Investigation of Forbush Decreases and Other Solar/Geophysical Agents Associated With Lightning Over the U.S. Latitude Band and the Continental Africa

Okike, O.

doi:10.1029/2018ja026456

Cited by 14 publications

(5 citation statements)

References 63 publications

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“…While it may be inferred from Table 2 that the magnitudes of the simultaneous FDs vary appreciably between the two stations, the close variation rate with respect to IMF observed (see Table 4) at MOSC and APTY CR stations seems to suggest that the simultaneity of FDs may not be dependent on the point of observation. Nevertheless, several other parameters such as CME speed or transit speed, magnetospheric effects, sunspot number, current sheet tilt angle, solar magnetic turbulence level, CR anisotropy, heliospheric magnetic sector, rigidity, differences in the local time of the two stations, instrumental variations and so on, which affect CR time-intensity variations, should also be tested before reaching any definitive conclusions (Cliver & Cane 1996;Singh et al 1997;Smith 1990;Wibberenz et al 2001;Owens et al 2014;Okike 2019Okike , 2020aOkike & Nwuzor 2020). In some past articles that analyzed the relationship between FDs and these physical parameters, the magnitude and timing of Forbush events were manually estimated.…”

Section: Resultsmentioning

confidence: 99%

Investigation of the relation between space-weather parameters and Forbush decreases automatically selected from Moscow and Apatity cosmic ray stations during solar cycle 23

Alhassan

Okike

Chukwude

2021

Res. Astron. Astrophys.

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We present the results of an investigation of the relation between space-weather parameters and cosmic ray (CR) intensity modulation using algorithm-selected Forbush decreases (FDs) from Moscow (MOSC) and Apatity (APTY) neutron monitor (NM) stations during solar cycle 23. Our FD location program detected 408 and 383 FDs from MOSC and APTY NM stations respectively. A coincident computer code employed in this work detected 229 FDs that were observed at the same Universal Time (UT) at the two stations. Out of the 229 simultaneous FDs, we formed a subset of 139 large FDs(%) ≤ − 4 at the MOSC station. We performed a two-dimensional regression analysis between the FD magnitudes and the space-weather data on the two samples. We find that there were significant space-weather disturbances at the time of the CR flux depressions. The correlation between the space-weather parameters and decreases in galactic cosmic ray (GCR) intensity at the two NM stations is statistically significant. The implications of the present space-weather data on CR intensity depressions are highlighted.

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Section: Resultsmentioning

confidence: 99%

Investigation of the relation between space-weather parameters and Forbush decreases automatically selected from Moscow and Apatity cosmic ray stations during solar cycle 23

Alhassan

Okike

Chukwude

2021

Res. Astron. Astrophys.

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“…Additionally, the impact of FDs in the GEC parameters has been reported (Engfer & Tinsley, 1999; Märcz, 1997; Okike & Umahi, 2019; Okike, 2019; Sheftel et al., 1994). Sheftel et al.…”

Section: Introductionmentioning

confidence: 98%

“…Okike and Umahi (2019) found a reduction in the lightning occurrence on a global scale during the FD onset. Furthermore, Okike (2019) reported that lightning occurrences reduction during FDs showed significant correlations at the United States latitude band and within the African region. In fair weather conditions, Märcz (1997) found a decrease of the atmospheric electric field, after FD events recorded at Nagycenk observatory (Hungary).…”

Section: Introductionmentioning

confidence: 99%

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Investigating Effects of Solar Proton Events and Forbush Decreases on Ground‐Level Potential Gradient Recorded at Middle and Low Latitudes and Different Altitudes

et al. 2022

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High‐energetic charged particles, such as solar protons, and phenomena such as Forbush decreases are eligible candidates to affect the global electric circuit. These effects have been studied by analyzing disturbances of the potential gradient in ground‐based measurements in fair weather regions. In this paper, we investigate deviations in the potential gradient diurnal curve, during solar proton events, and Forbush decreases, from the mean values obtained in fair weather conditions. In each situation, we select only events which are not accompanied or followed by the other. Using the superposed epoch analysis, in order to enhance the visualization of small effects, we study the potential gradient data recorded between January 2010 and December 2019 at two stations located at low and middle‐latitudes, and at two different altitudes: the Complejo Astronómico El Leoncito (CASLEO), Argentina: 31.78°S, 2550 m a.s.l., and the Geophysical Observatory in Świder (SWIDER), Poland: 52.12°N, 100 m a.s.l., respectively. For intense solar proton events (>100 MeV) we found a statistically significant increase of the potential gradient after solar proton events recorded at CASLEO and no such deviation in the potential gradient recorded at SWIDER. For Forbush decrease events (greater than 4%), no significant deviation of the potential gradient after the start of the event was found in both stations, however for very intense Forbush decreases (>7%) we found an increase of the potential gradient recorded at CASLEO.

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“…These studies have focused on the disturbed and fair weather regions with inconclusive results. In disturbed weather regions, using the World Wide Lightning Location Network (WWLLN) data, Okike (2019) found a regional reduction in the lightning occurrence rate after 4 days of the FD onset (18% in the USA latitude band and 9% in Africa). Okike and Umahi (2019) also found a global lightning reduction of 3% on the same day of the FD onset.…”

Section: Introductionmentioning

confidence: 99%

Effects of Forbush Decreases on the Global Electric Circuit

Tacza,

Li,

Raulin

2024

Space Weather

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The suppression of high‐energy cosmic rays, known as Forbush decreases (FDs), represents a promising factor in influencing the global electric circuit (GEC) system. Researchers have delved into these effects by examining variations, often disruptive, of the potential gradient (PG) in ground‐based measurements taken in fair weather regions. In this paper, we aim to investigate deviations observed in the diurnal curve of the PG, as compared to the mean values derived from fair weather conditions, during both mild and strong Forbush decreases. Unlike the traditional classification of FDs, which are based on ground level neutron monitor data, we classify FDs using measurements of the Alpha Magnetic Spectrometer (AMS‐02) on the International Space Station. To conduct our analysis, we employ the superposed epoch method, focusing on PGs collected between January 2010 and December 2019 at a specific station situated at a low latitude and high altitude: the Complejo Astronómico El Leoncito (CASLEO) in Argentina (31.78°S, 2,550 m above sea level). Our findings reveal that for events associated with FDs having flux amplitude (A) decrease ≤10%, no significant change in the PG is observed. However, for FDs with A > 10%, a clear increase in the PG is seen. For these A > 10% events, we also find a good correlation between the variation of Dst and Kp indices and the variation of PG.

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Investigation of Forbush Decreases and Other Solar/Geophysical Agents Associated With Lightning Over the U.S. Latitude Band and the Continental Africa

Abstract: Regardless of the numerous significant contributions in the field (e.g., Svensmark, H. &

Cited by 14 publications

References 63 publications

Investigation of the relation between space-weather parameters and Forbush decreases automatically selected from Moscow and Apatity cosmic ray stations during solar cycle 23

Investigation of the relation between space-weather parameters and Forbush decreases automatically selected from Moscow and Apatity cosmic ray stations during solar cycle 23

Investigating Effects of Solar Proton Events and Forbush Decreases on Ground‐Level Potential Gradient Recorded at Middle and Low Latitudes and Different Altitudes

Effects of Forbush Decreases on the Global Electric Circuit

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