Search Publications

Reconstruction of the reconnection rate from Cluster measurements: Method improvements

Farrugia, C. J.; Penz, T.; Nakamura, R. +7 more

A remote-sensing method for reconstructing the reconnection rate and the location of X-line from single-spacecraft observations developed recently is extended to a compressible plasma and an asymmetric magnetic field configuration. The method is based on the two-dimensional analytical model of time-dependent Petschek-type magnetic reconnection. Th…

A three-dimensional kinetic-fluid numerical code to study the equilibrium structure of the magnetotail: The role of electrons in the formation of the bifurcated current sheet

Veltri, P.; Zimbardo, G.; Greco, A. +1 more

In this work we present a new stationary three-dimensional kinetic-fluid code with ions represented by particles and electrons by a massless fluid. The magnetotail current sheet is modeled as a magnetic field reversal with a normal magnetic field component B_n. A cross tail electric field E_y is included. An ion test particle s…

Polarization measurements of Saturn Electrostatic Discharges with Cassini/RPWS below a frequency of 2 MHz

Gurnett, D. A.; Kurth, W. S.; Fischer, G. +2 more

Early in 2006 the RPWS (Radio and Plasma Wave Science) instrument and the ISS (Imaging Science Subsystem) onboard the Cassini spacecraft detected a lightning storm on Saturn that lasted for about one month. The RPWS measured the so-called SEDs (Saturn Electrostatic Discharges), which are high frequency radio signals produced by lightning discharge…

Solar wind structure suggested by bimodal correlations of solar wind speed and density between the spacecraft SOHO and Wind

Coplan, M. A.; Ogilvie, K. W.; Roberts, D. A. +1 more

We calculate the cross-spacecraft maximum lagged-cross-correlation coefficients for 2-hour intervals of solar wind speed and density measurements made by the plasma instruments on the Solar and Heliospheric Observatory (SOHO) and Wind spacecraft over the period from 1996, the minimum of solar cycle 23, through the end of 2005. During this period, …

Modeled variations of the reconnection electric field at the dayside magnetopause during continued flux transfer event activity

Farrugia, C. J.; Penz, T.; Semenov, V. S. +5 more

Three periods of repeated flux transfer event (FTE) observations made by the Cluster satellites are investigated by a novel method for extracting from the observations the reconnection electric field E_rec. On 21 January 2001, a series of FTEs is observed at the poleward edge of the cusp around 15 magnetic local time (MLT). Another serie…

Characterization of waves in the vicinity of an interplanetary directional discontinuity

Dandouras, I.; Lucek, E. A.; Tjulin, A.

Directional discontinuities are frequently encountered in the solar wind. This study utilizes the possibility of simultaneous four-point measurements that the Cluster satellites provide for an investigation of the waves near one such interplanetary discontinuity event. In particular, the k-filtering technique has for the first time been applied fo…

Cluster observations of broadband ULF waves near the dayside polar cap boundary: Two detailed multi-instrument event studies

Farrugia, C. J.; Lucek, E. A.; Mouikis, C. G. +6 more

We study two examples of broadband ultra-low frequency (ULF) waves observed near the dayside polar cap boundary using data from multiple instruments on Cluster. These waves lie in a frequency range of ∼1-100 mHz with variable amplitudes. We have focused on their characteristics around the lowest frequency end. In the first event, the magnetic vari…

Fluid versus simulation model of solitons in solar wind: Application to Ulysses observations

Dubinin, E.; Sauer, K.; Baumgärtel, K. +1 more

This paper continues recent efforts based on Hall-MHD theory (Sauer et al., 2007) to explain a new class of magnetically compressive solitary structures in the interplanetary space, observed by the Ulysses magnetometer (Rees et al., 2006). The theoretical basis is extended by a kinetic approach via one-dimensional hybrid code simulations which rev…

Response of the magnetosheath-cusp region to a coronal mass ejection

Lucek, E.; Fazakerley, A. N.; Reme, H. +6 more

Cluster made an unusual magnetosheath-exterior cusp crossing during the first 2.5 hours of a coronal mass ejection (CME) that flowed past Earth for about 7 hours on 24 October 2003. During the first 2.5 hours (1525-1802 UT) the solar wind dynamic pressure remained high and stable though the CME had a discontinuity after 40 min (1605 UT), when the …

Reply to comment by P. Riley and J. T. Gosling on ``Are high-latitude forward-reverse shock pairs driven by overexpansion?''

Zurbuchen, T. H.; Manchester, W. B.