Search Publications
Properties of the magnetospheric backward wave oscillator inferred from CLUSTER measurements of VLF chorus elements
Gurnett, D.; MacúšOvá, E.; SantolíK, O. +6 more
According to the backward wave oscillator (BWO) model, a sharp gradient (or step-like deformation) on the electron distribution function is the most important factor in chorus generation, but such a feature is very difficult to observe directly. The properties of the step in the BWO model determine the dimensionless parameterqquantifying the exces…
Different Bz response regions in the nightside magnetosphere after the arrival of an interplanetary shock: Multipoint observations compared with MHD simulations
Wang, C.; Wang, Y.; Sun, T. R.
We present different magnetic field changes in the nightside magnetosphere in response to the interplanetary (IP) shock on 17 December 2007, using multiple spacecraft observations and global MHD simulations. The coexistence of two distinct Bz response regions in the nightside magnetosphere in a single event has been observationally iden…
Upstream-generated Pc3 ULF wave signatures observed near the Earth's cusp
Yeoman, T. K.; Wright, D. M.; Kim, H. +3 more
Pc3 pulsations (frequency ∼20-100 mHz) which originate in the ion foreshock upstream of the Earth's bow shock due to the interaction between reflected ions and the solar wind are frequently observed in ground-based pulsation magnetometer data. Previous studies have noted increased Pc3 wave power in the vicinity of the dayside cusp and inferred tha…
Cassini UVIS observations of Titan nightglow spectra
West, Robert A.; Esposito, Larry W.; Gustin, Jacques +6 more
In this paper we present the first nightside EUV and FUV airglow limb spectra of Titan showing molecular emissions. The Cassini Ultraviolet Imaging Spectrograph (UVIS) observed photon emissions of Titan's day and night limb-airglow and disk-airglow on multiple occasions, including during an eclipse observation. The 71 airglow observations analyzed…
A study of the changes of the near-Earth plasma sheet and lobe driven by multiple substorms: Comparison with a full particle simulation of reconnection
Sauvaud, J. -A.; Balogh, A.; Kistler, L. M. +9 more
Comparisons of multispacecraft observations and full-particle simulations are used to understand magnetotail changes during substorms and the related cross-tail current disruptions/reductions. We first show that the electric field accompanying current disruptions can be measured in the tail lobe from the drift velocity of oxygen beams. A stormy pe…
Deformation of plasma bubbles and the associated field aligned current system during substorm recovery phase
Deng, X. H.; Huang, S. Y.; Zhou, M. +2 more
Multiple plasma bubbles have been detected by CLUSTER satellites on August 15th 2001 in midtail (∼-18 Re). Those bubbles can be classified into two types. Type-I bubbles are similar to those bubbles in previous studies [ Sergeev et al., 1996; Walsh et al., 2009]. Unlike type-I bubbles, the trailing parts/tails of type-II bubbles are much more dyna…
Polarization and direction of arrival of Jovian quasiperiodic bursts observed by Cassini
Cecconi, B.; Kimura, T.; Misawa, H. +4 more
Jovian quasiperiodic (QP) radio bursts are suspected to be associated with relativistic particle accelerations occurring with a quasiperiodicity between a few minutes and a few tens of minutes in Jupiter's polar magnetosphere. Understanding the excitation and propagation of QP bursts could help us to better understand this periodic energization pr…
Experimental evaluation of common spacecraft data analysis techniques for reconnection region analysis in a laboratory plasma
Yoo, Jongsoo; Yamada, Masaaki
A laboratory plasma is utilized to assess the effectiveness of several prominent spacecraft data analysis techniques. These include minimum variance analysis on the magnetic field (MVAB) and various boundary-crossing time analyses (BCTA) such as the constant velocity approach (CVA), constant thickness approach (CTA), and minimum thickness variance…
Cluster observations of band-limited Pc 1 waves associated with streaming H+ and O+ ions in the high-altitude plasma mantle
Glassmeier, K. -H.; Lavraud, B.; Rème, H. +12 more
Bursts of band-limited Pc 1 waves (0.2 to ∼1.0 Hz) with normalized frequency f/fH+ ∼ 0.5 have been observed by the Cluster spacecraft during many passes through the high-latitude plasma mantle. These transverse, left-hand polarized waves are associated with regions of H+ and O+ ions streaming away from Earth along …
Entropy conservation and rate of propagation of bubbles in the Earth's magnetotail: A case study
Wing, Simon; Sanchez, Ennio R.; Spanswick, Emma +1 more
Earthward propagation of low-density flux tubes, called “plasma bubbles,” is a candidate mechanism to reduce total entropy in the plasma sheet. MHD models predict that bubbles conserve total entropy (S) as they propagate earthward, that the amount of density depletion governs the speed of propagation, and that bubbles slow down as their S nears th…