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Ali G. A. Abdelkawy

Publications and source records attributed to Ali G. A. Abdelkawy.

3 recordsLinked to original sources

Review of Machine Learning Models for Solar Energetic Particle Prediction

Solar energetic particle (SEP) events have attracted increasing attention due to their significant radiation hazards for aviation, spacecraft electronics, and human missions beyond Earth's magnetosphere. From a scientific perspective, SEP events are intriguing because they arise from a set of physical processes extending from the solar surface and corona through the heliosphere, offering insight into particle acceleration and transport mechanisms that are widely applicable across astrophysics. Therefore, advancing our ability to understand and predict SEP events is essential both for deepening our knowledge of such mechanisms and for safeguarding space technologies and exploration. Traditionally, researchers have modeled SEPs using physics-based simulations and empirical methods. More recently, machine learning (ML) has emerged as a new tool for understanding and predicting SEP events. The purpose of this manuscript is to review the currently available ML models for SEP prediction, identify the datasets used for training, compare their architectures, inputs, and outputs, and, based on these insights, outline good practices and recommendations for future research.

astro-ph.SR↗

The chromospheric magnetic field in active regions derived from spectropolarimetry of Ca II 8542

We analyze spectropolarimetric observations of the chromospheric Ca II 8542 line taken by the Interferometric Bidimensional Spectrometer (IBIS) at the Dunn Solar Telescope and photospheric Fe I 6302 lines obtained with the Solar Optical Telescope (SOT) of Spectro-polarimeter (SP) on board the Hinode satellite. The data were obtained on 2012 January 29 targeting NOAA active region (AR) 11408 and AR 11410. By using the center-of-gravity (COG) method we compute the line-of-sight (LOS) field strength for observed lines of Fe I 6301.5/6302.5 with SP spacecraft at every places in the active region. Also, we construct a COG map for the chromospheric IBIS data of Ca II 8542 line in comparison with COG maps derived from the SP of field strength. We found the photospheric field strength ranges up to 2 kG in plages and up to 2 kG or higher values inside the umbral region. In the case of chromospheric field strength, the LOS field inside the umbral region increases up to 800 G, and the field strength decreases toward the edges of sunspot.

astro-ph.SR↗

Inference of chromospheric magnetic fields in a sunspot derived from spectropolarimetry of Ca II 8542 A

We analyze spectropolarimetric observations of the chromospheric Ca II 8542 A line taken by the Interferometric Bidimensional Spectrometer (IBIS) at the Dunn Solar Telescope. The data were observed on 2012 January 29 for the NOAA active region 11408. Adopting the center-of-gravity (COG) approach we obtain the line-of-sight (LOS) field strength for the chromospheric IBIS data of Ca II 8542 A line. The LOS strength of the magnetic field is determined in the target active region inside a field of view 45 x 95 arcsec. The LOS field values were found to be increase up to 800 G inside the umbral region and decrease systematically toward the edges of a sunspot. Under the weak field approximation (WFA), the horizontal, vertical magnetic field components and azimuthal field vector are obtained.

astro-ph.SR↗