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30 results on '"Mason, G.M."'

1. The 18–19 March 2022 series of 3He-rich events observed by Solar Orbiter at 0.36 au compared with EUV, X-ray, and radio observations⋆

Author

Mason, G.M., Nitta, N.V., Bučík, R., Gómez-Herrero, R., Krupar, V, Krucker, S., Ho, G.C., Allen, R.C., Kouloumvakos, A., Wimmer-Schweingruber, R.F., Rodriguez-Pacheco, J., Vecchio, A., and Maksimovic, M.

Subjects
Space and Planetary Science, Astronomy, Astronomy and Astrophysics
Abstract

Context. During the first close perihelion pass of Solar Orbiter, a series of impulsive 3He-rich solar particle events was observed on 18–19 March 2022 from a distance of 0.36 au. In addition to the energetic particle, radio, and X-ray data from Solar Orbiter, the events were observed in radio and/or extreme ultraviolet by STEREO-A, SDO, Wind, and Parker Solar Probe. Aims. Observations of the event series along with remote sensing of flaring and radio emission with only small timing delays due to the close distance allow the association with energetic particles to be determined with much higher accuracy than previously possible from 1 au. Methods. By comparing the onsets of type-III bursts with the arrival of electrons of tens of keV at Solar Orbiter only a few minutes later, it can be seen that, overall, each of the more intense type-III bursts was associated with an electron and ion injection. Extreme ultraviolet data show that the times of the type-III bursts coincide with emission from a small (approximately Earth-sized) loop to the west of a nearby active region. Results. The energetic particle spectra and abundances show typical properties of impulsive 3He-rich flares and, when combined with the remote sensing observations, establish that the particle-accelerating mechanism in this series of events operates near the solar surface in association with magnetic loops, and in the absence of other phenomena such as jets and small coronal mass ejections.

Published
2023

3. MMS Observation of Inverse Energy Dispersion in Shock Drift Accelerated Ions

Author

Lee, S. H, Sibeck, D. G, Hwang, K.-J, Wang, Y, Silveira, M. V. D, Chu, C, Mauk, B. H, Cohen, I. J, Ho, G. C, Mason, G.M, Gold, R. E, Burch, J. L, Giles, B. L, Torbert, R. B, Russell, C. T, and Wei, H

Subjects
Solar Physics
Abstract

The four Magnetospheric Multiscale (MMS) spacecraft observed a ∼1 min burst of energetic ions (50–1000 keV) in the region upstream from the subsolar quasi-perpendicular bow shock on 6 December 2015. The composition, flux levels, and spectral indices of these energetic protons, helium, and oxygen ions greatly resemble those seen in the outer magnetosphere earlier while MMS crossed the magnetopause and differ significantly from those simultaneously observed far upstream by Advanced Composition Explorer (ACE). However, the event cannot be explained solely in terms of leakage from the magnetosphere. The strongly southward orientation of the interplanetary magnetic field (IMF) lines at the time of the event precludes any connection to the magnetosphere. This point is confirmed by the presence of energetic electrons, known to occur on magnetic field lines that graze the bow shock rather than connect to the magnetosphere. We suggest that the ions gradient drifted out of the nearby quasi-parallel foreshock and into the quasi-perpendicular bow shock. Each of the ion species exhibited an inverse energy dispersion. As predicted by models for shock drift acceleration, the energies of the ions increased as 𝜃(sub Bn), the angle between the IMF and the shock normal, increased. Finally, we note that a similar event was observed a few minutes later in the subsolar magnetosheath, indicating that such events can be swept downstream of the bow shock.

Published
2017
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5. Energetic ions in the Venusian system: Insights from the first Solar Orbiter flyby

Author

Allen, R.C., Cernuda, I., Pacheco, D., Berger, L., Xu, Z.G., Forstner, J.L. Freiherr von, Rodríguez-Pacheco, J., Wimmer-Schweingruber, R.F., Ho, G.C., Mason, G.M., Vines, S.K., Khotyaintsev, Y., Horbury, T., Maksimovic, M., Hadid, L.Z., Volwerk, M., Dimmock, A.P., Sorriso-Valvo, L., Stergiopoulou, K., Andrews, G.B., Angelini, V., Bale, S. D., Boden, S., Böttcher, S.I., Chust, T., Eldrum, S., Espada, P.P., Lara, F. Espinosa, Evans, V., Gómez-Herrero, R., Hayes, J.R., Hellín, A.M., Kollhoff, A., Krasnoselskikh, V., Kretzschmar, M., Kühl, P., Kulkarni, S.R., Lees, W.J., Lorfèvre, E., Martin, C., O’Brien, H., Plettemeier, D., Polo, O.R., Prieto, M., Ravanbakhsh, A., Sánchez-Prieto, S., Schlemm, C.E., Seifert, H., Souček, J., Steller, M., Štverák, Š., Terasa, J.C., Trávníček, P., Tyagi, K., Vaivads, A., Vecchio, A., Yedla, M., Allen, R.C., Cernuda, I., Pacheco, D., Berger, L., Xu, Z.G., Forstner, J.L. Freiherr von, Rodríguez-Pacheco, J., Wimmer-Schweingruber, R.F., Ho, G.C., Mason, G.M., Vines, S.K., Khotyaintsev, Y., Horbury, T., Maksimovic, M., Hadid, L.Z., Volwerk, M., Dimmock, A.P., Sorriso-Valvo, L., Stergiopoulou, K., Andrews, G.B., Angelini, V., Bale, S. D., Boden, S., Böttcher, S.I., Chust, T., Eldrum, S., Espada, P.P., Lara, F. Espinosa, Evans, V., Gómez-Herrero, R., Hayes, J.R., Hellín, A.M., Kollhoff, A., Krasnoselskikh, V., Kretzschmar, M., Kühl, P., Kulkarni, S.R., Lees, W.J., Lorfèvre, E., Martin, C., O’Brien, H., Plettemeier, D., Polo, O.R., Prieto, M., Ravanbakhsh, A., Sánchez-Prieto, S., Schlemm, C.E., Seifert, H., Souček, J., Steller, M., Štverák, Š., Terasa, J.C., Trávníček, P., Tyagi, K., Vaivads, A., Vecchio, A., and Yedla, M.

Abstract

Contains fulltext : 242950.pdf (Publisher’s version ) (Open Access)

Published
2021

12. IMPACT: Science goals and firsts with STEREO

Author

Luhmann, J.G., Curtis, D.W., Lin, R.P., Larson, D., Schroeder, P., Cummings, A., Mewaldt, R.A., Stone, E.C., Davis, A., Rosenvinge, T. von, Acuna, M.H., Reames, D., Ng, C., Ogilvie, K., Mueller-Mellin, R., Kunow, H., Mason, G.M., Wiedenbeck, M., Sauvaud, A., Aoustin, C., Louarn, P., Dandouras, J., Korth, A., Bothmer, V., Vasyliunas, V., Sanderson, T., Marsden, R.G., Russell, C.T., Gosling, J.T., Bougeret, J.L., McComas, D.J., Linker, J.A., Riley, P., Odstrcil, D., Pizzo, V.J., Gombosi, T., DeZeeuw, D., and Kecskemety, K.

Published
2005
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13. Epitaxial growth of oxides on semiconductors using flourides as a buffer layer

Author

Hung, L.S., Mason, G.M., Paz-Pujalt, G.R., Agostinelli, J.A., Mir, J.M., Lee, S.T., Blanton, T.N., and Ding, G.

Subjects
Semiconductors -- Research, Physics
Abstract

The stability of flouride against oxidation and the reactivity of the flouride with the oxide influences the successful epitaxial growth of oxides on Si. This was ascertained using intermediate flouride layer X-ray diffractometry and Rutherford backscattering spectrometry to study the flouride oxide reaction. A large number of oxides are stable on CaF2, and some having K, Ba and Li react with CaF2.

Published
1993

14. An overview of the Solar, Anomalous and Magnetospheric Particle Explorer (SAMPEX) mission

Author

Baker, D.N., Mason, G.M., Figueroa, O., Colon, G., Watzin, J.G., and Aleman, R.M.

Subjects
United States. National Aeronautics and Space Administration -- Research, Solar, Anomalous and Magnetospheric Particle Explorer (Artificial satellite) -- Research, Atmospheric research -- Reports, Astrophysics -- Research, Magnetosphere -- Research, Business, Earth sciences, Electronics and electrical industries
Abstract

The scientific objectives of the NASA Small-class Explorer Mission SAMPEX are summarized. A brief history of the Small Explorer program is provided along with a description of the SAMPEX project development and structure. The spacecraft and scientific instrument configuration is presented. The orbit of SAMPEX has an altitude of 520 by 670 km and an 82 |degrees~ inclination. Maximum possible power is provided by articulated solar arrays that point continuously toward the sun. Highly sensitive science instruments point generally toward the local zenith, especially over the terrestrial poles, in order to measure optimally the galactic and solar cosmic ray flux. Energetic magnetospheric particle precipitation is monitored at lower geomagnetic latitudes. The spacecraft uses several innovative approaches including an optical fiber bus, powerful onboard computers, and large solid state memories (instead of tape recorders). Spacecraft communication and data acquisition are discussed and the space- and ground-segment data flows are summarized. A mission lifetime of 3 years is sought with the goal of extending data acquisition over an even longer portion of the 11-year solar activity cycle.

Published
1993

19. ACE Observations of the Bastille Day 2000 Interplanetary Disturbances

Author

Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, USA, Bartol Research Institute, University of Delaware, Newark, Delaware, 19716, U.S.A, Code 692, NASA/Goddard Space Flight Center, Greenbelt, MD, 20771, U.S.A, Los Alamos National Laboratory, Los Alamos, NM, 87545, U.S.A, Space Science and Engineering Division, Southwest Research Institute, P.O. Drawer 28510, Applied Physics Laboratory, Johns Hopkins University, 11100, Johns Hopkins Road, Laurel, Department of Physics, University of Maryland, College Park, MD, U.S.A, Aerospace Corporation, El Segundo, CA, 90245-4691, U.S.A, Institute for the Study of Earth, Oceans and Space, University of New Hampshire, Durham, California Institute of Technology, Pasadena, CA, 91125, U.S.A, Florida Institute of Technology, Melbourne, FL, 32901, U.S.A, Ann Arbor, Zurbuchen, Thomas H., Skoug, R.M., Smith, C.W., Ness, N.F., Burlaga, L.F., McComas, D.J., Gloeckler, George, Haggerty, D.K., Gold, R.E., Desai, M.I., Mason, G.M., Mazur, J.E., Dwyer, J.R., Popecki, M.A., Möbius, E., Cohen, C.M.S., Leske, R.A., Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, USA, Bartol Research Institute, University of Delaware, Newark, Delaware, 19716, U.S.A, Code 692, NASA/Goddard Space Flight Center, Greenbelt, MD, 20771, U.S.A, Los Alamos National Laboratory, Los Alamos, NM, 87545, U.S.A, Space Science and Engineering Division, Southwest Research Institute, P.O. Drawer 28510, Applied Physics Laboratory, Johns Hopkins University, 11100, Johns Hopkins Road, Laurel, Department of Physics, University of Maryland, College Park, MD, U.S.A, Aerospace Corporation, El Segundo, CA, 90245-4691, U.S.A, Institute for the Study of Earth, Oceans and Space, University of New Hampshire, Durham, California Institute of Technology, Pasadena, CA, 91125, U.S.A, Florida Institute of Technology, Melbourne, FL, 32901, U.S.A, Ann Arbor, Zurbuchen, Thomas H., Skoug, R.M., Smith, C.W., Ness, N.F., Burlaga, L.F., McComas, D.J., Gloeckler, George, Haggerty, D.K., Gold, R.E., Desai, M.I., Mason, G.M., Mazur, J.E., Dwyer, J.R., Popecki, M.A., Möbius, E., Cohen, C.M.S., and Leske, R.A.

Abstract

We present ACE observations for the six-day period encompassing the Bastille Day 2000 solar activity. A high level of transient activity at 1 AU, including ICME-driven shocks, magnetic clouds, shock-accelerated energetic particle populations, and solar energetic ions and electrons, are described. We present thermal ion composition signatures for ICMEs and magnetic clouds from which we derive electron temperatures at the source of the disturbances and we describe additional enhancements in some ion species that are clearly related to the transient source. We describe shock acceleration of 0.3-2.0 MeV nucl −1 protons and minor ions and the relative inability of some of the shocks to accelerate significant energetic ion populations near 1 AU. We report the characteristics of < 20 MeV nucl −1 solar energetic ions and < 0.32 MeV electrons and attempt to relate the release of energetic electrons to particular source regions.

Published
2006

20. Observations of the longitudinal spread of solar energetic particle events in solar cycle 24

Author

Cohen, C.M.S., primary, Mason, G.M., additional, Wiedenbeck, M.E., additional, Haggerty, D.K., additional, Gomez-Herrero, R., additional, Christian, E. R., additional, Cummings, A.C., additional, Korth, A., additional, Labrador, A. W., additional, Leske, R.A., additional, Mall, U., additional, Mewaldt, R.A., additional, Stone, E.C., additional, and Rosenvinge, T.T. Von, additional

Published
2012
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21. How Common is Energetic 3He in the Inner Heliosphere?

Author

Wiedenbeck, M.E., Mason, G.M., Christian, E.R., Cohen, C.M.S., Cummings, A.C., Dwyer, J.R., Gold, R.E., Krimigis, S.M., Leske, R.A., Mazur, J.E., Mewaldt, R.A., Slocum, P.L., Stone, E.C., and von Rosenvinge, T.T.

Subjects
*HELIUM ions, *HELIOSPHERE, *INTERPLANETARY medium
Abstract

Using data from the SIS and ULEIS instruments on the Advanced Composition Explorer (ACE) we have identified periods during which energetic 3He is present in near-Earth interplanetary space between November 1997 and May 2002. The data, which cover the energy intervals 0.2–1 MeV/nuc (ULEIS) and 4.5–16.3 MeV/nuc (SIS), show that 3He is present a significant fraction of the time, as would be required if these suprathermal particles were the major source of the 3He being accelerated by shocks in the interplanetary medium. Specifically, we find that energetic 3He is present at least ∼ 60% of the time, and perhaps significantly more often. © 2003 American Institute of Physics [ABSTRACT FROM AUTHOR]

Published
2003
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22. Composition Variations during Large Solar Energetic Particle Events.

Author

Ho, G.C., Roelof, E.C., Mason, G.M., Lario, D., Gold, R.E., Mazur, J.E., and Dwyer, J.R.

Subjects
PARTICLES (Nuclear physics), HELIUM ions, HYDROGEN ions, IRON ions, OXYGEN
Abstract

Recent theoretical work has posited that proton-generated Alfvén waves scatter ions according to their rigidity during propagation from the acceleration region to the observed position. In particular, predictions have been made for the initial behavior of the high energy (> 2 MeV/nucleon) He/H and Fe/O ratios during large solar energetic particle (SEP) events based on this theory. In this paper, we have examined the temporal variations of low energy (∼0.3 MeV/nucleon) hydrogen, helium and iron ions throughout thirty large SEP events using the ULEIS instrument on the ACE spacecraft. These events originated from different solar longitudes; hence we compare events that have similar magnetic connection to minimize the transport effect. All events exhibited an eventual decrease in the He/H ratio as is suggested by the wave-particle model, but the degree of variation of He/H varies from event to event. However, the time variation of the Fe/O ratio does not correlate at all with that of the He/H in most of the events that we studied. © 2003 American Institute of Physics [ABSTRACT FROM AUTHOR]

Published
2003
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29. SAMPEX: NASA's first small explorer satellite

Author

Mason, G.M., primary, Baker, D.N., additional, Blake, J.B., additional, Boughner, R.E., additional, Callis, L.B., additional, Cummings, A.C., additional, Cummings, J.R., additional, Greenspan, M.E., additional, Hamilton, D.C., additional, Hovestadt, D., additional, Kanekal, S.G., additional, Klecker, B., additional, Leske, R.L., additional, Li, X., additional, Looper, M.D., additional, Mazur, J.E., additional, Mewaldt, R.A., additional, Oetliker, M., additional, Scholer, M., additional, Selesnick, R.S., additional, Stone, E.C., additional, von Rosenvinge, T.T., additional, and Williams, D.L., additional

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30. SAMPEX: NASA's first small explorer satellite.

Author

Mason, G.M., Baker, D.N., Blake, J.B., Boughner, R.E., Callis, L.B., Cummings, A.C., Cummings, J.R., Greenspan, M.E., Hamilton, D.C., Hovestadt, D., Kanekal, S.G., Klecker, B., Leske, R.L., Li, X., Looper, M.D., Mazur, J.E., Mewaldt, R.A., Oetliker, M., Scholer, M., and Selesnick, R.S.

Published
1998
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