Search Results - "Ledvina, S"

Pioneer Venus Orbiter Observations of Solar Wind Driven Magnetosonic Waves Interacting With the Dayside Venusian Ionosphere by Fowler, C. M., Ledvina, S., Chaston, C. C., Persson, M., Ramstad, R., Luhmann, J.

“…We use in situ plasma observations made by the Pioneer Venus Orbiter spacecraft to show for the first time that magnetosonic waves can couple the solar wind to…”
Get full text

Chemical interactions between Saturn's atmosphere and its rings by Waite, Jr, J H, Perryman, R S, Perry, M E, Miller, K E, Bell, J, Cravens, T E, Glein, C R, Grimes, J, Hedman, M, Cuzzi, J, Brockwell, T, Teolis, B, Moore, L, Mitchell, D G, Persoon, A, Kurth, W S, Wahlund, J-E, Morooka, M, Hadid, L Z, Chocron, S, Walker, J, Nagy, A, Yelle, R, Ledvina, S, Johnson, R, Tseng, W, Tucker, O J, Ip, W-H

“…The Pioneer and Voyager spacecraft made close-up measurements of Saturn's ionosphere and upper atmosphere in the 1970s and 1980s that suggested a chemical…”
Get full text

Fourier Analysis of Magnetic Fields in the Ionosphere of Mars by Cravens, T. E., Hamil, O., Renzaglia, A., Ledvina, S. A., Howard, S. K.

“…The two main sources of the magnetic field in the Martian ionosphere are the solar wind interaction with the planet, and, mainly in the southern hemisphere,…”
Get full text

Magnetic Reconnection in the Ionosphere of Mars: The Role of Collisions by Cravens, T. E., Fowler, C. M., Brain, D., Rahmati, A., Xu, S., Ledvina, S. A., Andersson, L., Renzaglia, A. R.

“…This paper evaluates the role of magnetic reconnection in the dayside ionosphere of Mars in the collisional regime and presents some relevant data from the…”
Get full text

A Comparison between Global Solar Magnetohydrodynamic and Potential Field Source Surface Model Results by Riley, Pete, Linker, J. A, Mikić, Z, Lionello, R, Ledvina, S. A, Luhmann, J. G

“…The large-scale, steady-state magnetic field configuration of the solar corona is typically computed using boundary conditions derived from photospheric…”
Get full text

Estimates of Ionospheric Transport and Ion Loss at Mars by Cravens, T. E., Hamil, O., Houston, S., Bougher, S., Ma, Y., Brain, D., Ledvina, S.

“…Ion loss from the topside ionosphere of Mars associated with the solar wind interaction makes an important contribution to the loss of volatiles from this…”
Get full text

Modeling and Simulating Flowing Plasmas and Related Phenomena by Ledvina, S. A., Ma, Y.-J., Kallio, E.

“…Simulation has become a valuable tool that compliments more traditional methods used to understand solar system plasmas and their interactions with planets,…”
Get full text

Energetic ion precipitation at Titan by Cravens, T. E., Robertson, I. P., Ledvina, S. A., Mitchell, D., Krimigis, S. M., Waite Jr, J. H.

“…Energetic protons and oxygen ions have been observed in Saturn's outer magnetosphere and can precipitate into Titan's atmosphere where they deposit energy,…”
Get full text

Pickup ion measurements by MAVEN: A diagnostic of photochemical oxygen escape from Mars by Rahmati, A., Cravens, T. E., Nagy, A. F., Fox, J. L., Bougher, S. W., Lillis, R. J., Ledvina, S. A., Larson, D. E., Dunn, P., Croxell, J. A.

“…A key process populating the oxygen exosphere at Mars is the dissociative recombination of ionospheric O2+, which produces fast oxygen atoms, some of which…”
Get full text

Composition of Titan's ionosphere by Cravens, T. E., Robertson, I. P., Waite, J. H., Yelle, R. V., Kasprzak, W. T., Keller, C. N., Ledvina, S. A., Niemann, H. B., Luhmann, J. G., McNutt, R. L., Ip, W.‐H., De La Haye, V., Mueller‐Wodarg, I., Wahlund, J.‐E., Anicich, V. G., Vuitton, V.

“…We present Cassini Ion and Neutral Mass Spectrometer (INMS) measurements of ion densities on the nightside of Titan from April 16, 2005, and show that a…”
Get full text

A Review of General Physical and Chemical Processes Related to Plasma Sources and Losses for Solar System Magnetospheres by Seki, K., Nagy, A., Jackman, C. M., Crary, F., Fontaine, D., Zarka, P., Wurz, P., Milillo, A., Slavin, J. A., Delcourt, D. C., Wiltberger, M., Ilie, R., Jia, X., Ledvina, S. A., Liemohn, M. W., Schunk, R. W.

“…The aim of this paper is to provide a review of general processes related to plasma sources, their transport, energization, and losses in the planetary…”
Get full text

Cone model-based SEP event calculations for applications to multipoint observations by Luhmann, J.G., Ledvina, S.A., Odstrcil, D., Owens, M.J., Zhao, X.-P., Liu, Yang, Riley, Pete

“…The problem of modeling solar energetic particle (SEP) events is important to both space weather research and forecasting, and yet it has seen relatively…”
Get full text

A comparison of global models for the solar wind interaction with Mars by Brain, D., Barabash, S., Boesswetter, A., Bougher, S., Brecht, S., Chanteur, G., Hurley, D., Dubinin, E., Fang, X., Fraenz, M., Halekas, J., Harnett, E., Holmstrom, M., Kallio, E., Lammer, H., Ledvina, S., Liemohn, M., Liu, K., Luhmann, J., Ma, Y., Modolo, R., Nagy, A., Motschmann, U., Nilsson, H., Shinagawa, H., Simon, S., Terada, N.

“…We present initial results from the first community-wide effort to compare global plasma interaction model results for Mars. Seven modeling groups participated…”
Get full text

Atomic structure and specificity of bacterial periplasmic receptors for active transport and chemotaxis: variation of common themes by Quiocho, F A, Ledvina, P S

“…Crystallographic structure refinement at very high resolutions of a dozen periplasmic receptors has revealed that, though they have different sizes (26 to 60…”
Get more information

Ion distributions in Saturn's magnetosphere near Titan by Ledvina, S. A., Cravens, T. E., Kecskeméty, K.

“…Titan's interaction with Saturn's magnetosphere is studied using a combination of a three‐dimensional (3‐D) single‐fluid magnetohydrodynamic (MHD) simulation…”
Get full text

Venus Express observations of atmospheric oxygen escape during the passage of several coronal mass ejections by Luhmann, J. G., Fedorov, A., Barabash, S., Carlsson, E., Futaana, Y., Zhang, T. L., Russell, C. T., Lyon, J. G., Ledvina, S. A., Brain, D. A.

“…The solar wind interaction contributes to the loss of Venus atmospheric constituents, especially oxygen, by direct antisunward acceleration of planetary ions…”
Get full text

Oxygen Ions Observed Near Saturn's A Ring by Waite, J. H, Cravens, T. E, Ip, W.-H, Kasprzak, W. T, Luhmann, J. G, McNutt, R. L, Niemann, H. B, Yelle, R. V, Mueller-Wodarg, I, Ledvina, S. A, Scherer, S

“…Ions were detected in the vicinity of Saturn's A ring by the Ion and Neutral Mass Spectrometer (INMS) instrument onboard the Cassini Orbiter during the…”
Get full text

Investigating magnetospheric interaction effects on Titan’s ionosphere with the Cassini orbiter Ion Neutral Mass Spectrometer, Langmuir Probe and magnetometer observations during targeted flybys by Luhmann, J.G., Ulusen, D., Ledvina, S.A., Mandt, K., Magee, B., Waite, J.H., Westlake, J., Cravens, T.E., Robertson, I., Edberg, N., Agren, K., Wahlund, J.-E., Ma, Y.-J., Wei, H., Russell, C.T., Dougherty, M.K.

“…► We examined the collected Cassini flyby ionospheric profiles for signs of magnetospheric influences. ► The previously found solar control dominates the…”
Get full text

Dynamical and magnetic field time constants for Titan's ionosphere: Empirical estimates and comparisons with Venus by Cravens, T. E., Richard, M., Ma, Y.-J., Bertucci, C., Luhmann, J. G., Ledvina, S., Robertson, I. P., Wahlund, J.-E., Ågren, K., Cui, J., Muller-Wodarg, I., Waite, J. H., Dougherty, M., Bell, J., Ulusen, D.

“…Plasma in Titan's ionosphere flows in response to forcing from thermal pressure gradients, magnetic forces, gravity, and ion‐neutral collisions. This paper…”
Get full text

Titan's ionosphere: Model comparisons with Cassini Ta data by Cravens, T. E., Robertson, I. P., Clark, J., Wahlund, J.-E., Waite Jr, J. H., Ledvina, S. A., Niemann, H. B., Yelle, R. V., Kasprzak, W. T., Luhmann, J. G., McNutt, R. L., Ip, W.-H., De La Haye, V., Müller-Wodarg, I., Young, D. T., Coates, A. J.

“…On October 26, 2004, during its first encounter with Titan (Ta), the Cassini Orbiter moved from the dayside to the nightside with a closest approach altitude…”
Get full text