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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…