Search

Space weather can have major impacts on electrical infrastructure. Multiple instances of transformer damage have been attributed to geomagnetic storms in recent decades, for example, the Hydro Quebec incident of 1989 and the November 2001 storm in New Zealand. While many studies exist on the impacts of geomagnetic storms on power transformers in New Zealand, no studies exist that employ Dissolved Gas Analysis (DGA) techniques to relate geomagnetic storms to transformer gassing. A relationship has been reported between geomagnetic activity and DGA for South Africa, while none was found in a recent study in Great Britain. This paper attempts to examine this research question by examining dissolved gas data across eight power transformers in different substations in New Zealand from 2016 to 2019. Case studies were conducted which analyzed the DGA readings of each transformer alongside horizontal magnetic field component rate of change measurements at Eyrewell across six geomagnetic storms. These case studies were then augmented with an analysis of the entire data set where magnetic field measurements were compared with individual gas rates to establish a correlation between gas production and geomagnetic activity. Analysis of the results of this study concluded that no link had been found between the production of combustible gasses in a transformer and geomagnetic activity during the observation period. However, we note our dissolved gas analysis was largely in a geomagnetically quieter period, which may limit our analysis. The production of combustible gasses is not correlated to geomagnetic storms for the time period and transformers analyzed. Plain Language Summary: Space weather (changes in the Earth's magnetic field due to changes in the suns atmosphere) is well known to have major impacts on electrical infrastructure. Multiple incidents have been observed over recent decades which have been directly linked to space weather events, for example, the Hydro Quebec incident of 1989 and the November 2001 storm in New Zealand. In this study the impacts of space weather on power station transformers in New Zealand was analyzed. Data on transformer health for eight different transformers was compared to magnetic field activity from 2016 to 2019 to look for evidence of transformer damage due to solar storms. Case studies were analyzed across six different storms using dissolved gas analysis, which looks at the gas levels inside a transformer to determine its condition. Following the case studies general trends in the data were analyzed. From our analysis we concluded that no link had been found between space weather and transformer damage during the observation period. This was likely due to the quiet nature of the sun's atmosphere at the time. Key Points: Gas data from eight NZ transformers from 2016 to 2019 were analyzed to relate geomagnetic activity with the production of combustible gassesA statistical investigation was conducted analyzing gas records alongside magnetic field and current measurements over the same periodNo link found between combustible gas production in these transformers and geomagnetic activity for this time period [ABSTRACT FROM AUTHOR]

Gas pipelines can experience elevated pipe to soil potentials (PSPs) during geomagnetic disturbances due to the induced geoelectric field. Gas pipeline operators use cathodic protection to keep PSPs between −0.85 and −1.2 V to prevent corrosion of the steel pipes and disbondment of the protective coating from the pipes. We have developed a model of the gas pipelines in the North Island of New Zealand to identify whether a hazard exists to these pipelines and how big this hazard is. We used a transmission line representation to model the pipelines and a nodal admittance matrix method to calculate the PSPs at nodes up to 5 km apart along the pipelines. We used this model to calculate PSPs resulting from an idealized 100 mVkm−1 electric field, initially to the north and east. The calculated PSPs are highest are at the ends of the pipelines in the direction of the applied electric field vector. The calculated PSP follows a characteristic curve along the length of the pipelines that matches theory, with deviations due to branchlines and changes in pipeline direction. The modeling shows that the PSP magnitudes are sensitive to the branchline coating conductance with higher coating conductances decreasing the PSPs at most locations. Enhanced PSPs produce the highest risk of disbondment and corrosion occurring, and hence this modeling provides insights into the network locations most at risk. Plain Language Summary: Steel pipelines are used to transport natural gas across long distances. These pipes are covered in an insulating coating to protect them from corrosion. During a geomagnetic storm, there are rapid changes in Earth's magnetic and electric fields. These changes cause electrical currents to flow through breaks in the insulating coating and on and off the pipelines, resulting in a voltage between Earth and the pipe. Over time the currents can cause corrosion and the voltages can lead to the coating separating from the pipe, resulting in further corrosion. We have developed a model of New Zealand's gas pipeline network and used it to calculate the voltages in the pipelines in New Zealand's North Island during a simplified geomagnetic storm. This model will help us understand where the greatest risk of corrosion is and how widespread the risk is. The highest risk is at the ends of the pipeline, aligned with the direction of the imposed electric field. Branchlines and changes in direction of the pipeline change the local voltages. Key Points: We modeled New Zealand's gas pipeline network to calculate pipe to soil potentials due to uniform electric fields of 100 mV/kmPotentials are greatest at ends of pipelines, following theoretical curves with variations due to branches and changes in directionThe lower coating conductance of the branchlines leads to higher potentials on both that line and connected lines [ABSTRACT FROM AUTHOR]

As part of a 5‐year project to assess the risk posed by geomagnetically induced currents (GIC) to the New Zealand electrical transmission network, long‐period magnetotelluric (MT) measurements have been made at 62 sites in southern South Island of New Zealand, a region where there was an absence of previous MT data. The data are largely 3‐dimensional in character, but show distinct features that can be related to the known tectonic and geological structure. In this work we focus on how the measured MT impedance tensors, and a simple interpretation of conductivity structure, can be used to assess the influence of tectonic and geological structure on GIC. We use the impedance tensors to calculate the magnitudes and orientations of induced electric fields in response to various orientations of inducing magnetic field. The electric fields so calculated are then used in a simplified model of the transmission network to calculate GIC at grounded substations. Our results confirm that tectonic/geological structure in the lower South Island and the resulting electrical conductivity variations have important impacts on the GIC magnitude. In the south‐west, smaller induced electric fields, associated with the higher conductivity in that region, lead to much reduced GIC at a substation in that area. In contrast, higher electric fields occurring in a NW‐SE band across the center of the region, contribute to much larger GIC in Dunedin city. Our results thus help explain the observed GIC reported at transformers in the region. Plain Language Summary: Variations in the Earth's magnetic field during magnetic storms produce induced currents in the ground which in certain circumstances may present a risk to an electricity transmission network. Understanding the risk in any given region requires knowledge of the local ground electrical conductivity structure. To help map the structure across southern South Island, New Zealand, we have made long period magnetotelluric measurements at 62 sites. We use these measurements to calculate the electric fields which would be induced in the ground due to magnetic field variations. Using a simplified representation of the electrical transmission network, we use these calculated electric fields to assess how particular features of the geological structure influence the currents (geomagnetically induced currents—GIC) that can be produced in the power network. Key Points: Magnetotelluric measurements have been made at 62 sites across southern South Island, New ZealandMT impedance tensors are used to calculate the induced electric fields resulting from a 100 nT variation in magnetic fieldA simplified representation of the transmission network is used to assess how enhanced/reduced fields associated with particular tectonic features influence calculated geomagnetically induced currents [ABSTRACT FROM AUTHOR]

Geomagnetically induced currents produced during geomagnetic storms present a potential risk to gas pipeline systems by disturbing the cathodic protection (CP) systems used to protect the pipeline from corrosion. In this study we look at CP monitoring data from a number of sites on the gas pipeline network in the North Island of New Zealand. We focus on variations during geomagnetic storms in three aspects of the CP system: (a) the output voltage of the constant current rectifiers, (b) the potential between the pipe and a Cu/CuSO4 reference cell, and (c) the potential between an installed metal coupon and the reference cell. The industry standard for suitable CP is that the latter potential should lie between −0.85 and −1.2 V when the rectifier is momentarily turned off. Three monitoring sites in particular are identified as showing very large variations in rectifier output voltage during geomagnetic storms, suggesting a possible risk to the system at these sites. Additionally, one of the three sites has coupon potentials which appear to rise above the −0.85 V level. Magnetotelluric impedance data are used to assess how effects at the monitoring sites relate to the magnitude and direction of induced electric fields. It clear that the response at any monitoring site is related to effects on the pipeline network as a whole. We also note the risks of disbonding and hydrogen induced cracking, issues we do not believe have been widely recognized in the research community. Plain Language Summary: Variations in Earth's magnetic field during geomagnetic storms induce electric currents (geomagnetically induced currents—GIC) in the ground which, in certain circumstances, may disrupt the cathodic protection (CP) systems used to protect buried gas pipelines from corrosion. In this study we examine monitoring data from the CP system on the gas pipeline network in the North Island of New Zealand to assess where GIC may present a possible threat to the integrity of the network. We identify four locations where significant variations in monitoring data occur in response to geomagnetic field variations and where additional monitoring is desirable. There appears to be a potential risk to the pipeline system at these sites. It is apparent that the complex geology and tectonics of New Zealand has a major influence on how GIC affect the pipeline network. Key Points: Variations in cathodic protection (CP) monitoring data on the New Zealand gas pipeline network during geomagnetic storms are reportedThree locations are identified as having variations which suggest that during large storms the level of CP may be compromisedAt any location the CP system responds to electric fields across the whole pipeline network and not to local electric field orientation [ABSTRACT FROM AUTHOR]

Geomagnetically induced currents (GICs) are induced in electrical power transmission networks during geomagnetic disturbances. Understanding the magnitude and duration of the GIC expected during worst‐case extreme storm scenarios is vital to estimate potential damages and disruptions to power networks. In this study we utilize the magnetic field waveforms measured during three large geomagnetic storms and scale them to expected worst case extreme storm magnitudes. Multiple methods are used to simulate the varying magnitude of the magnetic field across the different latitudes of New Zealand. Modeled GIC is produced for nine extreme storm scenarios, each covering 1–1.5 days in duration. Our industry partners, Transpower New Zealand Ltd provided GIC magnitude and duration levels which represent a risk to their transformers. Using these thresholds various extreme storm scenarios predict between 44 and 115 New Zealand transformers (13%–35%) are at risk of damaging levels of GIC. The transformers at risk are largely independent of the extreme storm time‐variations, but depend more on the latitude variation scenario. We show that these at‐risk transformers are not localized to any specific region of New Zealand but extend across all regions and include most of the major population centers. A peak mean absolute GIC over a 60‐min window of 920–2,210 A and an instantaneous 1‐min time resolution maximum GIC of 1,590–4,920 A occurs for a worst‐case extreme storm scenario. We believe this is one of the first studies to combine a reasonable worst‐case extreme geomagnetic storm with validated GIC modeling and industry‐provided GIC risk thresholds. Plain Language Summary: Space Weather events can cause unwanted DC currents in electrical power transmission networks during geomagnetic storms. We model multiple difference extreme storms to determine the worst case DC currents expected. We work with our industry partners in New Zealand to determine DC magnitudes and durations that would put different types of transformers at risk. Using these values we predict multiple transformers are at risk of damaging levels of DC current. We show that the transformers at risk are located throughout all regions of New Zealand. We believe this is one of the first studies that combines multiple extreme storms scenarios with industry provided DC current magnitudes and durations to determine the risk to transformers. Key Points: Magnetic fields from large geomagnetic events imposed with different latitude variations can produce theoretical extreme storm scenariosExtreme storm scenarios consistently predict between 13% and 35% of New Zealand transformers reaching dangerous levels of long lasting Geomagnetically induced current (GIC)The transformers at most risk of long lasting GIC are not confined to a small region, instead spread throughout the length of New Zealand [ABSTRACT FROM AUTHOR]

Variability of the geomagnetic field induces anomalous Geomagnetically Induced Currents (GICs) in grounded conducting infrastructure. GICs represent a serious space weather hazard but are not often measured directly and the rate of change of the magnetic field is often used as a proxy. We assess the correlation between the rate of change of the magnetic field and GICs during Sudden Commencements (SCs) at a location in New Zealand. We observe excellent correlations (r2 ∼0.9) between the maximum 1‐min rate of change of the field and maximum GIC. Nonetheless, though SCs represent a relatively simple geomagnetic signature, we find that the correspondence systematically depends on several factors. If the SC occurs when New Zealand is on the dayside of the Earth, then the magnetic changes are linked to 30% greater GICs than if New Zealand is on the nightside. We investigate the finding that the orientation of the strongest magnetic deflection is important: changes predominantly in the east‐west direction drive 36% stronger GICs. Dayside SCs are also associated with faster maximum rates of change of the field at a resolution of 1 s. Therefore, while the maximum rates of change of the magnetic field and GICs are well correlated, the orientation and sub‐1‐min resolution details of the field change are important to consider when estimating the associated currents. Finally, if the SC is later followed by a geomagnetic storm, then a given rate of change of the magnetic field is associated with 22% larger GICs, compared to if the SC is isolated. Plain Language Summary: Changes in the Earth's magnetic field will drive electrical currents that can flow in infrastructure, such as power networks and pipelines. These currents can pose a hazard to their operation and safety. We often do not have access to direct measurements of the currents that flow within our infrastructure, so we typically report and forecast magnetic perturbations to infer when we are likely to see large currents. In this work, we investigate the link between the magnetic changes and currents that are observed when the Earth is impacted by a sharp change in the solar wind dynamic pressure, that is, a shock. We also have access to direct measurements of current in infrastructure from New Zealand. In general, we find excellent correlations between the two parameters. However, we find that the type of shock event during which they are observed is important as is the location of the observations relative to the day/nightside of the Earth. We find that the orientation of the rate of change of the magnetic field as well as high time resolution (i.e., subminute resolution) information are both important to consider when attempting to estimate the currents that will be generated, even with relatively simple processes. Key Points: The rate of change of the magnetic field during Sudden Commencements (SCs) excellently correlates with observed Geomagnetically Induced Currents (GICs)Storm SCs are associated with 22% larger GICs than Sudden ImpulsesSCs that occur when New Zealand is on the dayside of the Earth are associated with 30% larger GICs [ABSTRACT FROM AUTHOR]

During the 17 March 2015 geomagnetic storm, citizen scientist observations from Dunedin (45.95°S, 170.32°E), New Zealand, revealed a bright wide red arc known as stable auroral red (SAR) arc evolving into a thin white‐mauve arc, known as Strong Thermal Emission Velocity Enhancement (STEVE). An all‐sky imager at the Mount John Observatory (43.99°S, 170.46°E), 200 km north of Dunedin, detected an extremely bright arc in 630.0 nm, with a peak of ∼6 kR, colocated with the arc measured at Dunedin at an assumed height of 425 km. Swarm satellite data measured plasma parameters that showed strong subauroral ion drift signatures when the SAR arc was observed. These conditions intensified to extremely high values in a thinner channel when STEVE was present. Our results highlight the fast evolution of plasma properties and their effects on optical emissions. Current theories and models are unable to reproduce or explain these observations. Plain Language Summary: A variety of optical structures are observed in the "subauroral" region. This region is at lower latitudes adjacent to the auroral zone. These phenomena are distinct from auroras, as their optical signatures appear to be triggered by extreme thermal and kinetic energy in Earth's atmosphere, rather than produced by energetic particles raining down into our atmosphere. Two such subauroral optical structures are "stable auroral red (SAR) arcs" and "Strong Thermal Emission Velocity Enhancement (STEVE)". Although, SAR arcs and STEVE, both occur during geomagnetically active conditions in the subauroral region, their appearance differs significantly with distinct spectra, scale‐size, and duration. We combined images captured by a citizen scientist in New Zealand on 17 March 2015 with data from a scientific all‐sky imager as well as satellites. We observed the evolution of an unusually bright SAR arc into STEVE. We show satellite measurements of a region of fast‐moving particles, known as "subauroral ion drift," at the same time the SAR arc occurred. Later, when STEVE was present, these conditions further intensified into a narrower band with higher temperature and faster flows. These observations highlight the benefits of combining citizen scientist observations with scientific data to help discover new connections in Geospace. Key Points: Citizen scientist images show for the first time the evolution of a stable auroral red (SAR) arc into Strong Thermal Emission Velocity Enhancement (STEVE)An all‐sky imager measured a bright, ∼6 kR, SAR arc colocated with the arc observed by the citizen scientist when the emission height is 425 kmSwarm data show subauroral ion drift conditions during a conjunction with the SAR arc observation. Later, these conditions intensify when STEVE is measured [ABSTRACT FROM AUTHOR]

Geomagnetically induced currents (GICs) in the North Island New Zealand power transmission network during two large magnetic storms are calculated from both magnetotelluric (MT) data and a thin‐sheet conductance model of New Zealand previously used to study GIC in the South Island. We focus on the 2015 St. Patrick's Day magnetic storm and the storm of 20 November 2003. Lack of MT data in the northwestern part of the Island means that the transmission network in this region is represented by an equivalent circuit. Lack of GIC observations in the North Island means that results cannot be directly compared with measured GIC. However, our calculation of GIC shows that substations and individual transformers in the lower part of the Island with significant currents are generally the same as those where total harmonic distortion has been observed during periods of enhanced geomagnetic activity. MT data in the period range 2–30 min are used to predict GIC associated with the sudden storm commencement and rapid variations in the magnetic field. In contrast, the thin‐sheet modeling approach shows that GIC may be expected to occur in conjunction with longer‐period variations. Calculations for the 2003 storm suggest that at some locations GIC in excess of 10 A may persist for long periods of time and may produce significant harmonic distortion which could lead to localized transformer heating. It is concluded that despite its relatively low latitude the North Island power network is potentially at risk from significant GIC during extreme storms. Plain Language Summary: Variations in the Earth's magnetic field with time during so‐called "magnetic storms" can result in currents (geomagnetically induced currents—GICs) entering and leaving power transmission lines through the ground connections on transformers. Large GIC, or even smaller currents occurring repeatedly, can not only damage transformers but, in the worst‐case scenario, cause disruption to an entire transmission network. To attempt to assess the potential vulnerability of the transmission network in the North Island of New Zealand to such effects, we present model calculations of GIC resulting from two magnetic storms. The results show that despite the relatively low geomagnetic latitude of New Zealand's North Island, there are some substations and individual transformers where large GIC can be expected and may be problematic. Key Points: GIC in the North Island of New Zealand was modeled for the St. Patrick's Day 2015 storm and the storm of 20 November 2003Calculations based on MT data and thin‐sheet modeling were comparedSubstations and individual transformers that may be at risk during significant space weather events were identified [ABSTRACT FROM AUTHOR]

Highlights • The global ionospheric scintillations on 17 March 2015 were investigated by using RO data from FY3C. • The strong scintillations were triggered near 160°E longitudes in MP, and almost inhibited in all longitudes in RP. • The PPEF and DDEF are main factors to drive the observed results in MP and RP, respectively. Abstract Global observations of S4 amplitude scintillation index by the GPS Occultation Sounder (GNOS) on FengYun-3 C (FY3C) satellite reveal global dynamic patterns of a strong pre-midnight scintillations in F-region of the ionosphere during the St. Patrick's Day geomagnetic super storm of 17–19 March 2015. The observed strong scintillations mainly occurred in the low latitudes, caused by equatorial plasma bubbles. During the main storm phase (March 17), the scintillations were first triggered in the New Zealand sector near 160°E longitudes, extending beyond 40°S dip latitude. They were also enhanced in the Indian sector, but significantly suppressed in East Asia near 120°E longitude and in Africa around 30°E longitude. During the initial recovery phase (March 18–19), the global scintillations were seldom observed in GNOS data. During the later recovery phase (after March 19), the scintillations recovered to the pre-storm level in Indian, African, and American sectors, but not in East Asian and any of Pacific sectors. These results closely correlate with observations of the density depletion structures by the Communication/Navigation Outage Forecasting System (C/NOFS) satellite, and ground-based instruments. Such consistency indicates reliability of our scintillation sensing approach even in a case-by-case comparison study. The prompt penetration electric field and disturbance dynamo electric field are suggested as the main factors that control the enhancement and inhibition of the scintillations during the storm, respectively. [ABSTRACT FROM AUTHOR]

The emerging GNSSs make single-frequency (SF) RTK positioning possible. In this contribution two different types of low-cost (few hundred USDs) RTK receivers are analyzed, which can track L1 GPS, B1 BDS, E1 Galileo and L1 QZSS, or any combinations thereof, for a location in Dunedin, New Zealand. These SF RTK receivers can potentially give competitive ambiguity resolution and positioning performance to that of more expensive (thousands USDs) dual-frequency (DF) GPS receivers. A smartphone implementation of one of these SF receiver types is also evaluated. The least-squares variance component estimation (LS-VCE) procedure is first used to formulate a realistic stochastic model, which assures that our receivers at hand can achieve the best possible ambiguity resolution and RTK positioning performance. The best performing low-cost SF RTK receiver types are then assessed against DF GPS receivers and survey-grade antennas. Real data with ionospheric disturbances at low, medium and high levels are analyzed, while making use of the ionosphere-weighted model. It will be demonstrated that when the presence of the residual ionospheric delays increases, instantaneous RTK positioning is not possible for any of the receivers, and a multi-epoch model is necessary to use. It is finally shown that the low-cost SF RTK performance can remain competitive to that of more expensive DF GPS receivers even when the ionospheric disturbance level reaches a Kp-index of 7−, i.e. for a strong geomagnetic storm, for the baseline at hand. [ABSTRACT FROM AUTHOR]

In this work, the results of the analysis on total electron content (TEC) data before, during and after the geomagnetic storm of 8 September 2017 are reported. One of the responses to geomagnetic storms due to the southern vertical interplanetary magnetic field (Bz) is the enhancement of the electron density in the ionosphere. Vertical TEC (VTEC) from the Center for Orbit determination in Europe (CODE) along with a statistical method were used to identify positive and/or negative ionospheric storms in response to the geomagnetic storm of 8 September 2017. When analyzing the response to the storm of 8 September 2017 it was indeed possible to observe an enhancement of the equatorial ionization anomaly (EIA); however, what was unexpected was the identification of a local TEC enhancement (LTE) to the south of the EIA (∼40 ∘ S, right over New Zealand and extending towards the southeastern coast of Australia and also eastward towards the Pacific). This was a very transitory LTE that lasted approximately 4 h, starting at ∼ 02:00 UT on 8 September where its maximum VTEC increase was of 241.2 %. Using the same statistical method, comparable LTEs in a similar category geomagnetic storm, the 2015 St. Patrick's Day storm, were looked for. However, for the aforementioned storm no LTEs were identified. As also indicated in a past recent study for a LTE detected during the 15 August 2015 geomagnetic storm, an association between the LTE and the excursion of Bz seen during the 8 September 2017 storm was observed as well. Furthermore, it is very likely that a direct impact of the super-fountain effect along with traveling ionospheric disturbances may be playing an important role in the production of this LTE. Finally, it is indicated that the 8 September 2017 LTE is the second one to be detected since the year 2016. [ABSTRACT FROM AUTHOR]

The variations of ionospheric Total electron content (TEC) due to coronal mass ejections (CMEs) and geomagnetic storms over New Zealand were studied. TEC data were collected from dual-frequency GPS sites operated by the University NAVSTAR Consortium in New Zealand, at Ous2 (−45.86°N, 170.51°E), Dund (−45.89°N, 170.59°E), Mtjo (−43.99°N, 170.46°E), and Quar (−43.53°N, 169.81°E) stations. The findings of this study show that the variability of ionospheric TEC was more noticeable during the main phase of the storm on September 08, 2017 than the initial phase on September 07, 2017, recovery phase on September 09, 2017, and during the CME day on September 06, 2017. Also, the enhancements of change in TEC (Δ TEC) were pronounced more over the Mtjo station during the CME day and over the Quar station during the geomagnetic storm day than over other stations. On September 06, 2017, two X-class solar flares, specifically X2.2 and X9.3, were observed with quiet geomagnetic storm conditions throughout the CME day, resulting in an increase in TEC. On September 07, 2017, the M7.3, X1.3, and on September 08, 2017, the X8.1 solar flare classes with disturbed geomagnetic conditions led to a significant enhancement of TEC over the stations at 02:00 UT (13:00 LT). Finally, during the main phase of the storm, the solar wind electric field (IEF Ey) and prompt penetration electric field (PPEF) showed good correlations in which the fluctuation of PPEF, an increase in Ey, Dst minimum, and horizontal Earth's magnetic field are well associated with strong changes in TEC. • The CME event on 6 Sept., 2021 increases TEC values over New Zealand stations. • CME and solar flares increased the scintillation more over Quar during 8 Sept. 2017. • High TEC values are occurred during storm days than CME event day over all stations. • Gradient TEC is nearly the same during 8 Sept., 2017 event over all stations. • TEC during storm due to solar flares over Dund, Ous2, mtjo, and Quar were studied. [ABSTRACT FROM AUTHOR]

The dual-frequency Global Positioning System (GPS) provides insights to detect the ionospheric perturbations with Total Electron Content (TEC) variations induced by the Earthquakes (EQs) or geomagnetic storm effects. In this paper, we investigate abnormal ionospheric signatures before three large magnitudes (M w > 6.5) and shallow hypocentral depth < 20 km EQs in New Zealand from daily GPS TEC time series retrieved from International GNSS Services (IGS) stations around the epicenter. Furthermore, geomagnetic activities are completely quiet within 5–15 days before two EQs (M w 7.8 and M w 6.8) and one EQ of M w 6.6 occurred in active storm days (hereafter, geomagnetic storm-EQ event). The anomalies are detected on the basis of a statistical analysis of running median and Inter Quartile Range (IQR) to signify the abnormality in daily TEC time series for 30 days before and 10 days after each EQ. We observe less intensity TEC anomalies of < 2 TECU during UT = 15–24 h (for New Zealand, UT = LT + 13) within 5–15 days before two EQs of M w 7.8 and M w 6.8. Whereas, a chain of positive and negative anomalies is generated by geomagnetic storm-EQ event (M w 6.6) far beyond 5–15 days before and after the main shock due to active storm conditions (Kp> 3; Dst < −50 nT). Furthermore, geomagnetic storm anomalies are dominant on M w 6.6 EQ day to active storm conditions. To validate the ionospheric anomalies as possible seismic precursors, the atmospheric anomalies in relative humidity and OLR (outgoing longwave radiations) are also examined to exhibit the evolution of ionospheric anomalies from the lithosphere to ionosphere via the atmosphere. Moreover, EQ induced regular and collocated atmospheric anomalies over the epicenters of M w 7.8 and M w 6.8 and irregular atmospheric anomalies exist over the seismogenic zone of M w 6.6 due to geomagnetic storm-EQ nature. The observed EQ anomalies will aid in the improvement of lithosphere atmosphere ionosphere coupling hypothesis during the seismic preparation phase over the epicenter of future EQ. [ABSTRACT FROM AUTHOR]