This paper presents the characterization of solar radio burst type III and IV obtained from e-CALLISTO website. Solar radio burst (SRB) is one of the tools in space weather studies as each type of SRB indicates the production of solar activity at that moment which can also bring it towards the prediction of solar events. Generally, SRB has five different type of emissions which are named as type I, II, III, IV and V, this paper will only focus on type III and IV. Data of type III and IV bursts were selected on 15th Sept. 2015 and 27th Feb. 2018 respectively and discussions on each type of bursts include two stations to make a comparison. At the end of this work, type III bursts show a rapidly drift structure from high to low frequency, strongly associated to solar flares and the burst is due to Langmuir waves. Meanwhile, type IV bursts are recognized by its broadband continuum with rapidly fine structure and they act as a hint of geomagnetic storm commencement. More details on the formation of these burst are discussed.
Climate change has a close relation with the variability of the Sun’s energy radiated, which is associated with solar activity and this issue has been the top debate topic among climate scientists in finding out the main source of the changing in Earth’s climate. Previous studies were discussing on human activities and formation of 14 C and 14 Be isotopes which are likely contributing to the temperature increment of Earth’s surface. However, the pattern of climate on this planet is always depending on the condition of its main source of energy; the Sun. In this paper, we briefly review the impact of production of 14 C and 14 Be isotopes to Earth’s temperature. We also discussed in this article on how the variability of solar activity contributes to climate change. The main method in carrying out this study is by solar observation. We present the summary of several sets of significant solar events in 2017 and its relationship with Earth’s temperature. It is believed that Earth’s climate is likely to be affected by the variability of solar activity, in the sense that solar minimum in 2017 causes it to be the second highest annual temperature with 0.89°C warmer than normal temperature.
Coronal Mass Ejections are significant solar events that involve intense explosions of magnetic fields and mass particles out from the corona. As the hot plasma are brought by the solar wind into the Earth’s magnetosphere, geomagnetic storm is generated and causing malfunctions in telecommunication and power systems. This study is aimed to investigate the distribution of flare-CMEs characteristics which occurred at the beginning phase of solar cycle 24, from Dec. 2008 until Dec. 2013. In the analysis, all events are classified according to their class of flares associated with the CMEs. The CMEs that are accompanied by A, B, and C flares are categorized as low group flare-CME, while CMEs with M and X flares are placed under high group flare-CME. Afterwards, they are analyzed to observe the distribution of their main CME properties; velocity, acceleration and angular width. At the end of the study, we found that velocity and angular width are the two properties that have high influential for high and low groups, with R value of 0.36 and 0.67, respectively. Most of high group flare-CMEs showed up in 360° as well as low group flare-CMEs if the associated minor flares lasted longer than 30 min. Furthermore, the speed range of 360° high and low class flare-CME cannot be defined from the results since all of them propagated at fluctuating velocity. Hence, it is believed that full halo CMEs have no velocity boundary as they can travel from 500 km/s and go beyond 2500 km/s.
Solar activity refers to every single Sun’s phenomenon, such as development of sunspots, solar flares, prominences etc. As determined by the number of sunspots, solar activity varies over an 11-year period. In this study, we examined the general distribution of thermosphere climate index (TCI) with respect to sunspot number during Solar Cycle 24 to obtain the pattern of thermal condition in thermosphere over the 11 years. Sunspot number, thermosphere climate index (TCI), mean temperature of surface air, and three latitudes, all obtained from NASA and NOAA, were used for this analysis. Our study found that sunspot number and TCI are directly correlated, meaning that low sunspot numbers during SC24 rising phase caused the thermosphere to cool off with low TCI readings and high sunspot numbers during solar maximum caused the thermosphere to heat up with high TCI levels. A low TCI reading of 0.25 W was recorded during solar minimum since fewer solar events penetrated the thermosphere, particularly magnetized plasma and radiation. At peak levels, Northern Hemisphere (NH) had a temperature anomaly of 1.6°C, Tropics had a temperature anomaly of 1°C, and Southern Hemisphere (SH) had a temperature anomaly of 0.6°C. Due to the lower sunspot number recorded throughout the 11 years, SC24 also happened to have the lowest TCI among many preceding cycles. There was a major correlation between the amount of plasma ejections during a specific phase and whether the thermosphere received much or little magnetized plasma. Along with SC24, mean temperatures for surface air and three latitudes also showed a gradual increase trend.
Geomagnetic storm has been one of greatest events in space weather studies. Apart from the formation of aurora, geomagnetic induced current (GIC) is also induced during the storm when the storm intensity gets severe. Coronal mass ejection (CME) is a massive eruption created by the Sun and is believed to be the driver of geomagnetic storm. This paper is aimed to examine the effects of CME-induced geomagnetic storm on geomagnetic induced current (GIC) at high and middle latitudes by studying four levels of storm: minor (Kp 5), moderate (Kp 6), strong (Kp 7) and severe (Kp 8). We applied qualitative analysis through descriptive approach to describe the relationship between the storm intensity and GIC activity. Since the exact value of GIC were inaccessible, we adopted horizontal component time derivative magnetic field (dH/dt) as the indicator for GIC activity. At the end of the study, we found that the GIC highly depends on the storm intensity, by which higher levels of storm triggers more actively induced current. Besides, high latitude ionosphere was showing strong reactions to the storm arrival compared to middle latitude ionosphere as the magnitudes of dH/dt recorded by Barrow station at high latitude fluctuated within wider and higher range.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.