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The Radiation Assessment Detector (RAD) instrument onboard the Mars Science Laboratory (MSL) mission's Curiosity rover has been measuring galactic cosmic rays (GCR) as well as solar energetic particles (SEP) on the surface of Mars for more…
Forecasting future solar activity has become crucial in our modern world, where intense eruptive phenomena mostly occurring during solar maximum are likely to be strongly damaging to satellites and telecommunications. We present a 4D…
On February 12, 2021 two subsequent eruptions occurred above the West limb, as seen along the Sun-Earth line. The first event was a typical slow Coronal Mass Ejection (CME), followed $\sim 7$ hours later by a smaller and collimated…
Ground-level enhancements (GLEs) generally accompany with fast interplanetary coronal mass ejections (ICMEs), the shocks driven by which are the effective source of solar energetic particles (SEPs). In the GLE event of 2000 July 14,…
The arrival time of coronal mass ejections (CMEs) in the vicinity of the Earth is one of the most important parameters in determining space weather. We have used a new approach to predicting this parameter. First, in our study, we have…
We investigate the source eruption, propagation and expansion characteristics, and heliospheric impacts of the 2020 November 29 coronal mass ejection (CME) and associated shock, using remote sensing and in situ observations from multiple…
The activity of the Sun alternates between a solar minimum and a solar maximum, the former corresponding to a period of "quieter" status of the heliosphere. During solar minimum, it is in principle more straightforward to follow eruptive…
We report the properties of electron distributions and turbulence during a Coronal Mass Ejection (CME) in April 2023 observed by Magnetospheric Multiscale (MMS). The CME exhibits a clear sheath and magnetic cloud (MC), and within the MC,…
The "extended" solar cycle 24 began in 1999 near 70 degrees latitude, similarly to cycle 23 in 1989 and cycle 22 in 1979. The extended cycle is manifested by persistent Fe XIV coronal emission appearing near 70 degrees latitude and slowly…
On 2012 March 7, the STEREO Ahead and Behind spacecraft, along with the near-earth spacecraft (e.g. SOHO, Wind) situated between the two STEREO spacecraft, observed an extremely large global solar energetic particle (SEP) event in Solar…
We could infer a secular decreasing trend in the poloidal to toroidal solar magnetic flux amplification factor ( Af) using geomagnetic observations ( classic and IHV corrected aa indices) during the sunspot cycles 9-23. A similar decreasing…
We present the study of two solar eruptive events observed on December 7 2020 and October 28 2021.Both events were associated with full halo CMEs and flares.These events were chosen because they show a strong non-radial direction of…
An unexpected strong geomagnetic storm occurred on 2018 August 26, which was caused by a slow coronal mass ejection (CME) from a gradual eruption of a large quiet-region filament. We investigate the eruption and propagation characteristics…
Interplanetary space is characteristically structured mainly by high-speed solar wind streams emanating from coronal holes and transient disturbances such as coronal mass ejections (CMEs). While high-speed solar wind streams pose a…
Methods: Stealth CMEs represent a particular class of solar eruptions that are clearly distinguished in coronagraph observations, but they don't have a clear source signature. A particular type of stealth CMEs occurs in the trailing current…
We report the result of the first search for multipoint in situ and imaging observations of interplanetary coronal mass ejections (ICMEs) starting with the first Solar Orbiter (SolO) data in 2020 April - 2021 April. A data exploration…
The successive coronal mass ejections (CMEs) from 2010 July 30 - August 1 present us the first opportunity to study CME-CME interactions with unprecedented heliospheric imaging and in situ observations from multiple vantage points. We…
This is the first of four companion papers, which analyze a complex eruptive event of 18 November 2003 in AR 10501 and the causes of the largest Solar Cycle 23 geomagnetic storm on 20 November 2003. Analysis of a complete data set, not…
The 23-24 April 2023 double-peak (SYM-H intensities of -179 and -233 nT) intense geomagnetic storm was caused by interplanetary magnetic field southward component Bs associated with an interplanetary fast-forward shock-preceded sheath (Bs…
In this study we overview recent advances with prediction of solar activity using as a proxy solar background magnetic field and detection of grand solar cycles of about 400 years separated by grand solar minima (GSMs).The previous GSM…