Geomagnetically Induced Currents (GIC) are a space weather effect, which affects ground-based technological structures at all latitudes on the Earth's surface. GIC occurrence and amplitudes have been monitored in power grids located at high and middle latitudes since 1970s and 1980s, respectively. This monitoring provides information about the GIC intensity and the frequency of occurrence during geomagnetic storms. In this paper, we investigate GIC occurrence in a power network at low latitudes (in the central Brazilian region) during the solar cycles 23 and 24. Calculated and measured GIC data are compared for the most intense geomagnetic storms (i.e. À50 < Dst < À50 nT) of the solar cycle 24. The results obtained from this comparison show a good agreement. The success of the model employed for the calculation of GIC leads to the possibility of determining GIC for events during the solar cycle 23 as well. Calculated GIC in one transformer reached ca. 30 A during the ''Halloween storm'' in 2003 whilst most frequent intensities lie below 10 A. The normalized inverse cumulative frequency for GIC data was calculated for the solar cycle 23 in order to perform a statistical analysis. It was found that a q-exponential Tsallis distribution fits the calculated GIC frequency distribution for more than 99% of the data. This analysis provides an overview of the long-term GIC monitoring at low latitudes and suggests new insight into critical phenomena involved in the GIC generation.
This contribution addresses the first assessment of the impact of geomagnetically induced currents (GIC) on the 400‐kV power grid of Mexico. As an initial approach, we modeled GIC using a uniform conductivity for the entire Mexican territory and spatially uniform geomagnetic disturbance. Power grid data were provided by the electric operator of Mexico; the geophysical data were inferred from the main features of Mexican geology. We calculate the power grid response during four geomagnetic storms from Solar Cycles 23 and 24 (i.e., 15 July 2000, 20 October 2003, 17 March 2015, and 7 September 2017), as well as during an extreme scenario (a Carrington‐like event). The results show that the Mexican power grid can be affected by three‐phase GIC ranging from 20 to 75 A during geomagnetic disturbances. According to the model, sites located in coastal areas or close to the edges of the network can experience large GIC during time intervals between 3 and 10 hr, depending on the intensity of the geomagnetic disturbance. It is an interesting result that these sites are of the major economic and strategic significance for the country. In the case of a Carrington‐like event, the power grid could be affected by GIC ranging between 25 and 150 A under a uniform 1 V/km EW geoelectric field. Such an event might produce significant distortions in the grid hardware (i.e., transformers and static VAR compensators), potentially leading to widespread damage.
The venue was a very good one. Its location was well-suited for easy walks to nearby restaurants; the meeting room was well-equipped and a good size for hosting the attendees; and having everyone stay at the same hotel made it conducive to fostering conversations with others outside of the main presentations, which is often where some of the most useful discussions take place.• II PANGEO was successful because of the number of participants from different countries, and because of the large number of students in attendance. I believe that the students found it very valuable to learn from more senior scientists and to exchange ideas with them.• The range of topics presented at the workshop was very good, covering a variety of areas of expertise.
Suggestions (for III PANGEO):• I would recommend trying to schedule more time for hands-on measurement sessions at the observatory. If people are encouraged to bring their own theodolites to the workshop, they should have more opportunity to work with experienced observers who can advise them on their techniques and methods of recording their absolute measurements.• I would encourage more time for hands-on equipment sessions, or demonstrations of software that can be used to view, analyze, or process data. I think this is one of the most important ways we can build capacity in other countries who may not have the means to develop such tools themselves.• All of the attendees would benefit from having the full workshop schedule available to them before traveling to the workshop, so that they can plan their travel and presentations accordingly.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.