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604 results on '"Mende, S. B"'

51. Space Experiments with Particle Accelerators: SEPAC

Author

Burch, J. L, Roberts, W. T, Taylor, W. W. L, Kawashima, N, Marshall, J. A, Moses, S. L, Neubert, T, Mende, S. B, and Choueiri, E. Y

Subjects
Meteorology And Climatology
Abstract

The Space Experiments with Particle Accelerators (SEPAC), which flew on the Atmospheric Laboratory for Applications and Science (ATLAS) 1 mission, used new techniques to study natural phenomena in the Earth's upper atmosphere, ionosphere and magnetosphere by introducing energetic perturbations into the system from a high power electron beam with known characteristics. Properties of auroras were studied by directing the electron beam into the upper atmosphere while making measurements of optical emissions. Studies were also performed of the critical ionization velocity phenomenon.

Published
1994
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52. Dynamics of the CRRES barium releases in the magnetosphere

Author

Fuselier, S. A, Mende, S. B, Geller, S. P, Miller, M, Hoffman, R. A, Wygant, J. R, Pongratz, M, Meredith, N. P, and Anderson, R. R

Subjects
Geophysics
Abstract

The Combined Release and Radiation Effects Satellite (CRRES) G-2, G-3, and G-4 ionized and neutral barium cloud positions are triangulated from ground-based optical data. From the time history of the ionized cloud motion perpendicular to the magnetic field, the late time coupling of the ionized cloud with the collisionless ambient plasma in the magnetosphere is investigated for each of the releases. The coupling of the ionized clouds with the ambient medium is quantitatively consistent with predictions from theory in that the coupling time increases with increasing distance from the Earth. Quantitative comparison with simple theory for the couping time also yields reasonable agreement. Other effects not predicted by the theory are discussed in the context of the observations.

Published
1994
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53. Artificial auroras in the upper atmosphere. I - Electron beam injections

Author

Burch, J. L, Mende, S. B, Kawashima, N, Roberts, W. T, Taylor, W. W. L, Neubert, T, Gibson, W. C, Marshall, J. A, and Swenson, G. R

Subjects
Geophysics
Abstract

The Atlas-1 Spacelab payload's Space Experiments with Particle Accelerators generated artificial electron beams for the stimulation of auroral emissions at southern auroral latitudes. Optical measurements were made by the Shuttle Orbiter's onboard TV cameras, as well as by the Atmospheric Emissions Photometric Imager (in both white light and the 427.8 nm N2(+) emission line). Shuttle-based auroral imaging furnished a novel perspective on the artificial auroras; the emissions were traced from 295 km to the 110 km level along the curved magnetic-field lines.

Published
1993

54. Artificial auroras in the upper atmosphere. II - Imaging results

Author

Mende, S. B, Burch, J. L, Swenson, G. R, Aamodt, E. K, Geller, S. P, Rairden, R. L, and Hassler, P. L

Subjects
Geophysics
Abstract

On the ATLAS 1 mission (STS-45, launched March 24, 1992) two experiments, AEPI (Atmospheric Emissions Photometric Imaging) and SEPAC (Space Experiments with Particle Accelerators) performed the first of a series of active experiments intended to probe the atmosphere, ionosphere and magnetosphere with electron beams. The luminous artificial aurora generated by the electron beam interaction was detected and measured by AEPI both in white light and in a narrow wavelength band at 427.8 nm (peak intensity 5 kR). Modelling calculation showed that there was a significant contribution from emissions originating near the spacecraft. The spatial intensity distribution of the observed auroral patch is consistent with emission contribution from both high and low altitude regions. An extended tail in the direction of the shuttle wake was observed in the 427.8 nm channel, consistent with a decay time associated with the dissipation of the hot electron plasma.

Published
1993

55. Spectral characteristics of Shuttle glow

Author

Viereck, R. A, Mende, S. B, Murad, E, Swenson, G. R, Pike, C. P, Culbertson, F. L, and Springer, R. C

Subjects
Spacecraft Design, Testing And Performance
Abstract

The glowing cloud near the ram surfaces of the Space Shuttle was observed with a hand-held, intensified spectrograph operated by the astronauts from the aft-flight-deck of the Space Shuttle. The spectral measurements were made between 400 and 800 nm with a resolution of 3 nm. Analysis of the spectral response of the instrument and the transmission of the Shuttle window was performed on orbit using earth-airglow OH Meinel bands. This analysis resulted in a correction of the Shuttle glow intensity in the spectral region between 700 and 800 nm. The data presented in this report is in better agreement with laboratory measurements of the NO2 continuum.

Published
1992

56. Medium resolution spectra of the shuttle glow in the visible region of the spectrum

Author

Viereck, R. A, Murad, E, Pike, C. P, Mende, S. B, Swenson, G. R, Culbertson, F. L, and Springer, B. C

Subjects
Space Transportation
Abstract

Recent spectral measurements of the visible shuttle glow (lambda = 400 - 800 nm) at medium resolution (1 nm) reveal the same featureless continuum with a maximum near 680 nm that was reported previously. This is also in good agreement with recent laboratory experiments that attribute the glow to the emissions of NO2 formed by the recombination of O + NO. The data that are presented were taken from the aft flight deck with a hand-held spectrograph and from the shuttle bay with a low-light-level television camera. Shuttle glow images and spectra are presented and compared with laboratory data and theory.

Published
1992

57. Charge exchange contamination of CRIT-II barium CIV experiment

Author

Swenson, G. R, Mende, S. B, Meyerott, R. E, and Rairden, R. L

Subjects
Geophysics
Abstract

Experiments have been recently performed which attempted to confirm critical ionization velocity (CIV) ionization by deploying chemicals at high velocity in the ionosphere. Specifically, the CRIT-II rocket performed a barium release in the ionosphere, where observations of Ba(+) resonant emissions following the release are believed to have resulted from the CIV process. Calculations are presented which suggest a significant fraction (if not all) of the Ba(+) observed likely resulted from charge exchange with the thermosphere ions and not through CIV processes. The results presented here are pertinent to other CIV experiments performed in the ionosphere. It is recommended that laboratory measurements should be made of the charge exchange cross section between O(+) and Ba as well as other metal vapors used in CIV experiments.

Published
1991

63. The leading role of atomic oxygen in the collocation of elves and hydroxyl nightglow in the low-latitude mesosphere

Author

Wu, Y. J., primary, Williams, E., additional, Chang, S. C., additional, Chou, J. K., additional, Hsu, R. R., additional, Friedrich, M., additional, Kuo, C. L., additional, Chen, A. B., additional, Peng, K. M., additional, Su, H. T., additional, Frey, H. U., additional, Mende, S. B., additional, Takahashi, Y., additional, and Lee, L. C., additional

Published
2017
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66. The Imager for Sprites and Upper Atmospheric Lightning (ISUAL)

Author

Frey, H. U., primary, Mende, S. B., additional, Harris, S. E., additional, Heetderks, H., additional, Takahashi, Y., additional, Su, H.‐T., additional, Hsu, R.‐R., additional, Chen, A. B., additional, Fukunishi, H., additional, Chang, Y.‐S., additional, and Lee, L.‐C., additional

Published
2016
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69. The Ionospheric Connection Explorer Mission: Mission Goals and Design.

Author

Immel, T. J., England, S. L., Mende, S. B., Heelis, R. A., Englert, C. R., Edelstein, J., Frey, H. U., Korpela, E. J., Taylor, E. R., Craig, W. W., Harris, S. E., Bester, M., Bust, G. S., Crowley, G., Forbes, J. M., Gérard, J.-C., Harlander, J. M., Huba, J. D., Hubert, B., and Kamalabadi, F.

Abstract

The Ionospheric Connection Explorer, or ICON, is a new NASA Explorer mission that will explore the boundary between Earth and space to understand the physical connection between our world and our space environment. This connection is made in the ionosphere, which has long been known to exhibit variability associated with the sun and solar wind. However, it has been recognized in the 21st century that equally significant changes in ionospheric conditions are apparently associated with energy and momentum propagating upward from our own atmosphere. ICON's goal is to weigh the competing impacts of these two drivers as they influence our space environment. Here we describe the specific science objectives that address this goal, as well as the means by which they will be achieved. The instruments selected, the overall performance requirements of the science payload and the operational requirements are also described. ICON's development began in 2013 and the mission is on track for launch in 2018. ICON is developed and managed by the Space Sciences Laboratory at the University of California, Berkeley, with key contributions from several partner institutions. [ABSTRACT FROM AUTHOR]

Published
2018
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71. Estimation of magnetic field mapping accuracy using the pulsating aurora-chorus connection

Author

Nishimura, Y., Bortnik, J., Li, W., Thorne, R. M., Lyons, L.R., Angelopoulos, V., Mende, S. B., Bonnell, J. W., Le Contel, Olivier, Cully, C. M., Ergun, R., Auster, U., Laboratoire de Physique des Plasmas (LPP), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], Physics::Space Physics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience; Although magnetic field models are widely used in magnetosphere-ionosphere coupling studies to perform field-line mapping, their accuracy has been difficult to estimate experimentally. Taking advantage of the high correlation between lower-band chorus and pulsating aurora, we located the THEMIS spacecraft footprint within ˜km accuracy and calculated the differences from mappings given in widely-used Tsyganenko models. Using 13 conjunctions of the THEMIS spacecraft and ground-based imagers, we found that the Tsyganenko model footprints were located within 1°-2° magnetic latitude and 0.1-0.2 h magnetic local time of our derived footprint. The deviation between the footprints has a consistent dependence on geomagnetic activity. Our results showed that the real magnetic field tends to be less stretched than that in the Tsyganenko models during quiet times and comparable to or more stretched during disturbed times. This approach can be used to advance modeling of field lines that connect to the near-Earth plasma sheet.

Published
2011
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72. Multievent study of the correlation between pulsating aurora and whistler mode chorus emissions

Author

Nishimura, Y., Bortnik, J., Li, W., Thorne, R. M., Chen, Lin, Lyons, L.R., Angelopoulos, V., Mende, S. B., Bonnell, J. W., Le Contel, Olivier, Cully, C. M., Ergun, R., Auster, U., Laboratoire de Physique des Plasmas (LPP), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], Physics::Space Physics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Physics::Geophysics
Abstract

International audience; A multievent study was performed using conjugate measurements of the Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft and an all-sky imager during periods of intense lower-band chorus waves. The thirteen identified cases support our previous finding, based on two events, that the intensity modulation of lower-band chorus near the magnetic equator is highly correlated with quasiperiodic pulsating auroral emissions near the spacecraft's magnetic footprint, indicating that lower-band chorus is the driver of the pulsating aurora. Furthermore, we identified a fortuitous measurement made simultaneously by two THEMIS spacecraft with small spatial separation. The two spacecraft were found to be located in a single pulsating chorus patch and the spacecraft footprints were in the same pulsating auroral patch when intense chorus bursts were measured simultaneously, whereas only one of the spacecraft's footprints was in a patch when the other spacecraft did not detect intense chorus. On the basis of this event, we can estimate the pulsating chorus patch size by mapping the pulsating auroral patches from the ionosphere toward the magnetic equator, giving a roughly circular region of ~5000 km diameter for corresponding azimuthally elongated patches with ~100 km size in the ionosphere. Using a ray-tracing-based calculation of the divergence of chorus raypaths from a point source, together with the corresponding resonant energies, we found that the chorus patch size is most probably not a result of ray divergence but a property of the wave excitation region.

Published
2011
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75. Substorms during the August 10-11 sawtooth event

Author

Henderson, M. G., Skoug, R., Donovan, E., Thomsen, M. F., Reeves, G. D., Denton, Michael H., Singer, H. J., McPherron, R. L., Mende, S. B., Immel, T. J., Sigwarth, J. B., and Frank, L. A.

Abstract

Sawtooth events have been identified at geosynchronous orbit as large-amplitude quasiperiodic (2–4 hour period) modulations of the energetic electron and ion fluxes. They are called sawtooth events because the shape of the flux versus time profiles are composed of rapid increases followed by gradual decreases that resemble the teeth on a saw blade. Although much of the phenomenology associated with sawtooth events is substorm-like, there is still debate as to whether the individual teeth are substorms or not. Here we examine each of the teeth associated with the 10–11 August 2000 sawtooth event in detail. We find that all but one of the teeth were associated with injections at geosynchronous orbit and that most of the teeth were consistent with the hypothesis that they are predominantly caused by unusually large and longitudinally extended substorms. A few were unclear or complex, and the final flux enhancement at 1845:36 UT was not a substorm but a solar wind shock-associated disturbance. In addition, the presence of numerous dispersionless flux perturbations in the LANL SOPA data provides support for the hypothesis that solar wind pressure variations can modulate the flux profiles to some extent. For the substorm events we find that the geosynchronous particle injections were neither globally simultaneous nor globally dispersionless but were instead consistent with a nightside/duskside source in most cases. Similarly, we show that the field dipolarizations were also not global and simultaneous. Each of the substorms was also associated with high-latitude negative H bays, middle- and low-latitude positive H bays, a partial recovery in Sym-H, and the onset of Pi2 ULF pulsations. In addition, we show that the auroral distribution develops in a systematic way during each cycle of a sawtooth substorm event. Specifically, a localized auroral onset develops on the lower branch of a thinned double-oval distribution. The location of onset is typically premidnight and often occurs to the west of intense omega band forms. This is followed by westward, eastward, and poleward expansion and the copious production of auroral streamers which can develop in complex patterns including a “spoke-like” morphology. The double-oval configuration thins again during the stretching phase until the next onset occurs and the cycle repeats. A schematic representation of the auroral dynamics associated with sawtooth substorms is also presented.

Published
2006
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79. THEMIS observations of a hot flow anomaly : Solar wind, magnetosheath, and ground-based measurements

Author

Eastwood, J. P., Sibeck, D. G., Angelopoulos, V., Phan, T. D., Bale, S. D., McFadden, J. P., Cully, Christopher, Mende, S. B., Larson, D., Frey, S., Carlson, C. W., Glassmeier, K. -H, Auster, H. U., Roux, A., Le Contel, O., Eastwood, J. P., Sibeck, D. G., Angelopoulos, V., Phan, T. D., Bale, S. D., McFadden, J. P., Cully, Christopher, Mende, S. B., Larson, D., Frey, S., Carlson, C. W., Glassmeier, K. -H, Auster, H. U., Roux, A., and Le Contel, O.

Abstract

The THEMIS spacecraft encountered a Hot Flow Anomaly ( HFA) on the dusk flank of the Earth's bow shock on 4 July 2007, observing it on both sides of the shock. Meanwhile, the THEMIS ground magnetometers traced the progress of the associated Magnetic Impulse Event along the dawn flank of the magnetosphere, providing a unique opportunity to study the transmission of the HFA through the shock and the subsequent downstream response. THEMIS-A, in the solar wind, observed classic HFA signatures. Isotropic electron distributions inside the upstream HFA are attributed to the action of the electron firehose instability. THEMIS-E, just downstream, observed a much more complex disturbance with the pressure perturbation decoupled from the underlying discontinuity. Simple calculations show that the pressure perturbation would be capable of significantly changing the magnetopause location, which is confirmed by the ground-based observations.

Published
2008
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81. Ionization emissions associated with N2+1N band in halos without visible sprite streamers

Author

Kuo, C. L., primary, Williams, E., additional, Bór, J., additional, Lin, Y. H., additional, Lee, L. J., additional, Huang, S. M., additional, Chou, J. K., additional, Chen, A. B., additional, Su, H. T., additional, Hsu, R. R., additional, Sátori, G., additional, Frey, H. U., additional, Mende, S. B., additional, Takahashi, Y., additional, and Lee, L. C., additional

Published
2013
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85. Cluster observation of plasma flow reversal in the magnetotail during a substorm

Author

Lui, A. T. Y., Zheng, Y., Zhang, Y., Livi, S., Reme, H., Dunlop, M. W., Gustafsson, Georg, Mende, S. B., Mouikis, C., Kistler, L. M., Lui, A. T. Y., Zheng, Y., Zhang, Y., Livi, S., Reme, H., Dunlop, M. W., Gustafsson, Georg, Mende, S. B., Mouikis, C., and Kistler, L. M.

Abstract

We investigate in detail a reversal of plasma flow from tailward to earthward detected by Cluster at the downstream distance of similar to 19 RE in the midnight sector of the magnetotail on 22 August 2001. This flow reversal was accompanied by a sign reversal of the B-z component and occurred during the late substorm expansion phase as revealed by simultaneous global view of auroral activity from IMAGE. We examine the associated Hall current system signature, current density, electric field, Lorentz force, and current dissipation/dynamo term, the last two parameters being new features that have not been studied previously for plasma flow reversals. It is found that (1) there was no clear quadrupole Hall current system signature organized by the flow reversal time, (2) the x-component of the Lorentz force did not change sign while the other two did, (3) the timing sequence of flow reversal from the Cluster configuration did not match tailward motion of a single plasma flow source, (4) the electric field was occasionally dawnward, producing a dynamo effect, and (5) the electric field was occasionally larger at the high-latitude plasma sheet than near the neutral sheet. These observations are consistent with the current disruption model for substorms in which these disturbances are due to shifting dominance of multiple current disruption sites and turbulence at the observing location.

Published
2006

86. Magnetospheric and auroral activity during the April 18, 2002 sawtooth event.

Author

Henderson, M. G., Reeves, G. D., Skoug, R., Thomsen, M .F., Denton, Michael H., Mende, S. B., Immel, T. J., Brandt, P. C., Singer, H., Henderson, M. G., Reeves, G. D., Skoug, R., Thomsen, M .F., Denton, Michael H., Mende, S. B., Immel, T. J., Brandt, P. C., and Singer, H.

Abstract

We examine the 18 April 2002 sawtooth event. We find that the strong magnetic field dipolarizations observed in association with each tooth are not global in occurrence but are rather confined to the nightside. In addition, we find that the flux increases are not globally dispersionless. Instead, each tooth is associated with a nonglobal, but wider-than-usual, dispersionless injection region that is consistent with the high Kp versions of the standard injection boundary model (which places the entire nightside segment of geosynchronous orbit tailward of the injection boundary for values of Kp above about 5). We also find evidence that at least one of the teeth was likely triggered by a pressure pulse. The auroral distribution shows a repeatable evolution in which a wide double-oval configuration gradually thins. Following this, a localized substorm-like brightening in the dusk to midnight sector occurs on the lower branch of the double oval which subsequently expands rapidly poleward and azimuthally. A new expanded double oval configuration emerges from this expansion phase activity and the cycle repeats itself for the duration of the sawtooth event. The observations presented give considerable support to the contention that sawtooth events are actually sequences of quasi-periodic substorms. We suggest that sawtooth events can be viewed as a magnetospheric mode similar to Steady Magnetospheric Convection intervals (SMCs) except that for sawtooth events, the flow of energy from the solar wind into the magnetosphere becomes too large to dissipate without the periodic occurrence of substorms. We further suggest that the quasi-periodicity arises because the magnetosphere may only become susceptible to external or internal triggering after it has been driven beyond a stability threshold. This hypothesis can account for the existence of more potential external triggers (in the interplanetary magnetic field or solar wind) than teeth in that the magnetosphere may be selecti

Published
2006

90. Occurrence of elves and lightning during El Niño and La Niña

Author

Wu, Y. J., primary, Chen, A. B., additional, Hsu, H. H., additional, Chou, J. K., additional, Chang, S. C., additional, Lee, L. J., additional, Lee, Y. J., additional, Su, H. T., additional, Kuo, C. L., additional, Hsu, R. R., additional, Frey, H. U., additional, Mende, S. B., additional, Takahashi, Y., additional, and Lee, L. C., additional

Published
2012
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98. The 762 nm emissions of sprites

Author

Kuo, C. L., primary, Chang, S. C., additional, Lee, L. J., additional, Huang, T. Y., additional, Chen, A. B., additional, Su, H. T., additional, Hsu, R. R., additional, Sentman, D. D., additional, Frey, H. U., additional, Mende, S. B., additional, Takahashi, Y., additional, and Lee, L. C., additional

Published
2011
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