Search Publications

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.

Correction to ``Orientation and motion of a plasma discontinuity from single-spacecraft measurements: Generic residue analysis of Cluster data''

Balogh, A.; RèMe, H.; Dunlop, M. W. +3 more

Solar activity variations of the ionospheric peak electron density

Liu, Libo; Wan, Weixing; Ning, Baiqi +2 more

The daily averaged Solar EUV Monitor (SEM)/Solar Heliospheric Observatory (SOHO) EUV measurements, solar proxies, and foF2 data at 20 ionosonde stations in the east Asia/Australia sector are collected to investigate the solar activity dependences of the ionospheric peak electron density (NmF2). The intensities of solar EUV from the SEM/SOHO measur…

Joint observations by Cluster satellites of bursty bulk flows in the magnetotail

Zhang, T. L.; Dandouras, I.; Lucek, E. +9 more

Using the observations of three satellites of Cluster (C1, C3, and C4) during the periods July to October 2001 and July to October 2002, we study 209 active time bursty bulk flows (BBFs), the difference between single satellite observations and multisatellite observations, and the difference among three selection criteria (two about BBFs and one a…