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Quasi-periodic Pulsations in Solar and Stellar Flares: Re-evaluating their Nature in the Context of Power-law Flare Fourier Spectra
Dominique, M.; Ireland, J.; Inglis, A. R.
The nature of quasi-periodic pulsations (QPPs) in solar and stellar flares remains debated. Recent work has shown that power-law-like Fourier power spectra are an intrinsic property of solar and stellar flare signals, a property that many previous studies of this phenomenon have not accounted for. Hence a re-evaluation of the existing interpretati…
Extreme Ultra-Violet Spectroscopy of the Lower Solar Atmosphere During Solar Flares (Invited Review)
Milligan, Ryan O.
The extreme ultra-violet (EUV) portion of the solar spectrum contains a wealth of diagnostic tools for probing the lower solar atmosphere in response to an injection of energy, particularly during the impulsive phase of solar flares. These include temperature- and density-sensitive line ratios, Doppler-shifted emission lines, nonthermal broadening…
Structure and Dynamics of the 2012 November 13/14 Eclipse White-light Corona
Seaton, D. B.; Rušin, V.; Saniga, M. +9 more
Continuing our series of observations of coronal motion and dynamics over the solar-activity cycle, we observed from sites in Queensland, Australia, during the 2012 November 13 (UT)/14 (local time) total solar eclipse. The corona took the low-ellipticity shape typical of solar maximum (flattening index ɛ = 0.01), a change from the composite corona…
SWAP Observations of Post-flare Giant Arches in the Long-Duration 14 October 2014 Solar Eruption
West, Matthew J.; Seaton, Daniel B.
On 2014 October 14 the Sun Watcher with Active Pixels and Image Processing EUV solar telescope on board the Project for On Board Autonomy 2 spacecraft observed an eruption that led to the formation of perhaps the largest post-eruptive loop system seen in the solar corona in solar cycle 24. The initial eruption occurred at about 18:30 UT on October…
Initiation of CMEs associated with filament eruption, and the nature of CME related shocks
Fainshtein, V. G.; Egorov, Ya. I.
Using data from SDO, PROBA2 and other spacecraft, Fainshtein and Egorov (2013) have discovered processes accompanying initiation of six limb CMEs and have studied features of their motion. The said CMEs occurred after eruption of prominence or hot emission loop and were associated with X-ray flares. The follow-up study of the CMEs, associated with…
Planetary period oscillations in Saturn's magnetosphere: Examining the relationship between abrupt changes in behavior and solar wind-induced magnetospheric compressions and expansions
Coates, A. J.; Dougherty, M. K.; Cowley, S. W. H. +2 more
We examine planetary period oscillations (PPOs) observed in Saturn's magnetospheric magnetic field data from the time of Saturn's equinox in 2009. In particular, we focus on the time period commencing February 2011, when the oscillations started to display sudden and unexpected changes in behavior at ~100-200 day intervals. These were characterize…
Where does the Thermospheric Ionospheric GEospheric Research (TIGER) Program go?
Schmidt, W.; Haberreiter, M.; Kretzschmar, M. +22 more
At the 10th Thermospheric Ionospheric GEospheric Research (TIGER/COSPAR) symposium held in Moscow in 2014 the achievements from the start of TIGER in 1998 were summarized. During that period, great progress was made in measuring, understanding, and modeling the highly variable UV-Soft X-ray (XUV) solar spectral irradiance (SSI), and its effects on…
Degradation assessment of LYRA after 5 years on orbit - Technology Demonstration -
Gissot, S.; Schühle, U.; Saito, T. +10 more
We present a long-term assessment of the radiometric calibration and degradation of the Large Yield Radiometer (LYRA), which has been on orbit since 2009. LYRA is an ultraviolet (UV) solar radiometer and is the first space experiment using aboard a pioneering diamond detector technology. We show that LYRA has degraded after the commissioning phase…
Solar Micro-Type III Burst Storms and Long Dipolar Magnetic Field in the Outer Corona
Misawa, H.; Kasaba, Y.; Miyoshi, Y. +4 more
Solar micro-type III radio bursts are elements of the so-called type III storms and are characterized by short-lived, continuous, and weak emissions. Their frequency of occurrence with respect to radiation power is quite different from that of ordinary type III bursts, suggesting that the generation process is not flare-related, but due to some re…
Particle-in-cell modeling of Dual Segmented Langmuir Probe on PROBA2
Imtiaz, Nadia; Marchand, Richard
We model the current characteristics of the Dual Segmented Langmuir Probe (DSLP), which is a part of the scientific payload of the ESA satellite PROBA2. It is used for the directional measurement of plasma parameters in the ionosphere at an altitude of approximately 725 km. The DSLP consists of two independent segmented Langmuir probes. Each probe…