Search Publications
Neural Network for Solar Irradiance Modeling (NN-SIM)
Mauceri, Steffen; Coddington, Odele; Lyles, Danielle +1 more
An understanding of solar variability over a broad range of wavelengths and timescales is needed by scientists studying Earth's climate. While the current understanding of solar irradiance from measurements and models is maturing, there remain notable areas of discrepancy that highlight a lack of understanding of the variability in solar spectral …
Can High-Mode Magnetohydrodynamic Waves Propagating in a Spinning Macrospicule Be Unstable Due to the Kelvin-Helmholtz Instability?
Zhelyazkov, I.; Chandra, R.
We investigate the conditions at which high-mode magnetohydrodynamic (MHD) waves propagating in a spinning solar macrospicule can become unstable with respect to the Kelvin-Helmholtz instability (KHI). We consider the macrospicule as a weakly twisted cylindrical magnetic flux tube moving along and rotating around its axis. Our study is based on th…
Polarimetric Reconstruction of Coronal Mass Ejections from LASCO-C2 Observations
Lamy, Philippe; Floyd, Olivier
The three-dimensional morphology and direction of propagation of coronal mass ejections (CMEs) are essential information for identifying their source on the solar disk, for understanding the processes of their ejection and propagation in the corona, and for forecasting their possible impact with the Earth or any other objects in the solar system. …
Onset of a CME-Related Shock Within the Large-Angle Spectrometric Coronagraph (LASCO) Field of View
Fainshtein, V. G.; Egorov, Y. I.
We investigated the onset of a CME-related shock within the Large-Angle Spectrometric Coronagraph (LASCO) field of view (FOV). To detect the first moment of the shock onset, we found a CME on 17 July 2012 that formed at a relatively high altitude and moved with slow acceleration. We examined the possible mechanisms of shock generation. It was show…
Study of Interplanetary CMEs/Shocks During Solar Cycle 24 Using Drag-Based Model: The Role of Solar Wind
Shanmugaraju, A.; Vršnak, Bojan; Suresh, K. +2 more
In this paper we analyze a set of 27 fast interplanetary coronal mass ejections (ICMEs) observed during the period January 2010 - December 2013 in Solar Cycle 24. The arrivals of interplanetary shocks and CMEs at 1 AU are found from OMNI spacecraft high resolution data and their travel times are compared with Empirical Shock Arrival (ESA; Gopalswa…
Comprehensive Determination of the Hinode/EIS Roll Angle
Warren, Harry P.; Brooks, David H.; Baker, Deborah +5 more
We present a new coalignment method for the EUV Imaging Spectrometer (EIS) on board the Hinode spacecraft. In addition to the pointing offset and spacecraft jitter, this method determines the roll angle of the instrument, which has never been systematically measured, and which is therefore usually not corrected. The optimal pointing for EIS is com…
Cosmic Ray Modulation with the Maximum CME Speed Index During Solar Cycles 23 and 24
Kilcik, Ali; Sarp, Volkan; Yurchyshyn, Vasyl +2 more
We analyzed modulation of cosmic-ray intensities (CRIs) during Solar Cycles 23 and 24 by using the international sunspot numbers (ISSN) and the maximum CME speed index (MCMESI) as proxies for solar activity. Temporal variations, cross-correlations, and hysteresis patterns of CRI, MCMESI, and ISSN data were investigated. As a result, we concluded t…
Association of Calcium Network Bright Points with Underneath Photospheric Magnetic Patches
Pant, Vaibhav; Banerjee, Dipankar; Narang, Nancy +1 more
Recent dedicated Hinode polar region campaigns revealed the presence of concentrated kilogauss patches of the magnetic field in the polar regions of the Sun, which are also shown to be correlated with facular bright points at the photospheric level. In this work, we demonstrate that this spatial intermittency of the magnetic field persists even up…
Comparative Study of Microwave Polar Brightening, Coronal Holes, and Solar Wind over the Solar Poles
Masuda, Satoshi; Yashiro, Seiji; Shibasaki, Kiyoto +3 more
We compared the long-term variation (1992 - 2017) in solar polar brightening observed with the Nobeyama Radioheliograph, the polar solar-wind velocity with interplanetary scintillation observations at the Institute for Space-Earth Environmental Research, and the coronal-hole distribution computed by potential-field calculations of the solar corona…
Characteristics of SEP Events and Their Solar Origin During the Evolution of Active Region NOAA 10069
Myagkova, I. N.; Kashapova, L. K.; Miteva, R. +1 more
We present the results of a comparative analysis of the properties of a series of successive solar flares, which occurred in active region (AR) 10069 in August 2002, and the associated solar energetic particle (SEP) events. The active region was extremely flare productive during its evolution. The solar flare characteristics are based on X-ray and…