Climatology of Ionospheric Amplitude Scintillation on GNSS Signals at South American Sector During Solar Cycle 24

Abstract Scintillations are caused by ionospheric irregularities and can affect the propagation of trans-ionospheric radio signals. One way to understand and predict the impact of such irregularities on Global Navigation Satellite System (GNSS) signals is through the climatological behavior of the ionospheric scintillation indexes during the different phases of a solar cycle. In this work, we investigate the amplitude scintillation index S4 during the full solar cycle 24 at South American (SA) sector, that is featured by the Ionospheric Anomaly (EIA) and by the South Atlantic Magnetic Anomaly (SAMA). We also investigate the daily variation of S4 and two case studies during geomagnetic storms. The results show a significant intensification of amplitude scintillations at northern and southern crest of EIA, especially during the southern hemisphere’s spring/summer seasons, with a higher increase during solar maximum, and after sunset. And particularly at the SAMA region, where the intensity of magnetic field lines is lower, the S4 fluctuations are much higher.

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Investigation of ionospheric response to two moderate geomagnetic storms using GPS–TEC measurements in the South American and African sectors during the ascending phase of solar cycle 24

Advances in Space Research ◽

10.1016/j.asr.2014.02.011 ◽

2014 ◽

Vol 53 (9) ◽

pp. 1313-1328 ◽

Cited By ~ 30

Author(s):

A.J. de Abreu ◽

P.R. Fagundes ◽

M. Gende ◽

O.S. Bolaji ◽

R. de Jesus ◽

...

Keyword(s):

Solar Cycle ◽

Geomagnetic Storms ◽

South American ◽

The South ◽

Ionospheric Response ◽

Gps Tec ◽

Solar Cycle 24 ◽

Cycle 24

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The Impact of Sunspots Number on Critical Frequencies foF2 for the IONOSPHERIC Layer-F2 Over Erbil Station During the Down Phase of Solar Cycle 24

NeuroQuantology ◽

10.14704/nq.2021.19.8.nq21128 ◽

2021 ◽

Vol 19 (8) ◽

pp. 157-168

Author(s):

Wafaa H.A. Zaki

Keyword(s):

Solar Activity ◽

Solar Cycle ◽

Sunspot Number ◽

Critical Frequency ◽

Radio Communication ◽

Ionospheric Layer ◽

Solar Cycle 24 ◽

Critical Frequency Fof2 ◽

Cycle 24 ◽

The Impact

The ionosphere layer (F2) is known as the most important layer for High frequency (Hf) radio communication because it is a permanent layer and excited during the day and night so it is able to reflect the frequencies at night and day due to its high critical frequency, and this layer is affected by daily and monthly solar activity. In this study the characteristics and behavior of F2 layer during Solar cycle 24 were studied, the effect of Sunspots number (Ri) on the critical frequency (foF2), were investigated for the years (2015, 2016, 2017, 2018, 2019, 2020) which represents the down phase of the solar cycle 24 over Erbil station (36° N, 44° E) by finding the critical frequency (foF2) values, the layer’ s impression times are determined for the days of solstice as well as equinox, where the solar activity was examined for the days of the winter and summer solstice and the days of the spring and autumn equinoxes for a period of 24 hours by applied the International Reference Ionosphere model IRI (2016). The output data for foF2 were verified by using the IRI-Ne- Quick option by specifying the time, date and Sunspot number parameters. Statistical analysis was caried out through the application of the Minitab (version 2018) in order to find the correlation between the critical frequency (foF2) of Ionospheric layer F2 and Sunspot number. It was concluded that the correlation is strong and positive, this indicate that critical frequency (foF2) increase with increasing Sunspots number (Ri) for solar cycle 24.

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

10.5194/egusphere-egu2020-1002 ◽

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

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.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.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.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.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.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.

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The response of African equatorial GPS-TEC to intense geomagnetic storms during the ascending phase of solar cycle 24

Journal of Atmospheric and Solar-Terrestrial Physics ◽

10.1016/j.jastp.2013.02.006 ◽

2013 ◽

Vol 98 ◽

pp. 50-62 ◽

Cited By ~ 14

Author(s):

A.O. Akala ◽

A.B. Rabiu ◽

E.O. Somoye ◽

E.O. Oyeyemi ◽

A.B. Adeloye

Keyword(s):

Solar Cycle ◽

Geomagnetic Storms ◽

Gps Tec ◽

Solar Cycle 24 ◽

Cycle 24

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Statistics of GNSS amplitude scintillation occurrences over Dakar, Senegal, at varying elevation angles during the maximum phase of solar cycle 24

Space Weather ◽

10.1002/2015sw001261 ◽

2016 ◽

Vol 14 (3) ◽

pp. 233-246 ◽

Cited By ~ 9

Author(s):

A. O. Akala ◽

A. Awoyele ◽

P. H. Doherty

Keyword(s):

Solar Cycle ◽

Maximum Phase ◽

Amplitude Scintillation ◽

Solar Cycle 24 ◽

Cycle 24

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Study of Geomagnetic Storms, Interplanetary Magnetic Field and Solar Wind

Journal of Mountain Research ◽

10.51220/jmr.v19i1.6 ◽

2019 ◽

Vol 14 (1) ◽

Author(s):

Chandrasekhar Bhoj ◽

Lalan Prasad

Keyword(s):

Magnetic Field ◽

Solar Wind ◽

Solar Cycle ◽

Interplanetary Magnetic Field ◽

Correlation Coefficient ◽

Geomagnetic Storms ◽

Solar Cycle 24 ◽

Time Periods ◽

Cycle 24 ◽

The Imf

The aim of this paper is to investigate the association of the geomagnetic storms with the IMF for solar cycle 24. Result of the present analysis shows that IMF is geoeffective parameter but its impact varies in accordance with different time periods. The correlation coefficient between Dst and IMF found to be -0.6 for solar cycle 24.

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