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3. Components of the geomagnetic field measurements for a sample Northern Hemisphere total field vector F inclined into the Earth. An explanation of the letters and symbols is given in the text.
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Coincidentally, as I sat down in late October 2003 to read and review the second edition of Wallace H. Campbell's text, Introduction to Geomagnetic Fields, we received warnings from the news media of a massive solar flare and its possible effect on power supply systems and satellite communications. News programs briefly explained the source of Sun-...
Citations
... The geomagnetic field is an extremely weak but essential component of the natural environment to which plants have been exposed throughout their history. Its intensity is commonly 25-65 µT at the level of the Earth's surface, while fluctuations in solar activity cause variations of up to 10% relative to these values [15]. A growing number of studies show that plants can sense magnetic fields and fit their processes to them [16][17][18][19]. ...
Temperature plays an essential role in a plant’s life. The current investigation reveals that photoreceptors, whose activity is affected by the geomagnetic field, are a critical element of its perception. This knowledge suggests that plants’ responses to temperature could shift in different geomagnetic conditions. To test this hypothesis, we studied the change in the growth response of the peat moss Sphagnum riparium to temperature with a gradual increase in the geomagnetic Kp index. Growth data for this species were collected from Karelian mires by detailed monitoring over eight full growing seasons. The growth of 209,490 shoots was measured and 1439 growth rates were obtained for this period. The analysis showed a strong positive dependence of sphagnum growth on temperature (r = 0.58; n = 1439; P = 1.7 × 10−119), which is strongest in the Kp range from 0.87 to 1.61 (r = 0.65; n = 464; P = 4.5 × 10−58). This Kp interval is clearer after removing the seasonal contributions from the growth rate and temperature and is preserved when diurnal temperature is used. Our results are consistent with the hypothesis and show the unknown contribution of the geomagnetic field to the temperature responses of plants.
... Plots of conductivity versus depth profile were done followed by error analyses based on the standard deviation of the conductivitydepth values. The depth in kilometers to a layer of conductivity ( in S/m) which can produce the observed field measurement is given by Campbell (1997) ...
... Changes in the north-south and east-west components correspond to ionospheric currents at an altitude of approximately 100 km above the Earth's surface [45]. Variations in the vertical geomagnetic field are attributed to underground currents [46,47]. No significant abnormal phenomena were detected in the north-south and vertical geomagnetic field. ...
Investigating various geophysical parameters from the Earth's crust to the upper atmosphere is considered a promising approach for predicting earthquakes. Scientists have observed that changes in these parameters can occur days to months before earthquakes. Understanding and studying the impending abnormal phenomena that precede earthquakes is both urgent and challenging. On 5 September 2022, a magnitude 6.8 earthquake occurred in Sichuan, China, at 4:52:18 (Universal Time). The earthquake happened approximately 175 km away from an instrumental array established in 2021 for monitoring vibrations and perturbations in the lithosphere, atmosphere , and ionosphere (MVP-LAI). This array consisted of over 15 instruments that regularly monitor changes in various geophysical parameters from the subsurface up to an altitude of approximately 350 km in the ionosphere. Its purpose was to gain insights into the mechanisms behind the coupling of these different geospheres during natural hazards. The seven geophysical parameters from the MVP-LAI system simultaneously exhibited abnormal behaviors approximately 3 h before the Luding earthquake. These parameters include ground tilts, air pressure, ra-don concentration, atmospheric vertical electric field, geomagnetic field, wind field, and total electron content. The abnormal increase in radon concentration suggests that the chemical channel could be a promising mechanism for the coupling of geospheres. Furthermore, air pressure, the geomagnetic field, and total electron content exhibited abnormal characteristics with similar frequencies. Horizontal wind experienced temporary cessation or weakening, while vertical wind displayed frequent reversals. These anomalies may be attributed to atmospheric resonance before the earthquake. The results demonstrate that the coupling of geospheres, as indicated by the anomalous phenomena preceding an earthquake, could be influenced by multiple potential mechanisms. The multiple anomalies observed in this study provided approximately 3 h of warning for people to prepare for the seismic event and mitigate hazards. Citation: Chen, C.-H.; Zhang, S.; Mao, Z.; Sun, Y.-Y.; Liu, J.; Chen, T.; Zhang, X.; Yisimayili, A.; Qing, H.; Luo, T.; et al. The Lithosphere
... Magnetism in (some) rocks forms a vital part of rock physics and mechanics, cf. [5,6,10,19,34]. Paleomagnetism refers to "frozen" magnetism in oceanic or continental rocks, which may give information about history of geomagnetic field generated in the Earth's outer core or history of deformation of continental crust, respectively. Interestingly, paleomagnetism exists also in other planets that nowadays do not have substantial magnetic fields, specifically Mars and Mercury. ...
... The rigorous mathematical analysis of the above models seems problematic and there is a certain agreement that some higher-gradient theories must be involved in them to pursue this analytical goal. 6 Our approach follows the theory by [11], as already considered in the general nonlinear context of so-called multipolar fluids by J. Nečas and his group, cf. [23][24][25], as originally inspired by [35] and [22]. ...
The thermodynamic model of visco-elastic deformable magnetic materials at finite strains is formulated in a fully Eulerian way in rates with the aim to describe thermoremanent paleomagnetism in crustal rocks. The Landau theory applied to a ferro-to-para-magnetic phase transition, the gradient theory for magnetization (leading to exchange energy) with general mechanically dependent coefficient, hysteresis in magnetization evolution by Gilbert equation involving objective corotational time derivative of magnetization, and demagnetizing field are considered in the model. The Jeffreys viscoelastic rheology is used with temperature-dependent creep to model solidification or melting transition. The model complies with energy conservation and the Clausius-Duhem entropy inequality.
... Indeed, the variations in the Earth's magnetic field and their spatiotemporal changes offer crucial insights into the planet's internal dynamics, lithospheric structures, tectonic movements and the state of space weather conditions resulting from Sun-Earth interactions [1]. Furthermore, geomagnetic data support a variety of practical applications, including geophysical mapping, mineral exploration, assessing space weather conditions and mapping of geoelectric hazard [2]. To facilitate these endeavors, a network of ground-based magnetic observatories has been established across the globe to provide accurate and long-term records of magnetic-field direction and intensity at fixed locations. ...
Using a dynamical systems approach, we examine the persistence and predictability of geomagnetic perturbations across a range of different latitudes and levels of geomagnetic activity. We look at the horizontal components of the magnetic field measured on the ground between 13 and 24 March 2015, at approximately 40 observatories in the Northern Hemisphere. We introduced two dynamical indicators: the extremal index θ, which quantifies the persistence of the system in a particular state and the instantaneous dimension d, which measures the active number of degrees of freedom of the system. The analysis revealed that during disturbed periods, the instantaneous dimension of the horizontal strength of the magnetic field, which depends on latitude, increases, indicating that the geomagnetic response is externally driven. Furthermore, during quiet times, the instantaneous dimension values fluctuate around the state-space dimension, indicating a more stochastic and thus less predictable nature system.
... Below are brief descriptions of the most important elements contributing to the total GMF. More detailed information is available in Chapman and Bartels (1940); Parkinson (1983); Skiles (1985); Blakely (1996);Campbell (2003) and Kono (2009). ...
The geomagnetic field (GMF) is a worldwide source of compass cues used by animals and humans alike. The inclination of GMF flux lines also provides information on geomagnetic latitude. A long-disputed question, however, is whether horizontal gradients in GMF intensity, in combination with changes in inclination, provide bicoordinate “map” information. Multiple sources contribute to the total GMF, the largest of which is the core field. The ubiquitous crustal field is much less intense, but in both land and marine settings is strong enough at low altitudes (< 700 m; sea level) to mask the core field’s weak N–S intensity gradient (~ 3–5 nT/km) over 10 s to 100 s of km. Non-orthogonal geomagnetic gradients, the lack of consistent E–W gradients, and the local masking of core-field intensity gradients by the crustal field, therefore, are grounds for rejection of the bicoordinate geomagnetic “map” hypothesis. In addition, the alternative infrasound direction-finding hypothesis is briefly reviewed. The GMF’s diurnal variation has long been suggested as a possible Zeitgeber (timekeeper) for circadian rhythms and could explain the GMF’s non-compass role in the avian navigational system. Requirements for detection of this weaker diurnal signal (~ 20–50 nT) might explain the magnetic alignment of resting and grazing animals.
... The total magnetization (J T ) is the vector sum of all these components. Therefore, the measured magnetic field is the result of the combination of various fields mainly ascribable to: (i) mineral-bearing rock types in the upper part of the crust, (ii) daily oscillations associated to the activity of the sun [35,36], (iii) unpredictable largeamplitude magnetic storms related to sunspot activity, and (iv) anthropogenic causes [37]. Other variations occur over the longer term; however, these do not affect the measurements involved in archaeological or cultural heritage-oriented investigations. ...
The need to study, protect, and conserve archaeological heritage has enhanced the application of geophysical techniques as non-invasive and reliable tools to investigate fragile and valuable assets. This review presents the most popular geophysical techniques suitable for archaeogeophysical investigations, namely, magnetometry, ground penetrating radar, and electrical resistivity tomography, together with a series of multiparametric measures taken from aerial platforms (UAS). For each method, we recall the basic physical principles, illustrate the operative procedures for field investigation, and provide indications about data processing and modeling. We propose a flowchart to address reliable and effective geophysical investigations, from its planning to the development of the final archaeogeophysical model. We underline the integrated approach, in which the combination of various techniques allows the best results in terms of resolution, coverage, investigation depth, speed, and costs to be obtained. We introduce a suite of studied cases in which this approach has been applied successfully.
... The integers, n and m are called degree and order respectively. Following Campbell [7] the equivalent current function, J(φ) in Amperes for an hour of the day, φ/15 (the longitude divided by 15 o ) is obtained from: Following Campbell [7] the equivalent current function, J(φ) in Amperes for an hour of the day, φ/15 (the longitude divided by 15 o ) is obtained from: ...
... The integers, n and m are called degree and order respectively. Following Campbell [7] the equivalent current function, J(φ) in Amperes for an hour of the day, φ/15 (the longitude divided by 15 o ) is obtained from: Following Campbell [7] the equivalent current function, J(φ) in Amperes for an hour of the day, φ/15 (the longitude divided by 15 o ) is obtained from: ...
... With 4 for the maximum value of m, and 12 for the maximum value of n. For the external current representation, we have: Following Campbell [7] the equivalent current function, J(φ) in Amperes for an hour of the day, φ/15 (the longitude divided by 15 o ) is obtained from: ...
The magnetometer data obtained for 2008 from geomagnetic stations installed across Africa by magnetic data acquisition set (MAGDAS) have been used to study the ionospheric Sq current system in the equatorial and lowlatitudes of Africa. The aim of this work is to separate the quiet-day feld variations obtained in the equatorial and low latitude regions of Africa into their external and internal feld contributions and then to use the paired external and internal coeffcients of the SHAto determine the source current and induced currents. The method used involved a spherical harmonic analysis (SHA). This was applied in the separation of the internal and external field/current contribution to the Sq variations. The result shows that the variation in the currents is seen to be a dawn-to-dusk phenomenon with the variation in the external currents different from that of the internal currents both in amplitude and in phase. Furthermore, the seasonal variation in the external current maximizes during the March equinox and minimizes during the December solstice. The maximum current observed in AAB and ILR is due to the Equatorial Electrojet Current present in the AAB and ILR stations. Seasonal variation was observed in the geomagnetic component variations as well as in the currents. This is attributed to the position of the sun with respect to the earth at different months of the year. The equinoctial maximum is observed in external current intensity which occurred mostly during the March Equinox.
... During storm times, high latitude ionospheric plasma convection is enhanced and causes a substantial increase in Joule heating. Joule heating rate is proportional to ionospheric Pedersen conductivity, which usually maximizes in the E region and is increased during storms too, due to enhanced auroral precipitation (Campbell, 2003). Auroral precipitation also brings extra energy inputs to the I/T system in the auroral region through ionization, dissociation, and excitation of neutral constituents (Qian & Solomon, 2012). ...
... There is a local peak of neutral temperature enhancement at ∼125 km altitude during the storm time. The temperature enhancement peak is attributed to the altitudinal distribution of Pedersen conductivity, which has a maximum value around this height and results in the maximum Joule heating deposition (Campbell, 2003). The storm time temperature enhancement increases with altitude because the background density decreases exponentially while Joule heating rate per unit mass increases with altitude (Deng et al., 2011;Huang et al., 2012). ...
The Starlink satellites launched on 3 February 2022 were lost before they fully arrived in their designated orbits. The loss was attributed to two moderate geomagnetic storms that occurred consecutively on 3–4 February. We investigate the thermospheric neutral mass density variation during these storms with the Multiscale Atmosphere‐Geospace Environment (MAGE) model, a first‐principles, fully coupled geospace model. Simulated neutral density enhancements are validated by Swarm satellite measurements at the altitude of 400–500 km. Comparison with standalone TIEGCM and empirical NRLMSIS 2.0 and DTM‐2013 models suggests better performance by MAGE in predicting the maximum density enhancement and resolving the gradual recovery process. Along the Starlink satellite orbit in the middle thermosphere (∼200 km altitude), MAGE predicts up to 150% density enhancement near the second storm peak while standalone TIEGCM, NRLMSIS 2.0, and DTM‐2013 suggest only ∼50% increase. MAGE also suggests altitudinal, longitudinal, and latitudinal variability of storm‐time percentage density enhancement due to height dependent Joule heating deposition per unit mass, thermospheric circulation changes, and traveling atmospheric disturbances. This study demonstrates that a moderate storm can cause substantial density enhancement in the middle thermosphere. Thermospheric mass density strongly depends on the strength, timing, and location of high‐latitude energy input, which cannot be fully reproduced with empirical models. A physics‐based, fully coupled geospace model that can accurately resolve the high‐latitude energy input and its variability is critical to modeling the dynamic response of thermospheric neutral density during storm time.
... Esta se denomina corriente en anillo, como se muestra en la Fig. 2.2. Las corrientes de la magnetopausa y la corriente en anillo son las principales contribuciones externas al campo magnético terrestre, (∼ 2 % de la variación total del campo (Campbell, 2003) (Russell, 2000) El principal mecanismo por el cual el viento solar energiza la magnetósfera es la reconexión magnética, propuesta originalmente por Dungey (1961). Cuando una perturbación en el viento solar (e.g. ...
... Como se puede ver en la Fig. 2.2, en regiones por encima de los 45 o de latitud, las mayores contribuciones a la variabilidad geomagnética son los electrochorros aurorales y las corrientes de la magnetocola. Sin embargo, en latitudes medias y bajas (0 o − 35 o ), resultan preponderantes los efectos del electrochorro ecuatorial, las corrientes en anillo y de la magnetopausa (Campbell (2003), cap. 3). ...
The study of Space Weather has gained relevance as our global civilization increasingly depends on the interconnection of various technological systems. This increasing integration has proven to be sensitive to severe solar activity events. One of the
The most relevant effects of space weather on the Earth's surface are Geomagnetically Induced Currents (GIC). This phenomenon arises as a result of electromagnetic induction processes created by variations of the geomagnetic field in conductor systems.
These geomagnetic field variations are produced mainly as a consequence of solar activity events that alter the Earth's space environment. Traditionally, the GIC phenomenon was considered typical of regions above 50o latitude, where the auroral electrojet contributes significantly to geomagnetic disturbances.
However, in recent decades we have experienced a paradigm shift in this regard. Since the early 2000s, failures caused by
by GIC in technological systems located in latitudes below 30 o . Currently the
Space weather effects are a matter of active research in many countries.
In 2014, the General Civil Protection Law of Mexico was modified to include events
of space weather in the list of disturbing phenomena that must be addressed by the National Civil Protection System and the Space Weather Service Mexico (SCIESMEX) was established at the Institute of Geophysics of the National Autonomous University of Mexico (UNAM). In 2015, SCIESMEX together with the National Center for Disaster Prevention (CENAPRED) and the Mexican Space Agency (AEM), established the Space Climate working group in Mexico to attend to the mandate of the law in matters of monitoring weather events. spatial and
develop public policies to increase the country's resilience to these natural phenomena. Subsequently, in 2016, the National Space Weather Laboratory (LANCE) was created, with the aim of increasing the capacity for observation and analysis of space weather events in Mexico.
In 2018, LANCE and the Federal Electricity Commission (CFE) began a collaboration to study the vulnerability of the National Electric System (SEN) to Space Weather events. Within this framework of collaboration, it was proposed to develop a numerical model to know the response of the SEN, before the occurrence of geomagnetic storms in the 400/230 kV network and the installation of GIC detectors in some critical substations of the CFE network. . These types of collaborations are very rare in the world, since electricity companies are generally reluctant to share their data with research groups.
The objective of this thesis work is to study the influence of space weather on the high-voltage electrical network in Mexico. Its objective is to address two very
important: (a) Evaluate the relevance of the effect of the GIC on the SEN and (b) Determine which are the most vulnerable points of the network and how intense these currents can be during the effects of a severe space weather event in Mexico .
The numerical model developed in this work provides, for the first time, realistic estimates of the GIC levels in the nodes of the 400/230 kV network. The analysis of the experimental data and the estimations of the numerical model allow us to conclude that the high voltage transmission network in Mexico is affected even during minor geomagnetic disturbances caused by solar activity.
Taking into account these results and the growing number of failure incidents in electrical systems caused by solar activity in the last 20 years, (e.g. Gaunt and Coetzee
(2007); Kappenmann (2005)). It is necessary to constantly monitor the space weather in SEN de México, as well as the design of prevention and reaction protocols aimed at mitigating these effects. By virtue of what has been stated above, we can affirm that Space Weather should be considered as a matter of national security due to the socioeconomic losses that a catastrophic failure in the SEN can cause.
Keywords: Space Weather, Geomagnetically Induced Currents, Geomagnetic Storms.
