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Interplanetary coronal mass ejection observed at STEREO-A, Mars, comet 67P/Churyumov-Gerasimenko, Saturn, and New Horizons en route to Pluto: Comparison of its Forbush decreases at 1.4, 3.1, and 9.9 AU
Barabash, S.; Krupp, N.; Roussos, E. +48 more
We discuss observations of the journey throughout the Solar System of a large interplanetary coronal mass ejection (ICME) that was ejected at the Sun on 14 October 2014. The ICME hit Mars on 17 October, as observed by the Mars Express, Mars Atmosphere and Volatile EvolutioN Mission (MAVEN), Mars Odyssey, and Mars Science Laboratory (MSL) missions,…
A new observational solar irradiance composite
Schmutz, Werner; Haberreiter, Margit; Schöll, Micha +4 more
Variations in the solar spectral irradiance (SSI) are an important driver of the chemistry, temperature, and dynamics of the Earth's atmosphere and ultimately the Earth's climate. To investigate the detailed response of the Earth's atmosphere to SSI variations, a reliable SSI data set is needed. We present an observational SSI composite data set t…
EMPIRE: A robust empirical reconstruction of solar irradiance variability
Solanki, S. K.; Yeo, K. L.; Krivova, N. A.
We present a new empirical model of total and spectral solar irradiance (TSI and SSI) variability entitled EMPirical Irradiance REconstruction (EMPIRE). As with existing empirical models, TSI and SSI variability is given by the linear combination of solar activity indices. In empirical models, UV SSI variability is usually determined by fitting th…
Using the Coronal Evolution to Successfully Forward Model CMEs' In Situ Magnetic Profiles
Gopalswamy, N.; Kay, C.
Predicting the effects of a coronal mass ejection (CME) impact requires knowing if impact will occur, which part of the CME impacts, and its magnetic properties. We explore the relation between CME deflections and rotations, which change the position and orientation of a CME, and the resulting magnetic profiles at 1 AU. For 45 STEREO-era, Earth-im…
Comparison of the coronal mass ejection shock acceleration of three widespread SEP events during solar cycle 24
St. Cyr, O. C.; Gopalswamy, N.; Mäkelä, P. +1 more
We studied three solar energetic particle (SEP) events observed on 14 August 2010, 3 November 2011, and 5 March 2013 by Solar Terrestrial Relations Observatory (STEREO) A, B, and near-Earth (L1) spacecraft with a longitudinal distribution of particles >90°. Using a forward modeling method combined with extreme ultraviolet and white-light images…
Coronal mass ejections and solar wind mass fluxes over the heliosphere during solar cycles 23 and 24 (1996-2014)
Lamy, P.; Quémerais, E.; Floyd, O. +2 more
Coronal mass ejections (CMEs) play a major role in the heliosphere, and their contribution to the solar wind mass flux, already considered in the Skylab and Solwind eras with conflicting results, is reexamined in the light of 19 years (1996-2014) of SOHO observations with the Large Angle and Spectroscopic Coronagraph (LASCO-C2) for the CMEs and ex…
CMEs' Speed, Travel Time, and Temperature: A Thermodynamic Approach
Flandes, Alberto; Lara, Alejandro; Durand-Manterola, Hector J. +2 more
Due to their important role in space weather, coronal mass ejections or CMEs have been thoroughly studied in order to forecast their speed and transit time from the Sun to the Earth. We present a thermodynamic analytical model that describes the dynamics of CMEs. The thermodynamic approach has some advantages with respect to the hydrodynamic appro…
Concerning the helium-to-hydrogen number density ratio in very slow ejecta and winds near solar minimum
Farrugia, C. J.; Galvin, A. B.; Vasquez, Bernard J. +2 more
Near the solar minimum the average value of the helium-to-proton number density ratio is a strong function of speed. The average ratios for both solar ejecta and ambient winds obey approximately the same relation with speed. At the lowest speeds, the ratio takes on small values near and below 0.01. Here winds and ejecta with very slow speeds (≲310…