Search Publications
CME interactions with coronal holes and their interplanetary consequences
Gopalswamy, N.; Yashiro, S.; Mäkelä, P. +2 more
A significant number of interplanetary shocks (~17%) during cycle 23 were not followed by drivers. The number of such ``driverless'' shocks steadily increased with the solar cycle with 15%, 33%, and 52% occurring in the rise, maximum, and declining phase of the solar cycle. The solar sources of 15% of the driverless shocks were very close the cent…
A homogeneous database of sunspot areas covering more than 130 years
Solanki, S. K.; Krivova, N. A.; Balmaceda, L. A. +1 more
The historical record of sunspot areas is a valuable and widely used proxy of solar activity and variability. The Royal Greenwich Observatory regularly measured this and other parameters between 1874 and 1976. After that time records from a number of different observatories are available. These, however, show systematic differences and often have …
Electron and proton heating by solar wind turbulence
Cranmer, S. R.; Matthaeus, W. H.; Kasper, J. C. +2 more
Previous formulations of heating and transport associated with strong magnetohydrodynamic (MHD) turbulence are generalized to incorporate separate internal energy equations for electrons and protons. Electron heat conduction is included. Energy is supplied by turbulent heating that affects both electrons and protons and is exchanged between them v…
Development of the 3-D MHD model of the solar corona-solar wind combining system
Tanaka, T.; Kubo, Y.; Shinagawa, H. +3 more
In the framework of integrated numerical space weather prediction, we have developed a 3-D MHD simulation model of the solar surface-solar wind system. We report the construction method of the model and its first results. By implementing a grid system with angularly unstructured and increasing radial spacing, we realized a spherical grid that has …
Three-dimensional MHD modeling of the solar wind structures associated with 13 December 2006 coronal mass ejection
Kataoka, R.; Ebisuzaki, T.; Kusano, K. +4 more
A 3-D magnetohydrodynamic (MHD) simulation is performed to reconstruct the interplanetary propagation of a coronal mass ejection (CME) that occurred on 13 December 2006. A spheromak-type magnetic field is superposed on a realistic ambient solar wind to reproduce the large-scale interplanetary magnetic field (IMF) associated with the CME. Here we s…
Linking two consecutive nonmerging magnetic clouds with their solar sources
Zhukov, A. N.; Rodriguez, L.; Mandrini, C. H. +10 more
On 15 May 2005, a huge interplanetary coronal mass ejection (ICME) was observed near Earth. It triggered one of the most intense geomagnetic storms of solar cycle 23 (Dst peak = -263 nT). This structure has been associated with the two-ribbon flare, filament eruption, and coronal mass ejection originating in active region 10759 (NOAA …
Multispacecraft recovery of a magnetic cloud and its origin from magnetic reconnection on the Sun
Luhmann, J. G.; Möstl, C.; Farrugia, C. J. +8 more
Multipoint spacecraft observations of a magnetic cloud on 22 May 2007 have given us the opportunity to apply a multispacecraft technique to infer the structure of this large-scale magnetic flux rope in the solar wind. Combining WIND and STEREO-B magnetic field and plasma measurements, we construct a combined magnetic field map by integrating the G…
A comparison of the formation and evolution of magnetic flux ropes in solar coronal mass ejections and magnetotail plasmoids
Moldwin, M. B.; Linton, M. G.
Solar coronal mass ejections and their interplanetary counterparts often show evidence of a twisted flux rope structure that is nearly identical, though of vastly different spatial scale, to plasmoids observed in the Earth's magnetotail. This paper reviews the current understanding of flux rope formation, morphology, and evolution in coronal mass …
Operational validation of HAFv2's predictions of interplanetary shock arrivals at Earth: Declining phase of Solar Cycle 23
Dryer, M.; Fry, C. D.; McKenna-Lawlor, S. M. P. +3 more
This is the third in a series of papers showing the performance of the Hakamada-Akasofu-Fry version 2 (HAFv2) model in predicting, in the operational environment, the arrival of interplanetary shocks at Earth. The first and second studies covered the time of the rise and maximum of Solar Cycle 23. This study covers the declining phase, through Dec…
Recurrent CIR-accelerated ions observed by STEREO SEPT
Gómez-Herrero, R.; Heber, B.; Müller-Mellin, R. +3 more
Fast solar wind streams originating from coronal holes interact with the preceding slow wind, leading to the formation of corotating interaction regions (CIRs) in the interplanetary medium. Near solar minimum CIR-associated shocks become the dominant source of energetic ion increases observed near 1 AU in the energy range between some tens of keV/…