Search Publications
Characteristics of decametric hectometric (DH) type IIs, CMEs and flares of geoeffective and non-geoeffective storm events in Solar Cycle 24
Pant, Charita; Pande, Bimal; Pande, Seema
In this paper, a statistical study on geoeffectiveness of CMEs integrated with decametric hectometric (DH) type-II radio bursts, association of Dst with plasma and interplanetary field parameters (T,V,P,
Long-term changes in solar activity and irradiance
Chatzistergos, Theodosios; Krivova, Natalie A.; Yeo, Kok Leng
The Sun is the main energy source to Earth, and understanding its variability is of direct relevance to climate studies. Measurements of total solar irradiance (TSI) exist since 1978, but this is too short compared to climate-relevant time scales. Coming from a number of different instruments, these measurements require a cross-calibration, which …
Forecasting the transit times of earth-directed halo CMEs using artificial neural network: A case study application with GCS forward-modeling technique
Kozarev, K.; Minta, F. N.; Elsaid, A. +2 more
Mitigating the lethal threats caused by coronal mass ejections (CMEs) on human and space operations can be accomplished with a fast and accurate forecast of Earth-directed CME transit times. The current paper presents a robust Cascade Forward Neural Network (CFNN) framework to predict the transit times of Earth-directed halo CMEs using a total of …
Solar active region magnetic parameters and their relationship with the properties of halo coronal mass ejections
Moon, Y. -J.; Shanmugaraju, A.; Ebenezer, E. +2 more
The coronal mass ejections (CMEs) from the sun consist of the plasma and strong magnetic fields (∼4-5 G at 1.3 R⊙) and generally, the fast CMEs are often associated with energetic particles of energy few hundreds of MeV. When the fast CMEs are ejected towards the Earth, they can disrupt the flow of solar wind in the heliosphere and impa…
Relating photometric and magnetic properties of structures at solar surface
Sokoloff, Dmitry; Obridko, Vladimir; Katsova, Maria
We investigate sharp structures visible in solar magnetic field tracers. It is shown that the sunspot magnetic boundaries do not coincide with the photometric ones. Moreover, there is no clear boundary of the magnetic field in the vicinity of sunspots. Thus, the widely accepted concept of magnetic tubes with sharp edges is not always correct and s…
Sunspot numbers and proton events in solar cycles 19 to 24
Bromage, B. J. I.; Birch, M. J.
In this study we compare the mean annual sunspot numbers for the six most recent solar cycles (19 to 24) with the number of solar energetic proton events occurring in those years. Though most of the individual cycles exhibit quite strong correlations, when they are combined into a generic solar cycle the result is very significant (ρ = 0.98). For …
Relations among eruptive prominence properties, flare evolution and CME kinematics in large solar energetic particle events
Koleva, K.; Duchlev, P.; Dechev, M.
We report a detailed study of the relationship between solar filament eruption, flare productivity and CME kinematics relevant to Solar Energetic Particle (SEP) events. We analyze kinematics and morphological behaviors of 32 filament eruptions appearing during the Solar Cycle 24, between Aug 14, 2010 and April 18, 2016. For our analysis a high res…
Chain of responses of geomagnetic and ionospheric storms to a bunch of central coronal hole and high speed stream of solar wind
Gulyaev, R. A.; Gulyaeva, T. L.
Results of analysis of the proxy of Coronal Hole (CH) Power index, Pch, combined with the high speed streams HSS of solar wind for a period from 2011 to 2019 are presented. It is found that the long-term variation of Pch index shows a trend of growing Pch towards the minimum of solar cycle while most of other identities of solar activity tend to d…
Source region identification and geophysical effects of stealth coronal mass ejections
Fainshtein, V. G.; Zagainova, Iu. S.; Gromova, L. I. +1 more
We use the example of two Stealth-type coronal mass ejections (stealth CMEs) registered by LASCO C2 on the quiescent Sun on 16 June 2010 and in the active region NOAA 11520 7 July 2012 to demonstrate that these mass ejections emerged in a lower-coronal area where an intense short-term radiation burst was registered in several extreme ultraviolet c…
Estimation of solar EUV flux from TIMED/GUVI data
Zhang, Yongliang; Paxton, Larry J.; Schaefer, Robert
This paper examines the relationships between the integrated solar EUV (26-34 nm and 5-45 nm) flux and the measured radiance in the N2 Lyman-Birge-Hopfield (LBH) 140-150 nm range (LBHS) under sunlit conditions. We find that both the (26-34 nm) and (5-45 nm) solar fluxes are linearly correlated with the daily median LBHS radiances with c…