Search Publications
The association of coronal mass ejections with their effects near the Earth
Schwenn, R.; Gonzalez, W. D.; Huttunen, E. +1 more
To this day, the prediction of space weather effects near the Earth suffers from a fundamental problem: The radial propagation speed of "halo" CMEs (i.e. CMEs pointed along the Sun-Earth-line that are known to be the main drivers of space weather disturbances) towards the Earth cannot be measured directly because of the unfavorable geometry. From …
Properties and geoeffectiveness of magnetic clouds in the rising, maximum and early declining phases of solar cycle 23
Schwenn, R.; Bothmer, V.; Koskinen, H. E. J. +1 more
The magnetic structure and geomagnetic response of 73 magnetic clouds (MC) observed by the WIND and ACE satellites in solar cycle 23 are examined. The results have been compared with the surveys from the previous solar cycles. The preselected candidate MC events were investigated using the minimum variance analysis to determine if they have a flux…
Electric current and magnetic field geometry in flapping magnetotail current sheets
Sauvaud, J. -A.; Balogh, A.; Zhang, T. L. +11 more
Using four-point magnetic field measurements by the Cluster spacecraft, we statistically analyze the magnetic field and electric current configurations during rapid crossings of the current sheet observed in July-October 2001 at geocentric distances of 19 RE. The database includes 78 crossings, specially selected to apply multi-point da…
The Double Star magnetic field investigation: instrument design, performance and highlights of the first year's observations
Balogh, A.; Zhang, T. L.; Glassmeier, K. -H. +19 more
One of the primary objectives of the Double Star mission is the accurate measurement of the magnetic field vector along the orbits of the two spacecraft. The magnetic field is an essential parameter for the understanding of space plasma processes and is also required for the effective interpretation of data from the other instruments on the spacec…
The Double Star mission
Escoubet, C. P.; Liu, Z. X.; Shen, C. +4 more
The Double Star Programme (DSP) was first proposed by China in March, 1997 at the Fragrant Hill Workshop on Space Science, Beijing, organized by the Chinese Academy of Science. It is the first mission in collaboration between China and ESA. The mission is made of two spacecraft to investigate the magnetospheric global processes and their response …
Propagation of whistler-mode chorus to low altitudes: divergent ray trajectories and ground accessibility
Santolík, O.; Chum, J.
We investigate the ray trajectories of nonductedly propagating lower-band chorus waves with respect to their initial angle θ0, between the wave vector and ambient magnetic field. Although we consider a wide range of initial angles θ0, in order to be consistent with recent satellite observations, we pay special attention to th…
Optimal reconstruction of magnetopause structures from Cluster data
Klecker, B.; Hasegawa, H.; Dunlop, M. W. +3 more
The Grad-Shafranov (GS) reconstruction technique, a single-spacecraft based data analysis method for recovering approximately two-dimensional (2-D) magnetohydrostatic plasma/field structures in space, is improved to become a multi-spacecraft technique that produces a single field map by ingesting data from all four Cluster spacecraft into the calc…
The HIA instrument on board the Tan Ce 1 Double Star near-equatorial spacecraft and its first results
Lundin, R.; Dandouras, I.; Klecker, B. +16 more
On 29 December 2003, the Chinese spacecraft Tan Ce 1 (TC-1), the first component of the Double Star mission, was successfully launched within a low-latitude eccentric orbit. In the framework of the scientific cooperation between the Academy of Sciences of China and ESA, several European instruments, identical to those developed for the Cluster spa…
First current density measurements in the ring current region using simultaneous multi-spacecraft CLUSTER-FGM data
Balogh, A.; Dandouras, I.; Lucek, E. +7 more
The inner magnetosphere's current mapping is one of the key elements for current loop closure inside the entire magnetosphere. A method for directly computing the current is the multi-spacecraft curlometer technique, which is based on the application of Maxwell-Ampère's law. This requires the use of four-point magnetic field high resolution measur…
Double Star/Cluster observation of neutral sheet oscillations on 5 August 2004
Balogh, A.; Zhang, T. L.; Nakamura, R. +8 more
Previous Cluster observations have shown that the flapping motions of the Earth's magnetotail are of internal origin and that kink-like waves are emitted from the central part of the tail and propagate toward the tail flanks. The newly launched Double Star Program (DSP) TC-1 satellite allows us to investigate neutral sheet at 10-13 Re in the tail.…