Milestones of the IAGA International Service of Rapid Magnetic Variations and its contribution to geomagnetic field knowledge

Curto, J. J.; Cardús, J. O.; Alberca, L. F.; Blanch, E.

doi:10.1186/bf03352708

Cited by 16 publications

(18 citation statements)

References 10 publications

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“…Therefore, no SI has been recorded during magnetic storms by the JMA standard. Araki (2014) (Curto et al 2007). Kurusu (1971) investigated magnetic events observed at Kakioka, Memambetsu, and Kanoya between July 1957 and December 1968 and developed criteria for determining the quality of the records, and JMA has since recorded the quality in conformity with those criteria.…”

Section: Datamentioning

confidence: 99%

Frequency distributions of magnetic storms and SI+SSC-derived records at Kakioka, Memambetsu, and Kanoya

2015

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The Japan Meteorological Agency keeps records of geomagnetic phenomena observed at Kakioka (magnetic latitude, 27.47°), Memambetsu (magnetic latitude, 35.44°), and Kanoya (magnetic latitude, 22.00°). We used these records to examine the cumulative frequency distribution of magnetic storms, sudden impulses, and storm sudden commencements. The distributions of magnetic storms resemble the Gutenberg-Richter relation between earthquake frequency and magnitude used in seismology. The coefficients determined with the maximum likelihood method show that when the H-range of a magnetic storm at Kakioka is doubled, the frequency of the magnetic storm is about one seventh, for example. Intense magnetic storms occur less frequently than calculated by the functions. This statistical analysis proves that there are no significant differences between slopes of the frequency distribution functions of the magnetic phenomena at Kakioka, Memambetsu, and Kanoya.

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Section: Datamentioning

confidence: 99%

Frequency distributions of magnetic storms and SI+SSC-derived records at Kakioka, Memambetsu, and Kanoya

2015

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“…They also have different relaxation times (Richmond and Venkateswaran, 1971). Thus, to achieve a certain degree of certainty in the Service of Rapid Magnetic Variations (Curto et al, 2007), other contemporary ionospheric effects are usually sought out (Tsurutani et al, 2009). …”

Section: Difficulties In Sfe Detectionmentioning

confidence: 99%

“…At the IAGA General Assembly (Rome, 1954) a new committee was created on rapid variations and Earth currents with A. Romañá from the Ebre Observatory elected as chairman. The task of the committee was to create lists of events, including sudden storm commencements (SSC), pulsations during sudden commencements (PSC), sudden impulses (SI) and solar flare effects (SFE), which were to be published in the IAGA annual bulletins (Curto et al, 2007). Since then, the working procedure to detect SSC and Sfe events has been more or less the same and it is still based on manual methods.…”

Section: Introductionmentioning

confidence: 99%

Automatic detection of Sfe: a proposal

et al. 2017

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Abstract. Solar flare effects (Sfe's) are rapid magnetic variations related to the enhancement of the amount of radiation produced during solar flare events. For several minutes, the ionosphere is activated and electron densities, electrical conductivities and electric currents are enhanced. The magnetic signature of a flare is visible in the illuminated hemisphere, and sometimes it shows up as small crochet-like movements in the magnetograms. However, regarding their detection using an automatized procedure, they have been very elusive because their small amplitude, which is close to the level of noise produced by other natural phenomena, and their highly variable irregular shapes make it extremely difficult to apply predesigned patterns. In this paper, we summarize the difficulties that Sfe detection presents and explain a line of work we initiated to overcome these difficulties with the goal of achieving a system capable of performing automatic detection. Some properties of Sfe's, including spherical symmetry around the vortex and different time durations between Sfe's and other natural variations, were used to construct an index allowing us to detect Sfe's.

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“…This task was entrusted by the International Association of Geomagnetism and Aeronomy (IAGA), resolution number 6 of the XVI IUGG General Assembly, Grenoble, 1975(Curto et al, 2007. One of these rapid variations is the SC phenomenon.…”

Section: Introductionmentioning

confidence: 99%

“…After IAGA meeting in Sopron (Hungry) in 2009, and taking in consideration some previous works as (Joselyn, 1985), and (Curto et al, 2007), more objective criteria to select events were introduced, e.g., at least a slope of 3 nT/min at minimum in 3 of 5 low-latitude stations. These criteria were tested in advance in order the new lists be coherent with the oldest lists (Mayaud, 1973).…”

Section: Introductionmentioning

confidence: 99%

Automatic detection of sudden commencements using neural networks

Segarra

Curto

2013

Earth Planet Sp

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The aim of this work is to develop an automatic system to detect sudden commencements (SCs). SCs are produced by a sudden increase of solar wind dynamic pressure and are detected simultaneously everywhere on the ground (Araki, 1994). Since 1975, Ebro Observatory is responsible to elaborate the list of SC, following the morphological rules given by Mayaud (1973). Nowadays, this task is still done manually and presents some difficulties; the most worrying one is the decreasing number of observatories who collaborate with this task because most of them opted for the installation of unattended observatories. Hence, the necessity of an alternative method to continue the service becomes a urgency. The automatic method presented in this work is based on neural network analysis. To succeed with neural networks, we did a previous work of characterization and parameterization of SCs by statistical analysis. In this way, we focused on the determination of the appropriate parameters to be used as the inputs of the network which resulted to be: slope, change of magnetic activity and difference of the levels before and after the jump. We worked with X component and also with Y component. An important criteria introduced in this work is the necessary coherence of the results obtained with this new automatic method with those obtained with the manual method and reported in the old list of SC. Finally, the neural network is able to recognize the SC pattern successfully, but now this is achieved in a non-manned way. A robust quasi-real-time detection can be undertaken in the future.

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Milestones of the IAGA International Service of Rapid Magnetic Variations and its contribution to geomagnetic field knowledge

Cited by 16 publications

References 10 publications

Frequency distributions of magnetic storms and SI+SSC-derived records at Kakioka, Memambetsu, and Kanoya

Frequency distributions of magnetic storms and SI+SSC-derived records at Kakioka, Memambetsu, and Kanoya

Automatic detection of Sfe: a proposal

Automatic detection of sudden commencements using neural networks

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