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Precursory Signs of Large Forbush Decreases
Mavromichalaki, H.; Belov, A.; Eroshenko, E. +4 more
The study of space-weather effects and more specifically Forbush decreases of the cosmic-ray intensity depends on space and ground measurements. Very often Forbush decreases and geomagnetic storms are accompanied by pre-increases and/or pre-decreases manifested in cosmic-ray behavior, known as precursory signs. These cosmic-ray intensity variation…
Properties of Type III and Type IIIb Bursts in the Frequency Band of 8 - 80 MHz During PSP Perihelion at the Beginning of April 2019
Konovalenko, A. A.; Melnik, V. N.; Dorovskyy, V. V. +4 more
Properties of type III and type IIIb bursts in the frequency band of 8 - 80 MHz observed by the radio telescopes Ukrainian Radio Interferometer of NASU-2 (URAN-2) (Poltava) and Giant Ukrainian Radio Telescope (GURT) (Kharkiv) during the Parker Solar Probe (PSP) perihelion in April 2019 are discussed. These correspond to those that were observed by…
Solar Soft X-ray Irradiance Variability, I: Segmentation of Hinode/XRT Full-Disk Images and Comparison with GOES (1 - 8 Å) X-Ray Flux
DeLuca, Edward; Weber, Mark; Adithya, H. N. +6 more
It is of great interest and importance to study the variabilities of solar EUV, UV and X-ray irradiance in heliophysics, in Earth's climate, and space weather applications. A careful study is required to identify, track, monitor and segment the different coronal features such as active regions (ARs), coronal holes (CHs), the background regions (BG…
Two-Stage Evolution of an Extended C-Class Eruptive Flaring Activity from Sigmoid Active Region NOAA 12734: SDO and Udaipur-CALLISTO Observations
Monstein, Christian; Joshi, Bhuwan; Mitra, Prabir K. +4 more
In this article, we present a multi-wavelength investigation of a C-class flaring activity that occurred in the active region NOAA 12734 on 8 March 2019. The investigation utilizes data from the Atmospheric Imaging Assembly (AIA) and the Helioseismic Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) and the Udaipur-CALLISTO solar…
Detection of Coronal Mass Ejections Using Unsupervised Deep Clustering
Alshehhi, Rasha; Marpu, Prashanth R.
Coronal mass ejection (CME) is a highly energetic solar phenomenon. It has a significant impact on the space weather in the near-Earth environment. With the accumulation of CME observations, it becomes more challenging to handle them manually. Therefore, we need an automatic method for identifying CMEs. We propose an unsupervised method for classi…
Formation of Isolated Radio Type II Bursts at Low Frequencies
Pohjolainen, Silja; Talebpour Sheshvan, Nasrin
The first appearance of radio type II burst emission at decameter-hectometer (DH) waves typically occurs in connection, and often simultaneously, with other types of radio emissions. As type II bursts are signatures of propagating shock waves that are associated with flares and coronal mass ejections (CMEs), a rich variety of radio emissions can b…
Probing Upflowing Regions in the Quiet Sun and Coronal Holes
Hara, Hirohisa; Sterling, Alphonse C.; Orozco Suárez, David +5 more
Recent observations from Parker Solar Probe have revealed that the solar wind has a highly variable structure. How this complex behaviour is formed in the solar corona is not yet known, since it requires omnipresent fluctuations, which constantly emit material to feed the wind. In this article we analyse 14 upflow regions in the solar corona to fi…
Occurrence Rate of Radio-Loud and Halo CMEs in Solar Cycle 25: Prediction Using their Correlation with the Sunspot Number
Moon, Y. -J.; Pappa Kalaivani, P.; Prakash, O. +1 more
Solar coronal mass ejections (CMEs) are known for their space-weather and geomagnetic consequences. Among all CMEs, the so-called radio-loud (RL) and halo CMEs are considered the most energetic in the sense that they are usually faster and wider than the general population of CMEs. Hence the study of RL and halo CMEs has become important and the p…
Plasma Upflows Induced by Magnetic Reconnection Above an Eruptive Flux Rope
Long, David M.; Janvier, Miho; Brooks, David H. +6 more
One of the major discoveries of Hinode's Extreme-ultraviolet Imaging Spectrometer (EIS) is the presence of upflows at the edges of active regions. As active regions are magnetically connected to the large-scale field of the corona, these upflows are a likely contributor to the global mass cycle in the corona. Here we examine the driving mechanism(…
The Fengyun-3E/Joint Total Solar Irradiance Absolute Radiometer: Instrument Design, Characterization, and Calibration
Zhao, Yan; Fang, Wei; Finsterle, Wolfgang +6 more
The Joint Total Solar Irradiance Monitor (JTSIM) is due to fly onboard the Fengyun-3E spacecraft and aims to measure the Total Solar Irradiance (TSI) in orbit. The instruments on the Fengyun-3E/JTSIM include the Digital Absolute Radiometer (DARA) from the Physikalisch Meteorologisches Observatorium, Davos and World Radiation Center (PMOD/WRC) and …