Search

Vela heavy ion and IMP solar wind data are used to identify the coronal origins of the interstream, low-speed solar wind as well as to understand the causes of the long-term trends in solar wind densities and electron temperatures observed at 1 AU. Several lines of evidence suggest a strong association be- tween interstream flows and the extensions of the

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

1981-01-01

162

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

NASA Technical Reports Server (NTRS)

The past history of the solar wind and solar cycle, inferred from records of geomagnetics and aurora, is examined. Records show that the solar wind apparently varied in a systematic manner throughout the period from 1770 to 1857 and that the period around 1810 resembled the 1901 minimum geomagnetic disturbance. Results show that the solar wind and hence the Sun changes on a time scale long compared to a solar cycle and short compared to the Maunder minimum. The inclusion of a study on the solar wind and solar cycle variations for the SCADM mission is discussed.

Feynman, J.; Silverman, S.

1980-01-01

163

Cosmic ray modulation by solar wind disturbances  

NASA Astrophysics Data System (ADS)

Aims: We perform a systematic statistical study of the relationship between characteristics of solar wind disturbances, caused by interplanetary coronal mass ejections and corotating interaction regions, and properties of Forbush decreases (FDs). Since the mechanism of FDs is still being researched, this analysis should provide a firm empirical basis for physical interpretations of the FD phenomenon. Methods: The analysis is based on the ground-based neutron monitor data and the solar wind data recorded by the Advanced Composition Explorer, where the disturbances were identified as increases in proton speed, magnetic field, and magnetic field fluctuations. We focus on the relative timing of FDs, as well as on the correlations between various FD and solar wind parameters, paying special attention to the statistical significance of the results. Results: It was found that the onset, the minimum, and the end of FDs are delayed after the onset, the maximum, and the end of the magnetic field enhancement. The t-test shows that at the 95% significance level the average lags have to be longer than 3, 7, and 26 h, respectively. FD magnitude (| FD|) is correlated with the magnetic field strength (B), magnetic field fluctuations (?B), and speed (v), as well as with combined parameters, BtB, Bv, vtB, and BvtB, where tB is the duration of the magnetic field disturbance. In the |FD|(B) dependence, a "branching" effect was observed, i.e., two different trends exist. The analysis of the FD duration and recovery period reveals a correlation with the duration of the magnetic field enhancement. The strongest correlations are obtained for the dependence on combined solar wind parameters of the product of the FD duration and magnitude, implying that combined parameters are in fact true variables themselves, rather than just a product of variables. Conclusions: From the time lags we estimate that "the penetration depth" in the disturbance, at which FD onset becomes recognizable, is on the order of 100 Larmor radii and is comparable to a typical shock-sheath dimension. The results for the FD time profile indicate "shadow effect" of the solar wind disturbance before and after it passes the observer. The importance of reduced parallel diffusion during the passage of the disturbance is discussed, along with the influence of terrestrial effects on the observed "branching effect". Appendices A-C are available in electronic form at http://www.aanda.org

Dumbovi?, M.; Vršnak, B.; ?alogovi?, J.; Karlica, M.

2011-07-01

164

Solar wind driving and substorm triggering  

NASA Astrophysics Data System (ADS)

We compare solar wind driving and its changes for three data sets: (1) 4861 identifications of substorm onsets from satellite global imagers (Polar UVI and IMAGE FUV); (2) a similar number of otherwise random times chosen with a similar solar wind distribution (slightly elevated driving); (3) completely random times. Multiple measures of solar wind driving were used, including interplanetary magnetic field (IMF) Bz, the Kan-Lee electric field, the Borovsky function, and d?MP/dt (all of which estimate dayside merging). Superposed epoch analysis verifies that the mean Bz has a northward turning (or at least averages less southward) starting 20 min before onset. We argue that the delay between IMF impact on the magnetopause and tail effects appearing in the ionosphere is about that long. The northward turning is not the effect of a few extreme events. The median field shows the same result, as do all other measures of solar wind driving. We compare the rate of northward turning to that observed after random times with slightly elevated driving. The subsequent reversion to mean is essentially the same between random elevations and substorms. To further verify this, we consider in detail the distribution of changes from the statistical peak (20 min prior to onset) to onset. For Bz, the mean change after onset is +0.14 nT (i.e., IMF becomes more northward), but the standard deviation is ? = 2.8 nT. Thus large changes in either direction are common. For EKL, the change is -15 nT km/s ± 830 nT km/s. Thus either a hypothesis predicting northward turnings or one predicting southward turnings would find abundant yet random confirming examples. Indeed, applying the Lyons et al. (1997) trigger criteria (excluding only the prior requirement of 22/30 min Bz < 0, which is often not valid for actual substorms) to these three sets of data shows that "northward turning triggers" occur in 23% of the random data, 24% of the actual substorms, and after 27% of the random elevations. These results strongly support the idea of Morley and Freeman (2007), that substorms require initial elevated solar wind driving, but that there is no evidence for external triggering. Finally dynamic pressure, p, and velocity, v, show no meaningful variation around onset (although p averages 10% above an 11 year mean).

Newell, Patrick T.; Liou, Kan

2011-03-01

165

Topological Origins of the Slow Solar Wind  

NASA Technical Reports Server (NTRS)

Although the slow solar wind has been studied for decades with both in situ and remote sensing observations, its origin is still a matter of intense debate. In the standard quasi-steady model, the slow wind is postulated to originate near coronal hole boundaries that define topologically well-behaved separatrices between open and closed field regions. In the interchange model, on the other hand, the slow wind is postulated to originate on open flux that is dynamically diffusing throughout the seemingly closed-field corona. We argue in favor of the quasi-steady scenario and propose that the slow wind is due to two effects: First, the open-closed boundary is highly complex due to the complexity of the photospheric flux distribution. Second, this boundary is continuously driven by the transport of magnetic helicity from the closed field region into the open. The implications of this model for the structure and dynamics of the corona and slow wind are discussed, and observational tests of the mode

Antiochos, Spiro

2008-01-01

166

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

SciTech Connect

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

Heber, Veronika S.; Baur, Heinrich; Wieler, Rainer [Institute for Geochemistry and Petrology, ETH Zurich, Clausiusstrasse 25, CH-8092 Zurich (Switzerland); Bochsler, Peter [Physikalisches Institut, Universitaet Bern, Sidlerstasse 5, CH-3012 Bern (Switzerland); McKeegan, Kevin D. [Department of Earth and Space Sciences, University of California Los Angeles, 595 Charles Young Drive East, Box 951567, Los Angeles, CA 90095-1567 (United States); Neugebauer, Marcia [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721-0092 (United States); Reisenfeld, Daniel B. [Department of Physics and Astronomy, University of Montana, Missoula, MT 59812 (United States); Wiens, Roger C., E-mail: heber@ess.ucla.edu [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2012-11-10

167

Variations of Strahl Properties with Fast and Slow Solar Wind  

NASA Technical Reports Server (NTRS)

The interplanetary solar wind electron velocity distribution function generally shows three different populations. Two of the components, the core and halo, have been the most intensively analyzed and modeled populations using different theoretical models. The third component, the strahl, is usually seen at higher energies, is confined in pitch-angle, is highly field-aligned and skew. This population has been more difficult to identify and to model in the solar wind. In this work we make use of the high angular, energy and time resolution and three-dimensional data of the Cluster/PEACE electron spectrometer to identify and analyze this component in the ambient solar wind during high and slow speed solar wind. The moment density and fluid velocity have been computed by a semi-numerical integration method. The variations of solar wind density and drift velocity with the general build solar wind speed could provide some insight into the source, origin, and evolution of the strahl.

Figueroa-Vinas, Adolfo; Goldstein, Melvyn L.; Gurgiolo, Chris

2008-01-01

168

Interpretation of Solar Wind Ion Composition Measurements from Ulysses  

NASA Technical Reports Server (NTRS)

The ion compositions measured in situ in the solar wind are important since the ion fractions carry information on the plasma conditions in the inner corona. The conditions in the inner corona define the properties of the solar wind plasma flow. Thus, if the ion fraction measurements can be used to unravel some of the plasma parameters in the inner corona, they will provide a valuable contribution to solving the heating and acceleration problem of the solar wind. The ion charge states in the solar wind carry information on electron temperature, electron density and ion flow speed. They are also sensitive to the shape of the electron distribution function. Through carefully modeling the solar wind and calculating the ion fractions predicted for different solar wind conditions, constraints on the electron temperature and ion flow speeds can be placed if the electron density is measured using polarization brightness measurements.

Esser, Ruth

1998-01-01

169

Solar wind rare gas analysis: Trapped solar wind helium and neon in Surveyor 3 material  

NASA Technical Reports Server (NTRS)

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 solar wind 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 solar protons, stripping by cosmic ray or energetic solar alpha particles, recycling of solar wind 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.

Buehler, F.; Eberhardt, P.; Geiss, J.; Schwarzmueller, J.

1972-01-01

170

Radial evolution of the energy density of solar wind fluctuations  

NASA Technical Reports Server (NTRS)

On the basis of transport theories appropriate to a radially expanding solar wind, we describe new results for the radial evolution of the energy density in solar wind fluctuations at MHD scales. These models include the effects of 'mixing' and driving as well as the possibility of non-isotropic MHD turbulence. Implications of these results for solar wind heating, cosmic ray diffusion and interstellar pick-up ions will also be addressed.

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

1995-01-01

171

Real-time solar wind forecasting: Capabilities and challenges  

Microsoft Academic Search

A user-friendly, real-time, observation-driven system for forecasting solar wind and interplanetary magnetic field conditions is described. The forecast system presently uses the Hakamada–Akasofu–Fry (version 2) kinematic solar wind model to predict, in real-time, solar wind conditions in the heliosphere, including at the location of Mars, and beyond. Properly characterizing and predicting this region of the space environment are essential steps

C. D. Fry; T. R. Detman; M. Dryer; Z. Smith; W. Sun; C. S. Deehr; S.-I. Akasofu; C.-C. Wu; S. McKenna-Lawlor

2007-01-01

172

Nitrogen in solar energetic particles: isotopically distinct from solar wind.  

PubMed

Stepwise etching of lunar soil ilmenite grains reveals that the 15N/14N ratio of implanted nitrogen decreases with increasing implantation depth within the ilmenite grains, i.e., with increasing energy of implantation. These results show that N derived from solar energetic particles, NSEP, is enriched in the light isotope, 14N, relative to solar-wind nitrogen, NSW. This is in striking contrast to the neon isotopic record: NeSEP is depleted in the light isotope, 20Ne, relative to NeSW. These data suggest either distinct signatures in the respective solar source regions, or fractionation in the acceleration mechanism(s). However, the observed opposite fractionation trends for light N and Ne isotopes do not agree with model predictions. PMID:11542821

Mathew, K J; Kerridge, J F; Marti, K

1998-12-01

173

Coronal streamer belt asymmetries and seasonal solar wind variations deduced from Wind and Ulysses data  

Microsoft Academic Search

Solar wind measurements from Wind during March 1995 are combined with those from Ulysses' fast latitude scan to construct a map of the streamer belt. On the timescale of coro- nal change, the map is nearly a snapshot view of solar wind speed contours threaded by the trace of the heliospheric current sheet (HCS) in the +30 ø heliolatitude range.

N. U. Crooker; A. J. Lazarus; J. L. Phillips; J. T. Steinberg; A. Szabo; R. P. Lepping; E. J. Smith

1997-01-01

174

Elemental and charge state composition of the fast solar wind observed with SMS instruments on WIND  

NASA Technical Reports Server (NTRS)

The elemental composition and charge state distributions of heavy ions of the solar wind provide essential information about: (1) atom-ion separation processes in the solar atmosphere leading to the 'FIP effect' (the overabundance of low First Ionization potential (FIP) elements in the solar wind compared to the photosphere); and (2) coronal temperature profiles, as well as mechanisms which heat the corona and accelerate the solar wind. This information is required for solar wind acceleration models. The SWICS instrument on Ulysses measures for all solar wind flow conditions the relative abundance of about 8 elements and 20 charge states of the solar wind. Furthermore, the Ulysses high-latitude orbit provides an unprecedented look at the solar wind from the polar coronal holes near solar minimum conditions. The MASS instrument on the WIND spacecraft is a high-mass resolution solar wind 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 solar wind composition in both the slow and the corotating fast streams. This unique combination of SWICS on Ulysses and MASS on WIND allows us to view for the first time the solar wind from two regions of the large coronal hole. Observations with SWICS in the coronal hole wind: (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 Wind will be compared with results from SWICS on Ulysses.

Gloeckler, G.; Galvin, A. B.; Ipavich, F. M.; Hamilton, D. C.; Bochsler, P.; Geiss, J.; Fisk, L. A.; Wilken, B.

1995-01-01

175

Current-sheet-like structures in different type of solar winds and their effects on the solar wind MHD turbulence  

NASA Astrophysics Data System (ADS)

Current-sheet-like structures are ubiquitous in the solar wind. It is an important component of solar wind MHD turbulence intermittency. In this work, we examine the effect of current sheet of the solar wind MHD turbulence by analyzing the power spectrum, cross-helicity, residual energy, and structure function etc in different periods of the solar wind that is characterized by the occurrence rate of current sheets. Our study is performed to different types of solar wind according to the O7+/O6+ ratio and entropy. Earlier works have shown that O7+/O6+ ratio and the proton specific entropy can be used to identify the solar wind type. Our results show that the presence of current sheets can affect the solar wind MHD turbulence in both coronal hole wind and streamer stalking wind. We also present a case study in which a group of current sheets are found to bound a delta-shape like magnetic structure. Our analysis suggests that it may be due to a reconnection at the solar surface and then convected out with the solar wind.

Hu, J.; Bratcher, A. D.; Zhao, L.; Miao, B.; Li, G.

2013-12-01

176

What Determines the Solar Wind Speed ?  

NASA Astrophysics Data System (ADS)

Recent observations by Interplanetary Scintillation measurements by Nagoya-STEL group (Hirano et al.2003; Kojima et al.2004) show that solar wind speed is well-correlated with B/f, where B is radial magnetic field strength at the solar 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 solar wind 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

Suzuki, T. K.; Fujiki, K.; Kojima, M.; Tokumaru, M.; Hirano, M.; Baba, D.; Yamasita, M.; Hakamada, K.

2005-05-01

177

Global Observations of Evolving 3D Solar Wind Structure  

NASA Astrophysics Data System (ADS)

Interplanetary scintillation (IPS) and Thomson scattered whitelight serve as effective tools to obtain a global view of the evolving solar wind structure, which is hardly accessible to in situ measurements using a limited number of spacecraft. This capability has been greatly enhanced owing to the use of the computer-assisted tomography (CAT) method. From a comparison between IPS reconstructions and photospheric magnetic field observations, we have identified the solar wind sources, which are consistent with plasma outflows observed by Hinode. We have also found a coronal parameter which is closely related to the terminal wind speed, and this result show excellent agreement with the nonlinear Alfven-wave-driven solar wind model. Our IPS observations over three cycles have revealed that the global distribution of solar wind speeds changes systematically depending on the solar activity. An excellent correlation between fast/slow wind areas and polar magnetic fields is demonstrated here. The important point to note is that the solar wind speed distribution for the current minimum differs significantly from that for the previous minimum. This difference is considered a consequence of weaker polar fields in the current minimum. Rapid evolution of the 3D solar wind structure associated with CMEs has been investigated from the combined analysis of IPS and whitelight observations. The results reveal global features of interplanetary CMEs and a drastic change in the expansion speed between the Sun and Earth orbit, suggesting important implications for the propagation dynamics of CMEs in the solar wind.

Tokumaru, M.; Fujiki, K.; Itoh, H.; Iju, T.; Kojima, M.

2012-08-01

178

Gaseous isotope separation using solar wind phenomena  

PubMed Central

A large evacuated drum-like chamber fitted with supersonic nozzles in the center, with the chamber and the nozzles corotating, can separate gaseous fluids according to their molecular weights. The principle of separation is essentially the same as that of the solar wind propagation, in which components of the plasma fluid are separated due to their difference in the time-of-flight. The process can inherently be very efficient, serving as a pump as well as a separator, and producing well over 105 separative work units (kg/year) for the hydrogen/deuterium mixture at high-velocity flows.

Wang, Chia-Gee

1980-01-01

179

ELECTRON TRANSPORT IN THE FAST SOLAR WIND  

SciTech Connect

The electron velocity distribution function is studied in the extended solar corona above coronal holes (i.e., the inner part of the fast solar wind) from the highly collisional corona close to the Sun to the weakly collisional regions farther out. The electron kinetic equation is solved with a finite-element method in velocity space using a linearized Fokker-Planck collision operator. The ion density and temperature profiles are assumed to be known and the electric field and electron temperature are determined self-consistently. The results show quantitatively how much lower the electron heat flux and the thermal force are than predicted by high-collisionality theory. The sensitivity of the particle and heat fluxes to the assumed ion temperature profile and the applied boundary condition at the boundary far from the Sun is also studied.

Smith, H. M.; Marsch, E. [Max-Planck-Institut fuer Sonnensystemforschung, Max-Planck-Strasse 2, 37191 Katlenburg-Lindau (Germany); Helander, P., E-mail: hakan.smith@ipp.mpg.de [Max-Planck-Institut fuer Plasmaphysik, Wendelsteinstrasse 1, 17491 Greifswald (Germany)

2012-07-01

180

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

NASA Technical Reports Server (NTRS)

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

Smith, E. J.

1997-01-01

181

Latitudinal Dependence of Coronal Hole-Associated Fast Solar Wind  

NASA Astrophysics Data System (ADS)

The fast solar wind can have at least two different coronal sources: high-latitude, polar coronal holes (PCH) and low-latitude, equatorial coronal holes (ECH). The in-situ differences in the PCH and ECH winds have not been well studied, nor have the differences in their evolution over the solar cycles. Ulysses' 19 years of observations from 1990 to 2009, combined with ACE observations from 1998 to the present, provide us with measurements of solar wind properties that span two entire solar cycles, which allow us to study the in-situ properties and evolution of the coronal hole-associated solar wind at different latitudes. In this work, we focus on the PCH and ECH solar winds during the minima between solar cycles 22–23 and 23–24. We use data from SWICS, SWOOPS, and VHM/FGM on board Ulysses, and SWICS, SWEPAM, and MAG on board ACE to analyze the proton dynamics, heavy ion composition, elemental abundance, and magnetic field properties of the PCH wind and ECH wind, with a special focus on their differences during the recent two solar minima. We also include the slow and hot, streamer-associated (ST) wind as a reference in the comparison. The comparison of PCH and ECH wind shows that: 1) the in-situ properties of ECH and PCH winds are significantly different during the two solar minima, and 2) the two types of coronal hole-associated solar wind respond differently to changes in solar activity strength from cycle 23 to cycle 24.

Zhao, L.; Landi, E.

2014-05-01

182

Association of Solar Wind Proton Flux Extremes with Pseudostreamers  

NASA Astrophysics Data System (ADS)

We investigate the characteristics and solar origins of a sub-population of the solar wind that possesses extreme values of proton flux. Ulysses observations including solar wind magnetic flux, proton flux, number density and velocity, and ionic composition are examined in this study. We find the departures of solar wind proton flux from its constancy occur for time intervals leading up to and encompassing the past two solar minima, and the extreme-proton-flux wind 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 wind; 3) it exhibits anticorrelation between electron temperature and proton velocity, as does the rest of the solar wind; 4) it has extreme proton density values relative to the rest of the solar wind; and 5) the extreme-high-proton-flux wind has radial component of open magnetic flux (Br) greater than the rest of the solar wind and both extreme-high and extreme-low wind do not possess the lowest values of Br flux. Comparing with SOHO EIT 195 A coronal images, we find the observed extreme-proton-flux wind has temporal and special coincidence with the appearance of low latitude coronal holes present in the recent two solar 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 wind can be associated with mid-to-low-latitude coronal holes and "pseudostreamer" structures.

Zhao, L.; Gibson, S. E.; Fisk, L. A.

2013-05-01

183

Electric conductivity of plasma in solar wind  

NASA Technical Reports Server (NTRS)

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

Chertkov, A. D.

1995-01-01

184

Solar Wind Spectrometer on Lunar Surface  

NASA Technical Reports Server (NTRS)

Sitting on the lunar surface, this Solar Wind Spectrometer is measuring the energies of the particles that make up the solar wind. 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.

1969-01-01

185

An asymmetric solar wind termination shock.  

PubMed

Voyager 2 crossed the solar wind 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 solar wind 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. PMID:18596802

Stone, Edward C; Cummings, Alan C; McDonald, Frank B; Heikkila, Bryant C; Lal, Nand; Webber, William R

2008-07-01

186

A view of solar magnetic fields, the solar corona, and the solar wind in three dimensions  

Microsoft Academic Search

In the last few years it has been recognized that the solar corona and the solar wind 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 solar structure, the

L. Svalgaard; J. M. Wilcox

1978-01-01

187

Solar Wind Interaction with Comet Bennett (1969I.  

National Technical Information Service (NTIS)

The relations are examined between the solar-wind and Comet Bennett during the period 23 March to 5 April 1970. A large kink was observed in the ion tail of the comet on April 4, but no solar wind stream was observed in the ecliptic plane which could have...

B. D. Donn J. Rahe L. F. Burlaga M. Neugebauer

1972-01-01

188

Solar Wind Response to a Magnetized Asteroid: Linear Theory  

Microsoft Academic Search

We study the interaction between a small, magnetized asteroid and the solar wind (SW) in the “submagnetospheric” regime, in which the asteroid's magnetic field is too small to establish either a cavity, from which the solar wind is excluded, or a magnetic tail. The interaction is described in terms of dispersive anisotropic MHD waves which are generated by a point-like

K. Baumgärtel; K. Sauer; T. R. Story; J. F. McKenzie

1997-01-01

189

The Interaction between the Solar Wind and the Earth's Magnetosphere  

Microsoft Academic Search

It is argued in this note that the interplanetary gas causefully be treated as a continuum as far as the interaction between the solar wind and the terrestrial magnestosphere is concerned. On this basis, since the solar wind is highly supersonic near the earth, a collision- free bow shock wave should be a permanent feature of iaterplanetary space on the

W. I. Axford

1962-01-01

190

Solar wind control of the magnetopause shape, location, and motion  

Microsoft Academic Search

The authors have assembled a data set of 1,821 magnetopause crossings. Separate fits to subsets of this data set determine the magnetopause location as a function of solar wind dynamic pressure and interplanetary magnetic field operation. Solar wind dynamic pressure variations produce self-similar magnetopause motion on time scales of one hour or longer. They verify the pressure balance relationship between

D. G. Sibeck; R. E. Lopez; E. C. Roelof

1991-01-01

191

Out-of-Ecliptic Solar Wind in the Outer Heliosphere  

Microsoft Academic Search

Dynamics of the solar wind in the outer heliosphere is governed by the pickup proton MHD equations. In this study the interstellar pickup protons and solar wind protons are treated as two distinct proton species, a hot hydrogen model is used to calculate the number density of interstellar neutral hydrogen at all latitudes, and real observational data are used as

Y. C. Whang

2004-01-01

192

Solar wind dynamic pressure variations: Quantifying the statistical magnetospheric response  

Microsoft Academic Search

Solar wind dynamic pressure variations are common and have large amplitudes. Existing models for the transient magnetospheric and ionospheric response to the solar wind dynamic pressure variation are quantified. The variations drive large amplitude (approx 1 RE) magnetopause motion with velocities of approx. 60 km\\/s and transient dayside ionospheric flows of 2 km\\/s which are organized into double convection vortices.

D. G. Sibeck

1990-01-01

193

Magnetospheric modes and solar wind energy coupling efficiency  

Microsoft Academic Search

Using observations and two different global MHD simulations, we demonstrate that the solar wind speed controls the magnetospheric response such that the higher the speed, the more dynamic and irregular is the magnetospheric response. For similar level of driving solar wind electric field, the magnetospheric modes can be organized in terms of speed: Low speed produces steady convection events, intermediate

T. I. Pulkkinen; M. Palmroth; H. E. J. Koskinen; T. V. Laitinen; C. C. Goodrich; V. G. Merkin; J. G. Lyon

2010-01-01

194

Large-scale solar wind structures impacting the magnetosphere  

Microsoft Academic Search

Large-scale solar wind structures such as magnetic clouds or other periods of steady solar wind parameters on one hand often drive a specific type of activity in the magnetosphere - ionosphere system, and on the other hand allow us to examine the various parameters separately when the driving remains approximately constant for periods longer than typical transport times in the

T. I. Pulkkinen

2009-01-01

195

Simulation of period doubling of recurrent solar wind structures  

Microsoft Academic Search

Based on satellite observations of a recurrent solar wind structure conducted in 1974, an MHD simulation model, and input functions generated from plasma and magnetic field data, the continuing evolution of the solar wind structure outside 5 AU is studied. The model uses the Rankine-Hugoniot relations to describe the jumps in flow properties across the shocks, and it treats shocks

Y. C. Whang; L. F. Burlaga

1990-01-01

196

The Effects of Solar Wind Structure on Magnetosphere Parameters  

Microsoft Academic Search

During the ISTP program we demonstrated that in order to understand the magnetospheric response to solar wind and interplanetary magnetic field changes we had to simulate the magnetosphere using actual spacecraft observations as input to our global MHD models [Frank et al., 1995]. In these studies, we assumed that plasmas and fields observed by the spacecraft monitoring the solar wind

L. M. Zelenyi; M. Ashour-Abdalla; F. V. Coroniti; M. El-Alaoui; J. Berchem; R. J. Walker; V. Peroomian; G. N. Zastenker

2002-01-01

197

Recurrent solar wind structures in the outer heliosphere  

Microsoft Academic Search

The paper presents recent work on evolution of recurrent solar wind structures in the outer heliosphere. Corotating shocks, corotating interaction regions, and merged interaction regions are studied, and an MHD simulation model in which the jump conditions at all shock crossings satisfy the Rankine-Hugoniot solution is examined. Simulation results which describe the evolution of idealized recurrent solar wind structures between

Y. C. Whang; L. F. Burlaga

1989-01-01

198

Solar-wind tritium limit and nuclear processes in the solar atmosphere  

NASA Technical Reports Server (NTRS)

Tritium in Surveyor 3 material is measured, and the resulting H-3/H-1 ratio for the solar wind is applied in a solar flare-solar wind relation to investigate the mixing requirements for the solar atmosphere. The flare-wind relation is derived. None of the tritium can be attributed to solar-wind implantation. The upper limit for the H-3/He ratio in the solar wind 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 solar atmosphere if the H-3 production rate in solar-surface nuclear reactions is greater than 160/sq cm per sec.

Fireman, E. L.; Damico, J.; Defelice, J.

1975-01-01

199

The Interaction Between the Moon and the Solar Wind  

NASA Astrophysics Data System (ADS)

Bodies that lack a significant atmosphere and internal magnetic fields, such as the Moon, are obstacles to the solar wind. The solar wind ions and electrons directly impact the surface of the Moon due to the lack of atmosphere. Here we investigate the global Moon-solar wind interaction using a hybrid model (particle ions and fluid electrons). We focus in particular on the effects of non-uniform internal resistivity on the Moon-solar wind interaction. From seismic and magnetic field measurements it has been inferred that the Moon should have a conducting core, surrounded by a resistive shell. How does the presence of a core modify the solar wind interaction? Are the effects observable?

Holmstrom, M.

2012-12-01

200

OBSERVATION OF FLUX-TUBE CROSSINGS IN THE SOLAR WIND  

SciTech Connect

Current sheets are ubiquitous in the solar wind. They are a major source of the solar wind MHD turbulence intermittency. They may result from nonlinear interactions of the solar wind MHD turbulence or are the boundaries of flux tubes that originate from the solar 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 Wind 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 solar wind consists of flux tubes where distinct plasmas reside.

Arnold, L.; Li, G.; Li, X. [Department of Physics and CSPAR, University of Alabama in Huntsville, Huntsville, AL 35899 (United States)] [Department of Physics and CSPAR, University of Alabama in Huntsville, Huntsville, AL 35899 (United States); Yan, Y., E-mail: gang.li@uah.edu [Key Laboratory of Solar Activity, National Astronomical Observatories of Chinese Academy of Sciences, Beijing 100012 (China)

2013-03-20

201

High coronal structure of high velocity solar wind stream sources  

NASA Technical Reports Server (NTRS)

It is shown analytically that the transition from a high-speed stream source to the ambient coronal conditions is quite rapid in longitude in the high corona. This sharp eastern coronal boundary for the solar wind stream sources is strongly suggested by the solar wind 'dwells' which appear in plots of solar wind velocity against constant-radial-velocity-approximation source longitudes. The possibility of a systematic velocity-dependent effect in the constant-radial-velocity approximation, which would cause this boundary to appear sharper than it is, is investigated. A velocity-dependent interplanetary propagation effect or a velocity-dependent 'source altitude' are two possible sources of such a systematic effect. It is shown that, for at least some dwells, significant interplanetary effects are not likely. The variation of the Alfvenic critical radius in solar wind dwells is calculated, showing that the high-velocity stream originates from a significantly lower altitude than the ambient solar wind.

Nolte, J. T.; Krieger, A. S.; Roelof, E. C.; Gold, R. E.

1977-01-01

202

INTERPRETING MAGNETIC VARIANCE ANISOTROPY MEASUREMENTS IN THE SOLAR WIND  

SciTech Connect

The magnetic variance anisotropy (A{sub m}) of the solar wind has been used widely as a method to identify the nature of solar wind turbulent fluctuations; however, a thorough discussion of the meaning and interpretation of the A{sub m} has not appeared in the literature. This paper explores the implications and limitations of using the A{sub m} as a method for constraining the solar wind fluctuation mode composition and presents a more informative method for interpreting spacecraft data. The paper also compares predictions of the A{sub m} from linear theory to nonlinear turbulence simulations and solar wind measurements. In both cases, linear theory compares well and suggests that the solar wind for the interval studied is dominantly Alfvenic in the inertial and dissipation ranges to scales of k{rho}{sub i} {approx_equal} 5.

TenBarge, J. M.; Klein, K. G.; Howes, G. G. [Department of Physics and Astronomy, University of Iowa, Iowa City, IA (United States); Podesta, J. J., E-mail: jason-tenbarge@uiowa.edu [Space Science Institute, Boulder, CO (United States)

2012-07-10

203

A study of the composition of the solar corona and solar wind  

Microsoft Academic Search

Effects of diffusion on the composition of the solar corona and solar wind have been examined. Multi-component diffusion equations have been solved simultaneously in attempts to account for the flux of He and heavier elements in the solar wind. Large enhancements of these elements at the base of the assumed isothermal corona appear to be required to give observed fluxes.

M. P. Nakada

1970-01-01

204

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

Microsoft Academic Search

Solar and wind energy systems are considered as promising power generating sources due to its availability and topological advantages in local power generations. However, a drawback, common to solar and wind options, is their unpredictable nature and dependence on weather changes, both of these energy systems would have to be oversized to make them completely reliable. Fortunately, the problems caused

Wei Zhou

2008-01-01

205

A new view of solar wind structures: Combined interplanetary scintillation and STEREO HI studies of the inner solar wind  

Microsoft Academic Search

The heliospheric imagers (HI) on the STEREO A and B spacecraft are now providing the first continuous, detailed images of structures in the interplanetary solar wind. When combined with simultaneous radio measurements of interplanetary scintillation (IPS), STEREO images allow the structure of the solar wind to be studied with much greater certainty than has been possible before. The STEREO HI

R. A. Fallows; A. R. Breen; G. D. Dorrian; I. Whittaker; M. Grande

2009-01-01

206

Polar solar wind and interstellar wind properties from interplanetary Lyman-alpha radiation measurements  

NASA Technical Reports Server (NTRS)

The analysis of Mariner 10 observations of Lyman-alpha resonance radiation shows an increase of interplanetary neutral hydrogen densities above the solar poles. This increase is caused by a latitudinal variation of the solar wind velocity and/or flux. Using both the Mariner 10 results and other solar wind observations, the values of the solar wind flux and velocity with latitude are determined for several cases of interest. The latitudinal variation of interplanetary hydrogen gas, arising from the solar wind latitudinal variation, is shown to be most pronounced in the inner solar system. From this result it is shown that spacecraft Lyman-alpha observations are more sensitive to the latitudinal anisotropy for a spacecraft location in the inner solar system near the downwind axis.

Witt, N.; Blum, P. W.; Ajello, J. M.

1981-01-01

207

Tracking the Solar Wind Event to Its Source  

NSDL National Science Digital Library

This is an activity about cause and effect. Learners will calculate the approximate travel time of each solar wind event identified in the previous activity in this set to estimate the time at which the disturbance would have left the Sun. Then, they will examine solar images in an attempt to identify the event on the Sun that may have caused the specific solar wind episode. This is Activity 12 of the Space Weather Forecast curriculum.

208

Genesis capturing the sun: Solar wind irradiation at Lagrange 1  

Microsoft Academic Search

Genesis, a member of NASAs Discovery Mission program, is the world’s first sample return mission since the Apollo program to bring home solar matter in ultra-pure materials. Outside the protection of Earth’s magnetosphere at the Earth–Sun Lagrange 1 point, the deployed sample collectors were directly exposed to solar wind irradiation. The natural process of solar wind ion implantation into a

Michael J. Calaway; Eileen K. Stansbery; Lindsay P. Keller

2009-01-01

209

Parametric study of hybrid (wind + solar + diesel) power generating systems  

Microsoft Academic Search

The combined utilization of renewables such as solar and wind energy is becoming increasingly attractive and is being widely used for substitution of oil-produced energy, and eventually to reduce air pollution. In the present investigation, hourly wind-speed and solar radiation measurements made at the solar radiation and meteorological monitoring station, Dhahran (26°32?N, 50°13?E), Saudi Arabia, have been analyzed to study

M. A. Elhadidy; S. M. Shaahid

2000-01-01

210

Variation of the plasmasheet O+ and H+ density with solar activity and solar wind conditions  

NASA Astrophysics Data System (ADS)

A modulation of the outflow rate of ionospheric ions - among which a high proportion of O+ ions - by solar EUV flux and solar wind conditions has been evidenced in several observational studies. Similarly, the amount of solar wind plasma - mostly H+ ions - penetrating into the magnetosphere also depends on solar wind conditions. We use long-term measurements from the CODIF ion detector onboard the Cluster spacecraft to quantify the resulting O+ and H+ density variations in the plasmasheet. CODIF data are mapped along magnetic field lines to assess the spatial distribution of O+ and H+ ions at the magnetospheric equatorial plane. We make a multi-correlation analysis between the O+ and H+ density and solar wind parameters to investigate their impact on the plasmasheet composition in various regions. An emphasis is placed on the effect of solar wind pressure on the plasmasheet O+ content. Solar wind pressure is expected to affect the energy and momentum input into the ionosphere, which in turn should modulate the ionospheric ion outflow rate and thus the plasmasheet O+ density. On the other hand, when the solar wind pressure increases, the magnetosphere is compressed, resulting in an increase of the O+ and H+ densities independently of the ionospheric outflow rate variation. To infer the actual influence of the solar wind pressure on the plasmasheet O+ content we compare the O+ and H+ density variations associated with solar wind pressure changes with density variations due to magnetospheric compression alone.

Maggiolo, Romain; Kistler, Lynn; Keyser Johan, De; Emmanuel, Gamby

2014-05-01

211

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

NASA Technical Reports Server (NTRS)

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

Feynman, Joan

1989-01-01

212

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

NASA Astrophysics Data System (ADS)

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

Feynman, Joan

213

Synthetic four-solar-cycle solar wind at 1 AU generated from the OMNI data set  

NASA Astrophysics Data System (ADS)

Abstract Numerical modeling provides key insights into the physics of the outer heliosphere. The <span class="hlt">solar</span> <span class="hlt">wind</span> data utilized by these models impact their accuracy and should be as close as possible to the actual <span class="hlt">solar</span> <span class="hlt">wind</span>. Because of the time scales involved, such a data set should also span several <span class="hlt">solar</span> cycles. Yet the bulk of <span class="hlt">solar</span> <span class="hlt">wind</span> measurements in such a time frame was obtained near Earth. A method to infer the <span class="hlt">solar</span> <span class="hlt">wind</span> at points not directly observed is developed such that a 1 AU ring in the ecliptic plane is filled with four <span class="hlt">solar</span> cycles of <span class="hlt">solar</span> <span class="hlt">wind</span> data. Hourly OMNI data are used as the seed data. The OMNI data are separated into four separate categories, and those categories are first extrapolated, generating a continuous 2-D category map of the <span class="hlt">solar</span> <span class="hlt">wind</span> for the full four <span class="hlt">solar</span> cycles covered by OMNI. The category map is used to determine <span class="hlt">solar</span> <span class="hlt">wind</span> characteristics. The <span class="hlt">solar</span> <span class="hlt">wind</span> values are determined by local running averages coupled with a random walk technique. The averages provide baseline values and the random walk adds short-duration deviations from this baseline. The statistics from the extrapolated data are compared to the statistics of the original OMNI data set. Category durations, relative coverage, variable distributions, and correlations are similar to those of the OMNI data, although with some discrepancies.</p> <div class="credits"> <p class="dwt_author">Thatcher, L. J.; Müller, H.-R.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-02-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">214</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19960021367&hterms=solar+corona+topology&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsolar%2Bcorona%2Btopology"> <span id="translatedtitle">Coronal roots of <span class="hlt">solar</span> <span class="hlt">wind</span> streams: 3-D MHD modeling</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Pisanko, Yu. V.</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">215</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014PhRvE..89e2812M"> <span id="translatedtitle">Stationarity of extreme bursts in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> ? 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> <div class="credits"> <p class="dwt_author">Moloney, N. R.; Davidsen, J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">216</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20030110686&hterms=implanted+designed&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dimplanted%2Bdesigned"> <span id="translatedtitle">The Genesis <span class="hlt">Solar</span> <span class="hlt">Wind</span> Collection Mission: Current Status</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The NASA Genesis spacecraft was launched August 8, 2001 on a mission to collect samples of <span class="hlt">solar</span> <span class="hlt">wind</span> for greater than or equal to 2 years and then return them to Earth in 2004. Detailed analyses of the <span class="hlt">solar</span> <span class="hlt">wind</span> ions implanted into high-purity collection substrates will subsequently be carried out in earth-based laboratories using various mass spectrometry techniques. These analyses are expected to determine key isotopic ratios and elemental abundances in the <span class="hlt">solar</span> <span class="hlt">wind</span> and, by extension, in the <span class="hlt">solar</span> photosphere. Further, the photospheric composition is thought to be representative of the <span class="hlt">solar</span> nebula with a few exceptions so that the Genesis mission will provide a baseline for the average <span class="hlt">solar</span> nebula composition with which to compare present-day compositions of planets, meteorites, and asteroids. The implications of the <span class="hlt">solar</span> oxygen isotopic composition have been discussed. A list of other isotopic and elemental measurement objectives, and some of the rationale behind them, is given.</p> <div class="credits"> <p class="dwt_author">Barraclough, B. L.; Wiens, R. C.; Steinberg, J. T.; Dors, E. E.; Neugebauer, M.; Burnett, D. S.; Gosling, J.; Bremmer, R. R.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">217</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/22039160"> <span id="translatedtitle">COMPOSITION OF THE <span class="hlt">SOLAR</span> CORONA, <span class="hlt">SOLAR</span> <span class="hlt">WIND</span>, AND <span class="hlt">SOLAR</span> ENERGETIC PARTICLES</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Along with temperature and density, the elemental abundance is a basic parameter required by astronomers to understand and model any physical system. The abundances of the <span class="hlt">solar</span> corona are known to differ from those of the <span class="hlt">solar</span> photosphere via a mechanism related to the first ionization potential of the element, but the normalization of these values with respect to hydrogen is challenging. Here, we show that the values used by <span class="hlt">solar</span> physicists for over a decade and currently referred to as the 'coronal abundances' do not agree with the data themselves. As a result, recent analysis and interpretation of <span class="hlt">solar</span> data involving coronal abundances may need to be revised. We use observations from coronal spectroscopy, the <span class="hlt">solar</span> <span class="hlt">wind</span>, and <span class="hlt">solar</span> energetic particles as well as the latest abundances of the <span class="hlt">solar</span> photosphere to establish a new set of abundances that reflect our current understanding of the coronal plasma.</p> <div class="credits"> <p class="dwt_author">Schmelz, J. T. [Physics Department, University of Memphis, Memphis, TN 38152 (United States); Reames, D. V. [IPST, University of Maryland, College Park, MD 20742 (United States); Von Steiger, R. [ISSI, Hallerstrasse 6, 3012 Bern (Switzerland); Basu, S., E-mail: jschmelz@memphis.edu [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520 (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-08-10</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">218</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/43128471"> <span id="translatedtitle">Abundance of iron ions in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">For a period of 4 yr near the maximum of <span class="hlt">solar</span> cycle 21 iron and helium fluxes were measured in the <span class="hlt">solar</span> <span class="hlt">wind</span>. The ratio of the summed fluxes from 45,000 spectra is 400 (+50 percent, -30 percent) which is approximately 5 times lower than estimates of the <span class="hlt">solar</span> surface value. This difference is attributed to the difference of first</p> <div class="credits"> <p class="dwt_author">J. Schmid; P. Bochsler; J. Geiss</p> <p class="dwt_publisher"></p> <p class="publishDate">1988-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">219</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014AAS...22432358K"> <span id="translatedtitle"><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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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">winds</span> (SWs) as classified by Richardson and Cane (2012). Gradual SEP (E > 10 MeV) events are produced in shocks driven by fast (V > 900 km/s) and wide (W > 60 deg) coronal mass ejections (CMEs). We find no differences between transient and fast or slow SW streams for SEP 20-MeV event timescales. It has recently been found that the peak intensities Ip of these SEP events scale with the ~ 2 MeV proton background intensities, which may be a proxy for the near-Sun shock seed particles. Both the intensities Ip and their 2 MeV backgrounds are significantly enhanced in transient SW compared to those of fast and slow SW streams, and the values of Ip normalized to the 2 MeV backgrounds only weakly correlate with CME V for all SW types. This result implies that forecasts of SEP events could be improved by monitoring both the Sun and the local SW stream properties and that the well known power-law size distributions of Ip may differ between transient and long-lived SW streams. We interpret an observed correlation between CME V and the 2 MeV background for SEP events in transient SW as a manifestation of enhanced <span class="hlt">solar</span> activity.</p> <div class="credits"> <p class="dwt_author">Kahler, Stephen W.; Vourlidas, Angelos</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">220</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/servlets/purl/86287"> <span id="translatedtitle"><span class="hlt">Solar</span> semidiurnal tidal <span class="hlt">wind</span> oscillations above the CART site</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Whiteman, C.D.; Bian, X.</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-03-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_10");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" 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showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_13");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">221</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2002cosp...34E..74H"> <span id="translatedtitle">Numerical study of disturbance propagation in structured <span class="hlt">solar</span> <span class="hlt">wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The magnetic structure of the <span class="hlt">solar</span> corona has been believed to control coronal activities such as <span class="hlt">solar</span> flares and coronal mass ejections. Many simulations manifest that any single arcade model fail to simulate the <span class="hlt">solar</span> eruptions. Spacecraft observations also tell us that CMEs occur accompanying very complex magnetic topologies. Here, in order to discuss the disturbance propagation in structured <span class="hlt">solar</span> <span class="hlt">wind</span>, we adopt a <span class="hlt">solar</span> <span class="hlt">wind</span> background initialized by multi-polar magnetic field model. Employing a free-force formulation, we introduce a method about how to get the magnetic field with multi-streamers or current-sheets. Using this magnetic field and Parker <span class="hlt">solar</span> <span class="hlt">wind</span> solution as initiations, the <span class="hlt">solar</span> <span class="hlt">wind</span> background is achieved by a 3-D MHD model of TVD type. The steady state magnetic field gotten by this method has multi-polar topologies with sheared structure. As usual, by adding disturbances at different positions of the <span class="hlt">solar</span> surface to the background field, the propagation in such structured <span class="hlt">solar</span> <span class="hlt">wind</span> is discussed. This model can, to some extent, account for the energy requirement for <span class="hlt">solar</span> eruptions and has strong ability of modeling the complex CME pictures observed by LASCO/SOHO.</p> <div class="credits"> <p class="dwt_author">Huang, F.; Feng, X.; Wei, F.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">222</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/21929247"> <span id="translatedtitle">Nonaxisymmetric anisotropy of <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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. PMID:21929247</p> <div class="credits"> <p class="dwt_author">Turner, A J; Gogoberidze, G; Chapman, S C; Hnat, B; Müller, W-C</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-08-26</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">223</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/22215435"> <span id="translatedtitle">ASYMMETRIC ELECTRON DISTRIBUTIONS IN THE <span class="hlt">SOLAR</span> <span class="hlt">WIND</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Rha, Kicheol; Ryu, Chang-Mo [Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)] [Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Yoon, Peter H. [Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742 (United States)] [Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742 (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-09-20</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">224</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2010EOSTr..91..474E"> <span id="translatedtitle">Understanding <span class="hlt">Solar</span> <span class="hlt">Wind</span> and Magnetospheric Intermittent Turbulence</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Turbulence and Multifractals in Geophysics and Space; Brussels, Belgium, 9-11 June 2010; Space plasmas exhibit intermittent turbulent fluctuations, i.e., randomly alternating quietness and bursts. Fractals (discussed by Benoît Mandelbrot in 1967) describe self-similar, irregular geometrical objects with fractional dimension. Self-similarity manifests as the recurrence of the same topology at all scales. Multifractals are a generalization of fractals and describe with geometric analogs dynamical processes whose self-similarity depends on scale. Intermittency is one possible key to understanding the energy transfer from large (magnetohydrodynamic (MHD)) scales to much smaller, kinetic scales. To review the current understanding of multifractals and intermittent turbulence in the <span class="hlt">solar</span> <span class="hlt">wind</span> and magnetosphere, the Belgian Institute for Space Aeronomy (BIRA-IASB) organized a workshop in Belgium.</p> <div class="credits"> <p class="dwt_author">Echim, Marius; Chang, Tom; Lamy, Hervé</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">225</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014ApJ...789L..44S"> <span id="translatedtitle">Relaxation Processes in <span class="hlt">Solar</span> <span class="hlt">Wind</span> Turbulence</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Servidio, S.; Gurgiolo, C.; Carbone, V.; Goldstein, M. L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-07-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">226</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/servlets/purl/924986"> <span id="translatedtitle">Innovations in <span class="hlt">Wind</span> and <span class="hlt">Solar</span> PV Financing</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Cory, K.; Coughlin, J.; Jenkin, T.; Pater, J.; Swezey, B.</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-02-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">227</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012ApJ...746..184G"> <span id="translatedtitle">Kolmogorov Vectorial Law for <span class="hlt">Solar</span> <span class="hlt">Wind</span> Turbulence</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We investigate a class of axisymmetric magnetohydrodynamic turbulence which satisfies the exact relation for third-order Elsässer structure functions. Following the critical balance conjecture, we assume the existence of a power-law relation between correlation length scales along and transverse to the local mean magnetic field direction. The flow direction of the vector third-order moments F ± is then along axisymmetric concave/convex surfaces, the axis of symmetry being given by the mean magnetic field. Under this consideration, the vector F ± satisfies a simple Kolmogorov law which depends on the anisotropic parameter a ±, which measures the concavity of the surfaces. A comparison with recent in situ multispacecraft <span class="hlt">solar</span> <span class="hlt">wind</span> observations is made; it is concluded that the underlying turbulence is very likely convex. A discussion is given about the physical meaning of such an anisotropy.</p> <div class="credits"> <p class="dwt_author">Galtier, Sébastien</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-02-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">228</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/18046399"> <span id="translatedtitle">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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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. PMID:18046399</p> <div class="credits"> <p class="dwt_author">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 class="dwt_publisher"></p> <p class="publishDate">2007-11-29</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">229</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2011APS..MARV31015P"> <span id="translatedtitle">Analysis of <span class="hlt">Wind</span> Forces on Roof-Top <span class="hlt">Solar</span> Panel</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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-? 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.</p> <div class="credits"> <p class="dwt_author">Panta, Yogendra; Kudav, Ganesh</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-03-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">230</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/22127065"> <span id="translatedtitle">RESIDUAL ENERGY SPECTRUM OF <span class="hlt">SOLAR</span> <span class="hlt">WIND</span> TURBULENCE</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Chen, C. H. K.; Bale, S. D.; Salem, C. S.; Maruca, B. A., E-mail: chen@ssl.berkeley.edu [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-06-20</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">231</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AIPC.1539..364J"> <span id="translatedtitle">Using comet plasma tails to study the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The plasma tails of comets have been used as probes of the <span class="hlt">solar</span> <span class="hlt">wind</span> for many years, and well before direct <span class="hlt">solar</span> <span class="hlt">wind</span> measurements. Now, analyses utilizing the much greater regularity and extent of comet tails imaged from space detail outward <span class="hlt">solar</span> <span class="hlt">wind</span> flow much better than was previously possible. These analyses mark the location of the <span class="hlt">solar</span> <span class="hlt">wind</span> flow in three-dimensions over time much as do in-situ measurements. Data from comet plasma tails using coronagraphs and heliospheric white-light imagers provide a view closer to the Sun than where spacecraft have ventured to date. These views show that this flow is chaotic and highly variable, and not the benign regular outward motion of a quiescent plasma. While this is no surprise to those who study and characterize the <span class="hlt">solar</span> <span class="hlt">wind</span> in situ or use remotely-sensed interplanetary scintillation (IPS) techniques, these spacecraft images provide a visualization of this as never-before possible. Here we summarize the results of an analysis that determines <span class="hlt">solar</span> <span class="hlt">wind</span> velocity from multiple comet tails that were observed by the <span class="hlt">Solar</span> Mass Ejection Imager (SMEI) and also by the inner Heliospheric Imager (HI) on board the <span class="hlt">Solar</span> Terrestrial Relations Observatory Ahead (STEREOA) spacecraft. Finally, we present results using a similar analysis that measures this same behavior using coronagraph observations in the low corona.</p> <div class="credits"> <p class="dwt_author">Jackson, B. V.; Buffington, A.; Clover, J. M.; Hick, P. P.; Yu, H.-S.; Bisi, M. M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">232</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/54351043"> <span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">Wind</span> Structure at 1 AU: Comparison between <span class="hlt">Solar</span> Minima 22\\/23 and 23\\/24</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The current <span class="hlt">solar</span> minimum 23\\/24 has been unusually long and deep, compared with the <span class="hlt">solar</span> minima in the space era. In order to see the consequence of the extremely quiet Sun on the <span class="hlt">solar</span> <span class="hlt">wind</span>, we compare the <span class="hlt">solar</span> <span class="hlt">wind</span> structure during the current <span class="hlt">solar</span> minimum with the last <span class="hlt">solar</span> minimum 22\\/23, which represents the case of a short and</p> <div class="credits"> <p class="dwt_author">L. Jian; C. Russell; J. G. Luhmann; A. B. Galvin; R. M. Skoug; P. C. Schroeder</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">233</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AGUFMSH11C..02V"> <span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">Wind</span> Abundances From Ulysses-SWICS</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We are in the process of performing a thorough revision of the Ulysses-SWICS data analysis method using modern statistical tools and computing power. With this new tool we have reanalyzed the SWICS abundances, in particular the abundance of nitrogen and other elements that are affected by mutual peak overlaps in the raw data. We find that the nitrogen abundance may have been previously underestimated by as much as 30-40% during the four time periods published in 2000 (DOI: 10.1029/1999JA000358) For the other elements only small differences between the new results and those published previously have been found, all well within the stated systematic uncertainty of 20%. We are currently assessing the systematic uncertainty of the new analysis method but estimate that it will be of the order of 10% or even better. Ultimately this will enable us to provide improved <span class="hlt">solar</span> <span class="hlt">wind</span> abundances of C, N, O, Ne, Mg, Si, S, and Fe from nearly two decades of Ulysses-SWICS observations at all <span class="hlt">solar</span> activity levels.</p> <div class="credits"> <p class="dwt_author">von Steiger, R.; Shearer, P.; Zurbuchen, T.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">234</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19960021391&hterms=iron+ion&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Diron%2Bion"> <span id="translatedtitle">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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Galvin, A. B.; Cohen, C. M. S.; Ipavich, F. M.; Gloeckler, G.; Hamilton, D. C.; Chotoo, K.; Balsiger, H.; Sheldon, R.</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">235</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/21394380"> <span id="translatedtitle">MEASUREMENTS OF RAPID DENSITY FLUCTUATIONS IN THE <span class="hlt">SOLAR</span> <span class="hlt">WIND</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Malaspina, D. M.; Ergun, R. E. [Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303 (United States); Kellogg, P. J. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Bale, S. D., E-mail: David.Malaspina@colorado.ed [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-03-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">236</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/5548817"> <span id="translatedtitle">Relationship between Saturn kilometric radiation and the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Desch, M.D.; Rucker, H.O.</p> <p class="dwt_publisher"></p> <p class="publishDate">1983-03-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">237</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19960021293&hterms=solar+simulation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dsolar%2Bsimulation"> <span id="translatedtitle">Can we understand the turbulent <span class="hlt">solar</span> <span class="hlt">wind</span> via turbulent simulations?</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">We attempt to assess the present understanding of the turbulent <span class="hlt">solar</span> <span class="hlt">wind</span> using numerical simulations. The <span class="hlt">solar</span> <span class="hlt">wind</span> may be considered as a kind of <span class="hlt">wind</span> tunnel with peculiar properties: the tunnel is spherical; the source of the <span class="hlt">wind</span> is rotating; and the medium is a plasma containing a large-scale magnetic field. These constraints lead to anisotropic dynamics of the fluctuations on the one hand, and to non-standard (turbulent?) transport properties of the global plasma on the other hand. How much of this rich physics can we approach today via numerical simulations?</p> <div class="credits"> <p class="dwt_author">Grappin, R.; Mangeney, A.</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">238</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2009AGUFMSH51C..02S"> <span id="translatedtitle">The role of magnetic field in <span class="hlt">solar</span> <span class="hlt">wind</span> turbulent cascade</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The Yaglom law for the mixt third order moment of the Elsasser fields fluctuations has been recently observed in the <span class="hlt">solar</span> <span class="hlt">wind</span>. This observation confirm the existence of a MHD turbulent cascade in the interplanetary plasma, in both ecliptic and polar <span class="hlt">wind</span>. In the polar <span class="hlt">wind</span> measured by Ulysses spacecraft, the cascade occasionally holds up to scales of days. The nature of such cascade, and in particular the role of magnetic field at large scales, are discussed. The different possible scenaries show that <span class="hlt">solar</span> <span class="hlt">wind</span> turbulent cascade is not universal.</p> <div class="credits"> <p class="dwt_author">Sorriso-Valvo, L.; Marino, R.; Servidio, S.; Bruno, R.; Noullez, A.; Carbone, V.</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">239</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/42039135"> <span id="translatedtitle">Are energetic electrons in the <span class="hlt">solar</span> <span class="hlt">wind</span> the source of the outer radiation belt?</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Using data from <span class="hlt">WIND</span>, SAMPEX (<span class="hlt">Solar</span>, Anomalous, and Magnetospheric Particle Explorer), and the Los Alamos National Laboratory (LANL) sensors onboard geostationary satellites, we investigate the correlation of energetic electrons in the 20-200 keV range in the <span class="hlt">solar</span> <span class="hlt">wind</span> and of high speed <span class="hlt">solar</span> <span class="hlt">wind</span> streams with relativistic electrons in the magnetosphere to determine whether energetic electrons in the <span class="hlt">solar</span> <span class="hlt">wind</span></p> <div class="credits"> <p class="dwt_author">Xinlin Li; D. N. Baker; M. Temerin; D. Larson; R. P. Lin; G. D. Reeves; M. Looper; S. G. Kanekal; R. A. Mewaldt</p> <p class="dwt_publisher"></p> <p class="publishDate">1997-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">240</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/12743181"> <span id="translatedtitle">Structure of Mercury's magnetosphere for different pressure of the <span class="hlt">solar</span> <span class="hlt">wind</span>: Three dimensional hybrid simulations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">We have carried out a self-consistent three dimensional global hybrid simulation study examining the interaction of the <span class="hlt">solar</span> <span class="hlt">wind</span> with Mercury's magnetosphere. We consider two cases: one with relatively high <span class="hlt">solar</span> <span class="hlt">wind</span> pressure, and another with relatively low <span class="hlt">solar</span> <span class="hlt">wind</span> pressure. With lower <span class="hlt">solar</span> <span class="hlt">wind</span> pressure, the subsolar magnetopause forms at about 1.7 R M (where R M is the</p> <div class="credits"> <p class="dwt_author">Pavel Trávnícek; Petr Hellinger; David Schriver</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_11");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span 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</span> </span> <a id="NextPageLink" onclick='return showDiv("page_14");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">241</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008PhDT.........9C"> <span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">wind</span> driving of magnetospheric ultra-low frequency pulsations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Two <span class="hlt">solar</span> <span class="hlt">wind</span> parameters in particular are thought to be responsible for the majority of <span class="hlt">solar</span> <span class="hlt">wind</span>-driven ULF waves. These two parameters, <span class="hlt">solar</span> <span class="hlt">wind</span> dynamic pressure and <span class="hlt">solar</span> <span class="hlt">wind</span> velocity, are studied in this work through the use of global magnetohydrodynamic (MHD) simulations of the <span class="hlt">solar</span> <span class="hlt">wind</span>- magnetosphere interaction. We drive the global MHD simulations with idealized <span class="hlt">solar</span> <span class="hlt">wind</span> input conditions, chosen to mimic each of the above mechanisms. This allows us to study, in isolation, both of the <span class="hlt">solar</span> <span class="hlt">wind</span> parameters and to compare and contrast their effectiveness in the generation of magnetospheric ULF waves. Moreover, the global, three-dimensional nature of the MHD simulations allows us to fully characterize the spectral properties and global distribution of the ULF waves generated. These wave properties are known from a theoretical standpoint to be important for the interaction of ULF waves with radiation belt electrons. From these considerations, we are able to quantify the effect that the simulated ULF waves could have on radiation belt electrons, and thus, how the <span class="hlt">solar</span> <span class="hlt">wind</span> ultimately couples its energy into the radiation belts. Though this is the primary goal of our work, these investigations have uncovered two magnetospheric phenomenon, the MHD Kelvin-Helmholtz instability and magnetospheric cavity modes, that have never before been studied in the realistic magnetospheric configuration provided by global MHD simulations. The MHD Kelvin-Helmholtz instability has long been predicted to occur at the boundary interface between the <span class="hlt">solar</span> <span class="hlt">wind</span> and the magnetosphere and is often invoked as an explanation for various magnetospheric phenomenon. For example, several theoretical studies have suggested that the Kelvin-Helmholtz instability at the magnetospheric boundary drives magnetospheric field-line resonances, resonant oscillations of geomagnetic field lines analogous to standing waves on a string. In addition, the nonlinear evolution of the MHD Kelvin-Helmholtz instability leads to large-scale (several times the size of the Earth) vortices in the plasma flow. A number of studies have suggested that these vortical structures are responsible for the entry of <span class="hlt">solar</span> <span class="hlt">wind</span> plasma into the magnetosphere. This is an important process in the magnetosphere as <span class="hlt">solar</span> <span class="hlt">wind</span> plasma ultimately fuels geomagnetic storms and the auroras. Though the magnetospheric Kelvin-Helmholtz interaction has been studied from a theoretical standpoint in simple flow configurations for many years, it has received little attention in modern, global MHD simulations. Moreover, while many studies have presented surface wave observations that can be easily explained in terms of the Kelvin-Helmholtz theory, others argue that the observations can just as easily be explained by fluctuating upstream <span class="hlt">solar</span> <span class="hlt">wind</span> plasma parameters. We circumvent these ambiguities by driving global MHD simulations with idealized <span class="hlt">solar</span> <span class="hlt">wind</span> input conditions, where all of the upstream <span class="hlt">solar</span> <span class="hlt">wind</span> plasma parameters are held constant. Thus, any surface waves generated at the magnetospheric boundary cannot be due to fluctuations in the upstream <span class="hlt">solar</span> <span class="hlt">wind</span>. We show that the Kelvin-Helmholtz instability is excited at both edges of the magnetospheric boundary layer and over a wide range of <span class="hlt">solar</span> <span class="hlt">wind</span> speeds (400-800 km/s). The results presented in the first half of this work are the first comprehensive study of the MHD Kelvin-Helmholtz instability in a realistic magnetospheric configuration. Magnetospheric cavity modes have been studied for many years, both theoretically and through simple numerical simulations. The concept of magnetospheric cavity modes is physically quite appealing; however, such oscillations have proved elusive in magnetospheric observations. Moreover, global MHD simulations have yet to reproduce cavity mode oscillations, further calling into question their existence. The results presented in the second half of this work show the excitation of magnetospheric cavity modes in global MHD simulations of the <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere interaction. These resonant cavity mod</p> <div class="credits"> <p class="dwt_author">Claudepierre, Seth G.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">242</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/servlets/purl/6517833"> <span id="translatedtitle"><span class="hlt">Wind</span> loading on <span class="hlt">solar</span> concentrators: some general considerations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Roschke, E. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1984-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">243</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013EGUGA..1510078M"> <span id="translatedtitle">Ionospheric mid-latitude response to <span class="hlt">solar</span> <span class="hlt">wind</span> discontinuities</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Munteanu, Costel; Mosna, Zbysek; Kouba, Daniel; Echim, Marius</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">244</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/51349212"> <span id="translatedtitle">Magnetic Maps and Coronal\\/<span class="hlt">Solar</span> <span class="hlt">Wind</span> Modeling: Practices and Pitfalls (Invited)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The ambient <span class="hlt">solar</span> corona and <span class="hlt">solar</span> <span class="hlt">wind</span> play a crucial role in <span class="hlt">solar</span> and heliospheric physics. The Sun's magnetic field is an essential ingredient of any predictive model of the <span class="hlt">solar</span> <span class="hlt">wind</span>. It defines the structure of the heliosphere, including the position of the heliospheric current sheet and the regions of fast and slow <span class="hlt">solar</span> <span class="hlt">wind</span>. The geoeffectiveness of CMEs</p> <div class="credits"> <p class="dwt_author">J. A. Linker; Z. Mikic; P. Riley; R. Lionello; V. S. Titov</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">245</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/servlets/purl/112936"> <span id="translatedtitle">He abundance variations in the <span class="hlt">solar</span> <span class="hlt">wind</span>: Observations from Ulysses</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Barraclough, B.L.; Gosling, J.T.; Phillips, J.L.; McComas, D.J.; Feldman, W.C. [Los Alamos National Lab., NM (United States); Goldstein, B.E. [California Inst. of Technology, Pasadena, CA (United States). Jet Propulsion Lab.</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">246</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2009NIMPB.267.1101C"> <span id="translatedtitle">Genesis capturing the sun: <span class="hlt">Solar</span> <span class="hlt">wind</span> irradiation at Lagrange 1</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Genesis, a member of NASAs Discovery Mission program, is the world's first sample return mission since the Apollo program to bring home <span class="hlt">solar</span> matter in ultra-pure materials. Outside the protection of Earth's magnetosphere at the Earth-Sun Lagrange 1 point, the deployed sample collectors were directly exposed to <span class="hlt">solar</span> <span class="hlt">wind</span> irradiation. The natural process of <span class="hlt">solar</span> <span class="hlt">wind</span> ion implantation into a highly pure silicon (Si) bulk composition array collector has been measured by spectroscopic ellipsometry and scanning transmission electron microscopy (STEM). Ellipsometry results show that bulk <span class="hlt">solar</span> <span class="hlt">wind</span> ions composed of approximately 95% H +, 4% He + and <1% other elements physically altered the first 59-63 nm of crystalline silicon substrate during 852.8 days of <span class="hlt">solar</span> exposure. STEM analysis confirms that the <span class="hlt">solar</span> accelerated ions caused significant strain and visible structural defects to the silicon structure forming a 60-75 nm thick irradiation damage region directly below the surface SiO 2 native oxide layer. Monte Carlo simulations of <span class="hlt">solar</span> <span class="hlt">wind</span> H, He, C, O, Ne, Mg, Si and Fe ion collisions in the Si collector with fluences calculated from the Genesis and ACE spacecrafts were used to estimate the energy deposited and Si vacancies produced by nuclear stopping in a flight-like Si bulk array collector. The coupled deposited energy model with the flown Genesis Si in situ measurements provides new insight into the basic principles of <span class="hlt">solar</span> <span class="hlt">wind</span> diffusion and space weathering of materials outside Earth's magnetosphere.</p> <div class="credits"> <p class="dwt_author">Calaway, Michael J.; Stansbery, Eileen K.; Keller, Lindsay P.</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-04-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">247</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.gpo.gov:80/fdsys/pkg/FR-2013-12-18/pdf/2013-30036.pdf"> <span id="translatedtitle">78 FR 76609 - Genesis <span class="hlt">Solar</span>, LLC; NRG Delta LLC; Mountain View <span class="hlt">Solar</span>, LLC; Pheasant Run <span class="hlt">Wind</span>, LLC; Pheasant Run...</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013</a></p> <p class="result-summary">...EG13-64-000; FC13-13-000] Genesis <span class="hlt">Solar</span>, LLC; NRG Delta LLC; Mountain View <span class="hlt">Solar</span>, LLC; Pheasant Run <span class="hlt">Wind</span>, LLC; Pheasant...Tuscola <span class="hlt">Wind</span> II, LLC; Mountain <span class="hlt">Wind</span> Power, LLC; Mountain <span class="hlt">Wind</span> Power II, LLC; Summerhaven <span class="hlt">Wind</span>, LP;...</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-18</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">248</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AGUFMSH41F..05K"> <span id="translatedtitle">Integrating Multiple Approaches to Solving <span class="hlt">Solar</span> <span class="hlt">Wind</span> Turbulence Problems (Invited)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Karimabadi, H.; Roytershteyn, V.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">249</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19830052897&hterms=Magyar&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DMagyar"> <span id="translatedtitle">Charge exchange in <span class="hlt">solar</span> <span class="hlt">wind</span>-cometary interactions</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Gombosi, T. I.; Horanyi, M.; Kecskemety, K.; Cravens, T. E.; Nagy, A. F.</p> <p class="dwt_publisher"></p> <p class="publishDate">1983-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">250</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20080026012&hterms=mtg&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dmtg"> <span id="translatedtitle">Genesis <span class="hlt">Solar</span> <span class="hlt">Wind</span> Sample Curation: A Progress Report</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Allton, Judith H.; Calaway, M. J.; Rodriquez, M. C.; Hittle, J. D.; Wentworth, S. J.; Stansbery, E. K.; McNamara, K. M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">251</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AGUFMSH51C2117K"> <span id="translatedtitle">Ion Beam Instabilities in <span class="hlt">Solar</span> <span class="hlt">Wind</span> Reconnection Exhaust</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Observations of the <span class="hlt">solar</span> <span class="hlt">wind</span> proton velocity distribution using the <span class="hlt">Wind</span> faraday cups were studied during inside of and near previously published magnetic reconnection exhausts. We have attempted to test the hypothesis that interpenetrating ion beams in the <span class="hlt">solar</span> <span class="hlt">wind</span> can be driven by the reconnection process. The beam and core within the <span class="hlt">solar</span> <span class="hlt">wind</span> were fit as two bi-Maxwellian distributions and their velocities compared to Alfvén wave velocity and inflow speed. The differential flow between the beam and the core was found to be mostly in the range of Alfvénic to super Alfvénic instead of reflecting the inflow speed. Further analysis revealed that these beam configurations are frequently unstable and excite parallel-propagating plasma modes. This research was supported by the NSF grant for the <span class="hlt">Solar</span> Physics REU Program at the Smithsonian Astrophysical Observatory (AGS-1263241).</p> <div class="credits"> <p class="dwt_author">Kristensen, H.; Stevens, M. L.; Verscharen, D.; Kasper, J. C.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">252</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/6020000"> <span id="translatedtitle">Saturn radio emission and the <span class="hlt">solar</span> <span class="hlt">wind</span> - Voyager-2 studies</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Voyager 2 data from the Plasma Science experiment, the Magnetometer experiment and the Planetary Radio Astronomy experiment were used to analyze the relationship between parameters of the <span class="hlt">solar</span> <span class="hlt">wind</span>/interplanetary medium and the nonthermal Saturn radiation. <span class="hlt">Solar</span> <span class="hlt">wind</span> and interplanetary magnetic field properties were combined to form quantities known to be important in controlling terrestrial magnetospheric processes. The Voyager 2 data set used in this investigation consists of 237 days of Saturn preencounter measurements. However, due to the immersion of Saturn and the Voyager 2 spacecraft into the extended Jupiter magnetic tail, substantial periods of the time series were lacking <span class="hlt">solar</span> <span class="hlt">wind</span> data. To cope with this problem a superposed epoch method (CHREE analysis) was used. The results indicate the superiority of the quantities containing the <span class="hlt">solar</span> <span class="hlt">wind</span> density in stimulating the radio emission of Saturn - a result found earlier using Voyager 1 data - and the minor importance of quantities incorporating the interplanetary magnetic field. 10 references.</p> <div class="credits"> <p class="dwt_author">Desch, M.D.; Rucker, H.O.</p> <p class="dwt_publisher"></p> <p class="publishDate">1985-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">253</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008AGUFMSH23A1617B"> <span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">Wind</span> 3D Reconstructions of the Whole Heliospheric Interval</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">3D tomographic reconstructions of the inner heliosphere have been used for over a decade to visualise and investigate the structure of the <span class="hlt">solar</span> <span class="hlt">wind</span> and its various features such as transients and corotating structures. Interplanetary scintillation (IPS) observations of the <span class="hlt">solar</span> <span class="hlt">wind</span> have been carried out for a much longer period of time revealing information on the structure of the <span class="hlt">solar</span> <span class="hlt">wind</span> and the features within it. Here we present such 3D reconstructions using IPS observations from the <span class="hlt">Solar</span> Terrestrial Environment Laboratory (STELab) and the Ootacamund (Ooty) Radio Telescope (ORT) of the Whole Heliospheric Interval (WHI) Carrington Rotation 2068. This is part of the world-wide IPS community's International Heliosphysical Year (IHY) collaboration. We show the structure of the inner heliosphere during this time and how our global reconstructions compare with deep-space spacecraft measurements such as those taken by <span class="hlt">Wind</span>, ACE, STEREO, and Ulysses in terms of density and velocity.</p> <div class="credits"> <p class="dwt_author">Bisi, M. M.; Jackson, B. V.; Clover, J. M.; Hick, P. P.; Buffington, A.; Manoharan, P. K.; Tokumaru, M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">254</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/52946447"> <span id="translatedtitle">Five-Spacecraft Observations of <span class="hlt">Solar</span> <span class="hlt">Wind</span> Structure and Interplanetary Shocks Approaching <span class="hlt">Solar</span> Maximum</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">We combined <span class="hlt">solar</span> <span class="hlt">wind</span> observations from five different spacecraft: Helios 1, Helios 2, OMNI tape, Voyager 1, and Voyager 2, from November 1977 to February 1978, to study the structure of the <span class="hlt">solar</span> <span class="hlt">wind</span> streams and the propagation of interplanetary shocks and ejecta. We identified 12 shock events of different origin: 7 transient forward shocks (TFSs) and 5 corotating interaction</p> <div class="credits"> <p class="dwt_author">A. Gonzalez-Esparza</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">255</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19860047274&hterms=Provo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3D%2522Provo%2522"> <span id="translatedtitle">Comet-<span class="hlt">solar</span> <span class="hlt">wind</span> interaction - Dynamical length scales and models</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">ICE magnetometer measurements at Comet Giacobini-Zinner and model simulations of comet-<span class="hlt">solar</span> <span class="hlt">wind</span> interactions are analyzed. The magnetometer data reveal the existence of intense hydromagnetic turbulence, a draping of the magnetic field lines to form a magnetotail, a weak shock, and a magnetic barrier region in the magnetosphere. The global models of the comet-<span class="hlt">solar</span> <span class="hlt">wind</span> interaction are described. The observed data and models are compared and good correlation is displayed.</p> <div class="credits"> <p class="dwt_author">Mendis, D. A.; Smith, E. J.; Tsurutani, B. T.; Slavin, J. A.; Jones, D. E.</p> <p class="dwt_publisher"></p> <p class="publishDate">1986-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">256</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/48907397"> <span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">wind</span> charge exchange observed through the lunar exosphere</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">X-rays can be generated by charge exchange between highly-charged heavy <span class="hlt">solar</span> <span class="hlt">wind</span> ions and neutrals. Previously, simulations have only been performed for X-ray emission due to <span class="hlt">solar</span> <span class="hlt">wind</span> charge exchange (SWCX) with geocoronal and interstellar neutrals. However, X-rays can also be generated by SWCX with the Moon's tenuous exosphere, which should be detectable by an imaging X-ray instrument located on</p> <div class="credits"> <p class="dwt_author">I. P. Robertson; S. Sembay; T. J. Stubbs; K. D. Kuntz; M. R. Collier; T. E. Cravens; S. L. Snowden; H. K. Hills; F. S. Porter; P. Travnicek; J. A. Carter; A. M. Read</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">257</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19890005692&hterms=REPRINTS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2522REPRINTS%2522"> <span id="translatedtitle">Analysis of ISEE-3/ICE <span class="hlt">solar</span> <span class="hlt">wind</span> data</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Coplan, Michael A.</p> <p class="dwt_publisher"></p> <p class="publishDate">1989-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">258</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.spacegeneration.org/files/downloads/Move_An_Asteroid/Sini_Merikallio.pdf"> <span id="translatedtitle">Moving an asteroid with electric <span class="hlt">solar</span> <span class="hlt">wind</span> sail</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The electric <span class="hlt">solar</span> <span class="hlt">wind</span> sail (E-Sail) is a new propulsion method for interplanetary travel which was invented in 2006 and is currently under development. The E-Sail uses charged tethers to extract momentum from the <span class="hlt">solar</span> <span class="hlt">wind</span> particles to obtain propulsive thrust. According to current estimates, the E-Sail is 2-3 orders of magnitude better than traditional propulsion methods (chemical rockets and</p> <div class="credits"> <p class="dwt_author">Sini Merikallio; P. Janhunen</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">259</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19820024368&hterms=manure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3D%2522manure%2522"> <span id="translatedtitle">Calculation of <span class="hlt">solar</span> <span class="hlt">wind</span> flows about terrestrial planets</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Stahara, S. S.; Spreiter, J. R.</p> <p class="dwt_publisher"></p> <p class="publishDate">1982-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">260</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014AAS...22432363D"> <span id="translatedtitle">The Turbulent Origin of the Slow <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We report on preliminary analyses of early <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence via heliospheric imaging: both the brightness structure function in the STEREO-A HI-1 field of view and paths taken by individual boli of comet-tail material in the <span class="hlt">solar</span> <span class="hlt">wind</span>. The analyses are complementary and preliminary results indicate that turbulent processing is underway even within the early HI-1 field of view (as low as 20-30 Rs).</p> <div class="credits"> <p class="dwt_author">DeForest, Craig; Matthaeus, Bill; Howard, Tim A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-06-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_12");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> 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showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_15");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">261</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/56338655"> <span id="translatedtitle">Comets and three-dimensional <span class="hlt">solar</span> <span class="hlt">wind</span> structure</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The use of comet observations to characterize three-dimensional <span class="hlt">solar-wind</span> structure is discussed, including the plasma-tail orientations, the Lyman-alpha emission contours from the hydrogen cloud, and periodic disconnection of the plasma tail. Models based on observations of plasma-tail orientations produce <span class="hlt">solar-wind</span> radial speeds in the 400-420 km\\/s range, and azimuthal speeds of 5-7 km\\/s. Studies of disconnection events indicate that the</p> <div class="credits"> <p class="dwt_author">J. C. Brandt</p> <p class="dwt_publisher"></p> <p class="publishDate">1986-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">262</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://sprg.ssl.berkeley.edu/aurora_rocket/education/cereal/cerealtitle.html"> <span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">Wind</span> and Magnetosphere Interaction Lab: A Cereal Analogy</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://nsdl.org/nsdl_dds/services/ddsws1-1/service_explorer.jsp">NSDL National Science Digital Library</a></p> <p class="result-summary">This open-ended laboratory activity is useful in demonstrating how <span class="hlt">solar</span> <span class="hlt">wind</span> particles are deflected by the Earth's magnetosphere and how charged particles are aligned within it. After this lesson, students should be able to discuss and describe the components of <span class="hlt">solar</span> <span class="hlt">wind</span> particles, explain why the magnetosphere and ionosphere protect the Earth, and explain how moving particles behave (and align) in a magnetic field. Additional links lead to background material, standards, and assessment.</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">263</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19840005046&hterms=swiss&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dswiss%2BR%2526D"> <span id="translatedtitle">Mixed <span class="hlt">solar</span> <span class="hlt">wind</span> originating from coronal regions of different temperatures</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Bochsler, P.</p> <p class="dwt_publisher"></p> <p class="publishDate">1983-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">264</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AIPC.1539..291V"> <span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">wind</span> magnetic field discontinuities and turbulence generated current layers</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Hybrid simulations with particle protons and fluid electrons show that cross-field turbulence generates current layers. These can be associated with directional discontinuities observed in the <span class="hlt">solar</span> <span class="hlt">wind</span>. The layers can evolve quickly and can present a challenge to identification if this occurs in the <span class="hlt">solar</span> <span class="hlt">wind</span>. The protons become preferentially heated across the magnetic field in association with the turbulence. Some protons are likely demagnetized and are possibly heated by a stochastic mechanism in association with the turbulence generated layers.</p> <div class="credits"> <p class="dwt_author">Vasquez, Bernard J.; Markovskii, Sergei A.; Smith, Charles W.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">265</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2009EM%26P..104..115M"> <span id="translatedtitle">The Energy Cascade in <span class="hlt">Solar</span> <span class="hlt">Wind</span> MHD Turbulence</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Direct evidence for the presence of an inertial energy cascade, the most characteristic signature of hydromagnetic turbulence (MHD), is observed in the <span class="hlt">solar</span> <span class="hlt">wind</span> by the Ulysses spacecraft. A linear relation is indeed observed for the scaling of mixed third order structure functions involving Elsässer variables. This experimental result, confirming the prescription stemming from a theorem for MHD turbulence, firmly establishes the turbulent character of low-frequency velocity and magnetic field fluctuations in the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma.</p> <div class="credits"> <p class="dwt_author">Marino, R.; Sorriso-Valvo, L.; Carbone, V.; Noullez, A.; Bruno, R.; Bavassano, B.</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">266</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19790009952&hterms=Gold+making&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DGold%2Bmaking"> <span id="translatedtitle">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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Roelof, E. C.; Gold, R. E.</p> <p class="dwt_publisher"></p> <p class="publishDate">1978-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">267</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2007AGUFMSH14B..06L"> <span id="translatedtitle">New Forecasting Factor for <span class="hlt">Solar</span> <span class="hlt">Wind</span> Velocity From EIT Observations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Various <span class="hlt">solar</span> <span class="hlt">wind</span> velocity forecasting methods at 1AU have been developed during the last decade, such as Wang-sheeley model and Hakamada-Akasofu-Fry Version 2 (HAFv2) model. Some authors have found that Coronal hole(CH) areas can be used to forecast the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity with better results in low CME activity periods(e.g. Vršnak et.al.). The property of the <span class="hlt">solar</span> surface is a good indication of the following interplanetary and geomagnetic activities. We analyzed all EIT284Å images in almost the whole <span class="hlt">solar</span> cycle 23 and developed a new forecasting factor(Pch) from the brightness of the <span class="hlt">solar</span> Extreme Ultraviolet Images. and a good relationship was found between the Pch and <span class="hlt">solar</span> <span class="hlt">wind</span> velocity V three days later probed by ACE spacecraft. A simple method of forecasting the <span class="hlt">solar</span> <span class="hlt">wind</span> speed near earth in low CME activity periods is presented. For Pch and <span class="hlt">solar</span> <span class="hlt">wind</span> velocity, the linear correlation coefficients is R = 0.89 from 21 September until 26 December. For comparison we also analysed the same period data as Vršnak(2007) who using the coronal hole areas AM as input parameters for predicting <span class="hlt">solar</span> <span class="hlt">wind</span> velocity. The linear least-squares fit of Pch with the 3-day lag <span class="hlt">solar</span> <span class="hlt">wind</span> velocity showed a correlation coefficient R = 0.70, which is better than the result using AM(R = 0.62). The <span class="hlt">solar</span> <span class="hlt">wind</span> speed could be expressed as V (km s-1) = 337 + 0.00868 × Pch. The average of relative difference between the calculated and the observed values amounts to |?¯| ? 12.15%. Furthermore, for the ten peaks during the analysis period, AM and V just showed a correlation coefficient R = 0.32, much worse than using Pch factor which showed R = 0.75. Moreover, the Pch factor exterminated personal bias in the forecasting process, which existed in the method using AM as input parameters because the coronal hole boundary can not be easily determined since no quantitative criteria can be used to precisely locate coronal holes from observation. Finally, the expression of V by Pch is analysed, which showed the variation of background <span class="hlt">solar</span> <span class="hlt">wind</span> speed during the whole <span class="hlt">solar</span> cycle 23.</p> <div class="credits"> <p class="dwt_author">Luo, B.; Liu, S.; Zhong, Q.; Gong, J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">268</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19950032459&hterms=pizzo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2522pizzo%2522"> <span id="translatedtitle">Gasdynamic models of the <span class="hlt">solar</span> <span class="hlt">wind</span>/interstellar medium interaction</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The interaction between the <span class="hlt">solar</span> <span class="hlt">wind</span> and the interstellar medium is modeled self-consistently using numerical solutions of the time-dependent gasdynamic equations in spherical and cylindrical coordinates. For the results presented here it is assumed that the <span class="hlt">solar</span> system moves through the surrounding medium with a supersonic velocity. After an initial (nonequilibrium) state has been specified, the numerical solution follows the evolution in time until the interaction relaxes to a dynamic equilibrium. As would be expected, the solutions show the formation of a bow shock upstream of the traveling <span class="hlt">solar</span> system to deflect the interstellar plasma around the cavity created by the <span class="hlt">solar</span> <span class="hlt">wind</span>. A terminiation shock also forms to slow and compress the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma. For the simulation in spherical coordinates, the downstream portion of the termination shock reaches equilibrium more than three times further from the Sun than the equilibrium distance to the termination shock on the upstream side.</p> <div class="credits"> <p class="dwt_author">Steinolfson, R. S.; Pizzo, V. J.; Holzer, T.</p> <p class="dwt_publisher"></p> <p class="publishDate">1994-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">269</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20110013339&hterms=interaction&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dinteraction"> <span id="translatedtitle">The Character of the <span class="hlt">Solar</span> <span class="hlt">Wind</span>, Surface Interactions, and Water</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Farrell, William M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">270</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19730002067&hterms=Imp3&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2522Imp3%2522"> <span id="translatedtitle">Interplanetary shock waves and the structure of <span class="hlt">solar</span> <span class="hlt">wind</span> disturbances</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Hundhausen, A. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1972-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">271</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1984STIN...8432915R"> <span id="translatedtitle"><span class="hlt">Wind</span> loading on <span class="hlt">solar</span> concentrators: Some general considerations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Roschke, E. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1984-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">272</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1997ApJ...489..992B"> <span id="translatedtitle">Fast and Slow <span class="hlt">Wind</span> from <span class="hlt">Solar</span> Coronal Holes</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Coronal holes have been identified as the sources of high-speed streams that appear in the <span class="hlt">solar</span> <span class="hlt">wind</span>, but comparisons of the coronal structure and <span class="hlt">solar</span> <span class="hlt">wind</span> observations suggest that they may also be the sources of slow <span class="hlt">wind</span>, which could be emerging from the bordering, highly divergent regions of the hole. In this paper, we discuss the effect of flux-tube divergence on the properties of the <span class="hlt">solar</span> <span class="hlt">wind</span> from coronal holes, including mechanical heating and Alfvén waves, and present the results of global models that consider the differences in the geometry of individual flux tubes from different parts of polar coronal holes, including a self-consistent MHD model developed by us, with a complete energy equation including heat conduction along the field lines. We find that in order to obtain a center-to-border variation of plasma parameters in the <span class="hlt">solar</span> <span class="hlt">wind</span>, the plasma properties at the temperature maximum must already vary across the hole. We discuss recent observations of the corona and the <span class="hlt">solar</span> <span class="hlt">wind</span> near the Sun and show that the requirements of our model for the emission of fast and slow <span class="hlt">wind</span> from polar coronal holes seem to be supported by observations.</p> <div class="credits"> <p class="dwt_author">Bravo, S.; Stewart, G. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">1997-11-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">273</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/51090859"> <span id="translatedtitle">Potential of <span class="hlt">solar</span> radiation and <span class="hlt">wind</span> speed for photovoltaic and <span class="hlt">wind</span> power hybrid generation in Perlis, Northern Malaysia</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">This paper presents analysis of the <span class="hlt">solar</span> radiation and <span class="hlt">wind</span> speed characteristics in Perlis, Northern Malaysia for the year of 2006. The characteristics consist of daily and annual mean <span class="hlt">solar</span> radiation and <span class="hlt">wind</span> speed. Peak sun hours (PSHs) of the <span class="hlt">solar</span> radiation and PV power generation capacity are analyzed. The Weibull distribution function is applied to analyze the <span class="hlt">wind</span> speed</p> <div class="credits"> <p class="dwt_author">I. Daut; M. Irwanto; Y. M. Irwan; N. Gomesh; N. S. Ahmad Rosnazri</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">274</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/17790539"> <span id="translatedtitle"><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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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. PMID:17790539</p> <div class="credits"> <p class="dwt_author">Lundstedt, H; Wilcox, J M; Scherrer, P H</p> <p class="dwt_publisher"></p> <p class="publishDate">1981-06-26</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">275</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008STIN...0822945W"> <span id="translatedtitle">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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Wilson, Robert M.; Hathaway, David H.</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-02-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">276</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20080022945&hterms=Hgh&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DHgh"> <span id="translatedtitle">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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Wilson, Robert M.; Hathaway, David H.</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">277</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2009AGUFMSH11A1502A"> <span id="translatedtitle">Implications of the Deep Minimum for Slow <span class="hlt">Solar</span> <span class="hlt">Wind</span> Origin</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Antiochos, S. K.; Mikic, Z.; Lionello, R.; Titov, V. S.; Linker, J. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">278</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/43131355"> <span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">wind</span> speed and coronal flux-tube expansion</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The hypothesis that the <span class="hlt">solar</span> <span class="hlt">wind</span> speed at 1 AU and the rate of magnetic flux-tube expansion in the corona are inversely correlated is shown to be consistent with observations extending over the last 22 years. This empirical relationship allows the daily <span class="hlt">wind</span> speeds at earth to be predicted from a current-free extrapolation of the observed photospheric field into the</p> <div class="credits"> <p class="dwt_author">Y.-M. Wang</p> <p class="dwt_publisher"></p> <p class="publishDate">1990-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">279</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/27695607"> <span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">wind</span> induced magnetic field around the unmagnetized Earth</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The Earth is a planet with a dipolar magnetic field which is agitated by a magnetized plasma <span class="hlt">wind</span> streaming from the Sun. The magnetic field shields the Earth's surface from penetrating high energy <span class="hlt">solar</span> <span class="hlt">wind</span> particles, as well as interstellar cosmic rays. The magnetic dipole has reversed sign some hundreds of times over the last 400 million years. These polarity</p> <div class="credits"> <p class="dwt_author">G. T. Birk; H. Lesch; C. Konz</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">280</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2004A%26G....45d..38H"> <span id="translatedtitle"><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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Habbal, Shadia Rifia; Woo, Richard</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-08-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_13");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" 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showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_16");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">281</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19990028031&hterms=solar+corona+topology&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsolar%2Bcorona%2Btopology"> <span id="translatedtitle">Coronal hole structure and the high speed <span class="hlt">solar</span> <span class="hlt">wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The basic physical processes which are important in the acceleration of high speed <span class="hlt">wind</span> from coronal holes are reviewed. The early works of Birkeland and Parker are discussed. The extension of Parker's work is included. It is shown that the greatest area of uncertainty is that of coronal heating. It is demonstrated that in modeling <span class="hlt">solar</span> <span class="hlt">wind</span> acceleration, it is important to carry out a study on the chromosphere-corona-<span class="hlt">wind</span> system analysis.</p> <div class="credits"> <p class="dwt_author">Holzer, Thomas E.; Leer, Egil</p> <p class="dwt_publisher"></p> <p class="publishDate">1997-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">282</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19960021284&hterms=south+pole+solar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsouth%2Bpole%2Bsolar"> <span id="translatedtitle">Electron energy transport in the <span class="hlt">solar</span> <span class="hlt">wind</span>: Ulysses observations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Scime, Earl; Gary, S. Peter; Phillips, J. L.; Corniileau-Wehrlin, N.; Solomon, J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">283</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AGUSMSH21A..02P"> <span id="translatedtitle">Time-dependent <span class="hlt">solar</span> <span class="hlt">wind</span> flows in the heliosheath</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Recent observations on Voyager 1 and 2 spacecraft show complex and very different <span class="hlt">solar</span> <span class="hlt">wind</span> flows in the heliosheath region. Voyager 2 has been observing constant radial flows (Richardson and Wang 2013). At the beginning of 2011 Voyager 1 entered a region with zero and even negative radial velocity of the plasma flow (Krimigis et al. 2011). Since mid 2012 Voyager 1 continues observing a new region in the heliosheath with fast changing of intensities of anomalous and galactic cosmic rays. These puzzling observational data motivate us to explore different physical effects at the edges of the heliosphere in the models. In order to separate spatial from temporal effects the investigation of time-dependent effects are crucial. In this work we focus on time-dependent effects of the 11-year <span class="hlt">solar</span> cycle. We use a global MHD multi-fluid model of interaction of the <span class="hlt">solar</span> <span class="hlt">wind</span> with the local interstellar medium with time-dependent boundary conditions for the supersonic <span class="hlt">solar</span> <span class="hlt">wind</span>. Realistic boundary conditions (plasma density and velocity) at 1 AU for the plasma were obtained from the measurements of Ly-alpha intensities on SOHO/SWAN, OMNI data and interplanetary scintillations data. We present effects of realistic variations of the <span class="hlt">solar</span> <span class="hlt">wind</span> dynamic pressure on the <span class="hlt">solar</span> <span class="hlt">wind</span> flow in the heliosheath and in the vicinity of the heliopause. Comparing the results of time-dependent model along the Voyager 1 and 2 trajectory with observational data we describe effects of <span class="hlt">solar</span> cycle on the flows that Voyager measures.</p> <div class="credits"> <p class="dwt_author">Provornikova, E.; Opher, M.; Izmodenov, V.; Toth, G.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">284</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040182379&hterms=s2&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2522s2%2522"> <span id="translatedtitle">Interaction of Comets and the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Wagner, William (Technical Monitor); Raymond, John C.</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">285</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040000671&hterms=s2&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D%2522s2%2522"> <span id="translatedtitle">Interaction of Comets and the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Wagner, William (Technical Monitor); Raymond, John C.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">286</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20110005629&hterms=Solar+wind&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DSolar%2Bwind"> <span id="translatedtitle">Dissipation of Turbulence in the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Goldstein, Melvyn L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">287</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/12631215"> <span id="translatedtitle"><span class="hlt">Latitude-dependent</span> Effects in the Stellar <span class="hlt">Wind</span> of eta Carinae</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The Homunculus reflection nebula around eta Carinae provides a rare opportunity to observe the spectrum of a star from more than one direction. In the case of eta Car, the nebula's geometry is known well enough to infer how line profiles vary with latitude. We present Space Telescope Imaging Spectrograph (STIS) spectra of several positions in the Homunculus, showing directly</p> <div class="credits"> <p class="dwt_author">Nathan Smith; Kris Davidson; Theodore R. Gull; Kazunori Ishibashi; D. John Hillier</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">288</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19740035605&hterms=heavy+electron&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dheavy%2Belectron"> <span id="translatedtitle">Effects of heavy ions on electron temperatures in the <span class="hlt">solar</span> corona and <span class="hlt">solar</span> <span class="hlt">wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The effects of the reduction in the thermal conductivity due to heavy ions on electron temperatures in the <span class="hlt">solar</span> corona and <span class="hlt">solar</span> <span class="hlt">wind</span> are examined. Large enhancements of heavy ions in the corona appear to be necessary to give appreciable changes in the thermal gradient of the electrons. These enhancements, if they should occur, may contribute to the understanding of some low values of <span class="hlt">solar</span> <span class="hlt">wind</span> temperature measurements at 1 AU.</p> <div class="credits"> <p class="dwt_author">Nakada, M. P.</p> <p class="dwt_publisher"></p> <p class="publishDate">1974-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">289</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/7h0l330v117h3377.pdf"> <span id="translatedtitle">9. The venus ionosphere and <span class="hlt">solar</span> <span class="hlt">wind</span> interaction</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The current state of knowledge of the chemistry, dynamics and energetics of the upper atmosphere and ionosphere of Venus is reviewed together with the nature of the <span class="hlt">solar</span> <span class="hlt">wind</span>-Venus interaction. Because of the weak, though perhaps not negligible, intrinsic magnetic field of Venus, the mutual effects between these regions are probably strong and unique in the <span class="hlt">solar</span> system. The ability</p> <div class="credits"> <p class="dwt_author">S. J. Bauer; L. H. Brace; D. M. Hunten; D. S. Intriligator; W. C. Knudsen; A. F. Nagy; C. T. Russell; F. L. Scarf; J. H. Wolfe</p> <p class="dwt_publisher"></p> <p class="publishDate">1977-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">290</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/56677054"> <span id="translatedtitle">Observations of the <span class="hlt">solar</span> <span class="hlt">wind</span> speed near the sun</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Two-antenna scintillation (IPS) observations can provide accurate measurements of the velocity with which electron density fluctuations drift past the line of sight. These fluctuations can be used as tracers for the <span class="hlt">solar</span> plasma and allow us to estimate the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity near the Sun where spacecraft have not yet penetrated. We present recent IPS measurements made with the EISCAT</p> <div class="credits"> <p class="dwt_author">R. R. Grall; Wm. A. Coles; M. T. Klinglesmith</p> <p class="dwt_publisher"></p> <p class="publishDate">1996-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">291</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/54792206"> <span id="translatedtitle">Improving Data Drivers for Coronal and <span class="hlt">Solar</span> <span class="hlt">Wind</span> Models</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Global estimates of the <span class="hlt">solar</span> photospheric magnetic field distribution are critical for space weather forecasting. These global maps are the essential data input for accurate modeling of the corona and <span class="hlt">solar</span> <span class="hlt">wind</span>, which is vital for gaining the basic understanding necessary to improve space weather forecasting models. We are now testing the global photospheric field maps generated by the Air</p> <div class="credits"> <p class="dwt_author">C. N. Arge; C. J. Henney; J. Koller; W. A. Toussaint; J. W. Harvey; S. Young</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">292</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/51754368"> <span id="translatedtitle">STEREO In-situ Observations of <span class="hlt">Solar</span> <span class="hlt">Wind</span> Structure</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">STEREO, launched into the late declining phase of <span class="hlt">solar</span> cycle 23, has experienced one of the quietest activity periods on record due to the duration of the cycle 23-24 transition. While this circumstance has provided an exceptional opportunity to study ambient <span class="hlt">solar</span> <span class="hlt">wind</span> structure, it also has introduced atypical aspects such as unusually low interplanetary fields and densi-ties. From a</p> <div class="credits"> <p class="dwt_author">Janet G. Luhmann; C. T. Russell; C. O. Lee; Emilia Kilpua; Lan Jian; Andrea Opitz; Kristin Simunac; Antoinette Galvin; P. Riley</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">293</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/ja/v102/iA02/95JA03146/95JA03146.pdf"> <span id="translatedtitle">Charge exchange in the <span class="hlt">solar</span> <span class="hlt">wind</span>-comet interaction</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The interaction of the <span class="hlt">solar</span> <span class="hlt">wind</span> with the neutral environment of comets takes place by means of a number of microscopic processes. Photoionization of the neutral particles by <span class="hlt">solar</span> UV radiation allows a relatively simple analytical treatment and has been well described in theoretical models. However, it is well known that the charge exchange of protons with heavy cometary molecules</p> <div class="credits"> <p class="dwt_author">Ildar K. Khabibrakhmanov; Danny Summers</p> <p class="dwt_publisher"></p> <p class="publishDate">1997-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">294</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFMSH13B2256R"> <span id="translatedtitle">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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Ramanjooloo, Y.; Jones, G. H.; Coates, A. J.; Owens, M. J.; Battams, K.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">295</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012EOSTr..93R.372B"> <span id="translatedtitle">Velocity shear layers in <span class="hlt">solar</span> <span class="hlt">winds</span> affect Earth's magnetosphere</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Human society is increasingly reliant on technology that can be disrupted by space weather. For instance, geomagnetic storms can cause high-latitude air fights to be rerouted, costing as much as $100,000 per fight; induce errors of up to 46 meters in GPS systems; and affect satellites and the International Space Station. Space weather is determined by how the <span class="hlt">solar</span> <span class="hlt">wind</span>, a stream of hot plasma from the Sun, interacts with Earth's magnetic field. In studying space weather, scientists have largely neglected the fact that the <span class="hlt">solar</span> <span class="hlt">wind</span> contains layers of very strong velocity shear. Scientists understand very little about how these <span class="hlt">wind</span> shears affect space weather.</p> <div class="credits"> <p class="dwt_author">Bhattacharya, Atreyee</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">296</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/16090149"> <span id="translatedtitle">Generalized dimensions for fluctuations in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">We analyze time series of velocities of the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma including the outward-directed component of Alfvénic turbulence within slow <span class="hlt">wind</span> observed by the Helios 2 spacecraft in the inner heliosphere. We demonstrate that the influence of noise in the data can be efficiently reduced by a singular-value decomposition filter. The resulting generalized dimensions show a multifractal structure of the <span class="hlt">solar</span> <span class="hlt">wind</span> attractor in the inner heliosphere. The obtained multifractal spectrum is consistent with that for the multifractal measure on the self-similar weighted baker's map with two parameters describing uniform compression and natural invariant measure on the attractor of the system. PMID:16090149</p> <div class="credits"> <p class="dwt_author">Macek, Wies?aw M; Bruno, Roberto; Consolini, Giuseppe</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-07-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">297</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19960021285&hterms=remarks&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dremarks"> <span id="translatedtitle">Some remarks on waves in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Waves are significant to the <span class="hlt">solar</span> <span class="hlt">wind</span> in two ways as modifiers of the particle distribution functions, and as diagnostics. In addition, the <span class="hlt">solar</span> <span class="hlt">wind</span> serves as an important laboratory for the study of plasma wave processes, as it is possible to make detailed measurements of phenomena which are too small to be easily measured by laboratory sized sensors. There are two areas where waves (we include discontinuities under this heading) must make important modifications of the distribution functions: in accelerating the alpha particles to higher speeds than the protons (Marsch et al.) and in accelerating the <span class="hlt">solar</span> <span class="hlt">wind</span> itself. A third area is possibly in maintaining the relative isotropy of the <span class="hlt">solar</span> <span class="hlt">wind</span> ion distribution in the <span class="hlt">solar</span> <span class="hlt">wind</span> rest frame. As the <span class="hlt">solar</span> <span class="hlt">wind</span> is nearly collisionless, the ions should conserve magnetic moment in rushing out from the sun, and therefore Tperp/B should be relatively constant, but it is obviously not. This has not received much attention. The waves, both electromagnetic and electrostatic, which are pan of the <span class="hlt">solar</span> Type 111 burst phenomenon, have been extensively studied as examples of nonlinear plasma phenomena, and also used as remote sensors to trace the <span class="hlt">solar</span> magnetic field. The observations made by Ulysses show that the field can be traced in this way out to perhaps a little more than an A.U., but then the electromagnetic pan of the type 111 burst fades out. Nevertheless, sometimes Langmuir waves appear at Ulysses at an appropriate extrapolated time. This seems to support the picture in which the electromagnetic waves at the fundamental plasma frequency are trapped in density fluctuations. Langmuir waves in the <span class="hlt">solar</span> <span class="hlt">wind</span> are usually in quasi-thermal equilibrium quasi because the <span class="hlt">solar</span> <span class="hlt">wind</span> itself is not isothermal. The Observatory of Paris group (Steinberg. Meyer-Vernet, Hoang) has exploited this with an experiment on <span class="hlt">WIND</span> which is capable of providing density and temperature on a faster time scale than hitherto. Recently it has been found that Langmuir waves are associated with magnetic holes. This may help to elucidate the nature of magnetic holes. Nonlinear processes are important in the transformation of wave energy to panicle energy. Some recent examples from <span class="hlt">WIND</span> data will be shown.</p> <div class="credits"> <p class="dwt_author">Kellogg, Paul J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">298</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFMSH11B2203P"> <span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">wind</span> flow in the heliosheath due to latitudinal and time variations over the <span class="hlt">solar</span> cycle</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Recent observations by Voyager 2 in the heliosheath showed strong variations of the <span class="hlt">solar</span> <span class="hlt">wind</span> density, velocity and temperature. Magnetic field fluctuates considerably as observed on both Voyager 1 and 2. Anomalous and galactic cosmic rays also present large fluctuations of intensity. Spatial variations and temporal effects in the <span class="hlt">solar</span> <span class="hlt">wind</span> due to <span class="hlt">solar</span> cycle attribute to the observed fluctuations. In this work we aim to explore effects of realistic <span class="hlt">solar</span> cycle on the 3D <span class="hlt">solar</span> <span class="hlt">wind</span> flow in the outer heliosphere. We use time and latitudinal variations of the <span class="hlt">solar</span> <span class="hlt">wind</span> density and velocity over two last <span class="hlt">solar</span> cycles as the boundary conditions in a 3D MHD multi-fluid model of the interaction between the <span class="hlt">solar</span> <span class="hlt">wind</span> and interstellar medium based on BATSRUS code. These realistic boundary conditions at 1 AU for the plasma were obtained on the base of the measurements of Ly-alpha intensities on SOHO/SWAN and interplanetary scintillations data (IPS). In our simulation a numerical spatial grid is highly refined along the Voyager 2 trajectory in order to capture disturbances propagating in the <span class="hlt">solar</span> <span class="hlt">wind</span> and compare the model with the observations. To validate the model and used boundary conditions we compare our results with Voyager 2 plasma data. In particular we focus on the time-dependent plasma flow in the heliosheath.</p> <div class="credits"> <p class="dwt_author">Provornikova, E.; Opher, M.; Izmodenov, V.; Toth, G.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">299</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013EPSC....8..763B"> <span id="translatedtitle">Hybrid Simulations of <span class="hlt">Solar</span> <span class="hlt">Wind</span> Interactions of Mars</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">In this paper the results of hybrid simulations of Mars will be presented. These simulations include the crustal magnetic fields and examine their role in the <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with Mars. The focus is the ionospheric response to differing situations on the ionosphere as well as the ionospheric loss from Mars. A comparison between <span class="hlt">solar</span> maximum conditions and <span class="hlt">solar</span> minimum conditions will be presented. Further, the effect of different crustal magnetic field orientations will also be presented.</p> <div class="credits"> <p class="dwt_author">Brecht, S. H.; Ledvina, S. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">300</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19910055754&hterms=tds&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dtds"> <span id="translatedtitle">Shuffling foot points and magnetohydrodynamic discontinuities in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">ISEE three-field and plasma data are used to investigate the frequency of occurrence of isolated, large-amplitude rotational (RD) and tangential (TD) discontinuities in different types of <span class="hlt">solar</span> <span class="hlt">wind</span> flow. It is found that there are relatively more TDs in <span class="hlt">solar</span> <span class="hlt">wind</span> that originates in closed field regions and is ejected into interplanetary space by coronal transients than in the <span class="hlt">solar</span> <span class="hlt">wind</span> that originates in open field regions. The speed of the <span class="hlt">wind</span> from open field regions is approximately linearly related to the number of RDs per hour; such a relation does not exist for the <span class="hlt">wind</span> associated with coronal mass ejections. These results are consistent with the hypothesis that the convection-driven shuffling of magnetic foot points at the <span class="hlt">solar</span> surface leads to TDs, magnetic reconnection, and heating of the corona on closed field lines, while in the open field regions the disturbances created by the shuffling are carried off by waves which contribute to the acceleration of the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> <div class="credits"> <p class="dwt_author">Neugebauer, M.; Alexander, C. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1991-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_14");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' 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showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a style="font-weight: bold;">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_17");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">301</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/18764383"> <span id="translatedtitle">Eigenmode structure in <span class="hlt">solar-wind</span> Langmuir waves.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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. PMID:18764383</p> <div class="credits"> <p class="dwt_author">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 class="dwt_publisher"></p> <p class="publishDate">2008-08-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">302</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22304144"> <span id="translatedtitle">Scale-free texture of the fast <span class="hlt">solar</span> <span class="hlt">wind</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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. PMID:22304144</p> <div class="credits"> <p class="dwt_author">Hnat, B; Chapman, S C; Gogoberidze, G; Wicks, R T</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">303</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFMSH53A2268M"> <span id="translatedtitle">Coronal Streamers and Their Associated <span class="hlt">Solar</span> <span class="hlt">Wind</span> Streams</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Miralles, M. P.; Landi, E.; Cranmer, S. R.; Cohen, O.; Raymond, J. C.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">304</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/21560559"> <span id="translatedtitle">EVIDENCE FOR INHOMOGENEOUS HEATING IN THE <span class="hlt">SOLAR</span> <span class="hlt">WIND</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary"><span class="hlt">Solar</span> <span class="hlt">wind</span> observations and magnetohydrodynamic (MHD) simulations are used to probe the nature of turbulence heating. In particular, the electron heat flux, electron temperature, and ion temperature in the <span class="hlt">solar</span> <span class="hlt">wind</span> are studied using ACE and <span class="hlt">Wind</span> data. These heating diagnostics are also compared with MHD simulation estimates of the local dissipation density. Coherent structures, which are sources of inhomogeneity and intermittency in MHD turbulence, are found to be associated with enhancements in every heating-related diagnostic. This supports the hypothesis that significant inhomogeneous heating occurs in the <span class="hlt">solar</span> <span class="hlt">wind</span>, connected with current sheets that are dynamically generated by MHD turbulence. Indeed, a subset of these coherent current sheets might be candidates for magnetic reconnection. However, the specific kinetic mechanisms that heat and accelerate particles within these structures require further study.</p> <div class="credits"> <p class="dwt_author">Osman, K. T.; Matthaeus, W. H. [Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, DE 19716 (United States); Greco, A.; Servidio, S., E-mail: kto@udel.edu [Dipartimento di Fisica, Universita della Calabria, I-87036 Cosenza (Italy)</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-20</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">305</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013DPS....4531107R"> <span id="translatedtitle">Modeling <span class="hlt">Solar</span> <span class="hlt">Wind</span> Mass-Loading Due to Cometary Dust</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Collisionless mass-loading was first discussed to describe interactions between the <span class="hlt">solar</span> <span class="hlt">wind</span> and cometary atmospheres. Recent observations have led to an increased interest in coronal mass-loading due to sun-grazing comets and collisional debris by sunward-migrating interplanetary dust particles. Using three-dimensional MHD simulations with the Block-Adaptive-Tree-Solarwind-Roe-Upwind-Scheme (BATS-R-US) we have shown the impact on the <span class="hlt">solar</span> <span class="hlt">wind</span> from abrupt mass-loading in the coronal region. We also use the model as an application for a mass-loaded coronal <span class="hlt">wind</span> due to a cometary source, which helps predict the impacts on <span class="hlt">solar</span> <span class="hlt">wind</span> acceleration and composition from past and upcoming sungrazing comets.</p> <div class="credits"> <p class="dwt_author">Rasca, Anthony; Horanyi, M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-10-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">306</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013ApJ...769..111G"> <span id="translatedtitle">The Yaglom Law in the Expanding <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Gogoberidze, G.; Perri, S.; Carbone, V.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">307</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2006AGUFMSH11B..06V"> <span id="translatedtitle">Coronal heating and <span class="hlt">solar</span> <span class="hlt">wind</span> acceleration by turbulence</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Observations such as Spartan and SOHO UVCS have challenged ideas for the acceleration of the <span class="hlt">solar</span> <span class="hlt">wind</span> by constraining models to produce >1.5 Million K protons, several hundred km~s-1 radial outflows, and >700 km~s-1 terminal speeds in the <span class="hlt">wind</span> emanating from polar coronal holes, with coronal electrons remaining cooler than protons. Observed properties of the <span class="hlt">solar</span> <span class="hlt">wind</span> at 1AU and by Ulysses provide additional constraints on these models. It was recognized some time ago that these conditions probably require adding internal energy in sufficient quantities at altitudes <1.5 R_\\odot, but the origin of this energy and its method of transport and conversion to heat have remained unclear. The involvement of turbulence in this process was suggested some time ago, but various issues regarding the physics of cascade and dissipation have persisted and a <span class="hlt">wind</span> model compatible with magnetohydrodynamic theories of turbulence, including the physics of low frequency anisotropic cascade, has not yet been presented to our knowledge. Here we suggest some simplifications and assumptions that allow a self-consistent treatment of the <span class="hlt">solar</span> <span class="hlt">wind</span> acceleration problem. Numerical implementation of the coupled <span class="hlt">solar</span> <span class="hlt">wind</span>- turbulence equations is described, and computations for a super-radially expanding coronal hole show results for <span class="hlt">wind</span> speed, temperature, density, and cross helicity profiles that are promising in comparison with known observational constraints.</p> <div class="credits"> <p class="dwt_author">Verdini, A.; Velli, M.; Matthaeus, W. H.</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">308</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2011AGUFMSM54B..01D"> <span id="translatedtitle">Evolution of Coronal Holes with the <span class="hlt">Solar</span> Cycle: Implications for the <span class="hlt">Solar</span> <span class="hlt">Wind</span> at Earth</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The two main sources of space weather are coronal mass ejections (CMEs) and high speed <span class="hlt">solar</span> <span class="hlt">wind</span> streams, both of which vary with the <span class="hlt">solar</span> activity cycle. Fast CMEs with strong southward fields are responsible for the most intense geomagnetic storms. Because the CME rate and speed follows the <span class="hlt">solar</span> cycle, i.e. CMEs are more frequent and on average faster near <span class="hlt">solar</span> maximum, strong and short-duration geomagnetic storms are prevalent during times of high <span class="hlt">solar</span> activity. High speed <span class="hlt">solar</span> <span class="hlt">wind</span> streams emanating from low-latitude coronal holes at the Sun can also drive weak to moderate but long-duration geomagnetic storms. This kind of storms are more common during the declining phase of the <span class="hlt">solar</span> cycle, when coronal holes at low latitudes tend to be large in size and long-lived. In this paper, we will focus on high speed <span class="hlt">solar</span> <span class="hlt">wind</span> streams and their <span class="hlt">solar</span> sources. We will show how the distribution of coronal holes at the Sun affects the <span class="hlt">solar</span> <span class="hlt">wind</span> speeds seen at Earth and will discuss the importance of the <span class="hlt">solar</span> polar magnetic fields for coronal holes near <span class="hlt">solar</span> minimum, and particularly during recent minima. The past <span class="hlt">solar</span> minimum and early phase of <span class="hlt">solar</span> cycle 24 were characterized by low magnetic activity and weak polar magnetic fields. This magnetic configuration gave rise to small polar coronal holes and allowed large, low- to mid-latitude coronal holes to survive during times of very low <span class="hlt">solar</span> activity, resulting in <span class="hlt">solar</span> <span class="hlt">wind</span> properties markedly different from the previous minima during the Space Age.</p> <div class="credits"> <p class="dwt_author">de Toma, G.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">309</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/servlets/purl/419263"> <span id="translatedtitle">Ulysses <span class="hlt">solar</span> <span class="hlt">wind</span> plasma observations at high latitudes</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Ulysses reached its peak northerly heliolatitude of 80.2{degrees}N on July 31, 1995, and now is moving towards aphelion at 5.41 AU which it will reach in May, 1998. We summarize measurements from the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma experiment, SWOOPS, emphasizing northern hemispheric observations but also providing southern and equatorial results for comparison. The <span class="hlt">solar</span> <span class="hlt">wind</span> momentum flux during Ulysses` fast pole-to- pole transit at <span class="hlt">solar</span> minimum was significantly higher over the poles than at near-equatorial latitudes, suggesting a non-circular cross section for the heliosphere. Furthermore, modest asymmetries in the <span class="hlt">wind</span> speed, density, and mass flux were observed between the two hemispheres during the fast latitude scan. The <span class="hlt">solar</span> <span class="hlt">wind</span> was faster and less dense in the north than in the south. These asymmetries persist in the most recent high- and mid-latitude data but are less pronounced. As of July 1, 1996 the northern fast <span class="hlt">solar</span> <span class="hlt">wind</span> has lacked any strong stream interactions or shocks and, although a comprehensive search has not yet been made, no CMEs have yet been identified during this interval. On the other hand, Alfv{acute e}nic, compressional, and pressure balanced features are abundant at high latitudes. The most recent data, at 4 AU and 32{degrees}N, has begun to show the effects of <span class="hlt">solar</span> rotation modulated features in the form of recurrent compressed regions.</p> <div class="credits"> <p class="dwt_author">Riley, P.; Bame, S.J.; Barraclough, B.L. [and others</p> <p class="dwt_publisher"></p> <p class="publishDate">1996-10-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">310</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1999GMS...109..143P"> <span id="translatedtitle">A multi-spacecraft study of <span class="hlt">solar</span> <span class="hlt">wind</span> structure at 1 AU</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Studies of the correlations between <span class="hlt">solar</span> <span class="hlt">wind</span> parameters observed at different spacecraft have two complementary foci. The recent interest in space weather prediction and the launch of ACE as a real-time <span class="hlt">solar</span> <span class="hlt">wind</span> monitor have precipitated studies on how well such monitors actually predict <span class="hlt">solar</span> <span class="hlt">wind</span> conditions at Earth. Studies of magnetospheric response to <span class="hlt">solar</span> <span class="hlt">wind</span> activity generally assume 100% correlation between the <span class="hlt">solar</span> <span class="hlt">wind</span> observed at the monitor, wherever it may be, and the <span class="hlt">solar</span> <span class="hlt">wind</span> affecting the Earth environment. The second focus is on the intrinsic scale lengths of plasma variation in the <span class="hlt">solar</span> <span class="hlt">wind</span>. These lengths may provide information on the scale sizes of <span class="hlt">solar</span> <span class="hlt">wind</span> source regions and/or interaction lengths for the propagating <span class="hlt">solar</span> <span class="hlt">wind</span>. Also, an examination of the lags which give the best correlations shows that average front normals are neither radial nor perpendicular to the magnetic field, but are roughly halfway between.</p> <div class="credits"> <p class="dwt_author">Paularena, K. I.; Richardson, J. D.; Dashevskiy, F.; Zastenker, G. N.; Dalin, P. A.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">311</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2002EGSGA..27.2004S"> <span id="translatedtitle">Results From The Genesis Autonomous <span class="hlt">Solar</span> <span class="hlt">Wind</span> Regime Algorithm</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Launched on August 8, 2001, the NASA Genesis mission is now collecting samples of the <span class="hlt">solar</span> <span class="hlt">wind</span> in various materials, and will return those samples to Earth for analysis in 2004. A primary science goal of Genesis is the determination of the elemental and isotopic composition of the <span class="hlt">solar</span> atmosphere from the <span class="hlt">solar</span> <span class="hlt">wind</span> material returned. Because the <span class="hlt">solar</span> <span class="hlt">wind</span> itself is known to exhibit compositional variations across dif- ferent types of <span class="hlt">solar</span> <span class="hlt">wind</span> flows, Genesis exposes different collectors to <span class="hlt">solar</span> <span class="hlt">wind</span> originating from three flow types: coronal hole (CH), coronal mass ejection (CME), and interstream (IS) flows. Flow types are identified using in situ measurements of so- lar <span class="hlt">wind</span> ions and electrons from electrostatic analyzers carried by Genesis. The flow regime selection algorithm and subsequent collector deployment on Genesis act au- tonomously. The algorithm takes into account the proton speed, proton temperature, alpha particle abundance, and the presence of counter-streaming suprathermal elec- trons as determined onboard. Autonomous determination of counter-streaming elec- trons is novel, as is the simultaneous utilization of electron information and ion mo- ments in logic that autonomously controls the science payload. Results to date show that <span class="hlt">solar</span> <span class="hlt">wind</span> has recently been dominated by IS flow with frequent CMEs. Between 24 August 2001 and 31 December 2001, the Genesis algo- rithm categorized the flow to be 67 % IS, 26% CME, and 7% CH. Counter-streaming electrons signatures were identified for 23% of that total time interval. The Genesis onboard shock detector was set seventeen times, and nearly all were verified to be ac- tual CME-associated shocks. We will present the results of the autonomous algorithm obtained up to the time of the EGS meeting, as well as our assessment of the validity of those onboard results.</p> <div class="credits"> <p class="dwt_author">Steinberg, J. T.; Barraclough, B. L.; Dors, E. E.; Neugebauer, M.; Wiens, R. C.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">312</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19960021392&hterms=opposing+views&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2528opposing%2Bviews%2529"> <span id="translatedtitle">SWICS/Ulysses and MASS/<span class="hlt">wind</span> observations of <span class="hlt">solar</span> <span class="hlt">wind</span> sulfur charge states</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">As Ulysses journeys from the southern to the northern <span class="hlt">solar</span> pole, the newly launched <span class="hlt">Wind</span> spacecraft is monitoring the <span class="hlt">solar</span> <span class="hlt">wind</span> near 1 AU, slightly upstream of the Earth. Different <span class="hlt">solar</span> <span class="hlt">wind</span> structures pass over both spacecraft as coronal holes and other features rotate in and out of view. Ulysses and <span class="hlt">Wind</span> are presently on opposing sides of the sun allowing us to monitor these streams for extended periods of time. Composition measurements made by instruments on both spacecraft provide information concerning the evolution and properties of these structures. We have combined data from the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Ion Composition Spectrometer (SWICS) on Ulysses and the high mass resolution spectrometer (MASS) on <span class="hlt">Wind</span> to determine the charge state distribution of sulfur in the <span class="hlt">solar</span> <span class="hlt">wind</span>. Both instruments employ electrostatic deflection with time-of-flight measurement. The high mass resolution of the MASS instrument (M/Delta-M approximately 100) allows sulfur to be isolated easily while the stepping energy/charge selection provides charge state information. SWICS measurements allow the unique identification of heavy ions by their mass and mass/charge with resolutions of M/Delta-M approximately 3 and M/q/Delta(M/q) approximately 20. The two instruments complement each other nicely in that MASS has the greater mass resolution while SWICS has the better mass/charge resolution and better statistics.</p> <div class="credits"> <p class="dwt_author">Cohen, C. M. S.; Galvin, A. B.; Hamilton, D. C.; Gloeckler, G.; Geiss, J.; Bochsler, P.</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">313</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20000072880&hterms=south+pole+solar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsouth%2Bpole%2Bsolar"> <span id="translatedtitle">Fine Structure in the Corona and <span class="hlt">Solar</span> <span class="hlt">Wind</span> at High Heliographic Latitudes at <span class="hlt">Solar</span> Maximum</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Microstreams and pressure balance structures in fast <span class="hlt">solar</span> <span class="hlt">wind</span> were more easily detected at Ulysses at 2.2 AU over the poles than at Helios at 0.3 AU. This is because <span class="hlt">solar</span> rotation brings sources of fast <span class="hlt">solar</span> <span class="hlt">wind</span> beneath sources of slow <span class="hlt">solar</span> <span class="hlt">wind</span> at a rate that depends on latitude, for the same size features. Dynamic interaction between the fast and slow <span class="hlt">wind</span> tends to mix the flows and make features more difficult to detect with increasing distance from the Sun. A given sized feature takes proportionally longer to pass a longitude when it is at 80 degrees latitude than when it is at the equator. At <span class="hlt">solar</span> maximum, Ulysses will mainly be sampling <span class="hlt">solar</span> <span class="hlt">wind</span> coming from above streamers and from near streamers. The data will provide information on fine structure at the tops of streamers - the stalks - and on the source of slow <span class="hlt">solar</span> <span class="hlt">wind</span>, The visibility of the boundaries between fast and slow <span class="hlt">wind</span> and of the stalk will increase with increasing latitude. We will present quantitative calculations of the visibility of various sized features, with various differences in flow speed, at the location of Ulysses when it is over the south (in 2000) and north (in 2001) polar regions of the Sun.</p> <div class="credits"> <p class="dwt_author">Suess. S. T.; Poletto, G.</p> <p class="dwt_publisher"></p> <p class="publishDate">2000-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">314</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20010021227&hterms=south+pole+solar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsouth%2Bpole%2Bsolar"> <span id="translatedtitle">Fine Structure in the Corona and <span class="hlt">Solar</span> <span class="hlt">Wind</span> at High Heliographic Latitudes at <span class="hlt">Solar</span> Maximum</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Microstreams and pressure balance structures in fast <span class="hlt">solar</span> <span class="hlt">wind</span> were more easily detected at Ulysses at 2.2 AU over the poles than at Helios at 0.3 AU. This is because <span class="hlt">solar</span> rotation brings sources of fast <span class="hlt">solar</span> <span class="hlt">wind</span> beneath sources of slow <span class="hlt">solar</span> <span class="hlt">wind</span> at a rate that depends on latitude, for the same size features. Dynamic interaction between the fast and slow <span class="hlt">wind</span> tends to mix the flows and make features more difficult to detect with increasing distance from the Sun. A given sized feature takes proportionally longer to pass a longitude when it is at 80 degrees latitude than when it is at the equator. At <span class="hlt">solar</span> maximum, Ulysses will mainly be sampling <span class="hlt">solar</span> <span class="hlt">wind</span> coming from above streamers and from near streamers. The data will provide information on fine structure at the tops of streamers - the stalks - and on the source of slow <span class="hlt">solar</span> <span class="hlt">wind</span>. The visibility of the boundaries between fast and slow <span class="hlt">wind</span> and of the stalk will increase with increasing latitude. I will present quantitative calculations of the visibility of various sized features, with various differences in flow speed, at the location of Ulysses when it is over the south (in 2000) and north (in 2001) polar regions of the Sun.</p> <div class="credits"> <p class="dwt_author">Suess, S. T.; Rose, M. Franklin (Technical Monitor)</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">315</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1994PhDT........87T"> <span id="translatedtitle">Application of AN Empirically-Derived Polytropic Index for the <span class="hlt">Solar</span> <span class="hlt">Wind</span> to a <span class="hlt">Solar</span> <span class="hlt">Wind</span> Shock Propagation Model.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Data from the Helios 1 spacecraft have been used to determine an empirical value for the polytropic index for the free-streaming <span class="hlt">solar</span> <span class="hlt">wind</span>. Application of this non-adiabatic polytropic index to a two-dimensional <span class="hlt">solar</span> <span class="hlt">wind</span> computer model to simulate the effects of thermal heat conduction has been investigated. The current project involves the insertion of this empirically-derived polytropic index into a magnetohydrodynamic model of <span class="hlt">solar</span> <span class="hlt">wind</span> propagation. This computer model is used to predict the time for shocks originating at the Sun to travel to Earth. This information is important for the protection of Earth-orbiting satellites. The model is a two and one-half-dimensional numerical code that solves the magnetohydrodynamic equations using the two-step Lax -Wendroff scheme. The shock jump ratios of the plasma parameters are determined using the Rankine-Hugoniot relations. In addition, the shock model requires a representative background <span class="hlt">solar</span> <span class="hlt">wind</span> as an initial condition. The original background <span class="hlt">solar</span> <span class="hlt">wind</span> is similar to the results obtained by Parker (Astrophysical Journal, 1958) and Weber and Davis (Astrophysical Journal, 1967). Changes to this initial condition are made by applying the non-adiabatic polytropic index to a three-dimensional, steady-state, magnetohydrodynamic model of the <span class="hlt">solar</span> <span class="hlt">wind</span>. The adjustments to the steady -state model produce a background <span class="hlt">solar</span> <span class="hlt">wind</span> that compares well to Helios 1 data. This new background <span class="hlt">solar</span> <span class="hlt">wind</span> is used as the initial condition for the 2D shock model. The shock model is also adjusted to include the effects of heat conduction. Comparison of model results with observational data indicate that these changes produce average transit times that are only 45 minutes late. Before the changes to the 2D shock model and its initial <span class="hlt">solar</span> <span class="hlt">wind</span> condition were made, the average prediction time was two hours late. Adjusting the shock model to include the effects of heat conduction but using the original background <span class="hlt">solar</span> <span class="hlt">wind</span> produces an average transit time that is less than one hour early. A few specific events are discussed in greater detail.</p> <div class="credits"> <p class="dwt_author">Totten, Tracy Lynn</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">316</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.gpo.gov:80/fdsys/pkg/FR-2012-08-13/pdf/2012-19780.pdf"> <span id="translatedtitle">77 FR 48138 - Topaz <span class="hlt">Solar</span> Farms LLC; High Plains Ranch II, LLC; Bethel <span class="hlt">Wind</span> Energy LLC; Rippey <span class="hlt">Wind</span> Energy LLC...</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013</a></p> <p class="result-summary">...EG12-66-000; EG12- 67-000; EG12-68-000; EG12-69-000] Topaz <span class="hlt">Solar</span> Farms LLC; High Plains Ranch II, LLC; Bethel <span class="hlt">Wind</span> Energy LLC; Rippey <span class="hlt">Wind</span> Energy LLC; Pacific <span class="hlt">Wind</span>, LLC; Colorado Highlands <span class="hlt">Wind</span>, LLC; Shooting Star <span class="hlt">Wind</span> Project,...</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate">2012-08-13</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">317</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/56044301"> <span id="translatedtitle"><span class="hlt">Solar</span>-terrestrial relations: Flare and <span class="hlt">solar</span> <span class="hlt">wind</span> effects</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The existence of <span class="hlt">solar</span> terrestrial relations is clearly shown during <span class="hlt">solar</span> flare events. During these catastrophic events the enhanced flux of XUV <span class="hlt">solar</span> radiation as well as the sudden outburst of energetic <span class="hlt">solar</span> cosmic ray particles induce a series of well identified effects in the Earth's magnetic field, in the terrestrial ionosphere and in the upper atmosphere. These geophysical effects</p> <div class="credits"> <p class="dwt_author">J. Lemaire</p> <p class="dwt_publisher"></p> <p class="publishDate">1989-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">318</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20060039430&hterms=broadening&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2522broadening%2522"> <span id="translatedtitle">Latitudinal Variation of <span class="hlt">Solar</span> <span class="hlt">Wind</span> Speed and Mass Flux in the Acceleration Region of the <span class="hlt">Solar</span> <span class="hlt">Wind</span> during <span class="hlt">Solar</span> Minimum Inferred from Spectral Broadening measurements</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">In this paper, we use an aggregate of S-band 2.3 GHz (13 cm) spectral broadening observations conducted during <span class="hlt">solar</span> minimum conditions by the Mariner 4, Pioneer 10, Mariner 10, Helios 1 & 2 and Viking spacecraft to infer the first measurements of the latitudinal variation of <span class="hlt">solar</span> <span class="hlt">wind</span> speed and mass flux in the acceleration region of the <span class="hlt">solar</span> <span class="hlt">wind</span> at 3-8 R(sub o).</p> <div class="credits"> <p class="dwt_author">Woo, R.; Goldstein, R.</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">319</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19730013022&hterms=Peterson&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DC.%2BPeterson"> <span id="translatedtitle"><span class="hlt">Solar</span> cosmic ray, <span class="hlt">solar</span> <span class="hlt">wind</span>, <span class="hlt">solar</span> flare, and neutron albedo measurements, part C</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">All mineral detectors exposed on Apollo 16 had high surface track densities probably produced by a <span class="hlt">solar</span> flare that occurred during the mission. The heavy ions followed a power law spectrum with exponent approximately 3 down to approximately 200 KeV/nucleon. The abundance of low-energy particle tracks observed in this flare may explain the high track densities observed in lunar dust grains. Pristine heavy-particle tracks in feldspar give long tracks. Shallow pits similar to those expected from extremely heavy <span class="hlt">solar</span> <span class="hlt">wind</span> ions were observed in about the expected number. Initial results give a low apparent value of neutron albedo relative to theory.</p> <div class="credits"> <p class="dwt_author">Burnett, D.; Hohenberg, C.; Maurette, M.; Monnin, M.; Walker, R.; Wollum, D.</p> <p class="dwt_publisher"></p> <p class="publishDate">1972-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">320</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19990056503&hterms=stream+composition&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dstream%2Bcomposition"> <span id="translatedtitle">Charge state composition in coronal hole and CME related <span class="hlt">solar</span> <span class="hlt">wind</span>: Latitudinal variations observed by Ulysses and <span class="hlt">WIND</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Iron charge states in recurrent coronal hole-associated <span class="hlt">solar</span> <span class="hlt">wind</span> flows are obtained in the ecliptic by <span class="hlt">WIND</span>/SMS, while measurements of iron and silicon from the polar coronal holes are available from Ulysses/SWICS. Ulysses/SWICS also provides ion composition of coronal mass ejection (CME)-related <span class="hlt">solar</span> <span class="hlt">wind</span>. Both coronal hole-associated and CME-related <span class="hlt">solar</span> <span class="hlt">wind</span> charge charges show heliographic latitudinal variations.</p> <div class="credits"> <p class="dwt_author">Galvin, A. B.; Gloeckler, G.</p> <p class="dwt_publisher"></p> <p class="publishDate">1997-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_15");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return 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id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_16");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a onClick='return showDiv("page_5");' href="#">5</a> <a onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a onClick='return showDiv("page_9");' href="#">9</a> <a onClick='return showDiv("page_10");' href="#">10</a> <a onClick='return showDiv("page_11");' href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a style="font-weight: bold;">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_18");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">321</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/17677760"> <span id="translatedtitle">Self-similar signature of the active <span class="hlt">solar</span> corona within the inertial range of <span class="hlt">solar-wind</span> turbulence.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">We quantify the scaling of magnetic energy density in the inertial range of <span class="hlt">solar-wind</span> turbulence seen in situ at 1 AU with respect to <span class="hlt">solar</span> activity. At <span class="hlt">solar</span> maximum, when the coronal magnetic field is dynamic and topologically complex, we find self-similar scaling in the <span class="hlt">solar</span> <span class="hlt">wind</span>, whereas at <span class="hlt">solar</span> minimum, when the coronal fields are more ordered, we find multifractality. This quantifies the <span class="hlt">solar-wind</span> signature that is of direct coronal origin and distinguishes it from that of local MHD turbulence, with quantitative implications for coronal heating of the <span class="hlt">solar</span> <span class="hlt">wind</span>. PMID:17677760</p> <div class="credits"> <p class="dwt_author">Kiyani, K; Chapman, S C; Hnat, B; Nicol, R M</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-05-25</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">322</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19930049627&hterms=charge+separation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcharge%2Bseparation"> <span id="translatedtitle">Ions with low charges in the <span class="hlt">solar</span> <span class="hlt">wind</span> as measured by SWICS on board Ulysses. [<span class="hlt">Solar</span> <span class="hlt">Wind</span> Ion Composition Spectrometer</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">We present new data on rare ions in the <span class="hlt">solar</span> <span class="hlt">wind</span>. Using the Ulysses-SWICS instrument with its very low background we have searched for low-charge ions during a 6-d period of low-speed <span class="hlt">solar</span> <span class="hlt">wind</span> and established sensitive upper limits for many species. In the <span class="hlt">solar</span> <span class="hlt">wind</span>, we found He(1+)/He(2+) of less than 5 x 10 exp -4. This result and the charge state distributions of heavier elements indicate that all components of the investigated ion population went through a regular coronal expansion and experienced the typical electron temperatures of 1 to 2 million Kelvin. We argue that the virtual absence of low-charge ions demonstrates a very low level of nonsolar contamination in the source region of the <span class="hlt">solar</span> <span class="hlt">wind</span> sample we studied. Since this sample showed the FlP effect typical for low-speed <span class="hlt">solar</span> <span class="hlt">wind</span>, i.e., an enhancement in the abundances of elements with low first ionization potential, we conclude that this enhancement was caused by an ion-atom separation mechanism operating near the <span class="hlt">solar</span> surface and not by foreign material in the corona.</p> <div class="credits"> <p class="dwt_author">Geiss, J.; Ogilvie, K. W.; Von Steiger, R.; Mall, U.; Gloeckler, G.; Galvin, A. B.; Ipavich, F.; Wilken, B.; Gliem, F.</p> <p class="dwt_publisher"></p> <p class="publishDate">1992-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">323</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/18063784"> <span id="translatedtitle">Chromospheric alfvenic waves strong enough to power the <span class="hlt">solar</span> <span class="hlt">wind</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Alfvén waves have been invoked as a possible mechanism for the heating of the Sun's outer atmosphere, or corona, to millions of degrees and for the acceleration of the <span class="hlt">solar</span> <span class="hlt">wind</span> to hundreds of kilometers per second. However, Alfvén waves of sufficient strength have not been unambiguously observed in the <span class="hlt">solar</span> atmosphere. We used images of high temporal and spatial resolution obtained with the <span class="hlt">Solar</span> Optical Telescope onboard the Japanese Hinode satellite to reveal that the chromosphere, the region sandwiched between the <span class="hlt">solar</span> surface and the corona, is permeated by Alfvén waves with strong amplitudes on the order of 10 to 25 kilometers per second and periods of 100 to 500 seconds. Estimates of the energy flux carried by these waves and comparisons with advanced radiative magnetohydrodynamic simulations indicate that such Alfvén waves are energetic enough to accelerate the <span class="hlt">solar</span> <span class="hlt">wind</span> and possibly to heat the quiet corona. PMID:18063784</p> <div class="credits"> <p class="dwt_author">De Pontieu, B; McIntosh, S W; Carlsson, M; Hansteen, V H; Tarbell, T D; Schrijver, C J; Title, A M; Shine, R A; Tsuneta, S; Katsukawa, Y; Ichimoto, K; Suematsu, Y; Shimizu, T; Nagata, S</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">324</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/22039263"> <span id="translatedtitle">THE TURBULENT CASCADE AND PROTON HEATING IN THE <span class="hlt">SOLAR</span> <span class="hlt">WIND</span> DURING <span class="hlt">SOLAR</span> MINIMUM</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">The recently protracted <span class="hlt">solar</span> minimum provided years of interplanetary data that were largely absent in any association with observed large-scale transient behavior on the Sun. With large-scale shear at 1 AU generally isolated to corotating interaction regions, it is reasonable to ask whether the <span class="hlt">solar</span> <span class="hlt">wind</span> is significantly turbulent at this time. We perform a series of third-moment analyses using data from the Advanced Composition Explorer. We show that the <span class="hlt">solar</span> <span class="hlt">wind</span> at 1 AU is just as turbulent as at any other time in the <span class="hlt">solar</span> cycle. Specifically, the turbulent cascade of energy scales in the same manner proportional to the product of <span class="hlt">wind</span> speed and temperature. Energy cascade rates during <span class="hlt">solar</span> minimum average a factor of 2-4 higher than during <span class="hlt">solar</span> maximum, but we contend that this is likely the result of having a different admixture of high-latitude sources.</p> <div class="credits"> <p class="dwt_author">Coburn, Jesse T.; Smith, Charles W.; Vasquez, Bernard J. [Physics Department and Space Science Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH (United States); Stawarz, Joshua E. [Department of Astrophysical and Planetary Sciences, University of Colorado at Boulder, Boulder, CA (United States); Forman, Miriam A., E-mail: jtu46@wildcats.unh.edu, E-mail: Charles.Smith@unh.edu, E-mail: Bernie.Vasquez@unh.edu, E-mail: Joshua.Stawarz@Colorado.edu, E-mail: Miriam.Forman@sunysb.edu [Department of Physics and Astronomy, State University of New York at Stony Brook, Stony Brook, NY (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-08-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">325</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AGUMA..SH31B03M"> <span id="translatedtitle">Determining the Coronal Origins of the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Using Remote Sensing and In Situ Observations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We study the origin and evolution of the <span class="hlt">solar</span> <span class="hlt">wind</span> by characterizing the physical properties of the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma with multi-spacecraft (Hinode, SDO, SOHO, STEREO, ACE, Ulysses, <span class="hlt">WIND</span>) and ground-based (MLSO, MWO, NSO, WSO) observations. We discuss the results for the fast <span class="hlt">solar</span> <span class="hlt">wind</span> from polar and low-latitude coronal-hole <span class="hlt">wind</span> streams and for the slow <span class="hlt">wind</span> from coronal-streamer <span class="hlt">wind</span> streams. We also compare the characteristics of these <span class="hlt">wind</span> streams with results from the previous <span class="hlt">solar</span> cycle. This work is supported by NASA grant NNX10AQ58G to the Smithsonian Astrophysical Observatory.</p> <div class="credits"> <p class="dwt_author">Miralles, Mari Paz</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">326</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AGUSMSH31B..03M"> <span id="translatedtitle">Determining the Coronal Origins of the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Using Remote Sensing and In Situ Observations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We study the origin and evolution of the <span class="hlt">solar</span> <span class="hlt">wind</span> by characterizing the physical properties of the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma with multi-spacecraft (Hinode, SDO, SOHO, STEREO, ACE, Ulysses, <span class="hlt">WIND</span>) and ground-based (MLSO, MWO, NSO, WSO) observations. We discuss the results for the fast <span class="hlt">solar</span> <span class="hlt">wind</span> from polar and low-latitude coronal-hole <span class="hlt">wind</span> streams and for the slow <span class="hlt">wind</span> from coronal-streamer <span class="hlt">wind</span> streams. We also compare the characteristics of these <span class="hlt">wind</span> streams with results from the previous <span class="hlt">solar</span> cycle.</p> <div class="credits"> <p class="dwt_author">Miralles, M. P.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">327</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19900044783&hterms=johannes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Djohannes"> <span id="translatedtitle">The abundances of elements and isotopes in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary"><span class="hlt">Solar</span> <span class="hlt">wind</span> abundances have now been measured for eleven elements and the isotopes of the noble gases. Aside from <span class="hlt">solar</span> <span class="hlt">wind</span> protons and alpha particles, which have been studied extensively since the 1960's, information for heavier elements is limited. Nevertheless, two effects stand out. First is the enrichment of abundances of elements with low first ionization potential (FIP), most likely the combined result of an atom-ion separation process in the upper chromosphere, and a marginal coupling of low-charge-state heavy ions to protons and alphas during the acceleration of the <span class="hlt">solar</span> <span class="hlt">wind</span>. Second, there is variability in the <span class="hlt">solar</span> <span class="hlt">wind</span> composition over a whole range of time scales. Recent measurements carried out in the earth's magnetosheath during times that included high-speed coronal-hole-associated flows indicate a significantly lower overabundance of low FIP elements. Given the fact that the He/H ratio is remarkably constant in the coronal hole <span class="hlt">solar</span> <span class="hlt">wind</span>, this result suggests that both enrichment and variability are reduced in such flows.</p> <div class="credits"> <p class="dwt_author">Gloeckler, George; Geiss, Johannes</p> <p class="dwt_publisher"></p> <p class="publishDate">1989-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">328</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/22133859"> <span id="translatedtitle">COLLISIONLESS DAMPING AT ELECTRON SCALES IN <span class="hlt">SOLAR</span> <span class="hlt">WIND</span> TURBULENCE</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">The dissipation of turbulence in the weakly collisional <span class="hlt">solar</span> <span class="hlt">wind</span> plasma is governed by unknown kinetic mechanisms. Two candidates have been suggested to play an important role in the dissipation, collisionless damping via wave-particle interactions and dissipation in small-scale current sheets. High resolution spacecraft measurements of the turbulent magnetic energy spectrum provide important constraints on the dissipation mechanism. The limitations of popular fluid and hybrid numerical schemes for simulation of the dissipation of <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence are discussed, and instead a three-dimensional kinetic approach is recommended. We present a three-dimensional nonlinear gyrokinetic simulation of <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence at electron scales that quantitatively reproduces the exponential form of the turbulent magnetic energy spectrum measured in the <span class="hlt">solar</span> <span class="hlt">wind</span>. A weakened cascade model that accounts for nonlocal interactions and collisionless Landau damping also quantitatively agrees with the observed exponential form. These results establish that a turbulent cascade of kinetic Alfven waves that is terminated by collisionless Landau damping is sufficient to explain the observed magnetic energy spectrum in the dissipation range of <span class="hlt">solar</span> <span class="hlt">wind</span> turbulence.</p> <div class="credits"> <p class="dwt_author">TenBarge, J. M.; Howes, G. G. [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States); Dorland, W., E-mail: jason-tenbarge@uiowa.edu [Department of Physics, University of Maryland, College Park, MA 20742-3511 (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-09-10</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">329</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014EGUGA..16.9519L"> <span id="translatedtitle">Influence of interplanetary <span class="hlt">solar</span> <span class="hlt">wind</span> sector polarity on the ionosphere</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Knowledge of <span class="hlt">solar</span> sector polarity effects on the ionosphere may provide some clues in understanding of the ionospheric day-to-day variability. A <span class="hlt">solar</span>-terrestrial connection ranging from <span class="hlt">solar</span> sector boundary (SB) crossings, geomagnetic disturbance and ionospheric perturbations has been demonstrated. The increases in interplanetary <span class="hlt">solar</span> <span class="hlt">wind</span> speed within three days are seen after SB crossings, while the decreases in <span class="hlt">solar</span> <span class="hlt">wind</span> dynamic pressure and magnetic field intensity immediately after SB crossings are confirmed by the superposed epoch analysis results. Furthermore, the interplanetary magnetic field (IMF) Bz component turns from northward to southward in March equinox and June solstice as the Earth passes from a <span class="hlt">solar</span> sector of outward to inward directed magnetic fields, whereas the reverse situation occurs for the transition from toward to away sectors. The F2 region critical frequency (foF2) covering about four <span class="hlt">solar</span> cycles and total electron content (TEC) during 1998-2011 are utilized to extract the related information, revealing that they are not modified significantly and vary within the range of 15% on average. The responses of the ionospheric TEC to SB crossings exhibit complex temporal and spatial variations and have strong dependencies on season, latitude, and <span class="hlt">solar</span> cycle. This effect is more appreciable in equinoctial months than in solstitial months, which is mainly caused by larger southward Bz components in equinox. In September equinox, latitudinal profile of relative variations of foF2 at noon is featured by depressions at high latitudes and enhancements in low-equatorial latitudes during IMF away sectors. The negative phase of foF2 is delayed at <span class="hlt">solar</span> minimum relative to it during other parts of <span class="hlt">solar</span> cycle, which might be associated with the difference in longevity of major interplanetary <span class="hlt">solar</span> <span class="hlt">wind</span> drivers perturbing the Earth's environment in different phases of <span class="hlt">solar</span> cycle.</p> <div class="credits"> <p class="dwt_author">liu, jing</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">330</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/21190105"> <span id="translatedtitle">Application of grazing incidence x-ray fluorescence technique to discriminate and quantify implanted <span class="hlt">solar</span> <span class="hlt">wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">NASA launched the Genesis return mission to obtain pristine <span class="hlt">solar</span> <span class="hlt">wind</span> samples in order to better understand <span class="hlt">solar</span> <span class="hlt">wind</span> mechanics, <span class="hlt">solar</span> physics, and <span class="hlt">solar</span> system evolution. Unfortunately, the probe crash-landed shattering the collector plates necessitating the application of a grazing incidence x-ray fluorescence technique. This nondestructive methodology differentiates the terrestrial contamination from the low concentration implanted <span class="hlt">solar</span> <span class="hlt">wind</span>. Using this technique, the elemental depth distribution is obtained resulting in the determination of absolute <span class="hlt">solar</span> <span class="hlt">wind</span> elemental abundance. We describe this application and present the <span class="hlt">solar</span> <span class="hlt">wind</span> Fe concentration determination as an example.</p> <div class="credits"> <p class="dwt_author">Kitts, K.; Choi, Y. [Department of Geology and Environment Geosciences, Northern Illinois University, Davis Hall 312, Normal Road, DeKalb, Illinois 60115 (United States); Eng, P. J.; Ghose, S. K.; Sutton, S. R. [Department of Geophysical Sciences and Consortium for Advanced Radiation Sources, University of Chicago, Chicago, Illinois 60637 (United States); Rout, B. [Department of Physics, University of North Texas, Denton, Texas 76203 (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-03-15</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">331</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014EGUGA..16.4727T"> <span id="translatedtitle">Parametric decay of Alfvén wave in the <span class="hlt">solar</span> <span class="hlt">wind</span> acceleration</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Large amplitude Alfvén waves are commonly observed in the <span class="hlt">solar</span> <span class="hlt">wind</span> and it is widely believed that these magnetic waves may contribute to the <span class="hlt">solar</span> <span class="hlt">wind</span> heating and acceleration through turbulent dissipation and ponderomotive force. In-situ observations show that a nonlinear cascade of Alfvén waves, mainly propagating outward, is taking place, and that it evolves with heliocentric distance. In spite of the well defined observational signatures, the evolution of such Alfvénic turbulence in the <span class="hlt">solar</span> <span class="hlt">wind</span> is still a matter under debate. Parametric decay of large amplitude Alfvén waves has been invoked as a possible driver of such evolution: the decay of an outward Alfvén wave into an inward one and, on the other hand, into a sound wave which naturally tends to steepen, provides the key ingredients for the onset of a turbulent cascade as well as for energy dissipation. In spite of many theoretical and numerical studies on the parametric decay instability, possible effects of the <span class="hlt">solar</span> <span class="hlt">wind</span> radial expansion have not yet been taken into account. However, the expansion of the underlying <span class="hlt">solar</span> atmosphere is an indiscernible element to the extent that the observed decrease in overall rms energies is well accounted for by expansion effects. We provide here a study on the onset and evolution of the parametric decay within the Accelerating Expanding Box model. This model takes into account the effects of the accelerating radial expansion of the <span class="hlt">solar</span> <span class="hlt">wind</span>, including the crossing of the critical Alfvén point, where wave amplitudes are expected to peak. The aim is to inspect if and in which manner the non-uniform radial expansion of the <span class="hlt">solar</span> <span class="hlt">wind</span> affects the growth and evolution of the instability itself and in which way it may affect the alfvénic spectrum at large heliocentric distances.</p> <div class="credits"> <p class="dwt_author">Tenerani, Anna; Velli, Marco</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">332</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008PhDT.......144G"> <span id="translatedtitle">A hybrid reconfigurable <span class="hlt">solar</span> and <span class="hlt">wind</span> energy system</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We study the feasibility of a novel hybrid <span class="hlt">solar-wind</span> hybrid system that shares most of its infrastructure and components. During periods of clear sunny days the system will generate electricity from the sun using a parabolic concentrator. The concentrator is formed by individual mirror elements and focuses the light onto high intensity vertical multi-junction (VMJ) cells. During periods of high <span class="hlt">wind</span> speeds and at night, the same concentrator setup will be reconfigured to channel the <span class="hlt">wind</span> into a <span class="hlt">wind</span> turbine which will be used to harness <span class="hlt">wind</span> energy. In this study we report on the feasibility of this type of <span class="hlt">solar/wind</span> hybrid energy system. The key mechanisms; optics, cooling mechanism of VMJ cells and air flow through the system were investigated using simulation tools. The results from these simulations, along with a simple economic analysis giving the levelized cost of energy for such a system are presented. An iterative method of design refinement based on the simulation results was used to work towards a prototype design. The levelized cost of the system achieved in the economic analysis shows the system to be a good alternative for a grid isolated site and could be used as a standalone system in regions of lower demand. The new approach to <span class="hlt">solar</span> <span class="hlt">wind</span> hybrid system reported herein will pave way for newer generation of hybrid systems that share common infrastructure in addition to the storage and distribution of energy.</p> <div class="credits"> <p class="dwt_author">Gadkari, Sagar A.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">333</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2010AGUFMSH11B1620K"> <span id="translatedtitle">The <span class="hlt">Solar</span> <span class="hlt">Wind</span> Electrons Alphas and Protons (SWEAP) Investigation for <span class="hlt">Solar</span> Probe Plus</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The NASA <span class="hlt">Solar</span> Probe Plus mission will be humanity’s first direct visit to the atmosphere of our Sun. The spacecraft will close to within nine <span class="hlt">solar</span> radii (about four million miles) of the <span class="hlt">solar</span> surface in order to observe the heating of the corona and the acceleration of the <span class="hlt">solar</span> <span class="hlt">wind</span> first hand. A key requirement for <span class="hlt">Solar</span> Probe Plus is the ability to make continuous, accurate, and fast measurements of the electrons and ionized helium (alpha-particles) and hydrogen (protons) that constitute the bulk of the <span class="hlt">solar</span> <span class="hlt">wind</span>. The <span class="hlt">Solar</span> <span class="hlt">Wind</span> Electrons Alphas and Protons (SWEAP) Investigation is a two-instrument suite that provides these observations. The purpose of this talk is to describe the science motivation for SWEAP, the instrument designs, and the expected data products. SWEAP consists of the <span class="hlt">Solar</span> Probe Cup (SPC) and the <span class="hlt">Solar</span> Probe Analyzers (SPAN). SWEAP measurements enable discovery and understanding of <span class="hlt">solar</span> <span class="hlt">wind</span> acceleration and formation, coronal and <span class="hlt">solar</span> <span class="hlt">wind</span> heating, high-energy particle acceleration, and the interaction between <span class="hlt">solar</span> <span class="hlt">wind</span> and the dust environment of the inner heliosphere. SPC is a Faraday Cup (FC) that looks at the Sun and measures ion and electron fluxes and flow angles as a function of energy. SPAN consists of an ion and electron electrostatic analyzer (ESA) on the ram side of SPP (SPAN-A) and an electron ESA on the anti-ram side (SPAN-B). SPAN-A and -B are rotated 90 degrees relative to one another so their broad FOV combine like the seams on a baseball to view the entire sky except for the region obscured by the heat shield. SWEAP data products include ion and electron velocity distribution functions with high energy and angular resolution at 0.5-16 Hz and flow angles and fluxes at 128 Hz. Continuous buffering provides triggered burst observations during shocks, reconnection events, and other transient structures with no changes to the instrument operating mode.</p> <div class="credits"> <p class="dwt_author">Kasper, J. C.; SWEAP Investigation Team</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">334</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2009AGUFMSH51B1272R"> <span id="translatedtitle">“Persistence” in <span class="hlt">Solar</span> <span class="hlt">Wind</span> Fluctuations: A Virtual Observatory Assisted Study</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The <span class="hlt">solar</span> <span class="hlt">wind</span> contains “fluctuations”--defined as any deviations from a uniform Parker spiral--that are very likely imprinted at the Sun, as well as others that are the result of nonlinear, often turbulent, processes. Near <span class="hlt">solar</span> minimum, many features persist for times as long as several <span class="hlt">solar</span> rotations. While this is well known and expected for quantities such as <span class="hlt">solar</span> <span class="hlt">wind</span> speed, where streams recur, we have found that at times unexpected quantities such as the normal component of the magnetic field show remarkable persistence from one <span class="hlt">solar</span> rotation to the next. To study this phenomenon, which will have consequences for what we consider to be turbulent fluctuations and on the predictability of <span class="hlt">solar</span> <span class="hlt">wind</span> input to the Earth, we have used data from STEREO, ACE, <span class="hlt">WIND</span>, and many other spacecraft to see what quantities persist and on what time scales. This preliminary investigation has been considerably aided by the easy access to data provided by Heliophysics Virtual Observatories (especially VSPO) and their links to CDAWeb, OMNIWeb, and other tools. This talk will illustrate the advantages of the various tools that now exist in the Heliophysics Data Environment, and indicate some areas where advances are still needed to fix existing problems.</p> <div class="credits"> <p class="dwt_author">Roberts, D.</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">335</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014SoPh..289..379S"> <span id="translatedtitle">Visibility-Graph Analysis of the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Velocity</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We analyze in situ measurements of the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity obtained by the Advanced Composition Explorer (ACE) and the Helios spacecraft during the years 1998 - 2012 and 1975 - 1983, respectively. The data mainly belong to <span class="hlt">solar</span> cycles 23 (1996 - 2008) and 21 (1976 - 1986). We used the directed horizontal-visibility-graph (DHVg) algorithm and estimated a graph functional, namely, the degree distance ( D), which is defined using the Kullback-Leibler divergence (KLD) to understand the time irreversibility of <span class="hlt">solar</span> <span class="hlt">wind</span> time-series. We estimated this degree-distance irreversibility parameter for these time-series at different phases of the <span class="hlt">solar</span> activity cycle. The irreversibility parameter was first established for known dynamical data and was then applied to <span class="hlt">solar</span> <span class="hlt">wind</span> velocity time-series. It is observed that irreversibility in <span class="hlt">solar</span> <span class="hlt">wind</span> velocity fluctuations show a similar behavior at 0.3 AU ( Helios data) and 1 AU (ACE data). Moreover, the fluctuations change over the phases of the activity cycle.</p> <div class="credits"> <p class="dwt_author">Suyal, Vinita; Prasad, Awadhesh; Singh, Harinder P.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">336</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014AAS...22440801D"> <span id="translatedtitle">Observing MHD Waves in the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Acceleration Region</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We have, for the first time, observed and characterized compressive waves propagating both outward and inward in the outer <span class="hlt">solar</span> corona above 4 Rs. In addition to detecting the waves, we have used them to measure outflow in the all-important <span class="hlt">wind</span> acceleration region. Because the corona is an MHD system, any disturbance in the corona launches low-frequency waves that propagate at the familiar MHD speeds and serve to communicate that disturbance to other parts of the system. Through careful filtration of synoptic STEREO-A/COR-2 data, we have been able to measure both inbound and outbound waves at all locations in the <span class="hlt">solar</span> corona. By measuring in/out asymmetries in the wave characteristics we have been able to estimate the <span class="hlt">solar</span> <span class="hlt">wind</span> acceleration profile. Further, we are able to estimate the location of the Alfvén surface - the hard-to-measure transition between the corona and the superalfvénic <span class="hlt">solar</span> <span class="hlt">wind</span>, and the boundary at which <span class="hlt">solar</span> magnetic field lines transition from "closed" to "open". There is a great deal of work to be done beyond these preliminary results, which - it is hoped - open a new avenue for understanding coronal dynamics and the origin of the <span class="hlt">solar</span> <span class="hlt">wind</span>.</p> <div class="credits"> <p class="dwt_author">DeForest, Craig; McComas, Dave; Howard, Tim A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">337</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014SoPh..289.3109H"> <span id="translatedtitle">Tracking Back the <span class="hlt">Solar</span> <span class="hlt">Wind</span> to Its Photospheric Footpoints from <span class="hlt">Wind</span> Observations - A Statistical Study</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">It is of great importance to track the <span class="hlt">solar</span> <span class="hlt">wind</span> back to its photospheric source region and identify the related current sheets; this will provide key information for investigating the origin and predictions of the <span class="hlt">solar</span> <span class="hlt">wind</span>. We report a statistical study relating the photospheric footpoint motion and in-situ observation of current sheets in the <span class="hlt">solar</span> <span class="hlt">wind</span>. We used the potential force-free source-surface (PFSS) model and the daily synoptic charts to trace the <span class="hlt">solar</span> <span class="hlt">wind</span> back from 1 AU, as observed by the <span class="hlt">Wind</span> spacecraft, to the <span class="hlt">solar</span> surface. As the footpoints move along the <span class="hlt">solar</span> surface we obtain a time series of the jump times between different points. These jumps can be within a cell and between adjacent cells. We obtained the distribution of the jump times and the distribution for a subset of the jump times in which only jumps between adjacent cells were counted. For both cases, the distributions clearly show two populations. These distributions are compared with the distribution of in-situ current sheets reported in an earlier work of Miao, Peng, and Li ( Ann. Geophys. 29, 237, 2011). Its implications on the origin of the current sheets are discussed.</p> <div class="credits"> <p class="dwt_author">Huang, Chong; Yan, Yihua; Li, Gang; Deng, Yuanyong; Tan, Baolin</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-08-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">338</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040082015&hterms=charge+profile&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcharge%2Bprofile"> <span id="translatedtitle">XMM-Newton Observations of <span class="hlt">Solar</span> <span class="hlt">Wind</span> Charge Exchange Emission</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">We present an XMM-Newton spectrum of diffuse X-ray emission from within the <span class="hlt">solar</span> system. The spectrum is dominated by O VII and O VIII lines at 0.57 keV and 0.65 keV, O VIII (and possibly Fe XVII) lines at approximately 0.8 keV, Ne IX lines at approximately 0.92 keV, and Mg XI lines at approximately 1.35 keV. This spectrum is consistent with what is expected from charge exchange emission between the highly ionized <span class="hlt">solar</span> <span class="hlt">wind</span> and either interstellar neutrals in the heliosphere or material from Earth's exosphere. The emission is clearly seen as a low-energy ( E less than 1.5 keV) spectral enhancement in one of a series of observations of the Hubble Deep Field North. The X-ray enhancement is concurrent with an enhancement in the <span class="hlt">solar</span> <span class="hlt">wind</span> measured by the ACE satellite. The <span class="hlt">solar</span> <span class="hlt">wind</span> enhancement reaches a flux level an order of magnitude more intense than typical fluxes at 1 AU, and has ion ratios with significantly enhanced higher ionization states. Whereas observations of the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma made at a single point reflect only local conditions which may only be representative of <span class="hlt">solar</span> <span class="hlt">wind</span> properties with spatial scales ranging from less than half of an Earth radii (approximately 10 s) to 100 Earth radii, X-ray observations of <span class="hlt">solar</span> <span class="hlt">wind</span> charge exchange are remote sensing measurements which may provide observations which are significantly more global in character. Besides being of interest in its own right for studies of the <span class="hlt">solar</span> system, this emission can have significant consequences for observations of more cosmological objects. It can provide emission lines at zero redshift which are of particular interest (e.g., O VII and O VIII) in studies of diffuse thermal emission, and which can therefore act as contamination in objects which cover the entire detector field of view. We propose the use of <span class="hlt">solar</span> <span class="hlt">wind</span> monitoring data, such as from the ACE and <span class="hlt">Wind</span> spacecraft, as a diagnostic to screen for such possibilities.</p> <div class="credits"> <p class="dwt_author">Snowden, S. L.; Collier, M. R.; Kuntz, K. D.</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">339</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19960021350&hterms=ips&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dips"> <span id="translatedtitle">Features of <span class="hlt">solar</span> <span class="hlt">wind</span> acceleration according to radio occultation data</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">In addressing one of the fundamental problems in <span class="hlt">solar</span> physics establishing the mechanism(s) responsible for the <span class="hlt">solar</span> <span class="hlt">wind</span> acceleration and the corona heating - it is essential to have a reliable knowledge of the heliocentric radial dependence of the <span class="hlt">solar</span> <span class="hlt">wind</span> properties. Adequate data are available for small <span class="hlt">solar</span> distances R less than 4 R(<span class="hlt">solar</span> mass) from coronal white light and EUV observations and at distances R greater than 60 R(<span class="hlt">solar</span> mass) from in situ measurements. One of the few methods available to fill in the gap between these boundaries is the radio scintillation technique. Taking the example of the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity, the most reliable such measurements are obtained when phase fluctuation observations of scattered radio waves, which are not susceptible to saturation effects, are recorded at two or more widely-spaced ground stations. Two extensive observation campaigns of this type were carried out with the Venus-orbiting satellites Venera 10 in 1976 and Venera 15/16 in 1984. The observations were performed over the course of three months near superior conjunction at <span class="hlt">solar</span> offset distances R approximately 6-80 R(<span class="hlt">solar</span> mass). The main results from the subsequent analysis of these data are: (1) velocities vary between 250 and 380 km s(exp -1) for R greater than 20 R(<span class="hlt">solar</span> mass), agreeing with similar measurements using natural sources (IPS); (2) velocities derived from two-station phase fluctuation observations varv between 70 and 120 km s(exp -1) for R less than 12 R(<span class="hlt">solar</span> mass), i.e. values substantially lower than those derived from conventional IPS data; and (3) it is suggested that the different velocity profiles derived from the two data sets at small R may be due to the effects of magnetosonic and Alfvenic waves on radio wave scattering. Further analysis of additional radio sounding data should help resolve the apparent discrepancy.</p> <div class="credits"> <p class="dwt_author">Efimov, A. I.</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">340</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19750043961&hterms=latitudinal+gradients&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dlatitudinal%2Bgradients"> <span id="translatedtitle">Evidence of a velocity gradient in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Sector-boundary velocity data obtained by Mariner 5 near Venus and by Explorers 33, 34, and 35 near earth are analyzed to determine why higher velocities were measured at earth. Differences in the corresponding velocities are plotted as a function of the heliocentric latitude separation of Mariner and earth, and evidence of a significant latitude gradient in the <span class="hlt">solar</span> <span class="hlt">wind</span> is found. Several indirect arguments in support of a latitude gradient are presented, and it is concluded that if the <span class="hlt">solar</span> <span class="hlt">wind</span> velocity varies with latitude, latitudinal stresses may have a significant effect on the properties of the <span class="hlt">solar</span> <span class="hlt">wind</span>, such as the existence and character of the north-south component of the interplanetary magnetic field.</p> <div class="credits"> <p class="dwt_author">Smith, E. J.; Rhodes, E. J., Jr.</p> <p class="dwt_publisher"></p> <p class="publishDate">1974-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_16");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' 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showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a style="font-weight: bold;">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_19");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">341</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2009EGUGA..11.8300F"> <span id="translatedtitle">A new view of <span class="hlt">solar</span> <span class="hlt">wind</span> structures: Combined interplanetary scintillation and STEREO HI studies of the inner <span class="hlt">solar</span> <span class="hlt">wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The heliospheric imagers (HI) on the STEREO A and B spacecraft are now providing the first continuous, detailed images of structures in the interplanetary <span class="hlt">solar</span> <span class="hlt">wind</span>. When combined with simultaneous radio measurements of interplanetary scintillation (IPS), STEREO images allow the structure of the <span class="hlt">solar</span> <span class="hlt">wind</span> to be studied with much greater certainty than has been possible before. The STEREO HI images provide information on the global structure of large-scale features, while the IPS measurements provide fine-scale information on the structures embedded within the large features. In the paper we discuss the techinques employed to combine the IPS and STEREO measurements and go on to present results from a series of combined studies of coronal mass ejections and co-roating interaction regions in the inner <span class="hlt">solar</span> <span class="hlt">wind</span>. We also show that structures seen in the inner <span class="hlt">solar</span> <span class="hlt">wind</span> by STEREO HI and in IPS results can be related to disturbances in the <span class="hlt">solar</span> <span class="hlt">wind</span> at Venus recorded by the ASPERA instrument on the Venus Express spacecraft.</p> <div class="credits"> <p class="dwt_author">Fallows, R. A.; Breen, A. R.; Dorrian, G. D.; Whittaker, I.; Grande, M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">342</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/22118611"> <span id="translatedtitle">The turbulent cascade and proton heating in the <span class="hlt">solar</span> <span class="hlt">wind</span> during <span class="hlt">solar</span> minimum</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary"><span class="hlt">Solar</span> <span class="hlt">wind</span> measurements at 1 AU during the recent <span class="hlt">solar</span> minimum and previous studies of <span class="hlt">solar</span> maximum provide an opportunity to study the effects of the changing <span class="hlt">solar</span> cycle on in situ heating. Our interest is to compare the levels of activity associated with turbulence and proton heating. Large-scale shears in the flow caused by transient activity are a source that drives turbulence that heats the <span class="hlt">solar</span> <span class="hlt">wind</span>, but as the <span class="hlt">solar</span> cycle progresses the dynamics that drive the turbulence and heat the medium are likely to change. The application of third-moment theory to Advanced Composition Explorer (ACE) data gives the turbulent energy cascade rate which is not seen to vary with the <span class="hlt">solar</span> cycle. Likewise, an empirical heating rate shows no significan changes in proton heating over the cycle.</p> <div class="credits"> <p class="dwt_author">Coburn, Jesse T.; Smith, Charles W.; Vasquez, Bernard J. [Physics Department and Space Science Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, New Hampshire (United States); Stawarz, Joshua E. [Department of Astrophysical and Planetary Sciences, University of Colorado at Boulder, Boulder, Colorado (United States); Forman, Miriam A. [Department of Physics and Astronomy, State University of New York at Stony Brook, Stony Brook, New York (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-06-13</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">343</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AGUFMSH43A..03W"> <span id="translatedtitle">Turbulent Heating and Wave Pressure in <span class="hlt">Solar</span> <span class="hlt">Wind</span> Acceleration Modeling: New Insights to Empirical Forecasting of the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The study of <span class="hlt">solar</span> <span class="hlt">wind</span> acceleration has made several important advances recently due to improvements in modeling techniques. Existing code and simulations test the competing theories for coronal heating, which include reconnection/loop-opening (RLO) models and wave/turbulence-driven (WTD) models. In order to compare and contrast the validity of these theories, we need flexible tools that predict the emergent <span class="hlt">solar</span> <span class="hlt">wind</span> properties from a wide range of coronal magnetic field structures such as coronal holes, pseudostreamers, and helmet streamers. ZEPHYR (Cranmer et al. 2007) is a one-dimensional magnetohydrodynamics code that includes Alfven wave generation and reflection and the resulting turbulent heating to accelerate <span class="hlt">solar</span> <span class="hlt">wind</span> in open flux tubes. We present the ZEPHYR output for a wide range of magnetic field geometries to show the effect of the magnetic field profiles on <span class="hlt">wind</span> properties. We also investigate the competing acceleration mechanisms found in ZEPHYR to determine the relative importance of increased gas pressure from turbulent heating and the separate pressure source from the Alfven waves. To do so, we developed a code that will become publicly available for <span class="hlt">solar</span> <span class="hlt">wind</span> prediction. This code, TEMPEST, provides an outflow solution based on only one input: the magnetic field strength as a function of height above the photosphere. It uses correlations found in ZEPHYR between the magnetic field strength at the source surface and the temperature profile of the outflow solution to compute the <span class="hlt">wind</span> speed profile based on the increased gas pressure from turbulent heating. With this initial solution, TEMPEST then adds in the Alfven wave pressure term to the modified Parker equation and iterates to find a stable solution for the <span class="hlt">wind</span> speed. This code, therefore, can make predictions of the <span class="hlt">wind</span> speeds that will be observed at 1 AU based on extrapolations from magnetogram data, providing a useful tool for empirical forecasting of the sol! ar <span class="hlt">wind</span>.</p> <div class="credits"> <p class="dwt_author">Woolsey, L. N.; Cranmer, S. R.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">344</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/h7t059714k551170.pdf"> <span id="translatedtitle">Acceleration of the High Speed <span class="hlt">Solar</span> <span class="hlt">Wind</span> in Coronal Holes</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">We outline a theory for the origin and acceleration of the fast <span class="hlt">solar</span> <span class="hlt">wind</span> as a consequence of network microflares releasing\\u000a a spectrum of high frequency Alfvén waves which heat (by cyclotron absorption) the corona close to the Sun. The significant\\u000a features of our model of the fast <span class="hlt">wind</span> are that the acceleration is rapid with the sonic point at</p> <div class="credits"> <p class="dwt_author">W. I. Axford; J. F. McKenzie; G. V. Sukhorukova; M. Banaszkiewicz; A. Czechowski; R. Ratkiewicz</p> <p class="dwt_publisher"></p> <p class="publishDate">1999-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">345</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/q7q12262k583u602.pdf"> <span id="translatedtitle">Interplanetary Shocks and <span class="hlt">Solar</span> <span class="hlt">Wind</span> Structure Approaching <span class="hlt">Solar</span> Maximum: Helios, IMP8 and Voyager Observations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">We studied <span class="hlt">solar</span> <span class="hlt">wind</span> observations of five different spacecraft: Helios 1, Helios 2, IMP-8, Voyager 1 and Voyager 2, from November 1977 to February 1978. In this period the large-scale dynamics of the <span class="hlt">solar</span> <span class="hlt">wind</span> near of the ecliptic plane\\u000a was characterized by transient forward shocks (TFSs), ejecta, unstable corotating interaction regions (CIRs), and complex\\u000a and variable magnetic sector structures.</p> <div class="credits"> <p class="dwt_author">A. González-Esparza</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">346</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2011AGUFMSH33B2061R"> <span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">Wind</span> Mass-Loading Due to Dust</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Collisionless mass-loading by interplanetary dust particles is expected to cause a significant disruption in the flow of the <span class="hlt">solar</span> <span class="hlt">wind</span>. Dust particles near the Sun can become a source of ions and neutrals due to evaporation and sputtering. This mass-loading effect can lead to the formation of collisionless shocks, as it was first discussed in the case of <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with comets. This effect can also be compared with a de Laval nozzle, which behaves differently between subsonic and supersonic flows. We investigate the effects of mass-loading resulting from sun-grazing comets or collisions in the vicinity of the Sun, where the <span class="hlt">solar</span> <span class="hlt">wind</span> transitions from subsonic to supersonic speeds. We implement a hydrodynamic numerical model to generate a steady <span class="hlt">wind</span> extending out to the inner heliosphere. Dust is introduced through a set of mass-loading source terms, and the model is evolved using a shock-capturing scheme. These results are relevant for understanding the acceleration of the <span class="hlt">solar</span> <span class="hlt">wind</span> and possible changes in its composition due to dust.</p> <div class="credits"> <p class="dwt_author">Rasca, A.; Horanyi, M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">347</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AIPC.1539..418R"> <span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">wind</span> mass-loading due to dust</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Collisionless mass-loading by interplanetary dust particles is expected to cause a significant disruption in the flow of the <span class="hlt">solar</span> <span class="hlt">wind</span>. Dust particles near the Sun can become a source of ions and neutrals due to evaporation and sputtering. This mass-loading effect can lead to the formation of collisionless shocks, as it was first discussed in the case of <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with comets. This effect can also be compared with a de Laval nozzle, which behaves differently between subsonic and supersonic flows. We investigate the effects of mass-loading resulting from sun-grazing comets or collisions by larger bodies in the vicinity of the Sun, where the <span class="hlt">solar</span> <span class="hlt">wind</span> transitions from subsonic to supersonic speeds. We look at results obtained using a simple 1D hydrodynamic model to mass-load ionized dust into the the <span class="hlt">wind</span> near the sonic point, which are relevant for understanding the acceleration of the <span class="hlt">solar</span> <span class="hlt">wind</span> and possible changes in its composition due to dust.</p> <div class="credits"> <p class="dwt_author">Rasca, A. P.; Horányi, M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">348</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1983STIA...8334147T"> <span id="translatedtitle">Source reliability in a combined <span class="hlt">wind-solar</span>-hydro system</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The results of an examination of the feasibility of using coupled <span class="hlt">wind-solar</span>-hydro power generation systems to provide all of Portugal's electricity by the year 2000 are reported. Portugal used 15.6 TWh of electricity in 1981, of which hydro supplied 10 TWh. Demand is expected to reach 34 TWh in 2000 AD. The full development of hydropower resource would furnish 18 TWh and a storage capacity of 4.5 TWh. The installed hydro system could meet the peak demand of 6 GW, while <span class="hlt">solar</span> cells and <span class="hlt">wind</span> turbines must produce 16 TWh annually plus a reserve. The Growian <span class="hlt">wind</span> turbine, 100 m tall, is considered for its 2.2 MW output. A coastal strip of <span class="hlt">wind</span> turbines 150 x 20 km, with 1 km spacing between the machines, would be needed to produce 5.4 GW of power. Partially tracking <span class="hlt">solar</span> cell arrays generating 9.4 GW of electricity would require an area of 100 sq km. Computer simulations of the annual rainfall, combined with projections of the variations in <span class="hlt">wind-solar</span> output, demonstrates that a reserve margin of 1.20 will be necessary. The costs of installation of the renewable energy converters are estimated at about three times that currently necessary for obtaining the same capacity from fission power plants, although the situation may change due to import and technical considerations.</p> <div class="credits"> <p class="dwt_author">Traca de Almeida, A.; Martins, A.; Jesus, H.; Climaco, J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1983-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">349</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/17994092"> <span id="translatedtitle">Modulation of Saturn's radio clock by <span class="hlt">solar</span> <span class="hlt">wind</span> speed.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The internal rotation rates of the giant planets can be estimated by cloud motions, but such an approach is not very precise because absolute <span class="hlt">wind</span> speeds are not known a priori and depend on latitude: periodicities in the radio emissions, thought to be tied to the internal planetary magnetic field, are used instead. Saturn, despite an apparently axisymmetric magnetic field, emits kilometre-wavelength (radio) photons from auroral sources. This emission is modulated at a period initially identified as 10 h 39 min 24 +/- 7 s, and this has been adopted as Saturn's rotation period. Subsequent observations, however, revealed that this period varies by +/-6 min on a timescale of several months to years. Here we report that the kilometric radiation period varies systematically by +/-1% with a characteristic timescale of 20-30 days. Here we show that these fluctuations are correlated with <span class="hlt">solar</span> <span class="hlt">wind</span> speed at Saturn, meaning that Saturn's radio clock is controlled, at least in part, by conditions external to the planet's magnetosphere. No correlation is found with the <span class="hlt">solar</span> <span class="hlt">wind</span> density, dynamic pressure or magnetic field; the <span class="hlt">solar</span> <span class="hlt">wind</span> speed therefore has a special function. We also show that the long-term fluctuations are simply an average of the short-term ones, and therefore the long-term variations are probably also driven by changes in the <span class="hlt">solar</span> <span class="hlt">wind</span>. PMID:17994092</p> <div class="credits"> <p class="dwt_author">Zarka, Philippe; Lamy, Laurent; Cecconi, Baptiste; Prangé, Renée; Rucker, Helmut O</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-11-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">350</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014GeCoA.127..326M"> <span id="translatedtitle">Heavy noble gases in <span class="hlt">solar</span> <span class="hlt">wind</span> delivered by Genesis mission</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">One of the major goals of the Genesis Mission was to refine our knowledge of the isotopic composition of the heavy noble gases in <span class="hlt">solar</span> <span class="hlt">wind</span> and, by inference, the Sun, which represents the initial composition of the <span class="hlt">solar</span> system. This has now been achieved with permil precision: 36Ar/38Ar = 5.5005 ± 0.0040, 86Kr/84Kr = .3012 ± .0004, 83Kr/84Kr = .2034 ± .0002, 82Kr/84Kr = .2054 ± .0002, 80Kr/84Kr = .0412 ± .0002, 78Kr/84Kr = .00642 ± .00005, 136Xe/132Xe = .3001 ± .0006, 134Xe/132Xe = .3691 ± .0007, 131Xe/132Xe = .8256 ± .0012, 130Xe/132Xe = .1650 ± .0004, 129Xe/132Xe = 1.0405 ± .0010, 128Xe/132Xe = .0842 ± .0003, 126Xe/132Xe = .00416 ± .00009, and 124Xe/132Xe = .00491 ± .00007 (error-weighted averages of all published data). The Kr and Xe ratios measured in the Genesis <span class="hlt">solar</span> <span class="hlt">wind</span> collectors generally agree with the less precise values obtained from lunar soils and breccias, which have accumulated <span class="hlt">solar</span> <span class="hlt">wind</span> over hundreds of millions of years, suggesting little if any temporal variability of the isotopic composition of <span class="hlt">solar</span> <span class="hlt">wind</span> krypton and xenon. The higher precision for the initial composition of the heavy noble gases in the <span class="hlt">solar</span> system allows (1) to confirm that, exept 136Xe and 134Xe, the mathematically derived U-Xe is equivalent to <span class="hlt">Solar</span> <span class="hlt">Wind</span> Xe and (2) to provide an opportunity for better understanding the relationship between the starting composition and Xe-Q (and Q-Kr), the dominant current “planetary” component, and its host, the mysterious phase-Q.</p> <div class="credits"> <p class="dwt_author">Meshik, Alex; Hohenberg, Charles; Pravdivtseva, Olga; Burnett, Donald</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-02-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">351</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22181719"> <span id="translatedtitle">Modified temperature-anisotropy instability thresholds in the <span class="hlt">solar</span> <span class="hlt">wind</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The proton and electron temperature anisotropies in the <span class="hlt">solar</span> <span class="hlt">wind</span> are constrained by the instability thresholds for temperature-anisotropy-driven kinetic plasma instabilities. The modifications to the marginal instability conditions from accounting for the influence of damping connected with the collisional effects in the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma are calculated for right- and left-handed polarized parallel propagating Alfvén waves and mirror and firehose fluctuations. These modifications provide tighter threshold constraints compared to the marginal thresholds but do not fully explain the observations at small values of the parallel plasma beta. PMID:22181719</p> <div class="credits"> <p class="dwt_author">Schlickeiser, R; Michno, M J; Ibscher, D; Lazar, M; Skoda, T</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-11-11</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">352</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AGUFMSM13B2151E"> <span id="translatedtitle">Observations of Colliding Reconnection Jets in the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The existence of multiple X-lines in a single current sheet is believed to generate flux ropes which appear as topological O-line regions (magnetic islands) in a 2D cross-section. The O-line region is also considered a place where the reconnection jets from two X-lines collide. We present the first multi-spacecraft observations at asymmetric current sheets in the <span class="hlt">solar</span> <span class="hlt">wind</span> which are in agreement with kinetic reconnection simulations of colliding jets. Current sheets in the <span class="hlt">solar</span> <span class="hlt">wind</span> thus support the formation of multiple X-lines and flux ropes.</p> <div class="credits"> <p class="dwt_author">Eriksson, S.; Newman, D. L.; Lapenta, G.; Angelopoulos, V.; Goldman, M. V.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">353</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2004AGUFMSH51C0288S"> <span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">Wind</span> Heating: Critical Tests of a Turbulence Theory</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We review observations of <span class="hlt">solar</span> <span class="hlt">wind</span> heating in the outer heliosphere as measured by the Voyager 2 and Pioneer 11 spacecraft and described previously by a theory of pickup ion wave excitation and turbulent transport. That theory was most recently applied to observations by Smith et al. [2001] and with significant revision of the pickup proton component by Isenberg et al. [2003]. We extend the application of the theory to include time variation of <span class="hlt">solar</span> <span class="hlt">wind</span> parameters as recorded by the Omnitape dataset of 1 AU measurements. We also extend the range of heliocentric distances made available by the more recent Voyager data. By averaging Omnitape observations over several <span class="hlt">solar</span> rotations and using the resulting values as input to the theory, we are able to reproduce the variability of the thermal proton temperatures observed in the outer heliosphere. This is seen to be a direct result of the dependence of energy injection by pickup protons upon bulk <span class="hlt">solar</span> <span class="hlt">wind</span> parameters such as Alfven speed and <span class="hlt">wind</span> speed and the fact that these parameters persist in a predictable manner from 1 AU to the outer heliosphere. There is also evidence of latitudinal effects during <span class="hlt">solar</span> minimum that may be explainable by using high-latitude observations by Ulysses as input for the theory. Smith et al., JGR, A106, 8253-8272 [2001] Isenberg et al., ApJ, 592, 564-573 [2003</p> <div class="credits"> <p class="dwt_author">Smith, C. W.; Isenberg, P. A.; Matthaeus, W. H.; Richardson, J. D.</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">354</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/21567634"> <span id="translatedtitle">THE SPECTROSCOPIC FOOTPRINT OF THE FAST <span class="hlt">SOLAR</span> <span class="hlt">WIND</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">We analyze a large, complex equatorial coronal hole (ECH) and its immediate surroundings with a focus on the roots of the fast <span class="hlt">solar</span> <span class="hlt">wind</span>. We start by demonstrating that our ECH is indeed a source of the fast <span class="hlt">solar</span> <span class="hlt">wind</span> at 1 AU by examining in situ plasma measurements in conjunction with recently developed measures of magnetic conditions of the photosphere, inner heliosphere, and the mapping of the <span class="hlt">solar</span> <span class="hlt">wind</span> source region. We focus the bulk of our analysis on interpreting the thermal and spatial dependence of the non-thermal line widths in the ECH as measured by SOHO/SUMER by placing the measurements in context with recent studies of ubiquitous Alfven waves in the <span class="hlt">solar</span> atmosphere and line profile asymmetries (indicative of episodic heating and mass loading of the coronal plasma) that originate in the strong, unipolar magnetic flux concentrations that comprise the supergranular network. The results presented in this paper are consistent with a picture where a significant portion of the energy responsible for the transport of heated mass into the fast <span class="hlt">solar</span> <span class="hlt">wind</span> is provided by episodically occurring small-scale events (likely driven by magnetic reconnection) in the upper chromosphere and transition region of the strong magnetic flux regions that comprise the supergranular network.</p> <div class="credits"> <p class="dwt_author">McIntosh, Scott W. [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307 (United States); Leamon, Robert J. [ADNET Systems Inc., NASA Goddard Space Flight Center, Code 671.1, Greenbelt, MD 20771 (United States); De Pontieu, Bart, E-mail: mscott@ucar.edu, E-mail: robert.j.leamon@nasa.gov, E-mail: bdp@lmsal.com [Lockheed Martin Solar and Astrophysics Lab, 3251 Hanover Street, Org. ADBS, Building 252, Palo Alto, CA 94304 (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-20</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">355</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/22167206"> <span id="translatedtitle">ACCELERATION OF THE <span class="hlt">SOLAR</span> <span class="hlt">WIND</span> BY ALFVEN WAVE PACKETS</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">A scale separation kinetic model of the <span class="hlt">solar</span> <span class="hlt">wind</span> acceleration is presented. The model assumes an isotropic Maxwellian distribution of protons and a constant influx of outward propagating Alfven waves with a single exponent Kolmogorov-type spectrum at the base of a coronal acceleration region ({approx}2 R {sub Sun }). Our results indicate that nonlinear cyclotron resonant interaction taking energy from Alfven waves and depositing it into mostly perpendicular heating of protons in initially weakly expanding plasma in a spherically non-uniform magnetic field is able to produce the typical fast <span class="hlt">solar</span> <span class="hlt">wind</span> velocities for the typical plasma and wave conditions after expansion to about 5-10 <span class="hlt">solar</span> radii R {sub Sun }. The acceleration model takes into account the gravity force and the ambipolar electric field, as well as the mirror force, which plays the most important role in driving the <span class="hlt">solar</span> <span class="hlt">wind</span> acceleration. Contrary to the recent claims of Isenberg, the cold plasma dispersion only slightly slows down the acceleration and actually helps in obtaining the more realistic fast <span class="hlt">solar</span> <span class="hlt">wind</span> speeds.</p> <div class="credits"> <p class="dwt_author">Galinsky, V. L.; Shevchenko, V. I., E-mail: vit@ucsd.edu [ECE Department, UC San Diego, MC 407, La Jolla, CA 92093-0407 (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-20</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">356</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2003DPS....35.3822L"> <span id="translatedtitle">Bow Shock in Interaction of <span class="hlt">Solar</span> <span class="hlt">Wind</span> with Cometary Coma</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The process of interaction of <span class="hlt">Solar</span> <span class="hlt">wind</span> with cometary coma is considered. The description is performed on the basis of a self-consistent model which takes into account <span class="hlt">solar</span> radiation; dust particle charging; evaporation and formation of neutral particles; photoionization; electric fields; the evolution of <span class="hlt">Solar</span> <span class="hlt">wind</span> ions, cometary ions and dust particles; as well as the dust charge variation. It is shown that the presence of dust in cometary coma can modify shock wave formed as a result of <span class="hlt">Solar</span> <span class="hlt">wind</span> interaction with a comet. The outer shock wave (bow shock) can be considered as an ion acoustic shock wave modified by dust particle charging process. Possible formation of dust structures in the region of the interaction of <span class="hlt">Solar</span> <span class="hlt">wind</span> with cometary coma is discussed. The developed model allows us to determine the shock front structure. For large enough dust densities (exceeding 106 cm-3 near the comet nucleus) at the region of bow shock front dust particles acquiring positive variable charges influence drastically the structure of the shock front. Its width is in accordance with the theory of dust ion acoustic shocks [1, 2]. The work is supported by the Russian Foundation for Basic Research (grants No. 02-02-17369, 03-02-16664). [1] S.I. Popel, M.Y. Yu, and V.N. Tsytovich, Phys. Plasmas 3, 4313 (1996). [2] S.I. Popel, A.A. Gisko, A.P. Golub', and T.V. Losseva et al. Phys. Plasmas 7, 2410 (2000).</p> <div class="credits"> <p class="dwt_author">Losseva, T. V.; Gisko, A. A.; Popel, S. I.; Vladimirov, S. V.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">357</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014AAS...22420302S"> <span id="translatedtitle">Origin of the Wang-Sheeley-Arge <span class="hlt">Solar</span> <span class="hlt">Wind</span> Model</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">A correlation between <span class="hlt">solar</span> <span class="hlt">wind</span> speed at Earth and the amount of field line expansion in the corona was verified in 1989 using 22 years of <span class="hlt">solar</span> and interplanetary observations. This talk will trace the history of this discovery from its birth 15 years earlier in the Skylab era to its current use as a space weather forecasting technique. This research was supported by NASA and ONR.</p> <div class="credits"> <p class="dwt_author">Sheeley, Neil R.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">358</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/42736865"> <span id="translatedtitle">IPS tomographic observations of 3D <span class="hlt">solar</span> <span class="hlt">wind</span> structure</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Interplanetary scintillation (IPS) observations have been improved by development of deconvolution methods for the line-of-sight integration effect. One deconvolution method is to use a computer-assisted tomographic analysis (CAT) technique. In this work, four different kinds of CAT method have been developed. Two of them can be applied to stable <span class="hlt">solar</span> <span class="hlt">wind</span> structure in the <span class="hlt">solar</span> minimum phase, one to quasi-stable</p> <div class="credits"> <p class="dwt_author">M. Kojima; M. Tokumaru; K. Fujiki; K. Hayashi; B. V. Jackson</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">359</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://spacemath.gsfc.nasa.gov/sun/8Page43.pdf"> <span id="translatedtitle">Exploring the <span class="hlt">Solar</span> <span class="hlt">Wind</span> and Coronal Mass Ejections</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://nsdl.org/nsdl_dds/services/ddsws1-1/service_explorer.jsp">NSDL National Science Digital Library</a></p> <p class="result-summary">This is an activity about the <span class="hlt">solar</span> activity cycle. Learners will construct a graph to identify a pattern of the number of observed sunspots and the number of coronal mass ejections emitted by the Sun over a fifteen year time span. A graphing calculator is recommended, but not required, for this activity. This is the second activity in the <span class="hlt">Solar</span> Storms and You: Exploring the <span class="hlt">Wind</span> from the Sun educator guide.</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">360</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/n116157511101545.pdf"> <span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">Wind</span> Electron Proton Alpha Monitor (SWEPAM) for the Advanced Composition Explorer</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The <span class="hlt">Solar</span> <span class="hlt">Wind</span> Electron Proton Alpha Monitor (SWEPAM) experiment provides the bulk <span class="hlt">solar</span> <span class="hlt">wind</span> observations for the Advanced\\u000a Composition Explorer (ACE). These observations provide the context for elemental and isotopic composition measurements made\\u000a on ACE as well as allowing the direct examination of numerous <span class="hlt">solar</span> <span class="hlt">wind</span> phenomena such as coronal mass ejections, interplanetary\\u000a shocks, and <span class="hlt">solar</span> <span class="hlt">wind</span> fine structure, with</p> <div class="credits"> <p class="dwt_author">D. J. McComas; S. J. Bame; P. Barker; W. C. Feldman; J. L. Phillips; P. Riley; J. W. Griffee</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_17");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' 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class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_18");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a onClick='return showDiv("page_5");' href="#">5</a> <a onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a onClick='return showDiv("page_9");' href="#">9</a> <a onClick='return showDiv("page_10");' href="#">10</a> <a onClick='return showDiv("page_11");' href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a style="font-weight: bold;">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_20");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">361</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/50934898"> <span id="translatedtitle">Design of <span class="hlt">wind-solar</span> and pumped-storage hybrid power supply system</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">To overcome the inherent defects in <span class="hlt">wind-solar</span> hybrid system: power generation and electricity load's imbalance because of uncertainty of resources. this article aiming at XJ Group's project design of <span class="hlt">wind-solar</span> hybrid power supply system, by way of pumped-storage to replace the battery of <span class="hlt">wind-solar</span> hybrid power supply system, this method can effectively overcome above problems. <span class="hlt">Wind-solar</span> and pumped-storage hybrid power</p> <div class="credits"> <p class="dwt_author">Ruisheng Lil; Bingxin Wul; Xianwei Lil; Fengquan Zhoul; Yanbin Li</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">362</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014EGUGA..16.9652R"> <span id="translatedtitle">Comparison of <span class="hlt">solar</span> <span class="hlt">wind</span> driving of the aurora in the two hemispheres due to the <span class="hlt">solar</span> <span class="hlt">wind</span> dynamo</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Event studies of simultaneous global imaging of the aurora in both hemispheres have suggested that an asymmetry of the <span class="hlt">solar</span> <span class="hlt">wind</span> driving between the two hemispheres could explain observations of non-conjugate aurora during specific driving conditions. North-South asymmetries in energy transfer from the <span class="hlt">solar</span> <span class="hlt">wind</span> across the magnetopause is believed to depend upon the dipole tilt angle and the x-component of the interplanetary magnetic field (IMF). Both negative tilt (winter North) and negative IMF Bx is expected to enhance the efficiency of the <span class="hlt">solar</span> <span class="hlt">wind</span> dynamo in the Northern Hemisphere. By the same token, positive tilt and IMF Bx is expected to enhance the <span class="hlt">solar</span> <span class="hlt">wind</span> dynamo efficiency in the Southern Hemisphere. We show a statistical study of the auroral response from both hemispheres using global imaging where we compare results during both favourable and not favourable conditions in each hemisphere. By this study we will address the question of general impact on auroral hemispheric asymmetries by this mechanism - the asymmetric <span class="hlt">solar</span> <span class="hlt">wind</span> dynamo. We use data from the Wideband Imaging Camera on the IMAGE spacecraft which during its lifetime from 2000-2005 covered both hemispheres. To ease comparison of the two hemispheres, seasonal differences in auroral brightness is removed as far as data coverage allows by only using events having small dipole tilt angles. Hence, the IMF Bx is expected to be the controlling parameter for the hemispheric preference of strongest <span class="hlt">solar</span> <span class="hlt">wind</span> dynamo efficiency in our dataset. Preliminary statistical results indicate the expected opposite behaviour in the two hemispheres, however, the effect is believed to be weak.</p> <div class="credits"> <p class="dwt_author">Reistad, Jone Peter; Østgaard, Nikolai; Magnus Laundal, Karl; Haaland, Stein; Tenfjord, Paul; Oksavik, Kjellmar</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">363</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19730002080&hterms=prion&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dprion"> <span id="translatedtitle">Elemental and isotopic abundances in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The use of collecting foils and lunar material to assay the isotopic composition of the <span class="hlt">solar</span> <span class="hlt">wind</span> is reviewed. Arguments are given to show that lunar surface correlated gases are likely to be most useful in studying the history of the <span class="hlt">solar</span> <span class="hlt">wind</span>, though the isotopic abundances are thought to give a good approximation to the <span class="hlt">solar</span> <span class="hlt">wind</span> composition. The results of the analysis of Surveyor material are also given. The conditions leading to a significant component of the interstellar gas entering the inner <span class="hlt">solar</span> system are reviewed and suggestions made for experimental searches for this fraction. A critical discussion is given of the different ways in which the basic <span class="hlt">solar</span> composition could be modified by fractionation taking place between the sun's surface and points of observation such as on the Moon or in interplanetary space. An extended review is made of the relation of isotopic and elemental composition of the interplanetary gas to the dynamic behavior of the <span class="hlt">solar</span> corona, especially processes leading to fractionation. Lastly, connection is made between the subject of composition, nucleosynthesis and the convective zone of the sun, and processes leading to modification of initial accretion of certain gases on the Earth and Moon.</p> <div class="credits"> <p class="dwt_author">Geiss, J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1972-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">364</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20110016219&hterms=MDI&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3D%2522MDI%253F%253F%253F%2522"> <span id="translatedtitle">A Model fot the Sources of the Slow <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Models for the origin of the slow <span class="hlt">solar</span> <span class="hlt">wind</span> must account for two seemingly contradictory observations: the slow <span class="hlt">wind</span> has the composition of the closed-field corona, implying that it originates from the continuous opening and closing of flux at the boundary between open and closed field. On the other hand, the slow <span class="hlt">wind</span> also has large angular width, up to approx.60deg, suggesting that its source extends far from the open-closed boundary. We propose a model that can explain both observations. The key idea is that the source of the slow <span class="hlt">wind</span> at the Sun is a network of narrow (possibly singular) open-field corridors that map to a web of separatrices and quasi-separatrix layers in the heliosphere. We compute analytically the topology of an open-field corridor and show that it produces a quasi-separatrix layer in the heliosphere that extends to angles far from the heliospheric current sheet. We then use an MHD code and MDI/SOHO observations of the photospheric magnetic field to calculate numerically, with high spatial resolution, the quasi-steady <span class="hlt">solar</span> <span class="hlt">wind</span>, and magnetic field for a time period preceding the 2008 August 1 total <span class="hlt">solar</span> eclipse. Our numerical results imply that, at least for this time period, a web of separatrices (which we term an S-web) forms with sufficient density and extent in the heliosphere to account for the observed properties of the slow <span class="hlt">wind</span>. We discuss the implications of our S-web model for the structure and dynamics of the corona and heliosphere and propose further tests of the model. Key words: <span class="hlt">solar</span> <span class="hlt">wind</span> - Sun: corona - Sun: magnetic topology</p> <div class="credits"> <p class="dwt_author">Antiochos, S. K.; Mikic, Z.; Titov, V. S.; Lionello, R.; Linker, J. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">365</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2002EGSGA..27.2918R"> <span id="translatedtitle">Large and Fast <span class="hlt">Solar</span> <span class="hlt">Wind</span> Ion Flux (density) Pulses and Their Possible <span class="hlt">Solar</span> Sources</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The special consideration was performed of the large disturbances of <span class="hlt">solar</span> <span class="hlt">wind</span> ion flux (or density, or dynamic pressure) pulses with very sharp fronts. Study of such changes is important as for determination of the nature and properties of plasma insta- bilities on the way of <span class="hlt">solar</span> plasma from Sun to the Earth, as for the understanding of the features of <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere interaction (Space Weather problems). The large set (about 30,000) of the significant (more than 0.5 · E + 08 cm-2 s-1) and fast (shorter than 10 min.) jumps of <span class="hlt">solar</span> <span class="hlt">wind</span> ion flux were selected by obser- vations with high time resolution onboard INTERBALL-1 satellite during 1996-1999 and were compared with other spacecraft (<span class="hlt">WIND</span>, IMP-8, Geotail) data. The absolute and relative values of flux (or pressure) changes, the frequency of their observations as the dependence on their amplitudes, and the behavior of other <span class="hlt">solar</span> <span class="hlt">wind</span> (velocity, temperature) and magnetic field (magnitude and direction) parame- ters were statistically studied. For the subset of about hundred the strongest density changes the conservation of pressure balance (thermal+ magnetic ones) was investi- gated and it was shown that in the many cases such balance is not supported for fast plasma jumps. Also we tried to associate these sharp pulses with possible <span class="hlt">solar</span> sources. Our statistics show that the strong plasma jumps are observed not homogeneously but concentrated in some groups of days that are definitely connected to the slow <span class="hlt">solar</span> <span class="hlt">wind</span> from streamer belts on the Sun or to the <span class="hlt">solar</span> <span class="hlt">wind</span> disturbed by interplanetary shocks.</p> <div class="credits"> <p class="dwt_author">Riazantseva, M. O.; Dalin, P. A.; Zastenker, G. N.; Eselevich, M. V.; Eselevich, V. G.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">366</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/55610865"> <span id="translatedtitle">The magnetic field near Mars, and its variation with the <span class="hlt">solar</span> <span class="hlt">wind</span> parameters</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">In analogy with the <span class="hlt">solar</span> <span class="hlt">wind</span> - magnetosphere coupling at the Earth, the strong crustal anomalies at Mars are expected to interact directly with the <span class="hlt">solar</span> <span class="hlt">wind</span>, but with a completely different geometry and scale-size. During the spring of 1999, Earth was located between the Sun and Mars, and the <span class="hlt">solar</span> <span class="hlt">wind</span> measurments near Earth therefore provides information on the</p> <div class="credits"> <p class="dwt_author">S. Vennerstroem; N. Olsen; M. Purucker</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">367</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/48933222"> <span id="translatedtitle">Weaker <span class="hlt">solar</span> <span class="hlt">wind</span> from the polar coronal holes and the whole Sun</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Observations of <span class="hlt">solar</span> <span class="hlt">wind</span> from both large polar coronal holes (PCHs) during Ulysses' third orbit showed that the fast <span class="hlt">solar</span> <span class="hlt">wind</span> was slightly slower, significantly less dense, cooler, and had less mass and momentum flux than during the previous <span class="hlt">solar</span> minimum (first) orbit. In addition, while much more variable, measurements in the slower, in-ecliptic <span class="hlt">wind</span> match quantitatively with Ulysses and</p> <div class="credits"> <p class="dwt_author">D. J. McComas; R. W. Ebert; H. A. Elliott; B. E. Goldstein; J. T. Gosling; N. A. Schwadron; R. M. Skoug</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">368</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/48899278"> <span id="translatedtitle">Proposed model for Saturn's auroral response to the <span class="hlt">solar</span> <span class="hlt">wind</span>: Centrifugal instability model</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">We present a model of Saturn's global auroral response to the <span class="hlt">solar</span> <span class="hlt">wind</span> as observed by simultaneous Hubble Space Telescope (HST) auroral images and Cassini upstream measurements of the <span class="hlt">solar</span> <span class="hlt">wind</span> taken during the month of January 2004. These observations show a direct correlation between <span class="hlt">solar</span> <span class="hlt">wind</span> dynamic pressure and (1) auroral brightening toward dawn local time, (2) an increase</p> <div class="credits"> <p class="dwt_author">E. C. Sittler Jr; M. F. Blanc; J. D. Richardson</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">369</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/61297986"> <span id="translatedtitle">Feasibility study of a <span class="hlt">solar</span> and <span class="hlt">wind</span> powered desalinization device (SOWIDE). Final report</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The scope, need and feasibility of a <span class="hlt">solar-wind</span> desalinization (SOWIDE) system is examined. A climatological study shows the scope and need where a water deficit, a saline source and <span class="hlt">solar</span> and <span class="hlt">wind</span> power coincide. Representative stations around the globe serve as examples. When climatological data are used, relatively few locations meet all requirements. Optimization of <span class="hlt">wind</span> and <span class="hlt">solar</span> energy through</p> <div class="credits"> <p class="dwt_author">M. Garstang; D. C. David; J. W. Snow</p> <p class="dwt_publisher"></p> <p class="publishDate">1980-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">370</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/61226370"> <span id="translatedtitle">Feasibility study of a <span class="hlt">solar-and-wind</span>-powered desalinization device (SOWIDE). Final report</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The scope, need and feasibility of a <span class="hlt">solar-wind</span> desalinization (SOWIDE) system is examined. A climatological study shows the scope and need where a water deficit, a saline source and <span class="hlt">solar</span> and <span class="hlt">wind</span> power coincide. Representative stations around the globe serve as examples. When climatological data are used, relatively few locations meet all requirements. Optimization of <span class="hlt">wind</span> and <span class="hlt">solar</span> energy through</p> <div class="credits"> <p class="dwt_author">M. Garstang; D. C. David; J. W. Snow</p> <p class="dwt_publisher"></p> <p class="publishDate">1980-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">371</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19920001723&hterms=lucy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dlucy"> <span id="translatedtitle">Asteroid surface processes: Experimental studies of the <span class="hlt">solar</span> <span class="hlt">wind</span> on reflectance and optical properties of asteroids</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The effect of the <span class="hlt">solar</span> <span class="hlt">wind</span> on the optical properties of meteorites was studied to determine whether the <span class="hlt">solar</span> <span class="hlt">wind</span> can alter the properties of ordinary chondrite parent bodies resulting in the spectral properties of S-type asteroids. The existing database of optical properties of asteroids was analyzed to determine the effect of <span class="hlt">solar</span> <span class="hlt">wind</span> in altering asteroid surface properties.</p> <div class="credits"> <p class="dwt_author">Mcfadden, Lucy-Ann</p> <p class="dwt_publisher"></p> <p class="publishDate">1991-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">372</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/4018187"> <span id="translatedtitle">Transport of <span class="hlt">solar</span> <span class="hlt">wind</span> into Earth's magnetosphere through rolled-up Kelvin-Helmholtz vortices</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Establishing the mechanisms by which the <span class="hlt">solar</span> <span class="hlt">wind</span> enters Earth's magnetosphere is one of the biggest goals of magnetospheric physics, as it forms the basis of space weather phenomena such as magnetic storms and aurorae. It is generally believed that magnetic reconnection is the dominant process, especially during southward <span class="hlt">solar-wind</span> magnetic field conditions when the <span class="hlt">solar-wind</span> and geomagnetic fields are</p> <div class="credits"> <p class="dwt_author">H. Hasegawa; M. Fujimoto; T.-D. Phan; H. Rème; A. Balogh; M. W. Dunlop; C. Hashimoto; R. TanDokoro</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">373</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/26587606"> <span id="translatedtitle">Feasibility of hybrid (<span class="hlt">wind</span> + <span class="hlt">solar</span>) power systems for Dhahran, Saudi Arabia</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Hourly mean <span class="hlt">wind</span>-speed and <span class="hlt">solar</span> radiation data for the period 1986–1993 [except the years 1989 (some data is missing) and 1991 (Gulf War)] recorded at the <span class="hlt">solar</span> radiation and meteorological monitoring station, Dhahran (26° 32? N, 50° 13? E), Saudi Arabia, have been analyzed to report the monthly variation of <span class="hlt">wind</span> speed and <span class="hlt">solar</span> radiation, probability distribution of <span class="hlt">wind</span> speed</p> <div class="credits"> <p class="dwt_author">M. A. Elhadidy; S. M. Shaahid</p> <p class="dwt_publisher"></p> <p class="publishDate">1999-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">374</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/26457227"> <span id="translatedtitle">Optimal design and techno-economic analysis of a hybrid <span class="hlt">solar–wind</span> power generation system</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Solar</span> energy and <span class="hlt">wind</span> energy are the two most viable renewable energy resources in the world. Good compensation characters are usually found between <span class="hlt">solar</span> energy and <span class="hlt">wind</span> energy. This paper recommend an optimal design model for designing hybrid <span class="hlt">solar–wind</span> systems employing battery banks for calculating the system optimum configurations and ensuring that the annualized cost of the systems is minimized</p> <div class="credits"> <p class="dwt_author">Hongxing Yang; Zhou Wei; Lou Chengzhi</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">375</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/48907335"> <span id="translatedtitle">Magnetic field variations in the Jovian magnetotail induced by <span class="hlt">solar</span> <span class="hlt">wind</span> dynamic pressure enhancements</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">In order to understand the response of the Jovian magnetosphere to <span class="hlt">solar</span> <span class="hlt">wind</span> dynamic pressure enhancements, we investigate magnetic field variations observed by the Galileo spacecraft. The lack of <span class="hlt">solar</span> <span class="hlt">wind</span> monitoring just upstream of the Jovian magnetosphere is overcome by simulating a one-dimensional magnetohydrodynamic (MHD) propagation of the <span class="hlt">solar</span> <span class="hlt">wind</span> from the Earth. We identify the events with an</p> <div class="credits"> <p class="dwt_author">Chihiro Tao; Ryuho Kataoka; Hiroshi Fukunishi; Yukihiro Takahashi; Takaaki Yokoyama</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">376</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/41270376"> <span id="translatedtitle">Prediction of daily average <span class="hlt">solar</span> <span class="hlt">wind</span> velocity from <span class="hlt">solar</span> magnetic field observations using hybrid intelligent systems</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">A hybrid intelligent system, combining theory driven and data driven models, is used to predict the daily <span class="hlt">solar</span> <span class="hlt">wind</span> velocity at 1 AU from <span class="hlt">solar</span> magnetic field observations. The Potential Field Model (theory driven) is used to calculate the coronal magnetic field up to the source surface placed at 2.5R?. The Earth's position is projected onto the source surface using</p> <div class="credits"> <p class="dwt_author">P. Wintoft; H. Lundstedt</p> <p class="dwt_publisher"></p> <p class="publishDate">1997-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">377</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/42013886"> <span id="translatedtitle">Development of the 3-D MHD model of the <span class="hlt">solar</span> corona-<span class="hlt">solar</span> <span class="hlt">wind</span> combining system</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">In the framework of integrated numerical space weather prediction, we have developed a 3-D MHD simulation model of the <span class="hlt">solar</span> surface-<span class="hlt">solar</span> <span class="hlt">wind</span> system. We report the construction method of the model and its first results. By implementing a grid system with angularly unstructured and increasing radial spacing, we realized a spherical grid that has no pole singularity and realized a</p> <div class="credits"> <p class="dwt_author">A. Nakamizo; T. Tanaka; Y. Kubo; S. Kamei; H. Shimazu; H. Shinagawa</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">378</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19740005409&hterms=heavy+electron&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dheavy%2Belectron"> <span id="translatedtitle">Effects of heavy ions on electron temperatures in the <span class="hlt">solar</span> corona and <span class="hlt">solar</span> <span class="hlt">wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The effects of the reduction in the thermal conductivity due to heavy ions on electron temperatures in the <span class="hlt">solar</span> corona and <span class="hlt">solar</span> <span class="hlt">wind</span> are examined. Large enhancements of heavy ions in the corona appear to be necessary to give appreciable changes in the thermal gradient of the electrons.</p> <div class="credits"> <p class="dwt_author">Nakada, M. P.</p> <p class="dwt_publisher"></p> <p class="publishDate">1972-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">379</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/1045074"> <span id="translatedtitle">Enabling Technologies for High Penetration of <span class="hlt">Wind</span> and <span class="hlt">Solar</span> Energy</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">High penetration of variable <span class="hlt">wind</span> and <span class="hlt">solar</span> electricity generation will require modifications to the electric power system. This work examines the impacts of variable generation, including uncertainty, ramp rate, ramp range, and potentially excess generation. Time-series simulations were performed in the Texas (ERCOT) grid where different mixes of <span class="hlt">wind</span>, <span class="hlt">solar</span> photovoltaic and concentrating <span class="hlt">solar</span> power provide up to 80% of the electric demand. Different enabling technologies were examined, including conventional generator flexibility, demand response, load shifting, and energy storage. A variety of combinations of these technologies enabled low levels of surplus or curtailed <span class="hlt">wind</span> and <span class="hlt">solar</span> generation depending on the desired penetration of renewable sources. At lower levels of penetration (up to about 30% on an energy basis) increasing flexible generation, combined with demand response may be sufficient to accommodate variability and uncertainty. Introduction of load-shifting through real-time pricing or other market mechanisms further increases the penetration of variable generation. The limited time coincidence of <span class="hlt">wind</span> and <span class="hlt">solar</span> generation presents increasing challenges as these sources provide greater than 50% of total demand. System flexibility must be increased to the point of virtually eliminating must-run baseload generators during periods of high <span class="hlt">wind</span> and <span class="hlt">solar</span> generation. Energy storage also becomes increasingly important as lower cost flexibility options are exhausted. The study examines three classes of energy storage - electricity storage, including batteries and pumped hydro, hybrid storage (compressed-air energy storage), and thermal energy storage. Ignoring long-distance transmission options, a combination of load shifting and storage equal to about 12 hours of average demand may keep renewable energy curtailment below 10% in the simulated system.</p> <div class="credits"> <p class="dwt_author">Denholm, P.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">380</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20020069138&hterms=giannina&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dgiannina"> <span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">Wind</span> Characteristics from SOHO-Sun-Ulysses Quadrature Observations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Over the past few years, we have been running SOHO (<span class="hlt">Solar</span> and Heliospheric Observatory)-Sun-Ulysses quadrature campaigns, aimed at comparing the plasma properties at coronal altitudes with plasma properties at interplanetary distances. Coronal plasma has been observed by SOHO experiments: mainly, we used LASCO (Large Angle and Spectrometric Coronagraph Experiment) data to understand the overall coronal configuration at the time of quadratures and analyzed SUMER (<span class="hlt">Solar</span> Ultraviolet Measurements of Emitted Radiation), CDS (Coronal Diagnostic Spectrometer) and UVCS (Ultraviolet Coronagraph Spectrometer) data to derive its physical characteristics. At interplanetary distances, SWICS (<span class="hlt">Solar</span> <span class="hlt">Wind</span> Ion Composition Spectrometer) and SWOOPS (<span class="hlt">Solar</span> <span class="hlt">Wind</span> Observation over the Poles of the Sun) aboard Ulysses provided us with interplanetary plasma data. Here we report on results from some of the campaigns. We notice that, depending on the geometry of the quadrature, i.e. on whether the radial to Ulysses traverses the corona at high or low latitudes, we are able to study different kinds of <span class="hlt">solar</span> <span class="hlt">wind</span>. In particular, a comparison between low-latitude and high-latitude <span class="hlt">wind</span>, allowed us to provide evidence for differences in the acceleration of polar, fast plasma and equatorial, slow plasma: the latter occurring at higher levels and through a more extended region than fast <span class="hlt">wind</span>. These properties are shared by both the proton and heavy ions outflows. Quadrature observations may provide useful information also on coronal vs. in situ elemental composition. To this end, we analyzed spectra taken in the corona, at altitudes ranging between approx. 1.02 and 2.2 <span class="hlt">solar</span> radii, and derived the abundances of a number of ions, including oxygen and iron. Values of the O/Fe ratio, at coronal levels, have been compared with measurements of this ratio made by SWICS at interplanetary distances. Our results are compared with previous findings and predictions from modeling efforts.</p> <div class="credits"> <p class="dwt_author">Poletto, Giannina; Suess, Steve T.; Six, N. Frank (Technical Monitor)</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_18");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return 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href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a style="font-weight: bold;">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_21");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">381</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012cosp...39.1229M"> <span id="translatedtitle">Electric <span class="hlt">Solar</span> <span class="hlt">Wind</span> Sail (E-sail) mission to asteroids</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">There are an estimated one to two million asteroids of diameter over 1 km in-between the orbits of Mars and Jupiter. Impact threat, mining prospects and the understanding of <span class="hlt">solar</span> system history make asteroids interesting objects for further in-situ studies. Electric <span class="hlt">Solar</span> <span class="hlt">Wind</span> Sail (E-sail) [1] technology enables touring several different asteroids with the same spacecraft. It is a propulsion technology first proposed in 2006 and currently developed with the EUs FP7 funding (http://www.electric-sailing.fi/fp7). The E-sail utilizes long, conducting, highly charged tethers to gather momentum from the <span class="hlt">solar</span> <span class="hlt">wind</span> ions. It does not consume any propellant and is well maneuverable. The Electric <span class="hlt">Solar</span> <span class="hlt">Wind</span> Sail producing 1 N of thrust at 1 AU distance from the Sun could be manufactured to weigh 100-150 kg in total. The constant acceleration gives a large advantage over traditional methods when calculated over the mission lifetime. In a ten year mission a baseline 1 N E-sail could produce 300 MNs of total impulse, Itot. As an example, such a total impulse would be able to move a 3 million ton Earth-threatening asteroid to a safer track [2]. With chemical propellant it would take 100 000 tons of fuel to achieve the same feat. Scientists and miners could have a closer look at several targets and they could decide the next target and the duration of investigations once at the vicinity of the asteroid, so the operations would be very flexible. Such a mission could characterize and map several asteroids, some with rapid fly-bys and a few chosen ones during lengthier rendezvous. [1] Janhunen, P., et. al, Electric <span class="hlt">solar</span> <span class="hlt">wind</span> sail: Towards test missions (Invited article), Rev. Sci. Instrum., 81, 111301, 2010. [2] Merikallio, S. and P. Janhunen, Moving an asteroid with electric <span class="hlt">solar</span> <span class="hlt">wind</span> sail, Astrophys. Space Sci. Trans., 6, 41-48, 2010</p> <div class="credits"> <p class="dwt_author">Merikallio, Sini; Janhunen, Pekka; Toivanen, Petri; Jouni Envall, M.(Tech.).</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-07-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">382</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2002AGUSMSH22C..04C"> <span id="translatedtitle">Inner Heliospheric Gas and Dust from <span class="hlt">Solar</span> <span class="hlt">Wind</span> Charge Exchange</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The Low Energy Neutral Atom (LENA) imager, launched on the IMAGE spacecraft in March of 2000, detects neutral atoms with energies from 10 eV up to >1 keV. Because LENA has low sensitivity to light and looks directly at the Sun every spin during six months of the year, it has observed a neutral component of the <span class="hlt">solar</span> <span class="hlt">wind</span> (NSW) that results when <span class="hlt">solar</span> <span class="hlt">wind</span> ions charge exchange with interstellar neutrals, with dust and with the Earth's geocorona [Collier et al., JGR, 106, 24,893, 2001]. We examine long-term variations in the intensity of the counting rate from the <span class="hlt">solar</span> direction (NSW). Results from year 2001, during which the instrument state remained constant, show a maximum in the count rate between June and July with a long, low count-rate period stretching from mid-November through early March. This annual modulation of <span class="hlt">solar</span> <span class="hlt">wind</span> energetic neutral atom flux at the Earth is interpreted as a pronounced variation of the neutral gas column density between the Sun and the Earth with season. This modulation is evidently dominated by interstellar neutral gas and the <span class="hlt">solar</span> erosion of that gas in the galactic downstream region. It also contains a relatively constant contribution from inner <span class="hlt">solar</span> system dust and relatively smaller variations produced by <span class="hlt">solar</span> <span class="hlt">wind</span> fluctuations and possibly structure in the dust population. The LENA observations place an upper limit on the column density of dust at 1 AU of less than 6x10-19 cm-1. Implications of the LENA data on the interpretation of observations of low frequency electromagnetic waves by Tsurutani et al. [GRL, 21, 633, 1994] will also be considered.</p> <div class="credits"> <p class="dwt_author">Collier, M. R.; Moore, T. E.; Ogilvie, K. W.; Simpson, D.; Fok, M.; Chornay, D.; Keller, J.; Fuselier, S.; Quinn, J.; Wurz, P.; Wuest, M.; Hsieh, J.; Tsurutani, B.</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">383</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/servlets/purl/971292"> <span id="translatedtitle">The genesis <span class="hlt">solar-wind</span> sample return mission</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">The compositions of the Earth's crust and mantle, and those of the Moon and Mars, are relatively well known both isotopically and elementally. The same is true of our knowledge of the asteroid belt composition, based on meteorite analyses. Remote measurements of Venus, the Jovian atmosphere, and the outer planet moons, have provided some estimates of their compositions. The Sun constitutes a large majority, > 99%, of all the matter in the <span class="hlt">solar</span> system. The elemental composition of the photosphere, the visible 'surface' of the Sun, is constrained by absorption lines produced by particles above the surface. Abundances for many elements are reported to the {+-}10 or 20% accuracy level. However, the abundances of other important elements, such as neon, cannot be determined in this way due to a relative lack of atomic states at low excitation energies. Additionally and most importantly, the isotopic composition of the Sun cannot be determined astronomically except for a few species which form molecules above sunspots, and estimates derived from these sources lack the accuracy desired for comparison with meteoritic and planetary surface samples measured on the Earth. The <span class="hlt">solar</span> <span class="hlt">wind</span> spreads a sample of <span class="hlt">solar</span> particles throughout the heliosphere, though the sample is very rarified: collecting a nanogram of oxygen, the third most abundant element, in a square centimeter cross section at the Earth's distance from the Sun takes five years. Nevertheless, foil collectors exposed to the <span class="hlt">solar</span> <span class="hlt">wind</span> for periods of hours on the surface of the Moon during the Apollo missions were used to determine the helium and neon <span class="hlt">solar-wind</span> compositions sufficiently to show that the Earth's atmospheric neon was significantly evolved relative to the Sun. Spacecraft instruments developed subsequently have provided many insights into the composition of the <span class="hlt">solar</span> <span class="hlt">wind</span>, mostly in terms of elemental composition. These instruments have the advantage of observing a number of parameters simultaneously, including charge state distributions, velocities, and densities, all of which have been instrumental in characterizing the nature of the <span class="hlt">solar</span> <span class="hlt">wind</span>. However, these instruments have lacked the ability to make large dynamic range measurements of adjacent isotopes (i.e., {sup 17}O/{sup 16}O {approx} 2500) or provide the permil (tenths of percent) accuracy desirable for comparison with geochemical isotopic measurements. An accurate knowledge of the <span class="hlt">solar</span> and <span class="hlt">solar-wind</span> compositions helps to answer important questions across a number of disciplines. It aids in understanding the acceleration mechanisms of the <span class="hlt">solar</span> <span class="hlt">wind</span>, gives an improved picture of the charged particle environment near the photosphere, it constrains processes within the Sun over its history, and it provides a database by which to compare differences among planetary systems with the <span class="hlt">solar</span> system's starting composition, providing key information on planetary evolution. For example, precise knowledge of <span class="hlt">solar</span> isotopic and elemental compositions of volatile species in the Sun provides a baseline for models of atmospheric evolution over time for Earth, Venus, and Mars. Additionally, volatile and chemically active elements such as C, H, O, N, and S can tell us about processes active during the evolution of the <span class="hlt">solar</span> nebula. A classic example of this is the oxygen isotope system. In the 1970s it was determined that the oxygen isotopic ratio in refractory inclusions in primitive meteorites was enriched {approx}4% in {sup 16}O relative to the average terrestrial, lunar, and thermally processed meteorite materials. In addition, all processed <span class="hlt">solar</span>-system materials appeared to each have a unique oxygen isotopic composition (except the Moon and Earth, which are thought to be formed from the same materials), though differences are in the fraction of a percent range, much smaller than the refractory material {sup 16}O enrichment. Several theories were developed over the years to account for the oxygen isotope heterogeneity, each theory predicting a different <span class="hlt">solar</span> isotopic composition and each invoking a differ</p> <div class="credits"> <p class="dwt_author">Wiens, Roger C [Los Alamos National Laboratory</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">384</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/51515714"> <span id="translatedtitle">STEREO's in-situ perspective on the <span class="hlt">solar</span> minimum <span class="hlt">solar</span> <span class="hlt">wind</span> structure</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">STEREO multipoint measurements of the <span class="hlt">solar</span> <span class="hlt">wind</span> structure with the IMPACT and PLASTIC investigations, near Earth but off the Sun-Earth line, allow its sources and structure to be examined at <span class="hlt">solar</span> minimum when such studies are particularly straightforward. With the aid of 3D models of the heliosphere available at the CCMC, we map the in-situ observations to their <span class="hlt">solar</span> sources</p> <div class="credits"> <p class="dwt_author">J. G. Luhmann; D. Larson; P. Schroeder; C. O. Lee; J. Sauvaud; M. H. Acuna; A. B. Galvin; C. T. Russell; L. Jian; C. N. Arge; D. Odstrcil; P. Riley; R. A. Howard; M. Aschwanden; P. MacNeice; A. Chulaki</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">385</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/22126712"> <span id="translatedtitle">HEMISPHERIC ASYMMETRIES IN THE POLAR <span class="hlt">SOLAR</span> <span class="hlt">WIND</span> OBSERVED BY ULYSSES NEAR THE MINIMA OF <span class="hlt">SOLAR</span> CYCLES 22 AND 23</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">We examined <span class="hlt">solar</span> <span class="hlt">wind</span> plasma and interplanetary magnetic field (IMF) observations from Ulysses' first and third orbits to study hemispheric differences in the properties of the <span class="hlt">solar</span> <span class="hlt">wind</span> and IMF originating from the Sun's large polar coronal holes (PCHs) during the declining and minimum phase of <span class="hlt">solar</span> cycles 22 and 23. We identified hemispheric asymmetries in several parameters, most notably {approx}15%-30% south-to-north differences in averages for the <span class="hlt">solar</span> <span class="hlt">wind</span> density, mass flux, dynamic pressure, and energy flux and the radial and total IMF magnitudes. These differences were driven by relatively larger, more variable <span class="hlt">solar</span> <span class="hlt">wind</span> density and radial IMF between {approx}36 Degree-Sign S-60 Degree-Sign S during the declining phase of <span class="hlt">solar</span> cycles 22 and 23. These observations indicate either a hemispheric asymmetry in the PCH output during the declining and minimum phase of <span class="hlt">solar</span> cycles 22 and 23 with the southern hemisphere being more active than its northern counterpart, or a <span class="hlt">solar</span> cycle effect where the PCH output in both hemispheres is enhanced during periods of higher <span class="hlt">solar</span> activity. We also report a strong linear correlation between these <span class="hlt">solar</span> <span class="hlt">wind</span> and IMF parameters, including the periods of enhanced PCH output, that highlight the connection between the <span class="hlt">solar</span> <span class="hlt">wind</span> mass and energy output and the Sun's magnetic field. That these enhancements were not matched by similar sized variations in <span class="hlt">solar</span> <span class="hlt">wind</span> speed points to the mass and energy responsible for these increases being added to the <span class="hlt">solar</span> <span class="hlt">wind</span> while its flow was subsonic.</p> <div class="credits"> <p class="dwt_author">Ebert, R. W.; Dayeh, M. A.; Desai, M. I.; McComas, D. J. [Southwest Research Institute, P.O. Drawer 28510, San Antonio, TX 78228 (United States); Pogorelov, N. V. [Physics Department, University of Alabama in Huntsville, Huntsville, AL 35899 (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-05-10</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">386</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013ApJ...768..160E"> <span id="translatedtitle">Hemispheric Asymmetries in the Polar <span class="hlt">Solar</span> <span class="hlt">Wind</span> Observed by Ulysses near the Minima of <span class="hlt">Solar</span> Cycles 22 and 23</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We examined <span class="hlt">solar</span> <span class="hlt">wind</span> plasma and interplanetary magnetic field (IMF) observations from Ulysses' first and third orbits to study hemispheric differences in the properties of the <span class="hlt">solar</span> <span class="hlt">wind</span> and IMF originating from the Sun's large polar coronal holes (PCHs) during the declining and minimum phase of <span class="hlt">solar</span> cycles 22 and 23. We identified hemispheric asymmetries in several parameters, most notably ~15%-30% south-to-north differences in averages for the <span class="hlt">solar</span> <span class="hlt">wind</span> density, mass flux, dynamic pressure, and energy flux and the radial and total IMF magnitudes. These differences were driven by relatively larger, more variable <span class="hlt">solar</span> <span class="hlt">wind</span> density and radial IMF between ~36°S-60°S during the declining phase of <span class="hlt">solar</span> cycles 22 and 23. These observations indicate either a hemispheric asymmetry in the PCH output during the declining and minimum phase of <span class="hlt">solar</span> cycles 22 and 23 with the southern hemisphere being more active than its northern counterpart, or a <span class="hlt">solar</span> cycle effect where the PCH output in both hemispheres is enhanced during periods of higher <span class="hlt">solar</span> activity. We also report a strong linear correlation between these <span class="hlt">solar</span> <span class="hlt">wind</span> and IMF parameters, including the periods of enhanced PCH output, that highlight the connection between the <span class="hlt">solar</span> <span class="hlt">wind</span> mass and energy output and the Sun's magnetic field. That these enhancements were not matched by similar sized variations in <span class="hlt">solar</span> <span class="hlt">wind</span> speed points to the mass and energy responsible for these increases being added to the <span class="hlt">solar</span> <span class="hlt">wind</span> while its flow was subsonic.</p> <div class="credits"> <p class="dwt_author">Ebert, R. W.; Dayeh, M. A.; Desai, M. I.; McComas, D. J.; Pogorelov, N. V.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">387</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19990028046&hterms=solar+corona+topology&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsolar%2Bcorona%2Btopology"> <span id="translatedtitle">Signature of open magnetic field lines in the extended <span class="hlt">solar</span> corona and of <span class="hlt">solar</span> <span class="hlt">wind</span> acceleration</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The observations carried out with the ultraviolet coronagraph spectrometer onboard the <span class="hlt">Solar</span> and Heliospheric Observatory (SOHO) are discussed. The purpose of the observations was to determine the line of sight and radial velocity fields in coronal regions with different magnetic topology. The results showed that the regions where the high speed <span class="hlt">solar</span> <span class="hlt">wind</span> flows along open field lines are characterized by O VI 1032 and HI Lyman alpha 1216 lines. The global coronal maps of the line of sight velocity were reconstructed. The corona height, where the <span class="hlt">solar</span> <span class="hlt">wind</span> reaches 100 km/s, was determined.</p> <div class="credits"> <p class="dwt_author">Antonucci, E.; Giordano, S.; Benna, C.; Kohl, J. L.; Noci, G.; Michels, J.; Fineschi, S.</p> <p class="dwt_publisher"></p> <p class="publishDate">1997-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">388</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/22036908"> <span id="translatedtitle">THREE-DIMENSIONAL EVOLUTION OF <span class="hlt">SOLAR</span> <span class="hlt">WIND</span> DURING <span class="hlt">SOLAR</span> CYCLES 22-24</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">This paper presents an analysis of three-dimensional evolution of <span class="hlt">solar</span> <span class="hlt">wind</span> density turbulence and speed at various levels of <span class="hlt">solar</span> activity between <span class="hlt">solar</span> cycles 22 and 24. The <span class="hlt">solar</span> <span class="hlt">wind</span> data used in this study have been obtained from the interplanetary scintillation (IPS) measurements made at the Ooty Radio Telescope, operating at 327 MHz. Results show that (1) on average, there was a downward trend in density turbulence from the maximum of cycle 22 to the deep minimum phase of cycle 23; (2) the scattering diameter of the corona around the Sun shrunk steadily toward the Sun, starting from 2003 to the smallest size at the deepest minimum, and it corresponded to a reduction of {approx}50% in the density turbulence between the maximum and minimum phases of cycle 23; (3) the latitudinal distribution of the <span class="hlt">solar</span> <span class="hlt">wind</span> speed was significantly different between the minima of cycles 22 and 23. At the minimum phase of <span class="hlt">solar</span> cycle 22, when the underlying <span class="hlt">solar</span> magnetic field was simple and nearly dipole in nature, the high-speed streams were observed from the poles to {approx}30 Degree-Sign latitudes in both hemispheres. In contrast, in the long-decay phase of cycle 23, the sources of the high-speed <span class="hlt">wind</span> at both poles, in accordance with the weak polar fields, occupied narrow latitude belts from poles to {approx}60 Degree-Sign latitudes. Moreover, in agreement with the large amplitude of the heliospheric current sheet, the low-speed <span class="hlt">wind</span> prevailed in the low- and mid-latitude regions of the heliosphere. (4) At the transition phase between cycles 23 and 24, the high levels of density and density turbulence were observed close to the heliospheric equator and the low-speed <span class="hlt">solar</span> <span class="hlt">wind</span> extended from the equatorial-to-mid-latitude regions. The above results in comparison with Ulysses and other in situ measurements suggest that the source of the <span class="hlt">solar</span> <span class="hlt">wind</span> has changed globally, with the important implication that the supply of mass and energy from the Sun to the interplanetary space has been significantly reduced in the prolonged period of low <span class="hlt">solar</span> activity. The IPS results are consistent with the onset and growth of the current <span class="hlt">solar</span> cycle 24, starting from the middle of 2009. However, the width of the high-speed <span class="hlt">wind</span> at the northern high latitudes has almost disappeared and indicates that the ascending phase of the current cycle has almost reached the maximum phase in the northern hemisphere of the Sun. However, in the southern part of the hemisphere, the <span class="hlt">solar</span> activity has yet to develop and/or increase.</p> <div class="credits"> <p class="dwt_author">Manoharan, P. K., E-mail: mano@ncra.tifr.res.in [Radio Astronomy Centre, National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Udhagamandalam (Ooty) 643001 (India)</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">389</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2004AGUFMSH51C0286I"> <span id="translatedtitle">The Turbulent Correlation Length in the Distant <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">A model of turbulent evolution in the distant <span class="hlt">solar</span> <span class="hlt">wind</span> has recently been presented which incorporates the detailed quasilinear generation of fluctuations by interstellar pickup protons to drive the turbulence [Isenberg et al., ApJ, 592, 564, 2003; Isenberg, ApJ, submitted, 2004]. The dissipation of the turbulent fluctuations at the standard Kolmogorov rate has been shown to provide a reasonable agreement with observed heating of the core <span class="hlt">solar</span> <span class="hlt">wind</span> protons out to almost 75 AU [Smith et al., ApJ, submitted, 2004]. In this model, the correlation length of the turbulence ? (r) is a fundamental quantity, since it controls the turbulent dissipation rate. Although analysis of observations out to 30 AU indicates that ? steadily increases with r, the model calls for this quantity to decrease beyond about 10 AU due to the turbulent driving by the pickup protons. Here, we investigate modifications to the present model which will bring the correlation length more in line with the observations. These modifications will, in turn, affect the predicted turbulent intensities and <span class="hlt">solar</span> <span class="hlt">wind</span> temperatures. We will present and discuss the modified model and compare its results with <span class="hlt">solar</span> <span class="hlt">wind</span> observations.</p> <div class="credits"> <p class="dwt_author">Isenberg, P. A.; Smith, C. W.</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">390</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19730003086&hterms=ruhe&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Druhe"> <span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">wind</span> interaction with Comet Bennett (1969i</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The relations are examined between the <span class="hlt">solar-wind</span> and Comet Bennett during the period 23 March to 5 April 1970. A large kink was observed in the ion tail of the comet on April 4, but no <span class="hlt">solar</span> <span class="hlt">wind</span> stream was observed in the ecliptic plane which could have caused the kink. Thus, either there was no correlation between the <span class="hlt">solar</span> <span class="hlt">wind</span> at the earth and that at Comet Bennett (which was 40 deg above the ecliptic) or the kink was caused by something other than a high-speed stream. The fine structure visible in photographs of the kink favors the second of these alternatives. It is shown that a shock probably passed through Comet Bennett on March 31, but no effect was seen in photographs of the comet. A stream preceded by another shock and a large abrupt change in momentum flux might have intercepted the comet between 24 March and 28 March, but again no effect was seen in photographs of the Comet. In view of these results, the possibility must be considered that a large, abrupt change in momentum flux of the <span class="hlt">solar-wind</span> is neither necessary nor sufficient to cause a large kink in a comet tail.</p> <div class="credits"> <p class="dwt_author">Burlaga, L. F.; Rahe, J.; Donn, B. D.; Neugebauer, M.</p> <p class="dwt_publisher"></p> <p class="publishDate">1972-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">391</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/41996036"> <span id="translatedtitle">Electromagnetic proton\\/proton instabilities in the <span class="hlt">solar</span> <span class="hlt">wind</span>: Simulations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Proton velocity distributions in the high-speed <span class="hlt">solar</span> <span class="hlt">wind</span> are sometimes observed as two components of approximately equal temperature with an average relative drift velocity parallel to the background magnetic field. This relative drift gives rise to several proton\\/proton instabilities; for representative parameters, linear Vlasov theory demonstrates that the electromagnetic modes most likely to grow are a magnetosonic instability and an</p> <div class="credits"> <p class="dwt_author">William Daughton; S. Peter Gary; Dan Winske</p> <p class="dwt_publisher"></p> <p class="publishDate">1999-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">392</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/54149807"> <span id="translatedtitle">Detection of fast nanoparticles in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Dust grains in the nanometer range bridge the gap between atoms and larger grains made of bulk material. Their small size embodies them with special properties. Due to their high relative surface area, they have a high charge-to-mass ratio, so that the Lorentz force in the <span class="hlt">solar</span> <span class="hlt">wind</span> magnetic field exceeds the gravitational force and other forces by a large</p> <div class="credits"> <p class="dwt_author">N. Meyer-Vernet; A. Czechowski; I. Mann; M. Maksimovic; A. Lecacheux; K. Goetz; M. L. Kaiser; O. C. St. Cyr; S. D. Bale; G. Le Chat</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">393</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/n851l842h68n552j.pdf"> <span id="translatedtitle">Energy coupling between the <span class="hlt">solar</span> <span class="hlt">wind</span> and the magnetosphere</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">This paper describes in detail how we are led to the first approximation expression for the <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere energy coupling function ?, which correlates well with the total energy consumption rate UTof the magnetosphere. It is shown that ? is the primary factor which controls the time development of magnetospheric substorms and storms. The finding of this particular expression ?</p> <div class="credits"> <p class="dwt_author">S.-I. Akasofu</p> <p class="dwt_publisher"></p> <p class="publishDate">1981-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">394</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/54205319"> <span id="translatedtitle">Planetary Mass Spectrometry: From Atmospheres to the <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Measurement of the bulk composition and isotopic fractionation of planetary atmospheres yields essential information about their origin, evolution and eventual loss. In particular, measurements from below the homopause out through the exosphere to the <span class="hlt">solar</span> <span class="hlt">wind</span> (e.g., at Mars and Venus) or to a planetary magnetosphere (e.g., at Titan) are essential to understanding processes driving atmospheric evolution and loss. Over</p> <div class="credits"> <p class="dwt_author">D. T. Young; J. H. Waite; A. de Los Santos; G. P. Miller; J. L. Burch; P. Wilson; K. S. Pickens; T. G. Brockwell; R. Gomez; J. Grimes; E. L. Patrick; A. Richter; J. M. Roberts; B. D. Teolis; J. H. Westlake</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">395</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ntis.gov/search/product.aspx?ABBR=N7918872"> <span id="translatedtitle">Studies on the <span class="hlt">Solar</span> <span class="hlt">Wind</span> Approaching the Magnetopause.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ntis.gov/search/index.aspx">National Technical Information Service (NTIS)</a></p> <p class="result-summary">The approach of the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma to the magnetopause is analyzed considering the particle motion only in the equatorial plane. The assumed radial-symmetric structure of the earth's dipole-residue field, reaching beyond the magnetopause, causes a defl...</p> <div class="credits"> <p class="dwt_author">H. Rucker O. M. Burkard</p> <p class="dwt_publisher"></p> <p class="publishDate">1976-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">396</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19950048909&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3D1.3"> <span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">wind</span> oscillations with a 1.3 year period</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The Interplanetary Monitoring Platform 8 (IMP-8) and Voyager 2 spacecraft have recently detected a very strong modulation in the <span class="hlt">solar</span> <span class="hlt">wind</span> speed with an approximately 1.3 year period. Combined with evidence from long-term auroral and magnetometer studies, this suggests that fundamental changes in the Sun occur on a roughly 1.3 year time scale.</p> <div class="credits"> <p class="dwt_author">Richardson, John D.; Paularena, Karolen I.; Belcher, John W.; Lazarus, Alan J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1994-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">397</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/54941789"> <span id="translatedtitle">Alfvénic Turbulence and the Acceleration of the Fast <span class="hlt">Solar</span> <span class="hlt">Wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Alfvenic turbulence is usually invoked and used in many <span class="hlt">solar</span> <span class="hlt">wind</span> models (Isenberg & Hollweg 1982, Tu et al. 1984, Hu et al. 2000, Li 2003, Isenberg 2004) as a process responsible for the transfer of energy released at large scales in the photosphere towards small scales in the corona, where it is dissipated. Usually an initial spectrum is prescribed</p> <div class="credits"> <p class="dwt_author">A. Verdini; M. Velli; E. Buchlin</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">398</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/jz/v069/i007/JZ069i007p01169/JZ069i007p01169.pdf"> <span id="translatedtitle">Shape of the Geomagnetic Field <span class="hlt">Solar</span> <span class="hlt">Wind</span> Boundary</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The shape of the boundary of the geomagnetic field in a <span class="hlt">solar</span> <span class="hlt">wind</span> has been calculated by a self-consistent method in which, in first order, approximate magnetic fields are used to calculate a boundary surface. The electric currents in this boundary produce mag- netic fields, which can be calculated once the first surface is known. These are added to the</p> <div class="credits"> <p class="dwt_author">Gilbert D. Mead; David B. Beard</p> <p class="dwt_publisher"></p> <p class="publishDate">1964-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">399</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/ja/v086/iA07/JA086iA07p05438/JA086iA07p05438.pdf"> <span id="translatedtitle">Coronal Streamers in the <span class="hlt">Solar</span> <span class="hlt">Wind</span> at 1 AU</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Examination of <span class="hlt">solar</span> <span class="hlt">wind</span> plasma data obtained by the Los Alamos experiments on Imp 6, 7, and 8 during the 1971 - 1978 interval has revealed a frequent association between minimums in helium abundance and maximums in proton density. These events occur at low flow speeds and are strongly correlated with polarity reversals in the interplanetary magnetic field. A large</p> <div class="credits"> <p class="dwt_author">J. T. Gosling; G. Borrini; J. R. Asbridge; S. J. Bame; W. C. Feldman; R. T. Hansen</p> <p class="dwt_publisher"></p> <p class="publishDate">1981-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">400</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/ja/v087/iA08/JA087iA08p06153/JA087iA08p06153.pdf"> <span id="translatedtitle">Geomagnetic and <span class="hlt">solar</span> <span class="hlt">wind</span> cycles, 1900-1975</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Using a criterion based on sunspot number alone, the time series of the annual average has been decomposed into the two periodic functions R and I, which are nearly 180 deg out of phase and have closely related amplitudes. The R and I components are interpreted in terms of the <span class="hlt">solar</span> <span class="hlt">wind</span>, and it is found that the R component</p> <div class="credits"> <p class="dwt_author">Joan Feynman</p> <p class="dwt_publisher"></p> <p class="publishDate">1982-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_19");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> 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showDiv("page_22");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">401</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/ja/v103/iA08/98JA01388/98JA01388.pdf"> <span id="translatedtitle">Characteristics of the <span class="hlt">solar</span> <span class="hlt">wind</span> controlled auroral emissions</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">We performed a high-time resolution (5 min) correlative study of the energy deposition rate in the northern auroral zone with the concurrent <span class="hlt">solar</span> <span class="hlt">wind</span> plasma and interplanetary magnetic field (IMF) observations for a 4 month period from March 30 to July 29, 1996. Auroral power, inferred by auroral emissions, was derived from images acquired by the ultraviolet imager (UVI) on</p> <div class="credits"> <p class="dwt_author">K. Liou; P. T. Newell; C.-I. Meng; M. Brittnacher; G. Parks</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">402</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/48924970"> <span id="translatedtitle">Exospheric distributions of minor ions in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">We investigate the acceleration of heavy <span class="hlt">solar</span> <span class="hlt">wind</span> ions on the basis of an exospheric Lorentzian model and show that the heavy ions can flow faster than the protons when their temperatures in the corona are more than proportional to their mass. The Lorentzian kinetic exospheric model [Pierrard and Lemaire, 1996], initially developed only for electrons and protons of the</p> <div class="credits"> <p class="dwt_author">V. Pierrard; H. Lamy; J. Lemaire</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">403</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/54605973"> <span id="translatedtitle">Magnetized vortex tubes in the <span class="hlt">solar</span> <span class="hlt">wind</span> plasma</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">We make new applications of our previously proposed method for estimating the strain-rate tensor and vorticity vector in plasmas (concerning the local deformation and self rotation of the plasma fluid elements, respectively) solely from magnetic field time series. Here we use <span class="hlt">solar</span> <span class="hlt">wind</span> measurements of Ulysses spacecraft made in the outer heliosphere, on and off the ecliptic plane, during the</p> <div class="credits"> <p class="dwt_author">J. M. Polygiannakis; X. Moussas</p> <p class="dwt_publisher"></p> <p class="publishDate">2000-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">404</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/sw/sw0606/2005SW000200/2005SW000200.pdf"> <span id="translatedtitle">On the geomagnetic effects of <span class="hlt">solar</span> <span class="hlt">wind</span> interplanetary magnetic structures</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">We present in this work a statistical study of the geoeffectiveness of the <span class="hlt">solar</span> <span class="hlt">wind</span> magnetic interplanetary structures over the entire observational period (1964–2003). The structures studied were magnetic clouds (MCs, 170 events), corotating interaction regions (CIRs, 727 events) and interplanetary shocks (830 events). The geoeffectiveness was assessed in terms of the geomagnetic index Kp, AE, and Dst peak values</p> <div class="credits"> <p class="dwt_author">E. Echer; W. D. Gonzalez; M. V. Alves</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">405</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013JGRA..118.1379J"> <span id="translatedtitle">Orientation of <span class="hlt">solar</span> <span class="hlt">wind</span> dynamic pressure phase fronts</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Orientation of structures in the <span class="hlt">solar</span> <span class="hlt">wind</span> plays an important role when attempting to use upstream observations at L1 for prediction of subsequent conditions near the Earth. In this study, the relationship between <span class="hlt">solar</span> <span class="hlt">wind</span> dynamic pressure forcing and geosynchronous magnetic field response is used to determine a very large set of lagged correlations between the ACE and GOES satellites. Effects due to tilted <span class="hlt">solar</span> <span class="hlt">wind</span> structures are explored using the dispersion of arrival times relative to a simple phase plane model. Assuming that structure phase-front normal vectors were located in the GSE-xy plane, we found a characteristic azimuth of 15°. Similar analysis carried out with velocity scaling according to the Parker spiral model did not produce an improved fit. Binning by average interplanetary magnetic field (IMF) B? orientation produced a clear pattern in characteristic azimuth, with phase-front normals perpendicular to both the predominant Parker spiral orientation and the less common ortho-spiral configuration. An empirical relationship ?n°=-45°sin(2?B) was found to predict phase-front normal azimuth over the entire range of observed IMF azimuths. The effects of lateral displacement from the Sun-Earth line in the GSE-z direction are comparable to those for GSE-y, indicating that <span class="hlt">solar</span> <span class="hlt">wind</span> structures are often significantly inclined with respect to the ecliptic plane.</p> <div class="credits"> <p class="dwt_author">Jackel, Brian J.; Cameron, Taylor; Weygand, James M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">406</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/19238948"> <span id="translatedtitle">Air emissions due to <span class="hlt">wind</span> and <span class="hlt">solar</span> power.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Renewables portfolio standards (RPS) encourage large-scale deployment of <span class="hlt">wind</span> and <span class="hlt">solar</span> electric power. Their power output varies rapidly, even when several sites are added together. In many locations, natural gas generators are the lowest cost resource available to compensate for this variability, and must ramp up and down quickly to keep the grid stable, affecting their emissions of NOx and CO2. We model a <span class="hlt">wind</span> or <span class="hlt">solar</span> photovoltaic plus gas system using measured 1-min time-resolved emissions and heat rate data from two types of natural gas generators, and power data from four <span class="hlt">wind</span> plants and one <span class="hlt">solar</span> plant. Over a wide range of renewable penetration, we find CO2 emissions achieve approximately 80% of the emissions reductions expected if the power fluctuations caused no additional emissions. Using steam injection, gas generators achieve only 30-50% of expected NOx emissions reductions, and with dry control NOx emissions increase substantially. We quantify the interaction between state RPSs and NOx constraints, finding that states with substantial RPSs could see significant upward pressure on NOx permit prices, if the gas turbines we modeled are representative of the plants used to mitigate <span class="hlt">wind</span> and <span class="hlt">solar</span> power variability. PMID:19238948</p> <div class="credits"> <p class="dwt_author">Katzenstein, Warren; Apt, Jay</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-15</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">407</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/49831235"> <span id="translatedtitle"><span class="hlt">Wind</span> and <span class="hlt">Solar</span>-Powered Hybrid Prime Power Systems</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">During the past five years, there has been rapid development in the field of <span class="hlt">wind</span> and <span class="hlt">solar</span>-powered hybrid prime power systems. This paper will discuss the following three aspects of this development: A review of accepted techniques for designing and installing a hybrid alternative energy system and also the possible pitfalls one might encounter. System controllers. System controllers play a</p> <div class="credits"> <p class="dwt_author">Allan Russell</p> <p class="dwt_publisher"></p> <p class="publishDate">1984-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">408</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40751773"> <span id="translatedtitle">Kinetic theory of sheath formation in <span class="hlt">solar</span> <span class="hlt">wind</span> plasma</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">We present a general self-consistent kinetic theory for plasma sheath formation in <span class="hlt">solar</span> <span class="hlt">wind</span> plasma. The theory could be applied to anisotropic, as well as to isotropic collisionless plasma without resorting to any simplifications, limitations, or assumptions, such as the necessary existence of a ‘pre-sheath’ region of ions acceleration to ensure the Bohm criterion. The kinetic framework is first applied</p> <div class="credits"> <p class="dwt_author">Vladimir Pines; Marianna Zlatkowski; Arnon Chait</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">409</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/52174946"> <span id="translatedtitle">Radial evolution of large-scale <span class="hlt">solar</span> <span class="hlt">wind</span> structures</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Stream interaction regions (SIRs) and interplanetary coronal mass ejections (ICMEs) are two types of large-scale <span class="hlt">solar</span> <span class="hlt">wind</span> structures. Both can cause interplanetary shocks, generate energetic particles, and affect planetary magnetospheres and ionospheres. One key element of successful space weather forecasting is being able to predict how these two structures evolve radially from the Sun. To answer this question and eliminate</p> <div class="credits"> <p class="dwt_author">Lan Jian</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">410</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/54699159"> <span id="translatedtitle">A statistical study of AE response to <span class="hlt">solar</span> <span class="hlt">wind</span> structures</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">We present in this work a statistical study of the Auroral Eletroject (AE) index response to <span class="hlt">solar</span> <span class="hlt">wind</span> magnetic interplanetary structures over the entire observational period (1964-2003). The structures studied were magnetic clouds (MCs, 170 events), corotating interaction regions (CIRs, 727 events) and interplanetary shocks (830 events). The geoeffectiveness of these structures was assessed in terms of the geomagnetic AE</p> <div class="credits"> <p class="dwt_author">M. V. Alves; E. Echer; W. D. Gonzalez</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">411</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/53656006"> <span id="translatedtitle">Evolution of the <span class="hlt">solar</span> <span class="hlt">wind</span> structure in the outer heliosphere</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Shocks and interaction regions play very important roles in the evolution of large-scale <span class="hlt">solar</span> <span class="hlt">wind</span> structure in the outer heliosphere. This study is based on (1) plasma and magnetic field data observed from Voyager and Pioneer spacecraft, and (2) a quantitative magnetohydrodynamic simulation model. Interaction regions bounded by a forward and a reverse shock begin to form near 1 AU</p> <div class="credits"> <p class="dwt_author">Y. C. Whang; L. F. Burlaga</p> <p class="dwt_publisher"></p> <p class="publishDate">1987-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">412</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/49060716"> <span id="translatedtitle">Tomographic analysis of <span class="hlt">solar</span> <span class="hlt">wind</span> structure using interplanetary scintillation</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">For space weather research it is important to know the quiet <span class="hlt">solar</span> <span class="hlt">wind</span> structure existing as background for transient interplanetary phenomena. Once we know the quiet background structure, transient phenomena are easily recognized as soon as they appear in interplanetary space. The background structure is also important to understand how interplanetary disturbances propagate in it and interact with it. Interplanetary</p> <div class="credits"> <p class="dwt_author">M. Kojima; K. Fujiki; M. Tokumaru; T. Ohmi; Y. Shimizu; A. Yokobe; B. V. Jackson; P. L. Hick</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">413</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/52744924"> <span id="translatedtitle">Multielement RIMS Analysis of Genesis <span class="hlt">Solar</span> <span class="hlt">Wind</span> Collectors</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The samples of <span class="hlt">Solar</span> <span class="hlt">Wind</span> (SW) delivered by the NASA Genesis mission, present significant challenges for surface analytical techniques, in part due to severe terrestrial contamination of the samples on reentry, in part due to the ultra-shallow and diffused ion implants in the SW collector materials. We are performing measurements of metallic elements in the Genesis collectors using Resonance Ionization</p> <div class="credits"> <p class="dwt_author">I. V. Veryovkin; C. E. Tripa; A. V. Zinovev; B. V. King; M. J. Pellin; D. S. Burnett</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">414</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/ja/v079/i025/JA079i025p03489/JA079i025p03489.pdf"> <span id="translatedtitle">Pioneer 10 observations of the <span class="hlt">solar</span> <span class="hlt">wind</span> interaction with Jupiter</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Detailed analysis of the Pioneer 10 plasma analyzer experiment flight data during the Jupiter flyby in late November and early December 1973 has been performed. The observations show that the interaction of Jupiter's magnetic field with the <span class="hlt">solar</span> <span class="hlt">wind</span> is similar in many ways to that at earth, but the scale size is over 100 times larger. Jupiter is found</p> <div class="credits"> <p class="dwt_author">J. H. Wolfe; J. D. Mihalov; H. R. Collard; D. D. McKibbin; L. A. Frank; D. S. Intriligator</p> <p class="dwt_publisher"></p> <p class="publishDate">1974-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">415</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/15042334"> <span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">Wind</span> Magnetic Field Bending of Jovian Dust Trajectories</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">From September 1991 to October 1992, the cosmic dust detector on the Ulysses spacecraft recorded 11 short bursts, or streams, of dust. These dust grains emanated from the jovian system, and their trajectories were strongly affected by <span class="hlt">solar</span> <span class="hlt">wind</span> magnetic field forces. Analyses of the on-board measurements of these fields, and of stream approach directions, show that stream-associated dust grain</p> <div class="credits"> <p class="dwt_author">H. A. Zook; E. Grun; M. Baguhl; D. P. Hamilton; G. Linkert; J.-C. Liou; R. Forsyth; J. L. Phillips</p> <p class="dwt_publisher"></p> <p class="publishDate">1996-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">416</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/42030146"> <span id="translatedtitle">Energy coupling function and <span class="hlt">solar</span> <span class="hlt">wind</span>-magnetosphere dynamo</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The power delivered by the <span class="hlt">solar</span> <span class="hlt">wind</span> dynamo to the open magnetosphere is calculated based on the concept of field line reconnection, independent of the MHD steady reconnection theories. By recognizing a previously overlooked geometrical relationship between the reconnection electric field and the magnetic field, the calculated power is shown to be approximately proportional to the Akasofu-Perreault energy coupling function</p> <div class="credits"> <p class="dwt_author">J. R. Kan; L. C. Lee</p> <p class="dwt_publisher"></p> <p class="publishDate">1979-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">417</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040010591&hterms=specialty+gas+purity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dspecialty%2Bgas%2Bpurity"> <span id="translatedtitle">Genesis <span class="hlt">Solar-Wind</span> Sample Return Mission: The Materials</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The Genesis spacecraft has two primary instruments which passively collect <span class="hlt">solar</span> <span class="hlt">wind</span>. The first is the collector arrays , a set of panels, each of which can deploy separately to sample the different kinds of <span class="hlt">solar</span> <span class="hlt">wind</span> (regimes). The second is the concentrator, an electrostatic mirror which will concentrate ions of mass 4 through mass 25 by about a factor of 20 by focusing them onto a 6 cm diameter target. When not deployed, these instruments fit into a compact canister. After a two year exposure time, the deployed instruments can be folded up, sealed into the canister, and returned to earth for laboratory analysis. Both the collector arrays and the concentrator will contain suites of ultra-high purity target materials, each of which is tailored to enable the analysis of a different family of elements. This abstract is meant to give a brief overview of the Genesis mission, insight into what materials were chosen for flight and why, as well as head s up information as to what will be available to planetary scientist for analysis when the <span class="hlt">solar-wind</span> samples return to Earth in 2003. Earth. The elemental and isotopic abundances of the <span class="hlt">solar</span> <span class="hlt">wind</span> will be analyzed in state-of-the-art laboratories, and a portion of the sample will be archived for the use of future generations of planetary scientists. Technical information about the mission can be found at www.gps.caltech.edu/genesis.</p> <div class="credits"> <p class="dwt_author">Jurewicz, A. J. G.; Burnett, D. S.; Wiens, R. C.; Woolum, D.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">418</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/p23047374x4020v5.pdf"> <span id="translatedtitle">Interaction of the <span class="hlt">solar</span> <span class="hlt">wind</span> with the outer planets</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The hypersonic analog for the interaction of the <span class="hlt">solar</span> <span class="hlt">wind</span> with Jupiter, Saturn, Uranus, Neptune and Pluto is used to provide estimates of shock shapes and locations as well as average magnetosheath and\\/or ionosheath properties for these planets. Several representative spacecraft flyby trajectories (designed for outer-planet ‘Grand Tour’ simulations) are superimposed upon a series of figures in order to provide</p> <div class="credits"> <p class="dwt_author">Murray Dryer; Arthur W. Rizzi; Wen-Wu Shen</p> <p class="dwt_publisher"></p> <p class="publishDate">1973-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">419</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2006AGUFMSM23A0283B"> <span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">Wind</span> Control of Hot Plasma Injections in Saturn's Magnetosphere</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The Ion and Neutral Camera (INCA) on board the Cassini spacecraft have obtained global energetic neutral atom (ENA) images of the hot plasma of Saturn's magnetosphere since July 2004. INCA obtains ENA images in the ~3-200 keV/nuc of protons and O+. The typical observations show hot plasma distributed roughly between 6 to 30 R_S orbiting the planet at a period around the 10h45min rotation period depending on energy and species. However, some observations show how ENA intensity builds up on the nightside during intervals longer than the rotation period which indicates a gradual source of plasma. The intervals are often ended by a dramatic ENA intensification followed by a rotation of the newly injected plasma around the planet. We have selected a few of such intervals when Cassini was in the <span class="hlt">solar</span> <span class="hlt">wind</span> and could obtain <span class="hlt">solar</span> <span class="hlt">wind</span> parameters and simulataneous ENA image sequences. We use the Magnetic Field Experiment (MFE), the Cassini Charge Energy Mass Spectrometer (CHEMS), and the Cassini Plasma Spectrometer Subsystem (CAPS) to study the IMF, <span class="hlt">solar</span> <span class="hlt">wind</span> speed and density during these events and find that Saturn's magnetospheric activity most likely depends more on <span class="hlt">solar</span> <span class="hlt">wind</span> pressure than magnetic field orientation.</p> <div class="credits"> <p class="dwt_author">Brandt, P. C.; Mitchell, D. G.; Rymer, A.; Hill, M.; Paranicas, C. P.</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">420</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/ja/v083/iA04/JA083iA04p01576/JA083iA04p01576.pdf"> <span id="translatedtitle">Numerical simulation of MHD shock waves in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The effects of the interplanetary magnetic field on the propagation speed of shock waves through an ambient <span class="hlt">solar</span> <span class="hlt">wind</span> are examined by numerical solutions of the time-dependent nonlinear equations of motion. The magnetic field always increases the velocity of strong shocks. Although the field may temporarily slow down weak shocks inside 1 AU, it eventually also causes weak shocks to</p> <div class="credits"> <p class="dwt_author">R. S. Steinolfson; Murray Dryer</p> <p class="dwt_publisher"></p> <p class="publishDate">1978-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_20");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return 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Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">421</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/50840996"> <span id="translatedtitle">The Development of <span class="hlt">Wind-Solar</span> Energy Systems in China</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">China is the largest developing country in the world. At present, more and more energy demand gives immense pressure to Chinese government. The inappropriate energy structure must be improved by Chinese government in order to achieve the sustainable development of economy and society. Development and application of renewable energy, such as <span class="hlt">wind</span> energy, <span class="hlt">solar</span> energy, biomass energy, etc., have been</p> <div class="credits"> <p class="dwt_author">Lan Ou-Yang; Yu Ren</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">422</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19850037008&hterms=slow+code&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dslow%2Bcode"> <span id="translatedtitle">Nonlinear evolution of slow waves in the <span class="hlt">solar</span> <span class="hlt">wind</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">It is shown by numerical simulation using a hybrid code that comparison of the nonlinear steepening rate, calculated from fluid theory, with the linear collisionless damping rate defines reasonably well the parameters for which fast and slow MHD waves should steepen. The results indicate that, whereas fast modes should ordinarly steepen, steepened slow waves should occur rarely in the <span class="hlt">solar</span> <span class="hlt">wind</span> near 1 AU.</p> <div class="credits"> <p class="dwt_author">Hada, T.; Kennel, C. F.</p> <p class="dwt_publisher"></p> <p class="pu