Impulsive Increase of Galactic Cosmic Ray Flux Observed by IceTop

Evenson, P. A.; Mangeard, P. S.; Muangha, Pradiphat; Pyle, R.; Ruffolo, D.; Sáiz, A.

doi:10.22323/1.301.0133

Cited by 3 publications

(4 citation statements)

References 7 publications

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“…In particular, these effects can lead to a short enhancement or burst of the CR count rate on the background of the main FD observed at some neutron monitors (NMs). Several such events recorded during Cycle 24 are analyzed in the recent papers by Evenson et al (2017), Gil et al (2018), Munakata et al (2018), Samara et al (2018). Even those CR bursts that stand out well at the FD recovery phase do not usually reach the pre-event count rate level.…”

Section: Introductionmentioning

confidence: 99%

Peculiar Solar Sources and Geospace Disturbances on 20–26 August 2018

et al. 2020

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On the approach to minimum of Solar Cycle 24, on 26 August 2018, an unexpectedly strong geomagnetic storm (GMS) suddenly occurred. Its D st index reached -174 nT, that is the third of the most intense storms during the cycle. The analysis showed that it was initiated by a two-step long filament eruption, which occurred on 20 August in the central sector of the solar disk. The eruptions were accompanied by two large-scale divergent ribbons and dimmings of a considerable size and were followed by relatively weak but evident Earth-directed coronal mass ejections. In the inner corona, their estimated speed was very low of about 200-360 km s -1 . The respective interplanetary transients apparently propagated between two high-speed solar wind streams originated from a two-component coronal hole and therefore their expansion was limited. The resulting ejecta arrived at the Earth only on 25 August and brought an unexpectedly strong field of B t ≈ 18.2 nT with a predominantly negative B z component of almost the same strength. The geospace storm also manifested itself in the form of a peculiar Forbush decrease (FD). Its magnitude was about 1.5 %, which is rather small for the observed G3-class GMS. The main unusual feature of the event is that large positive bursts with an enhancement up to 3% above the pre-event level were recorded on the FD background. We argue that these bursts were mainly caused by an unusually large and changeable cosmic ray anisotropy combined with lowering of the geomagnetic cutoff rigidity in the perturbed Earth's magnetosphere under conditions of the cycle minimum.

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Section: Introductionmentioning

confidence: 99%

Peculiar Solar Sources and Geospace Disturbances on 20–26 August 2018

et al. 2020

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“…В связи с этим, можно внести в сложившуюся дискуссию по проблеме происхождения всплеска космических лучей, зарегистрированных 22.06.2015 рядом установок [10], новый элемент геофизического характера. Этот факт, возможно ответит на вопрос, поставленный в [2] о границах возможностей традиционных моделей предсказывать возмущение порога геомагнитного обрезания. Причина разногласий лежит в условиях измерений последствий возмущения геомагнитного поля.…”

Section: Discussionunclassified

“…пользу такого утверждения выступала высокая степень автокорреляции временных профилей модуля межпланетного магнитного поля и вариаций мюонов. В работе группы исследователей [2] такая концепция была подвергнута критике. В качестве аргументов были предъявлены свидетельства локальности эффекта в регистрации всплеска нейтронными мониторами мировой сети, в то время как результаты расчётов, основанные на широко используемой модели Цыганенко [3], показывают его глобальность.…”

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Проникновение Отрицательного Заряда Из Ионосферы В Землю, На Фоне Магнитосферной Бури

Khaerdinov¹,

Dzhappuev²,

Канониди³

et al. 2021

Вестник КРАУНЦ. Физико-Математические Науки

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Во время магнитосферной бури 22.06.2015, сопровождаемой Форбуш – понижением, отдельные установки, регистрирующие космические лучи на уровне земли, зафиксировали положительное возмущение интенсивности частиц в период 19:00 –22:00 UT. В работе приводится регистрация указанного всплеска на территории Кавказских гор установкой «Ковёр» БНО ИЯИ РАН. Приводится экспериментальное свидетельство медленного спуска в этот период большого отрицательного заряда с ионосферы на землю. During a magnetic storm on June 22, 2015, was accompanied by a Forbush decrease, some detectors of cosmic rays on the ground level recorded a positive disturbance of the particle intensity in the period 19:00 – 22:00 UT. This paper presents the data of detecting this burst in the North Caucasus region by the Carpet air shower array of the Baksan Neutrino Observatory. Experimental evidence in favor of a slow transfer in this period of a large negative charge from the ionosphere to the ground is presented.

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“…In 2004 the BP-28 was replaced with He-3 detectors and operated until November 22, 2005, when the detectors were removed and stored [3]. In February 2010, the 3x1NM64 detectors were moved to a new platform some distance from the current station and reactivated [4].…”

Section: Introductionmentioning

confidence: 99%

Monte Carlo Simulations of South Pole Neutron Monitor Counting Rate since 1964

Pagwhan,

Seripienlert,

Nuntiyakul

et al. 2023

Proceedings of 38th International Cosmic Ray Conference — PoS(ICRC2023)

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Neutron monitors (NM) are ground-based cosmic ray detectors that measure the flux of primary cosmic rays at the GeV-energy range by counting (primarily) secondary neutrons in atmospheric cascades. The South Pole NM started in 1964 as an International Geophysical Year (IGY) monitor that operated until 1974. In 1977 three NM64 with boron-trifluoride proportional counters were installed. In January 2004, they were replaced with helium-3 detectors. Apart from a four-year gap (2005)(2006)(2007)(2008)(2009), the NM has operated continuously since then. Over decades of its operation, a decline of the South Pole NM counting rate was observed, significantly larger than temporal changes observed by other NM stations. To investigate this decline, we simulated the counting rates of the NM64, for boron-trifluoride and helium-3 configurations, using the FLUKA Monte-Carlo package. We compare the observed count rates from 1964 to December 2021 with simulated count rates obtained using monthly values of the modulation parameter (𝜙, in MV) determined in two different ways. The extended data set and the simulations indicate that most of the observed decline can be associated with the transition from the IGY to the NM64. Further work with a specific IGY simulation is required.

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Impulsive Increase of Galactic Cosmic Ray Flux Observed by IceTop

Cited by 3 publications

References 7 publications

Peculiar Solar Sources and Geospace Disturbances on 20–26 August 2018

Peculiar Solar Sources and Geospace Disturbances on 20–26 August 2018

Проникновение Отрицательного Заряда Из Ионосферы В Землю, На Фоне Магнитосферной Бури

Monte Carlo Simulations of South Pole Neutron Monitor Counting Rate since 1964

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