Investigation of the possibility of GIC development in Greece during the strongest magnetic storms of solar cycle 24 

2021 ◽  
Author(s):  
Adamantia Zoe Boutsi ◽  
Georgios Balasis ◽  
Ioannis A. Daglis ◽  
Kanaris Tsinganos ◽  
Omiros Giannakis
Keyword(s):  
Solar Cycle ◽  
Magnetic Storms ◽  
Geoelectric Field ◽  
Storm Events ◽  
Power Networks ◽  
Geomagnetically Induced Currents ◽  
Middle Latitudes ◽  
Solar Cycle 24 ◽  
Cycle 24 ◽  
Index Value

<p>Geomagnetically Induced Currents (GIC) constitute an integral part of the space weather research and a subject of ever-growing attention for countries located in the low and middle latitudes. A series of recent studies highlights the importance of considering GIC risks for the Mediterranean region. Here, we exploit data from the HellENIc GeoMagnetic Array (ENIGMA), which is located in Greece, complemented by magnetic observatories in Italy, to calculate corresponding values of the GIC index, i.e., a proxy of the geoelectric field calculated entirely from geomagnetic field variations. We perform our analysis for the most intense magnetic storms (Dst<-150 nT) of solar cycle 24. Our results show a good correlation between the storm sudden commencement (SSC) and an increase of the GIC index value. These investigations indicate that despite the elevated amplitude of the GIC index the associated risk remains at low level for the power networks in Greece and Italy during the considered storm events.</p>

MAG-GIC: Geomagnetically Induced Currents risk hazard in the Portuguese power network

2020 ◽  
Author(s):  
Joana Alves Ribeiro ◽  
Maria Alexandra Pais ◽  
Fernando J. G. Pinheiro ◽  
Fernando A. Monteiro Santos ◽  
Pedro Soares
Keyword(s):  
Solar Cycle ◽  
Geomagnetic Storms ◽  
Power Network ◽  
The South ◽  
Geomagnetically Induced Currents ◽  
Crust And Upper Mantle ◽  
Solar Cycle 24 ◽  
Induced Currents ◽  
Cycle 24 ◽  
Shunt Reactors

<p>The MAG-GIC project has as a main goal to produce the chart of Geomagnetically Induced Currents (GIC) risk hazard in the distribution power network of Portugal mainland.</p><p>The study of GICs is important as they represent a threat for infrastructures such as power grids, pipelines, telecommunication cables, and railway systems. A deeper insight into GICs hazard may help in planning and designing more resilient transmission systems and help with criteria for equipment selection.</p><p>GICs are a result of variations in the ionospheric and magnetospheric electric currents, that cause changes in the Earth's magnetic field. The Coimbra magnetic observatory (COI) is one of the oldest observatories in operation in the world and the only one in Portugal mainland. It has been (almost) continuously monitoring the geomagnetic field variations since 1866, and in particular, it has registered the imprint of geomagnetic storms during solar cycle 24. Besides the geomagnetic storm signal, which represents the GICs driver, the crust and upper mantle electrical conductivities determine the amplitude and geometry of the induced electric fields.</p><p>To present a better approximation of the Earth's conductivity structure below the Portuguese power network, we initiated a campaign to acquire magnetotelluric (MT) data in a grid of 50x50 km all over the territory. Nonetheless, there already exist enough MT data to create a realistic 3D conductivity model in the south of Portugal.</p><p>The other important input is the electric circuit for the network grid. We benefit from the collaboration of the Portuguese high voltage power network (REN) company, in providing the grid parameters as resistances and transformer locations, thus allowing us to construct a more precise model. In particular, we implement in our model the effect of shield wires and shunt reactors resistances.</p><p>In this study, we present the results of GIC calculations for the south of Portugal for some of the strongest geomagnetic storms in the 20015-17 period recorded at COI during solar cycle 24. We will focus on the sensitivity of results concerning two different conductivity models and different values of the shielding circuit parameters and shunt reactors devices.</p>

scholarly journals Occurrence climatology of equatorial plasma bubbles (EPBs) using optical observations over Kolhapur, India during solar cycle-24

2020 ◽  
Vol 63 (6) ◽  
Author(s):  
Onkar Gurav ◽  
Rupesh Ghodpage ◽  
Parashram Patil ◽  
Sripathi Samireddipalle ◽  
Ashok Sharma ◽  
...  
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Optical Observations ◽  
Occurrence Rate ◽  
High Solar Activity ◽  
Storm Events ◽  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles ◽  
Solar Cycle 24 ◽  
Cycle 24

In this paper, the occurrence characteristics of the equatorial plasma bubbles (EPBs) using OI 630.0 nm all sky imager (ASI) night airglow observations over Kolhapur (16.8o N, 74.2o E, 10.6o dip. Lat.) during the solar cycle-24 are presented. These results are discussed in terms of season, solar and magnetic activity during years 2011 to 2018. The ASI observations were only carried out during January to May and October to December months due to unfavorable weather conditions. The results suggest that while January, February and December are the only months where EPBs were found to occur over Kolhapur in any year, but the percentage of occurrence of EPBs during these months suggests their low occurrence rate during solar minimum. A total of 683 nights of observations were carried, out of which, 93 nights are found to be magnetically disturbed nights having Ap>18. In addition, the ASI observations are also correlated with Pre-Reversal Enhancement of the vertical drift of the evening sector at Tirunelveli on few storm events for comparison. The important findings of this study are: 1) increase in the occurrence of EPBs with respect to the solar activity; 2) suppression of EPBs on 71 disturbed nights, while enhancement of EPBs on 22 nights under magnetic disturbance; 3) EPBs occurrence during equinox months is found to be higher than winter months during ascending phase of solar cycle-24.; and, 4) EPBs are mostly observed in the pre-midnight sector in the high solar activity (HSA) period, while they are seen in the post-midnight to dawn sector during the low solar activity (LSA) period. We also noticed non-occurrence of EPBs during equinox month in the year 2018 which seems to be peculiar and needs further investigations.

Regression Analysis of Sunspot Numbers for the Solar Cycle 24 in Comparison to Previous Three Cycles

2014 ◽  
Vol 4 (2) ◽  
pp. 477-483
Author(s):  
Debojyoti Halder
Keyword(s):  
Regression Analysis ◽  
Solar Cycle ◽  
Sunspot Number ◽  
The Sun ◽  
Sunspot Numbers ◽  
Solar Cycle 24 ◽  
Current Cycle ◽  
Cycle 24

Sunspots are temporary phenomena on the photosphere of the Sun which appear visibly as dark spots compared to surrounding regions. Sunspot populations usually rise fast but fall more slowly when observed for any particular solar cycle. The sunspot numbers for the current cycle 24 and the previous three cycles have been plotted for duration of first four years for each of them. It appears that the value of peak sunspot number for solar cycle 24 is smaller than the three preceding cycles. When regression analysis is made it exhibits a trend of slow rising phase of the cycle 24 compared to previous three cycles. Our analysis further shows that cycle 24 is approaching to a longer-period but with smaller occurrences of sunspot number.

Empirical Relationship Between CME Parameters and Geo-effectiveness of Halo CMEs in the Rising Phase of Solar Cycle 24 (2011 – 2013)

Solar Physics ◽  
2015 ◽  
Vol 290 (5) ◽  
pp. 1417-1427 ◽  
Author(s):  
A. Shanmugaraju ◽  
M. Syed Ibrahim ◽  
Y.-J. Moon ◽  
A. Mujiber Rahman ◽  
S. Umapathy
Keyword(s):  
Solar Cycle ◽  
Empirical Relationship ◽  
Solar Cycle 24 ◽  
Halo Cmes ◽  
Cycle 24
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