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This paper is to introduce a proposed deep space mission, which aims to perform in situ detection of the central structure, namely the magnetic reconnection current sheet, which drives the large-scale eruption on a star. The main focus of this mission is on the fine physical characteristics of the large-scale magnetic reconnection taking place on the Sun, our nearest star, revealing the secret of the most violent energy release process, also known as the solar storm, in the solar system. The scientific goal of this mission, magnetic reconnection, is a kernel process of energy conversion occurring in the magnetized plasma in the universe, and has long been a fairly important research topic or even research area in solar physics, space science, plasma physics, and the related fields. The in situ detection with a 5 ∼ 20 times enhanced spatial resolution of the instruments used on the Earth will provide us with the extra-clear images of the Sun and the related information. We are thus able to study, to learn, and to understand the Sun on an unprecedented platform, and further resolve the longstanding puzzle in the solar community regarding the fine physical property of the kernel process driving the solar eruption, as well as that of the coronal heating.

Progress on the 4.0 industrial revolution was the most significant is the entire computer and robot is connected to the internet connection. Satellites as one of the internet network transmitters have the threat of destruction if a solar storm occurs. The size of the activity that is on the sun can be known by observing sunspots. Solar activity in the future is known by forecasting sunspot numbers. This research will forecast sunspot numbers using support vector regression (SVR), its aimed to minimized adverse effects on the earth as an outcome of solar storms. The best SVR results on forecast sunspot numbers are on annual sunspot number obtained using RBF kernel. Measurement results from MSE, RMSE, and MAAPE respectively by 35.32, 5.94, and 0.12. Forecasting concluded accurately based on MAAPE value, on 2020 and 2021 indicated potentially flare because the result of forecasting sunspot numbers is more than twenty. DOI: http://dx.doi.org/10.17977/um024v5i12020p006

Whale strandings occur in many places worldwide and numerous possible explanations for this phenomenon have been proposed, including the effects of astronomical events such as Solar eruptions on the Earth's magnetic field. Whales use the geomagnetic field for navigation, and its distortion can therefore result in whale strandings in certain regions. However, Solar storms do not have the same impact on the geomagnetic field across the whole of the Earth's surface, and positions nearer to the equator are less exposed to this phenomenon. It is therefore plausible that Solar storms can explain whale strandings at high latitude at least, but not necessarily worldwide. This review considers strandings in relation to the geographical and geomagnetic properties of locations at higher latitudes and to changes in the magnetic field over recent centuries. It also focuses on a Solar storm in December 2015. These considerations suggest that navigation errors due to Solar storms are more likely to occur at higher latitudes, particularly in sea areas where the animals might subsequently swim into a geographic trap and become stranded. For sperm whales (Physeter macrocephalus), the southern Norwegian Sea in conjunction with the shallow North Sea represents such an area.

We present a solar-centric approach to estimating the probability of extreme coronal mass ejections (CME) using the Solar and Heliospheric Observatory (SOHO)/Large Angle and Spectrometric Coronagraph Experiment (LASCO) CME Catalog observations updated through May 2018 and an updated list of near-Earth interplanetary coronal mass ejections (ICME). We examine robust statistical approaches to the estimation of extreme events. We then assume a variety of time-independent distributions fitting, and then comparing, the different probability distributions to the relevant regions of the cumulative distributions of the observed CME speeds. Using these results, we then obtain the probability that the velocity of a CME exceeds a particular threshold by extrapolation. We conclude that about 1.72% of the CMEs recorded with SOHO LASCO arrive at the Earth over the time both data sets overlap (November 1996 to September 2017). Then, assuming that 1.72% of all CMEs pass the Earth, we can obtain a first-order estimate of the probability of an extreme space weather event on Earth. To estimate the probability over the next decade of a CME, we fit a Poisson distribution to the complementary cumulative distribution function. We inferred a decadal probability of between 0.01 and 0.09 for an event of at least the size of the large 2012 event, and a probability between 0.0002 and 0.016 for the size of the 1859 Carrington event.

Solar-geomagnetic superstorms like the 1859 Carrington Event pose significant risks to electrical power utilities and satellite infrastructure. Damage to this critical infrastructure could have sig...

When there is a temporary disturbance of earth’s magnetosphere, then a geomagnetic storm (or solar storm) has occurred. It is caused by a solar wind shock wave and/or cloud of a magnetic field that interacts with the Earth's magnetic fields. The interaction of Interplanetary Magnetic Fields (IMF) of the sun with the earth’s magnetic fields in opposite directions is known as magnetic reconnection (Yousif, 2014). Magnetic reconnection (often referred as "reconnection") is the breaking and reconnecting of oppositely directed magnetic field lines in plasma at a neutral point which leads to converting the magnetic field energy into plasma kinetic and thermal energy. It occurs either in the day-time (day reconnection) where the sunward convection near the polar cusps allows energised particles to be transmitted earthward or night-time (tail reconnection) where particles injected into the magnetosphere are saturated, thus releasing stored energy in the form of auroral substorms. Sokolov (2011) suggested that a geomagnetic storm can be determined by changes in the Disturbed-storm time (Dst). However, not all geomagnetic storms have an initial phase and not all sudden increase in Dst or SYM-H are followed by a geomagnetic storm. This paper attempts to determine what are responsible for magnetic reconnections in the solar cycle 24 considering a low solar activity year 2009 and a high solar activity year 2012. We have to classify the geomagnetic storms using the Dst indices and rearrange the IMF Bz according to its negative, neutral and positive values. We measured the correlation between Bz and solar wind using a 1-min resolution OMNIweb dataset. Thereafter, establish the factors responsible for magnetic reconnections. We analysed 39 and 202 geomagnetic storms in 2009 and 2012 respectively considering the Dst indices and IMF Bz values of each month obtained from the OMNIWeb Database. Our results showed that geomagnetic storms occurred in 10% and 45% of days in the year 2009 and 2012 respectively which implies they were frequent and intense due to high solar activity caused by the frequent occurrence of coronal mass ejections (CMEs) and interplanetary coronal mass ejections (ICMEs) in the year 2012 than in the year 2009. This study also revealed that negative Bz occurrences were 47.54% and 52.18% in 2009 and 2012 respectively. Thus, the more intense the geomagnetic storms, the more Bz would go south and the more magnetic reconnections and subsequently auroral substorms which can increase radiation doses for occupants of transpolar flights, disruption of shortwave radio communications, distortion of compass readings in polar regions, failure of electrical transmission lines, increased corrosion in long pipelines, anomalies in the operations of communications satellites, and potentially lethal dosages of radiation for astronauts in interplanetary spacecraft.

A solar storm in the year 993 has allowed researchers to show that Vikings were in the Americas exactly 1,000 years ago. Hear the biggest stories from the world of science | 21 October 2021

An ancient solar storm helps pinpoint when Vikings lived in the Americas, and using magnets to deftly move non-magnetic metals. Hear the biggest stories from the world of science | 20 October 2021

Solar storm was an effect when Sun was active. Solar flares flame released a large amount of energy and caused a large-scale explosion. A large amount of coronal matter was ejected into space by plasma composed of electrons and protons. Their shock waves or magnetic clouds and the earth Magnetic storms generated by the interaction of magnetic fields caused disturbances and squeezing of the earth’s magnetosphere. A solar flare was a phenomenon of solar storm. It had huge eruptions of electromagnetic radiation. The sudden electromagnetic energy traveled with the speed of light. Large solar flare might affect the effects of reliability of electronic components in satellites and could cause economic losses by soft error and could affect human health through the space radiation, especially causing cancer.

The DC currents might flow in a power system due to Geomagnetic Disturbances (GMDs) that result from either a solar storm or a high-altitude nuclear detonation. The increasing inverter-based generation is also injecting small DC currents into the power systems. These currents could have serious implications for the power systems as they drive the transformers towards saturation, cause massive draw of reactive power, cause transformers internal heating and maloperation of protection equipment. This paper studies the impact of the DC currents flowing in a power transmission network on a 50MVA grid-tied solar farm. A variety of loading conditions that include both local and remote loads have been considered. A detailed harmonic analysis is performed and evaluated against IEEE-519. Also, the limitations imposed by the DC current flow in a power grid on the solar farm capabilities have been highlighted. Finally, the effectiveness of a Neutral Blocking Device (NBD) in restoring the normal operation of a solar farm has been evaluated. The PSCAD/EMTDC has been utilized as the simulation platform and the associated results are presented.

An intriguing aspect of the 2 September 1859 geomagnetic disturbance (or Carrington event) is the horizontal magnetic dataset measured in Colaba, India (magnetic latitude approximately 20 degrees N). This dataset exhibits a sharp decrease of over 1600 nT and a quick recovery of about 1300 nT, all within a few hours during the solar daytime. The mechanism behind this has previously been attributed to magnetospheric processes, ionospheric processes or a combination of both. In this talk, we outline our efforts to recreate this low-latitude magnetic dataset using the Space Weather Modelling Framework (SWMF). By simulating an array of extremely high pressure solar wind scenarios, we can recreate the low-latitude surface magnetic signal at Colaba. We find that the position of the magnetopause is an important factor for such quick deviations and recoveries in dayside surface magnetic measurements. In addition, we find that scenarios which accurately recreated surface magnetic field observations during the Carrington event had minimum Dst values of only -610 nT.

Geomagnetic indices are routinely used to characterize space weather event intensity. The DST index is well resolved, but is only available over 5 solar cycles. The aa index extends over 14 cycles but is highly discretized with poorly resolved extremes. We parameterize extreme aa activity by the annual averaged top few % of observed values, show these are exponentially distributed and they track annual DST index minima. This gives a 14 cycle average of ~ 4% chance of at least one great (DST nT) storm and ~ 28% chance of at least one severe (DST nT) storm per year. At least one DST=‐809 [‐663,‐955] nT event in a given year would be a 1:151 year event. Carrington event estimate DST ~ ‐850 nT is within the same distribution as other extreme activity seen in aa since 1868 so that its likelihood can be deduced from that of more moderate events. Events with DST ≲ ‐1000 nT are in a distinct class, requiring special conditions.

Transmission system operators are responsible for security and reliability of their grid. An important topic is the analysis of possible risks for the transmission system network. The paper presents actual results about geomagnetically induced currents (GIC) in the Austrian transmission system. Because of problems with unexpected noise at some transformers, investigations were started, which gave an indication that DC could be the source of this noise. Due to the particular geological structure of the country, the influence of GIC in Austria is higher than for the most other countries in Central Europe. A simulation model to compute GIC was set up and compared to the measured DC transformer neutral current. The comparison of the simulated and measured currents shows a good correlation. High geomagnetic disturbances, which lead to high currents according the simulation model, can be confirmed by the measurement. Differences between measurement and simulation can be seen in the region of “fast” fluctuation within seconds. By detailed analysis of the times of occurrence it was shown, that currents from underground railway, which are operating with DC, flow through the transmission grid, too.

The largest geomagnetic storm in solar cycle 24 is investigated from the dual perspective of (1) solar source – solar wind – geomagnetic storm chain and (2) the hazardous induced response as shown by the surface electric field. The study is based on heliospheric magnetic field and solar wind data, on one hand, and on recorded 1-min geomagnetic data from the INTERMAGNET network of European geomagnetic observatories, on the other. The lateral distribution of the induced electric response for the European continent during the considered storm is shown, and the timing of the maximum induced horizontal geoelectric vector is discussed in terms of specific moments of the storm development.

A passing coronal mass ejection (CME) will manifest a different response at an airless body compared to a magnetized planet. Specifically, because the regolith-rich surfaces of airless bodies are directly exposed to the variations in the plasma flow, the surfaces are found to undergo anomalous surface charging during the passing of CME fast plasma events. In this study, we model the surface charging expected at Phobos for nominal solar wind conditions and also those associated with disturbed solar wind conditions during the passage of a CME similar to that observed by MAVEN at Mars in early March 2015. We use an ambipolar diffusion model to examine the development of the trailing wake/void in the plasma flow behind Phobos and the formation of mini-wakes within obstruction regions like Stickney Crater. We also consider the roving of an astronaut in Stickney Crater for Phobos positioned near 10 h Local Time relative to Mars. We examine the plasma dissipation of the collected astronaut charge from contact electrification with the regolith.

We have investigated the consequences of extreme space weather on ion outflow from the polar ionosphere by analyzing the solar storm that occurred early September 2017, causing a severe geomagnetic storm. Several X‐flares and coronal mass ejections were observed between 4 and 10 September. The first shock—likely associated with a coronal mass ejection—hit the Earth late on 6 September, produced a storm sudden commencement, and began the initial phase of the storm. It was followed by a second shock, approximately 24 hr later, that initiated the main phase and simultaneously the Dst index dropped to Dst = −142 nT and Kp index reached Kp = 8. Using COmposition DIstribution Function data on board Cluster satellite 4, we estimated the ionospheric O+ outflow before and after the second shock. We found an enhancement in the polar cap by a factor of 3 for an unusually high ionospheric O+ outflow (mapped to an ionospheric reference altitude) of 1013 m−2 s−1. We suggest that this high ionospheric O+ outflow is due to a preheating of the ionosphere by the multiple X‐flares. Finally, we briefly discuss the space weather consequences on the magnetosphere as a whole and the enhanced O+ outflow in connection with enhanced satellite drag.

An extreme space weather event has the potential to disrupt or damage infrastructure systems and technologies that many societies rely on for economic and social well-being. Space weather events occur regularly, but extreme events are less frequent, with a small number of historical examples over the last 160 years. During the past decade, published works have (1) examined the physical characteristics of the extreme historical events and (2) discussed the probability or return rate of select extreme geomagnetic disturbances, including the 1859 Carrington event. Here we present initial findings on a unified framework approach to visualize space weather event probability, using a Bayesian model average, in the context of historical extreme events. We present disturbance storm time (Dst) probability (a proxy for geomagnetic disturbance intensity) across multiple return periods and discuss parameters of interest to policymakers and planners in the context of past extreme space weather events. We discuss the current state of these analyses, their utility to policymakers and planners, the current limitations when compared to other hazards, and several gaps that need to be filled to enhance space weather risk assessments.

The Earth's atmosphere and the Earth's magnetic field protects local life by shielding us against Solar particle flows, just like the sun's magnetic field deflects cosmic particle radiation. Generally, magnetic fields can affect terrestrial life such as migrating animals. Thus, terrestrial life is connected to astronomical interrelations between different magnetic fields, particle flows and radiation. Mass strandings of whales have often been documented, but their causes and underlying mechanisms remain unclear. We investigated the possible reasons for this phenomenon based on a series of strandings of 29 male, mostly bachelor, sperm whales (Physeter macrocephalus) in the southern North Sea in early 2016. Whales’ magnetic sense may play an important role in orientation and migration, and strandings may thus be triggered by geomagnetic storms. This approach is supported by the following: (1) disruptions of the Earth's magnetic field by Solar storms can last about 1 day and lead to short-term magnetic latitude changes corresponding to shifts of up to 460 km; (2) many of these disruptions are of a similar magnitude to more permanent geomagnetic anomalies; (3) geomagnetic anomalies in the area north of the North Sea are 50–150 km in diameter; and (4) sperm whales swim about 100 km day−1, and may thus be unable to distinguish between these phenomena. Sperm whales spend their early, non-breeding years in lower latitudes, where magnetic disruptions by the sun are weak and thus lack experience of this phenomenon. ‘Naïve’ whales may therefore become disoriented in the southern Norwegian Sea as a result of failing to adopt alternative navigation systems in time and becoming stranded in the shallow North Sea.

Ionization in Earth's troposphere is mainly due to Galactic cosmic rays. Occasionally, solar storms produce intense relativistic ion beams that significantly increase such ionization. One of the largest recorded solar radiation storms, on 20 January 2005, resulted in up to 55-fold increases in the count rates of ground-based particle detectors in polar regions. We use McMurdo and Inuvik neutron monitor data to estimate accurate time profiles of ion energy spectra above the atmosphere at each location. Using data-driven atmospheric models, we perform Monte Carlo simulations of particle-air interactions and calculate atmospheric ionization and potential biological dosage versus altitude and time for each location. We found that if airplane passengers had traversed the south polar region, they could have been exposed to the typical annual cosmic radiation dosage at sea level within 1 h. These techniques can help evaluate possible influences of solar activity on atmospheric properties.

Space weather events produce variations in the electric current in the Earth's magnetosphere and ionosphere. From these high-altitude atmospheric regions, resulting geomagnetically induced currents (GICs) can lead to fluctuations in ground currents that affect the electric power grid and potentially overload transformers during extreme storms. The most extreme geomagnetic storm on record, known as the 1859 Carrington event, was so intense that ground-based magnetometers were saturated at high magnetic latitudes. The most reliable, unsaturated observation is the hour resolution data from the Colaba Magnetic Observatory in India. However, higher-frequency components—fluctuations at second through minute time cadence—to the magnetic field can play a significant role in GIC-related effects. We present a new method for scaling higher-frequency observations to create a realistic Carrington-like event magnetic field model, using modern magnetometer observations. Using the magnetic field model and ground conductivity models, we produce an electric field model. This method can be applied to create similar magnetic and electric field models for studies of GIC effects on power grids.

A scheme is suggested and tested for forecasting severe space weather (SvSW) using solar wind velocity (V) and the north-south component (Bz) of the interplanetary magnetic field (IMF) measured using the ACE (Advanced Composition Explorer) satellite from 1998 to 2016. SvSW has caused all known electric power outages and telegraph system failures. Earlier SvSW events such as the Carrington event of 1859, Quebec event of 1989 and an event in 1958 are included with information from the literature. Dst storms are used as references to identify 89 major space weather events (DstMin ≤ -100 nT) in 1998-2016. The coincidence of high CME front (or CME shock) velocity ΔV (sudden increase in V over the background by over 275 km/s) and sufficiently large Bz southward at the time of the ΔV increase is associated with SvSW; and their product (ΔV x Bz) is found to exhibit a large negative spike at the speed increase. Such a product (ΔV x Bz) exceeding a threshold seems suitable for forecasting SvSW. However, the coincidence of high V (not containing ΔV) and large Bz southward does not correspond to SvSW, indicating the importance of the impulsive action of large Bz southward and high ΔV coming through when they coincide. The need for the coincidence is verified using the CRCM (Comprehensive Ring Current Model) model, that produces extreme Dst storms (

Few studies have collected and analyzed the astronomical events recorded in Arabic literature. In this paper, we present some additional events reported in four Arabic historical sources that could be classified as an aurora. These observations occurred from 9th to 20th century and cover a large geographic area: North Africa, Arabian-Peninsula and Middle-East. Some of them were observed at very low geomagnetic latitude, such as the event seen in Yemen in AD 1919 that can be considered as one of the lowest latitude auroras ever documented by Arabic scholars. In the same Yemenite source, the author describes a twilight phenomenon of 1883 October 03–November 01 which can be considered as an atmospheric-optical phenomenon arising from the major explosive eruptions of Krakatoa in 1883 August 26–27. We also noticed that one of the events which was seen for 7 days coincide probably with the prolonged manifestation of auroras of 1870 September 24–25. Including published records, we compiled a so far most complete catalog of potential auroral candidates in the Arabic sources. This data set can be used in order to study the solar activity variations and magnetic storms in the historical past. One of the interesting auroras was seen in Mecca ($\sim17^{\circ}$ MLAT) in 1872 February 04. This event is further evidence for the equatorward extension of auroral display and the planetary consequences of the great geomagnetic storm of 1872. Finally, it should be underlined that no aurora observations were recorded during the Maunder minimum (MM).

The largest variations in the plasma and fields that comprise the inner regions of the Earth’s space environment, or the magnetosphere, occur during geomagnetic storms and are related to the intensification of the ring current, the magnetically trapped charged particles that partially or fully encircle the Earth inside of ∼7 Earth radii. This chapter provides a historical introduction to the ring current and geomagnetic storms that have been investigated for more than 100 years. An overview of the relationship of the ring current to solar wind drivers and the development and decay of the ring current, in terms of the Sun-Earth connection is presented. Major space weather effects triggered by geomagnetic storms are briefly summarized. These effects intensify during extreme events, like the largest recorded geomagnetic storm that occurred in September 1859, known as the Carrington Event. Less severe storms have occurred since then, still causing many disruptions.

Plasma from solar events such as coronal mass ejections and solar flares can impact the Earth’s magnetosphere and cause disruptions of electrical systems on the ground. Warning systems exist to help prepare people for possible disruptions. Generally, it is thought that there would be a few days’ warning. However, larger flares on the scale of the Carrington Event have much faster travel times. For X-ray class flares above X of 17 with data available, all have travel times to one astronomical unit of 30 h or less. Since those are more likely to have the greatest impact on the operation of electrical systems, their travel time is more important than the average event.

Extreme cosmic radiation events occurred in the years 774/5 and 993/4 CE, as revealed by anomalies in the concentration of radiocarbon in known-age tree-rings. Most hypotheses point towards intense solar storms as the cause for these events, although little direct experimental support for this claim has thus far come to light. In this study, we perform very high-precision accelerator mass spectrometry (AMS) measurements on dendrochronological tree-rings spanning the years of the events of interest, as well as the Carrington Event of 1859 CE, which is recognized as an extreme solar storm even though it did not generate an anomalous radiocarbon signature. Our data, comprising 169 new and previously published measurements, appear to delineate the modulation of radiocarbon production due to the Schwabe (11-year) solar cycle. Moreover, they suggest that all three events occurred around the maximum of the solar cycle, adding experimental support for a common solar origin.

This paper studies the impacts of interplanetary coronal mass ejections (ICMEs) preceding storm (November 18–22, 2003) on several space weather components. The comprehensive study of different parameters such as solar wind speed, density, plasma temperature, plasma pressure, auroral electrojet, SYM-H, energy transfer, components of Earth’s magnetic field, total electron content, and cosmic ray received by Earth during the ICME storm has been studied, which accounts for the more precise knowledge of the storm from different dimensions. The solar storm of November 2003 had SYM-H value of − 472 nT. During the main phase of the storm, the velocity of solar wind reached approximately to 500 km/s, and plasma pressure cumulated to around 20 nPa. The total energy dissipated during the storm in the magnetosphere has been converted in the form of ring current, joule heating, and auroral precipitation. The joule heating leads to modification in thermospheric contents and traveling atmospheric contents that result in further modification of the density, composition, circulation, and dynamics of ionosphere–thermosphere system. This phenomena further result in the escalation and slumping of TEC. We found out the decrease in rate of cosmic ray received by the Earth during the main phase of the storm, which lead to our conclusion that there exists inverse relation between strength of solar storm and amount of cosmic ray fluxes received by the Earth. In addition, the study made on the change in TEC and SYM-H during the event hinted us toward the possible changes in the space weather caused by the solar superstorm of November 18–22, 2003.

An increase in the solar magnetic field gives rise to the number of visible sunspots in the Earth facing side of the Sun. This tends to impact the Earth’s magnetic field. Occurrence of a geomagnetic storm depends on the interaction of magnetic fields of both the Sun (captured in solar wind) and the Earth. The energy of the sun is given out in the form of high-speed solar wind, solar flares, coronal mass ejections (CMEs), solar uV light and energetic particles (MeV). The effect of such geomagnetic storms is borne by the trans-ionospheric message carrying signal and affects both satellite navigation and radio communication systems on Earth. Moreover, the ionosphere, being a refractive and dispersive medium, adds as a source of error to the message signal. Thus, it becomes important to study the effect of space weather activities on GNSS signal and try to overcome its impact. This paper studies the impact of one such solar storm in the mid-high latitude region during the winter solstice of 2015 on GPS and high-frequency airplane communication. A case study of an event that occurred in Stockholm, Sweden on the 4 November 2015 has been investigated using the geomagnetic and satellite geometric parameters, and the total electron content (TEC) variation in the ionosphere. The analysis undertaken in this paper demonstrates the importance of understanding the serious threats solar activity poses to GNSS and its related applications on Earth, which can have rippling effects on industries which are evidently reliable on space technology.

Birds possess a magnetic sense and rely on the Earth's magnetic field for orientation during migration. However, the geomagnetic field can be altered by solar activity at relative unpredictable intervals. How birds cope with the temporal geomagnetic variations caused by solar storms during migration is still unclear. We addressed this question by reproducing the effect of a solar storm on the geomagnetic field and monitoring the activity of three songbird species during autumn migration. We found that only the European robin reduced nocturnal migratory restlessness in response to simulated solar storms. At the same time, robins increased activity during early morning. We suggest that robins reduced activity at night when the perception of magnetic information would be strongly disrupted by temporal variations of the magnetic field, to extend their migration during daytime when several visual cues become available for orientation. The other two species, chiffchaff and dunnock, showing low or no nocturnal migratory activity, did not respond to the solar storm by changing activity.

This work presents results from simulations of the 2000 July 14 (“Bastille Day”) solar proton event. We used the Energetic Particle Radiation Environment Model (EPREM) and the CORona-HELiosphere (CORHEL) software suite within the SPE Threat Assessment Tool (STAT) framework to model proton acceleration to GeV energies due to the passage of a CME through the low solar corona, and we compared the model results to GOES-08 observations. The coupled simulation models particle acceleration from 1 to 20 R ⊙, after which it models only particle transport. The simulation roughly reproduces the peak event fluxes and the timing and spatial location of the energetic particle event. While peak fluxes and overall variation within the first few hours of the simulation agree well with observations, the modeled CME moves beyond the inner simulation boundary after several hours. The model therefore accurately describes the acceleration processes in the low corona and resolves the sites of most rapid acceleration close to the Sun. Plots of integral flux envelopes from multiple simulated observers near Earth further improve the comparison to observations and increase potential for predicting solar particle events. Broken power-law fits to fluence spectra agree with diffusive acceleration theory over the low energy range. Over the high energy range, they demonstrate the variability in acceleration rate and mirror the interevent variability observed in solar cycle 23 ground-level enhancements. We discuss ways to improve STAT predictions, including using corrected GOES energy bins and computing fits to the seed spectrum. This paper demonstrates a predictive tool for simulating low-coronal solar energetic particle acceleration.

A statistical analysis of the relation between exceptional solar events and daily numbers of deaths in the Czech Republic is presented. In particular, we concentrate on diseases of the nervous system (group VI from ICD-10—International Statistical Classification of Diseases and Related Health Problems 10th Revision) and diseases of the circulatory system (group IX from ICD-10). We demonstrate that the neurological diseases exhibit greater instability during the period of rising and falling solar activity. We study the daily numbers of deaths, separately for both sexes and two age groups (under 39 and 40+), during the Solar Cycles No. 23 and No. 24. We focus on exceptionally strong solar events in this period, such as the “Bastille Day event” on 14 July 2000, “Halloween solar storm” on 28 October 2003, and events on 7 January 1997, 2 April 2000, and on 7 September 2005. Special attention is paid to “St. Patrick’s Day storm” on 17 March 2015, the strongest geomagnetic storm of the Solar Cycle No. 24 that occurred following a coronal mass ejection (CME). We investigate the changes in the daily numbers of deaths during 1 month before and 1 month after these exceptional solar events. We take specific storm dynamics of their geophysical parameters into consideration. It has been verified that, for diseases of the nervous system, women are generally more sensitive than men. On the contrary, this differences between men and women have not been found for diseases of the circulatory system. Our findings suggest that the impact of the hazardous space weather conditions on human health depends on the specific dynamic and strength of the solar storm.

Extreme space weather events are low-frequency, high-risk phenomena. Estimating their rates of occurrence, as well as their associated uncertainties, is difficult. In this study, we derive statistical estimates and uncertainties for the occurrence rate of an extreme geomagnetic storm on the scale of the Carrington event (or worse) occurring within the next decade. We model the distribution of events as either a power law or lognormal distribution and use (1) Kolmogorov-Smirnov statistic to estimate goodness of fit, (2) bootstrapping to quantify the uncertainty in the estimates, and (3) likelihood ratio tests to assess whether one distribution is preferred over another. Our best estimate for the probability of another extreme geomagnetic event comparable to the Carrington event occurring within the next 10 years is 10.3% 95% confidence interval (CI) [0.9,18.7] for a power law distribution but only 3.0% 95% CI [0.6,9.0] for a lognormal distribution. However, our results depend crucially on (1) how we define an extreme event, (2) the statistical model used to describe how the events are distributed in intensity, (3) the techniques used to infer the model parameters, and (4) the data and duration used for the analysis. We test a major assumption that the data represent time stationary processes and discuss the implications. If the current trends persist, suggesting that we are entering a period of lower activity, our forecasts may represent upper limits rather than best estimates.

The so-called Carrington Event on September 1, 1859, is clearly the solar outburst that brought the realization to the inhabitants of Earth that weather existed in space, and that space weather was important to the rapidly developing technological infrastructure on Earth. It is important to understand not only how space weather affects our technological systems, but like the case of atmospheric weather, the possible intensity of such weather, the frequency of extreme events, and how to predict them. This paper reviews what we know about one class of extreme space weather events, the superfast arrival events, how best to compare them given our limited diagnostics in past events and even at the current time, and suggests a direction for progress in this field.

During the second Balloon Array for Radiation Belt Relativistic Electron Losses (BARREL) campaign two solar energetic proton (SEP) events were observed. Although BARREL was designed to observe X-rays created during electron precipitation events, it is sensitive to X-rays from other sources. The gamma lines produced when energetic protons hit the upper atmosphere are used in this paper to study SEP events. During the second SEP event starting on 7 January 2014 and lasting ∼3 days, which also had a solar energetic electron (SEE) event occurring simultaneously, BARREL had six payloads afloat spanning all magnetic local time (MLT) sectors and L values. Three payloads were in a tight array (∼2 h in MLT and ∼2 ΔL) inside the inner magnetosphere and at times conjugate in both L and MLT with the Van Allen Probes (approximately once per day). The other three payloads mapped to higher L values with one payload on open field lines for the entire event, while the other two appear to be crossing from open to closed field lines. Using the observations of the SEE and SEP events, we are able to map the open-closed boundary. Halford et al. (2015) demonstrated how BARREL can monitor electron precipitation following an interplanetary shock created by a coronal mass ejection (ICME-shock) arrival at Earth, while in this study we look at the SEP event precursor to the arrival of the ICME-Shock in our cradle-to-grave view: from flare, to SEE and SEP events, to radiation belt electron precipitation.

Existing literature on system defense mainly considers single or multiple intentional impacts. However, intentional impacts (strategic attacks) and unintentional impacts (natural disasters) can happen sequentially in practice. To overcome this limitation, we conduct a study that considers the optimal resource allocation for defending a k-out-of-n system against sequential intentional and unintentional impacts, which is motivated by the defense of a solar power grid system against the sequential hacker's attack and solar storm. We study the optimal defense strategies under different occurrence orders of intentional and unintentional impacts and analyze the impact of critical parameters on the defender's optimal defense strategy by a case study. We also investigate the scenario in which the defender offers supplemental protection to the elements that survive the first impact. The case study indicates that deploying as many elements as possible in the first stage may not be the optimal strategy for the defender no matter the unintentional impact comes first or the intentional impact comes first. Providing supplemental protection can reduce the expected loss of the system when the unintentional impact comes first.

We investigate the initiation and early evolution of 12 solar eruptions, including six active region hot channel and six quiescent filament eruptions, which were well observed by the \textsl{Solar Dynamics Observatory}, as well as by the \textsl{Solar TErrestrial RElations Observatory} for the latter. The sample includes one failed eruption and 11 coronal mass ejections, with velocities ranging from 493 to 2140~km~s$^{-1}$. A detailed analysis of the eruption kinematics yields the following main results. (1) The early evolution of all events consists of a slow-rise phase followed by a main-acceleration phase, the height-time profiles of which differ markedly and can be best fit, respectively, by a linear and an exponential function. This indicates that different physical processes dominate in these phases, which is at variance with models that involve a single process. (2) The kinematic evolution of the eruptions tends to be synchronized with the flare light curve in both phases. The synchronization is often but not always close. A delayed onset of the impulsive flare phase is found in the majority of the filament eruptions (5 out of 6). This delay, and its trend to be larger for slower eruptions, favor ideal MHD instability models. (3) The average decay index at the onset heights of the main acceleration is close to the threshold of the torus instability for both groups of events (although based on a tentative coronal field model for the hot channels), suggesting that this instability initiates and possibly drives the main acceleration., Accepted for publication in ApJ; 24 pages, 12 figures, 3 tables

Although knowing the occurrence frequency of severe space weather events is important for a modern society, it is insufficiently known due to the lack of magnetic or sunspot observations, before the Carrington event in 1859 known as one of the largest events during the last two centuries. Here, we show that a severe magnetic storm occurred on 8 March 1582 based on auroral records in East Asia. The equatorward boundary of auroral visibility reached 28.8{\deg} magnetic latitude. The equatorward boundary of the auroral oval is estimated to be 33.0{\deg} invariant latitude (ILAT), which is comparable to the storms on 25/26 September 1909 (~31.6{\deg} ILAT, minimum Dst of -595 nT), 28/29 August 1859 (~36.5{\deg} ILAT), and 13/14 March 1989 (~40{\deg} ILAT, minimum Dst of -589 nT). Assuming that the equatorward boundary is a proxy for the scale of magnetic storms, we presume that the storm on March 1582 was severe. We also found that the storm on March 1582 lasted, at least, for three days by combining European records. The auroral oval stayed at mid-latitude for the first two days and moved to low-latitude (in East Asia) for the last day. It is plausible that the storm was caused by a series of ICMEs (interplanetary coronal mass ejections). We can reasonably speculate that a first ICME could have cleaned up interplanetary space to make the following ICMEs more geo-effective, as probably occurred in the Carrington and Halloween storms., Comment: Accepted for publication in the Monthly Notices of the Royal Astronomical Society; main text 10 pages, reference 5 pages, appendix 4 pages, 2 tables, and 6 figures

The regular behavior of the electrodynamics of the low latitude ionosphere makes the scintillation on GNSS signals a daily phenomenon, occurring after the local sunset. The solar activity changes ionospheric conditions. In the specific, a solar storm hitting the Earth may change the ExB drift, leading to a suppression or to an intensification of the Equatorial Fountain. This result into a change in the mechanism regulating the formation of the plasma bubbles, and has strong dependence on the local time of the storm development. The regular and irregular behavior of the low latitude ionosphere in producing scintillation-effective irregularities pose then a challenge to model and predict the disruption of GNSS signals [1]. Mitigation of the degradation of the GNSS performance due to presence of ionospheric irregularities, i.e. the equatorial plasma bubbles, is of paramount importance for high-precision applications, such as precision agriculture.

Solar activity presents a potential risk of causing damage to different technological sectors such as communications and electrical networks. A total or partial collapse of an electrical network by an extreme solar storm would bring catastrophic consequences to the daily chores of our society. Power transformers connected in strategic locations of an interconnected electrical system such as that of the Mexican Republic, are at risk of suffering permanent damage due to geomagnetically induced currents caused by an extreme solar storm or cumulative damage along many years. The present work indicates the risk of the strategic power transformers connected to the national electricity grid in the face of a severe solar storm event and the need to develop a contingency plan in Mexico in face of the latent threat of this natural phenomenon.

Today life in many cities strongly depends on electricity. In many articles we can find designs of smart, clean and beautiful modern cities. All aspects of activity in cities are based on the use of control and supply systems. All of them use electricity as control signals and as power. A big but underconsidered problem is reliability of city substructures against Coronal Mass Ejection (CME) from the Sun. These events may damage elements of basic importance for life of people in cities. The article suggests some kinds of protection for the city substructures against CME.

A statistical study has been performed on all the geomagnetic storm events caused by Coronal Mass Ejections (CMEs) which are associated with flares from January 2010 to December 2012. The following results are obtained. The sources of the CMEs mentioned above are distributed mainly from 45°E to 45°W on the solar surface, accounting 78.95% of the total events, and most of them are distributed in the western hemisphere, thus the sources of CMEs located in the western hemisphere are more likely to cause geomagnetic effects. The X-class flares are more likely to be associated with geomagnetic effects, and geomagnetic storms will be observed in two or three days after the eruption of 60% of X-class flares, while the flares of other classes have a much lower probability to associate with geomagnetic effects, less than 10% for all of them. By analyzing all the X-class flares erupted during this period on the solar disk, it is found that for the X-class flares located from 45°E to 45°W in heliographic longitude, if there are no large-scale disturbances on the solar surface nor the accompanied CMEs during the eruptions, the probability of occurrence of geomagnetic storms after the flares will be very small. Therefore, a new method to forecast the geomagnetic storms by analyzing the observed solar image data has been proposed.

The Sun, the only star in our solar system, is an essential energy source for all human activities as well as the entire Earth biosphere. Galileo discovered the existence of sunspots in 1610, and 200 years later, Schwabe proved that our home star?s activities follow a cycle of 11 years. Using high-tech devices, scientists and engineers have gained a clearer vision of solar activities and are now better able to discern the sun?s behavior. Known solar activities include a combination of sunspots, solar flares, and coronal mass ejections. Solar activity occurs in peaks, with roughly equal intervals between them. The sun interacts significantly with Earth?s magnetosphere. Extraordinary solar activities (or solar storms) can severely interfere with Earth?s magnetospheric and ionospheric electrical current system, causing rapidly changing Earth surface potential (ESP). The destructive consequences become more evident with the ever-increasing propagation of electrical and electronic equipment. The first recorded example of the negative effects of solar activity on human society was an unprecedented solar storm that raged from 28 August through 2 September 1859 (cycle 10), in which telegraph systems all over Europe and North America failed.