Search Publications
A Model for the Sources of the Slow Solar Wind
Antiochos, S. K.; Linker, J. A.; Mikić, Z. +2 more
Models for the origin of the slow solar wind must account for two seemingly contradictory observations: the slow wind has the composition of the closed-field corona, implying that it originates from the continuous opening and closing of flux at the boundary between open and closed field. On the other hand, the slow wind also has large angular widt…
Observing Flux Rope Formation During the Impulsive Phase of a Solar Eruption
Liu, Y.; Cheng, X.; Ding, M. D. +1 more
Magnetic flux ropes are believed to be an important structural component of coronal mass ejections (CMEs). While there exists much observational evidence of flux ropes after the eruption, e.g., as seen in remote-sensing coronagraph images or in situ solar wind data, the direct observation of flux ropes during CME impulsive phase has been rare. In …
First Evidence of Coexisting EIT Wave and Coronal Moreton Wave from SDO/AIA Observations
Chen, P. F.; Wu, Y.
"EIT waves" are a globally propagating wavelike phenomenon. They were often interpreted as fast-mode magnetoacoustic waves in the corona, despite various discrepancies between the fast-mode wave model and observations. To reconcile these discrepancies, we suggested that "EIT waves" are the apparent propagation of the plasma compression due to succ…
The First Observation of a Rapidly Rotating Coronal Mass Ejection in the Middle Corona
Nieves-Chinchilla, T.; Stenborg, G.; Vourlidas, A. +1 more
In this Letter, we present the first direct detection of a rotating coronal mass ejection (CME) in the middle corona (5-15 R sun). The CME rotation rate is 60° day-1, which is the highest rate reported yet. The Earth-directed event was observed by the STEREO/SECCHI and SOHO/LASCO instruments. We are able to derive the three-d…
Observations and Magnetic Field Modeling of the Flare/coronal Mass Ejection Event on 2010 April 8
Golub, Leon; van Ballegooijen, Adriaan; DeLuca, Edward +2 more
We present a study of the flare/coronal mass ejection event that occurred in Active Region 11060 on 2010 April 8. This event also involves a filament eruption, EIT wave, and coronal dimming. Prior to the flare onset and filament eruption, both SDO/AIA and STEREO/EUVI observe a nearly horizontal filament ejection along the internal polarity inversi…
The Strength and Radial Profile of the Coronal Magnetic Field from the Standoff Distance of a Coronal Mass Ejection-driven Shock
Gopalswamy, Nat; Yashiro, Seiji
We determine the coronal magnetic field strength in the heliocentric distance range 6-23 solar radii (Rs) by measuring the shock standoff distance and the radius of curvature of the flux rope during the 2008 March 25 coronal mass ejection imaged by white-light coronagraphs. Assuming the adiabatic index, we determine the Alfvén Mach number, and hen…
Numerical Investigation of a Coronal Mass Ejection from an Anemone Active Region: Reconnection and Deflection of the 2005 August 22 Eruption
Gombosi, T. I.; Shibata, K.; Lugaz, N. +3 more
We present a numerical investigation of the coronal evolution of a coronal mass ejection (CME) on 2005 August 22 using a three-dimensional thermodynamic magnetohydrodynamic model, the space weather modeling framework. The source region of the eruption was anemone active region (AR) 10798, which emerged inside a coronal hole. We validate our modele…
Using a Differential Emission Measure and Density Measurements in an Active Region Core to Test a Steady Heating Model
Winebarger, Amy R.; Warren, Harry P.; Kashyap, Vinay L. +2 more
The frequency of heating events in the corona is an important constraint on the coronal heating mechanisms. Observations indicate that the intensities and velocities measured in active region cores are effectively steady, suggesting that heating events occur rapidly enough to keep high-temperature active region loops close to equilibrium. In this …
Influence of the Ambient Solar Wind Flow on the Propagation Behavior of Interplanetary Coronal Mass Ejections
Veronig, Astrid M.; Temmer, Manuela; Vršnak, Bojan +3 more
We study three coronal mass ejection (CME)/interplanetary coronal mass ejection (ICME) events (2008 June 1-6, 2009 February 13-18, and 2010 April 3-5) tracked from Sun to 1 AU in remote-sensing observations of Solar Terrestrial Relations Observatory Heliospheric Imagers and in situ plasma and magnetic field measurements. We focus on the ICME propa…
Interpreting the Properties of Solar Energetic Particle Events by Using Combined Imaging and Modeling of Interplanetary Shocks
St. Cyr, O. C.; Szabo, A.; Rouillard, A. P. +10 more
Images of the solar corona obtained by the Solar-Terrestrial Relations Observatory (STEREO) provide high-cadence, high-resolution observations of a compression wave forming ahead of a fast (940 km s-1) coronal mass ejection (CME) that erupted at ~9:00 UT on 2010 April 03. The passage of this wave at 1 AU is detected in situ by the Advan…