Search Publications
Coronal mass ejections, type II radio bursts, and solar energetic particle events in the SOHO era
Kaiser, M. L.; Howard, R. A.; Gopalswamy, N. +5 more
Using the extensive and uniform data on coronal mass ejections (CMEs), solar energetic particle (SEP) events, and type II radio bursts during the SOHO era, we discuss how the CME properties such as speed, width and solar-source longitude decide whether CMEs are associated with type II radio bursts and SEP events. We discuss why some radio-quiet CM…
Processes and mechanisms governing the initiation and propagation of CMEs
Vršnak, B.
The most important observational characteristics of coronal mass ejections (CMEs) are summarized, emphasizing those aspects which are relevant for testing physical concepts employed to explain the CME take-off and propagation. In particular, the kinematics, scalings, and the CME-flare relationship are stressed. Special attention is paid to 3-dimen…
A comparison of coronal mass ejections identified by manual and automatic methods
Gopalswamy, N.; Michalek, G.; Yashiro, S.
Coronal mass ejections (CMEs) are related to many phenomena (e.g. flares, solar energetic particles, geomagnetic storms), thus compiling of event catalogs is important for a global understanding these phenomena. CMEs have been identified manually for a long time, but in the SOHO era, automatic identification methods are being developed. In order t…
Two-spacecraft reconstruction of a magnetic cloud and comparison to its solar source
Möstl, C.; Farrugia, C. J.; Temmer, M. +5 more
This paper compares properties of the source region with those inferred from satellite observations near Earth of the magnetic cloud which reached 1 AU on 20 November 2003. We use observations from space missions SOHO and TRACE together with ground-based data to study the magnetic structure of the active region NOAA 10501 containing a highly curve…
A review of the quantitative links between CMEs and magnetic clouds
Démoulin, P.
Magnetic clouds (MCs), and more generally, interplanetary coronal mass ejections (ICMEs), are believed to be the interplanetary counterparts of CMEs. The link has usually been shown by taking into account the CME launch position on the Sun, the expected time delay and by comparing the orientation of the coronal and interplanetary magnetic field. M…
Review on the solar spectral variability in the EUV for space weather purposes
Auchère, F.; Kretzschmar, M.; Dudok de Wit, T. +4 more
The solar XUV-EUV flux is the main energy source in the terrestrial diurnal thermosphere: it produces ionization, dissociation, excitation and heating. Accurate knowledge of this flux is of prime importance for space weather. We first list the space weather applications that require nowcasting and forecasting of the solar XUV-EUV flux. We then rev…
Magnetic clouds seen at different locations in the heliosphere
Zhukov, A. N.; Rodriguez, L.; Mandrini, C. H. +9 more
We analyze two magnetic clouds (MCs) observed in different points of the heliosphere. The main aim of the present study is to provide a link between the different aspects of this phenomenon, starting with information on the origins of the MCs at the Sun and following by the analysis of in-situ observations at 1 AU and at Ulysses. The candidate sou…
Observations of recurrent cosmic ray decreases during solar cycles 22 and 23
Gómez-Herrero, R.; Heber, B.; Müller-Mellin, R. +5 more
During solar cycle 22, the modulation of several hundred MeV galactic cosmic rays (GCRs) by recurrent and transient cosmic ray decreases was observed by the Ulysses spacecraft on its descent towards the solar south pole. In solar cycle 23, Ulysses repeated this trajectory segment during a similar phase of the solar cycle, but with opposite heliosp…
Causal relationships between eruptive prominences and coronal mass ejections
Filippov, B.; Koutchmy, S.
A close association between eruptive prominences and CMEs, both slow and fast CMEs, was reported in many studies. Sometimes it was possible to follow the material motion starting from the prominence (filament) activation to the CME in the high corona. Remnants of the prominence were found in the bright core of the CME. However, detailed comparison…
Why are CMEs large-scale coronal events: nature or nurture?
Mandrini, C. H.; van Driel-Gesztelyi, L.; Démoulin, P. +2 more
The apparent contradiction between small-scale source regions of, and large-scale coronal response to, coronal mass ejections (CMEs) has been a long-standing puzzle. For some, CMEs are considered to be inherently large-scale events eruptions in which a number of flux systems participate in an unspecified manner, while others consider magnetic reco…