EMRP2.9 | Observing Earth with Swarm: Celebrating 10 Years in Orbit and Future Perspectives
Observing Earth with Swarm: Celebrating 10 Years in Orbit and Future Perspectives
Co-organized by G4/ST4
Convener: Georgios Balasis | Co-conveners: Anja Stromme, Nils Olsen, Gauthier Hulot
Orals
| Thu, 27 Apr, 08:30–12:30 (CEST), 14:00–15:45 (CEST)
 
Room -2.21
Posters on site
| Attendance Wed, 26 Apr, 14:00–15:45 (CEST)
 
Hall X2
Orals |
Thu, 08:30
Wed, 14:00
Swarm is ESA's first constellation mission for Earth Observation and consists of three identical spacecraft launched on 22 November 2013. Each of the three Swarm satellites performs high-precision and high-resolution measurements of the strength, direction and variation of the magnetic field, accompanied by precise navigation, accelerometer, plasma and electric field measurements. Each satellite is equipped with magnetic sensors, measuring a combination of various contributing sources: the Earth’s core field, magnetised rocks in the lithosphere, external contributions from electrical currents in the ionosphere and magnetosphere, currents induced by external fields in the Earth’s interior and a contribution produced by the oceans. This session invites contributions illustrating the achievements of Swarm for investigating all types of Earth and near-Earth processes, as well as contributions describing synergies with other missions and ongoing initiatives towards designing innovative new magnetic field measurements missions.

Orals: Thu, 27 Apr | Room -2.21

Chairpersons: Anja Stromme, Nils Olsen
08:30–08:40
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EGU23-6576
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solicited
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On-site presentation
Vincent Lesur and Guillaume Ropp

A series of models of the Earth magnetic field and core surface flow are presented. The models were derived sequentially from year 1999 to 2022, using magnetic satellite and ground observatory data. A linear Kalman filter approach and prior statistics based on numerical dynamo runs were used. The core field and secular variation models present the same characteristics as the most recent core field models with slightly higher resolution in time. The core surface flow series of models presents large variations at high latitudes and under the western part of the Pacific Ocean. Filtering out the flow variation periods longer than ∼11.5 years leads to a filtered azimuthal flow with ∼7 years periodicities and patterns propagating westward by ∼60o longitude per year. These patterns are present mainly at mid- and equatorial latitudes. They are compatible with a perturbation of the main flow made of small columnar flows with rotation axis intersecting the core-mantle boundary between 10o to 15o latitudes, and flow speed of less than 5km/y. These columnar flows can be identified at all longitudes, but are particularly strong under the Pacific Ocean or under the Atlantic Ocean from 2005 to 2015.

How to cite: Lesur, V. and Ropp, G.: Core surface flow variations derived from observatory and satellite magnetic data, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6576, https://doi.org/10.5194/egusphere-egu23-6576, 2023.

08:40–08:45
08:45–08:55
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EGU23-7679
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ECS
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On-site presentation
Frederik Dahl Madsen, Kathy Whaler, Magnus Hammer, Richard Holme, Will Brown, and Ciarán Beggan

The ESA Swarm mission has, with along- and across-track differences of the magnetic field measurements, made it possible to generate spatial gradients data of the geomagnetic field and its secular variation (SV). Inverting the SV data for core-surface flows allows us to investigate the Earth’s outer core with higher resolution than using vector component data.

We invert for core-surface flow models directly from the spatial gradient tensor SV data, without the use of stochastic or numerical models, imposing flow equatorial symmetry, quasi- or tangential geostrophy, or band-pass filtering. We develop three different types of model, all damped to minimise spatial complexity and minimise acceleration between epochs. The first set is otherwise unconstrained, and different spatial regularisations are used. In the second set, we allow for torsional oscillations by relaxing the temporal damping on certain flow coefficients. The third set has differential damping on the equatorially symmetric and asymmetric flow components, in order to investigate the extent to which asymmetric flow is required to fit the data. We predict the intradecadal variation in length-of-day (LOD) from each model, and find that only the model which allows for torsional oscillations shows a good fit to the LOD data.

The azimuthal acceleration of all three model types shows evidence of fast westward low-latitude waves at the core-surface.  During the 2017 geomagnetic jerk, there is an abrupt westward shift in these wave-features in all our models. Previous literature suggests that geomagnetic jerks may originate from Alfvén wave packets emitted from the inner-outer core boundary, propagating outwards. We suggest that the observed westward shift at the jerk epoch may occur when these wave-packets interfere with the waves at the core surface.

Finally, we consider the use of spatial gradients from the CHAMP mission. Spatial gradients can be derived from along-track differences of the magnetic field from CHAMP, which allows us to compare the quality of core surface flow models from the CHAMP and Swarm missions. Our analysis suggests it is unlikely that CHAMP yields data of sufficient resolution to observe this proposed wave-interaction, showcasing the success of the Swarm mission.

How to cite: Madsen, F. D., Whaler, K., Hammer, M., Holme, R., Brown, W., and Beggan, C.: Investigating geomagnetic jerks with Swarm: Using the spatial gradient tensor for flow modelling, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7679, https://doi.org/10.5194/egusphere-egu23-7679, 2023.

08:55–09:05
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EGU23-9725
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On-site presentation
Jerome Dyment, Yujin Choi, Vincent Lesur, Andreina Garcia Reyes, Manuel Catalan, Takemi Ishihara, Tamara Litvinova, and Mohamed Hamoudi

The World Digital Magnetic Anomaly Map is prepared under the auspices of IAGA and the CGMW (Commission for the Geological Map of the World) of UNESCO. A first version was released in 2007 (Korhonen et al., 2007), and a second one in 2015 (Dyment et al., 2015; Lesur et al., 2016) with the mandate to update the version 2.0 using the same methodology when the availability of new data would make it necessary. The present version 2.1, compiled at 5 km interval, at 5 km altitude above the continents and at sea-level over the oceans, includes new datasets: (1) the complete digital aeromagnetic map of Brasil made available by ANP; (2) an improved version of the aeromagnetic map of Russia prepared by V-SEGEI; (3) the second version of the Antarctic Digital Magnetic Anomaly maP (ADMAP; Golynsky et al., 2018) which results from a remarkable international effort during and after the Second International Polar Year; (4) a new map of the Caribbean plate and Gulf of Mexico resulting from the compilation and re-processing of existing marine and aeromagnetic data in the area (Garcia and Dyment, EPSL, 2021, 2022); (5) the updated Magnetic Anomaly Map of Eastern Asia prepared by the CCOP (MAMEA; Ishihara and Uchida, 2021); and (6) a new marine magnetic anomaly data compilation prepared by T. Ishihara and coworkers. The new map will be presented and its improvements over the previous version discussed.

We try to characterize the magnetic signature of the different geological provinces at global scale by comparing WDMAM v.2.1 and the Geological Map of the World (Bouysse et al., 2014, CGMW). The latitudinal and directional dependences of the magnetic anomaly amplitude and shape prevent a direct global comparison. Instead, we examine the distribution of magnetic anomaly amplitudes within the geological provinces continent by continent. We build an histogram of the magnetic anomaly amplitudes for each type of geological province within each studied continent. The histograms resemble normal distributions from which we determine the average amplitude and its standard deviation. The latter reflects how wide is the range of amplitudes in the distribution: a small standard deviation means a narrow distribution and low amplitudes, a large one a wide distribution and high amplitudes. On land, our first investigation suggests that cratons exhibit stronger magnetic anomalies, whereas regions covered by a significant thickness of sediments present weaker anomalies. At sea, large igneous provinces show stronger anomalies, whereas continental platforms and the oceanic crust show similar amplitudes.

How to cite: Dyment, J., Choi, Y., Lesur, V., Garcia Reyes, A., Catalan, M., Ishihara, T., Litvinova, T., and Hamoudi, M.: World Digital Magnetic Anomaly Map (WDMAM) v.2.1 and the magnetic signature of geological provinces, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9725, https://doi.org/10.5194/egusphere-egu23-9725, 2023.

09:05–09:15
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EGU23-4719
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On-site presentation
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Kaiguang Zhu, Dedalo Marchetti, Mengxuan Fan, Ting Wang, Yiqun Zhang, Wenqi Chen, Yuqi Cheng, Jiami Wen, Hanshuo Zhang, Donghua Zhang, Xuhui Shen, Zeren Zhima, and Rui Yan

The Swarm mission was successfully launched in November 2013 and it’s still in orbit and providing global continues measurements of Earth’s magnetic field and plasma parameters such as electron density (Ne).

In this presentation, several examples of research of pre-earthquake electromagnetic phenomena in the occasion of medium (M6+) or large (M7.5+) seismic events by using Swarm magnetic and electron density data will be shown. In most cases, an acceleration of the Y-East magnetic component of the anomalies has been detected one week to months in advance with respect to the incoming earthquake.

A recent study, based on the first 8 years of Swarm magnetic field and Ne data, shows statistical proof of the correlation between Swarm anomalies and incoming M5.5+ earthquakes. In particular, it was identified that the anticipation time of the anomalies increases with earthquake magnitude and in addition that earthquakes with an epicentre on the sea tend to show higher frequency (period = 2s-10s) anomalies than land earthquakes (period = 25s-50s). A possible influence of the focal mechanism was also investigated but the results are not statistically significant and further studies are necessary.

On 2nd February 2018, China successfully launched its first satellite completely dedicated to studying earthquakes, called China Seismo-Electromagnetic Satellite (CSES-01) or ZhangHeng-01 (ZH-01). CSES-01 is equipped with several payloads to measure the magnetic and electric fields, ionospheric plasma properties, and two particle detectors with the purpose of understanding the possible ionospheric disturbances induced by earthquakes. This data from CSES-01 allowed us to better understand the ionospheric environment together with the Swarm mission and we will show how the join use of the two missions can highly help to characterize the ionosphere and possible pre-earthquake phenomena. For example, before the occurrence of Mw=7.5 Indonesia 2018, Mw=7.1 Ridgecrest 2019 or Mw=7.7 Jamaica 2020 earthquakes, an enhancement of the electron density has been detected and better described by multi-missions (Swarm and CSES) investigation.

Finally, a test of the quasi-real-time application of Swarm data to monitor earthquakes will be shown. In fact, a very quick investigation of the seismicity that occurred North of Rome, Italy (Guidonia city) on December 2022 and 1st January 2023 (ML=3.3) has been conducted identifying an anomalous Swarm track which is compatible with seismic acceleration that occurred before these events, but further explanations are possible. This test, even if still a manual analysis shows the capability to implement in near future an automatic monitoring system which could get further advantage from the Swarm data produced by the proposed FAST processor by ESA, even though not strictly crucial.

 

How to cite: Zhu, K., Marchetti, D., Fan, M., Wang, T., Zhang, Y., Chen, W., Cheng, Y., Wen, J., Zhang, H., Zhang, D., Shen, X., Zhima, Z., and Yan, R.: 10 years of observations of earthquakes with Swarm satellites: results and open questions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4719, https://doi.org/10.5194/egusphere-egu23-4719, 2023.

09:15–09:25
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EGU23-5013
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On-site presentation
Jakub Velímský and Zdeněk Martinec

The large-scale electrical conductivity structures in the deep Earth's mantle, in the depth range of 670 to 1400 km, can be in principle determined from Swarm-observed induction response to time-variable magnetospheric currents (Velímský & Knopp 2021). However, these efforts have been so far encumbered by limited spatio-temporal description of the magnetospheric field from moving satellite platforms. In particular, the polar electrojets (PEJs) and field-aligned currents (FACs) are sources of a strong bias in the spherical-harmonic analysis of Swarm magnetic data. An electric circuit model of PEJs and FACs (Martinec & Velímský 2022) provides a novel data processing tool to suppress the bias and obtain a reliable model of the large-scale magnetospheric field during magnetically disturbed times. In this contribution we apply the new magnetospheric field model to the 3-D time-domain  forward and inverse modelling of global electromagnetic induction. We determine its impact on the sensitivity and resolution of the inverse problem, and proceed with regularized 1-D and 3-D inversions to update the electrical conductivity model of the deep mantle. 

How to cite: Velímský, J. and Martinec, Z.: Application of a new magnetospheric field model to 3-D inversion of Swarm magnetic data in terms of mantle electrical conductivity, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5013, https://doi.org/10.5194/egusphere-egu23-5013, 2023.

09:25–09:35
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EGU23-4356
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On-site presentation
Zdeněk Martinec and Jakub Velímský

We deal with the analysis of Swarm vector magnetic data to create a circuit model of electric currents flowing in the Earth’s polar ionosphere and the inner magnetosphere. The model is composed of a system of two-dimensional electric currents representing the magnetic fields of three-dimensional ionospheric polar electrojets (PEJs), the field-aligned currents (FACs), magnetospheric ring currents (MRCs) and magnetospherically induced electric currents inside the Earth (MICs) for each Swarm track. We aim to model PEJ and FAC magnetic fields in terms of electric currents on a track-by-track base, subtract those magnetic fields from along-track Swarm magnetic data and estimate the magnetospheric magnetic field (MMF) in discrete time bins. The final model of MMF, named MMC, is represented by the two-circular loop model. Reliability of the approach is demonstrated by the scatter plots of model MMC showing a significantly better agreement with Swarm magnetic field residuals than the existing MMFs. A novelty of the proposed electric circuit model is that it approximately accommodates the known topology of the electric currents flowing in the polar ionosphere and inner magnetosphere at magnetically disturbed times. The proposed method is primarily intended to apply to Swarm signals recorded during magnetic storms.

How to cite: Martinec, Z. and Velímský, J.: An electric circuit model of the Earth's polar electrojets and field-aligned currents for the estimation of magnetospheric magnetic field from along-track Swarm magnetic data, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4356, https://doi.org/10.5194/egusphere-egu23-4356, 2023.

09:35–09:45
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EGU23-5167
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On-site presentation
Pierdavide Coïsson, Louis Chauvet, Gauthier Hulot, Martin Jenner, Dalia Buresova, Vladimir Truhlik, Jaroslav Chum, Janusz Mlynarczyk, Jerzy Kubisz, Jean-Michel Léger, and Thomas Jager

Over the past 10 years, the ESA Swarm mission led to many scientific successes sometimes way beyond its primary science targets. One such example is the unanticipated science allowed by the experimental 250 Hz burst mode magnetic scalar data provided by the Absolute Scalar Magnetometers on board the satellites. This burst mode was originally meant to be run briefly for in-orbit calibration and validation activities during the initial months of the Swarm mission. However, and despite the fact that the 250 Hz sampling rate can only access the ELF part of the electromagnetic spectrum, numerous whistler signals could be detected. After carefully assessing the possibility of routinely detecting and characterising such whistlers, it was thus next decided to conduct campaigns of one-week duration every month on Swarm Alpha and Bravo. These started in 2019 and still continue today, the corresponding Burst mode data now being a routine product of the mission.

In this presentation, we will review the main scientific results of these campaigns: geographical and temporal distribution of whistler events as well as the detectability of whistler signals, which we assessed using joint campaigns on the Alpha and Bravo satellites during the recent counter-rotating phase of the Swarm mission. Using ground ionosondes and in-situ electron density measurements we also demonstrated the promising possibility of using whistlers to measure ionosphere plasma density parameters along their path up to the Swarm satellites. Finally, using data from the ground based ELF measurements from WERA, and data from the lightning detection network WWLLN, the originating strikes could also be identified. We found that only the most powerful lightning strikes produce detected whistlers, and that these strikes can sometimes occur several thousands of kilometres away from the satellites.

How to cite: Coïsson, P., Chauvet, L., Hulot, G., Jenner, M., Buresova, D., Truhlik, V., Chum, J., Mlynarczyk, J., Kubisz, J., Léger, J.-M., and Jager, T.: Swarm Absolute Scalar Magnetometer burst mode: from instrument validation to routine observation of intense lightning activity, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5167, https://doi.org/10.5194/egusphere-egu23-5167, 2023.

09:45–09:55
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EGU23-14094
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On-site presentation
Ewa Slominska, Marek Strumik, and Jan Slominski

The ESA Swarm mission has been designed to provide high-precision registrations of the Earth's magnetic field. Since its launch, the constellation, consisting of three LEO satellites, measures the magnetic signals coming from Earth's core, mantle, crust, oceans, ionosphere, and magnetosphere. Nearly a decade of Swarm observations, allowed us to expand main goals of the mission and improve our capabilities of detecting magnetic field fluctuations triggered by powerful thunderstorms.

Lightning can generate ultra low frequency fluctuations that leak into the upper ionosphere. This means that some lightning bolts are so powerful that they trigger disturbances in Earth's magnetic field and propagate hundreds of kilometers upwards from the thunderstorm, reaching the altitude of Swarm’s orbit. Thanks to two magnetometers,  the Absolute Scalar Magnetometer ASM and the Vector Fluxgate Magnetometer VFM, Swarm turned into a robust lightning hunter. 

Gathered analysis, utilizing mainly the VFM registrations, show that averaged amplitude of lightning generated fluctuations reaches magnitude of 0.5-1.3 nT (peak-to-peak for the scalar field), while typical time delay between the lightning occurrence and the satellite detection is 0.2-0.5 s and this indicates that Swarm detects rather a direct propagation of lightning-generated disturbance than effects of excitation of the ionospheric Alfvén resonance, which would require a longer time scale.

Since Swarm provides full representations of the magnetic field components, we transform data to the so-called MV frame to extract the maximum amplitude of a given fluctuation regardless of the lightning-satellite mutual orientation and wave polarization. In such a way, Swarm data help to comprehensively characterize  wave properties of detected fluctuations, and this is one of fundamental tasks, especially in the large variety of magnetic field disturbances caused by various types of natural hazard phenomena. 

How to cite: Slominska, E., Strumik, M., and Slominski, J.: A decade of measurements, which turned Swarm into a lightning hunter, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14094, https://doi.org/10.5194/egusphere-egu23-14094, 2023.

09:55–10:05
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EGU23-7872
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ECS
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On-site presentation
Elisabetta Iorfida, Ilias Daras, and Anja Strømme

The ESA Swarm mission was launched in November 2013, and it consists of a constellation of three identical satellites. The main mission objective is to model and analyze the geomagnetic field through the data provided by a vector and a scalar magnetometer on board of each spacecraft (A, B, C).  To fulfill the secondary objectives, the satellites do also carry other instruments, such as an accelerometer expected to measure the non-gravitational forces acting on each satellite. However, the quality of the data retrieved from this instrument was not at the anticipated level and, therefore, the post-processing required to calibrate the signal was significant. Therefore, initially the calibration focused on Swarm C only because it had the best signal-to-noise ratio of the constellation. For this satellite the calibrated accelerometer data are available since the beginning of the mission and they are disseminated bi-monthly. At the end of 2021, the first Swarm A dataset was released and it comprises some months in 2014. Swarm A and C, called the “lower pair”, have flown side-by-side for most of the mission with a separation that spanned from four to ten seconds. Therefore, their measurements are supposed to be nearly identical after calibration.

A recent publication, which is discussed in this talk, demonstrated that a comparison between Swarm A and Swarm C calibrated accelerometer dataset shows the expected correlation. After applying a high-pass filter to both satellites’ dataset, very similar features are visible at the equator and at the poles. The “long time scale” events at the equator show a correlation between the equatorial mass anomaly and the equatorial ionization anomaly. At the poles, the “short time scale” events can be related to the Polar Cap index and to the field-aligned currents, which are measured on board by the Swarm magnetometers. Furthermore, these features agree with previous literature based on CHAMP and GRACE data.

For the first time the Swarm accelerometer data deliver scientific results, in particular in the field of thermosphere and ionosphere coupling.

How to cite: Iorfida, E., Daras, I., and Strømme, A.: Swarm A and C Accelerometer - data analysis and scientific outcome, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7872, https://doi.org/10.5194/egusphere-egu23-7872, 2023.

10:05–10:15
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EGU23-8273
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ECS
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On-site presentation
Kevin Styp-Rekowski, Ingo Michaelis, Monika Korte, Claudia Stolle, and Odej Kao

So-called platform magnetometers, mounted on a variety of non-dedicated satellites in Low-Earth orbit, are promising instruments to increase the spatiotemporal coverage of space-based measurements of the Earth’s magnetic field. However, these instruments often need to be calibrated to ensure a scientific accuracy and usability of the data they collect. To do this, it is important to gather information about the satellite to correct artificial disturbances caused by other payload systems as well as other influencing properties. In the past, we demonstrated that a Machine Learning-based calibration achieves competitive results. By using machine learning techniques, the magnetometer signal can be adapted to account for artificial disturbances and the proposed non-linear regression method can automatically identify relevant features and their crosstalk, enabling the use of a wider range of inputs. This reduces the analytical work required for the calibration of platform magnetometers, resulting in faster, more precise, and easily accessible magnetic datasets from non-dedicated missions. The calibrated datasets are made publicly available.

In this work, we propose an extension for the known approach by incorporating the physical Biot-Savart formula into a neural network, which results in a physics-informed neural network. This improves the modeling and correction of the impact of current-induced artificial magnetic fields on the satellite and its magnetic measurements. In addition, the Average Magnetic field and Polar current System (AMPS) model is combined with the CHAOS-7 model, improving the reference model of the calibration, especially for the polar regions. This extended approach is applied to the GOCE and GRACE-FO satellite missions and their respective measurements. In the future, the underlying software shall be published and applied to a wider variety of satellites to improve the accuracy of their platform magnetometer measurements. By making this tool publicly available, we hope to enable other satellite operators to calibrate their instruments, improve the quality of their data, and make additional data available to the scientific community.

How to cite: Styp-Rekowski, K., Michaelis, I., Korte, M., Stolle, C., and Kao, O.: Improving Platform Magnetometer Measurements Using Physics-informed Neural Networks, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8273, https://doi.org/10.5194/egusphere-egu23-8273, 2023.

Coffee break
Chairpersons: Nils Olsen, Gauthier Hulot
10:45–10:55
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EGU23-9113
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solicited
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On-site presentation
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Karl Laundal, Jone Reistad, Spencer Hatch, Sara Gasparini, Simon Walker, Michael Madelaire, and Anders Ohma

The Swarm satellites accurately sample electromagnetic fields in-situ along the satellite tracks, but give little direct information about the spatial structures of the field away from the orbit. By making assumptions about temporal variations, in-situ satellite data is nevertheless useful for constructing climatological models that reveal average patterns of electromagnetic fields. Such models help us to understand large-scale average effects of solar wind-magnetosphere-ionosphere-thermosphere coupling, but their information about temporal variations is limited. For specific events, data from single satellites are insufficient for mapping spatio-temporal variations. Here we present a technique for combining Swarm data with measurements of magnetic and electric fields from other satellites, and from ground instruments. The technique, called Local mapping of polar ionospheric electrodynamics (Lompe) relies on the ionospheric Ohm’s law, and knowledge about ionospheric conductance. We discuss the importance of reliable conductance estimates for accurately relating magnetic and electric field observations.

How to cite: Laundal, K., Reistad, J., Hatch, S., Gasparini, S., Walker, S., Madelaire, M., and Ohma, A.: Mapping spatio-temporal variations in ionospheric electrodynamics, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9113, https://doi.org/10.5194/egusphere-egu23-9113, 2023.

10:55–11:00
11:00–11:10
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EGU23-2172
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On-site presentation
Andrew Yau and Andrew Howarth

The Enhanced Polar Outflow Probe (e-POP) was launched as part of the Canadian CASSIOPE small satellite into an elliptic polar orbit in September 2013. It then joined the ESA Swarm mision under ESA's Third Party Mission Programme in 2018, as a Fourth Element of the Swarm constellation of satellites, to take advantage of the highly complementary and synergistic instrumentation and orbital coverage between CASSIOPE/e-POP and the three Swarm satellites. This scientific synergy has made possible a new, high-resolution multipoint data set of magnetic field, GPS, and related optical, radio wave, and plasma composition observations, as an addition to the Swarm mission data system and the basis for a number of new scientific investigations. We will review examples of 'scientific success stories' from such investigations. We will also present examples of new investigations in the next chapter of Swarm Echo: these investigations were not planned previously but have become feasible after the recent partial failure of the spacecraft attitude control system, which necessitated a change to a new spacecraft attitude configuration that will serendipitously provide the necessary observing geometry for such innovative investigations

How to cite: Yau, A. and Howarth, A.: CASSIOPE - Swarm Echo as a Fourth Element of the Swarm Constellation: Scientific Synergies and the Next Chapter, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2172, https://doi.org/10.5194/egusphere-egu23-2172, 2023.

11:10–11:20
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EGU23-3667
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On-site presentation
Marzena Kastyak-Ibrahim, Andrew Howarth, Andrew White, and Andrew Yau

We have performed a statistical analysis of small-scale (sub-decameter) plasma density irregularities in the topside ionosphere (at 325-1500 km altitude) using the high-cadence (1000 samples/sec) sensor surface current data from the Imaging Rapid-scan Ion Mass Spectrometer (IRM) onboard the Swarm-E / Enhanced Polar Outflow Probe (e-POP). The measured current consists of contributions from the ambient and non-ambient electrons and ions, and it is proportional to and serves as a proxy for the local plasma density. The high-cadence current data are averaged over time intervals up to 0.5 s (to facilitate comparison with previous studies) and the analysis is undertaken separately for the case of positive and negative net currents, respectively. We have developed and validated an algorithm to identify small-scale structures of plasma density depletions and enhancements, by finding local minima (depletions) and maxima (enhancements) in the measured current amplitude in each case.  We will compare and contrast the statistical distributions of small-scale plasma density depletion and enhancement structures down to sub-100 m scale, including their altitude, magnetic latitude, magnetic local time distributions and spectral characteristics.

How to cite: Kastyak-Ibrahim, M., Howarth, A., White, A., and Yau, A.: Small-Scale (Sub-decameter) Plasma Density Irregularities in the Topside Ionosphere Using High-cadence Plasma Current Measurements on e-POP (Swarm-E), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3667, https://doi.org/10.5194/egusphere-egu23-3667, 2023.

11:20–11:30
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EGU23-9101
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ECS
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On-site presentation
E. Ceren Kalafatoglu Eyiguler, Donald W. Danskin, Kuldeep Pandey, Glenn C. Hussey, Robert G. Gillies, and Andrew W. Yau

Swarm-E carries the e-POP payload, which consists of eight scientific instruments. The Radio Receiver Instrument (RRI) on e-POP may be used to detect density structures that modify the characteristics of transionospheric HF radio waves from ground-based transmitters. RRI has a cross-dipole antenna designed to determine the polarisation characteristics of the incident radio waves. Joint experiments with other instruments, IRM (Imaging and Rapid-scanning ion Mass spectrometer) and MGF (Fluxgate Magnetometer), complement RRI for better understanding of the local ionosphere conditions and integrated conditions along the path between a ground-based transmitter and Swarm-E. Under optimum conditions, the RRI determines the full polarisation characteristics. This presentation discusses past and future contributions to ionospheric science of the Swarm constellation.

How to cite: Kalafatoglu Eyiguler, E. C., Danskin, D. W., Pandey, K., Hussey, G. C., Gillies, R. G., and Yau, A. W.: Understanding Ionospheric Conditions using the e-POP on Swarm-E, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9101, https://doi.org/10.5194/egusphere-egu23-9101, 2023.

11:30–11:40
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EGU23-11583
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On-site presentation
Paola De Michelis

The project “Characterization of Ionospheric TurbulENce Level by Swarm Constellation (INTENS)”, which was completed in 2021, was a collaboration between two Italian research institutes (INGV and INAF) and the National Observatory of Athens (NOA). It was funded by the European Space and was devoted to the investigation of turbulence and complexity in the ionospheric F2 region using data coming from the Swarm constellation. The obtained results were very intriguing because they provided the first global-scale characterization of the scaling properties of electron density and magnetic field fluctuations at the Swarm altitude as a function of geomagnetic activity and orientations of interplanetary magnetic fields. They also provided the opportunity to quantify changes in the complexity of the magnetosphere-ionosphere coupling system and to comprehend how it reacts to the onset and evolution of intense magnetic storms using entropy measures.

Despite the fact that the INTENS project is no longer active, research continues. The aim of this presentation is to summarize some recent results and to show how turbulence can be one of the most significant processes for the generation of plasma density irregularities which strongly affect the Global Navigation Satellite System. A thorough understanding of turbulent ionospheric fluctuations can be crucial in the future creation of GPS Loss of Lock hazard maps, greatly advancing the effort to minimize the effects of space weather. Any future satellite mission that can accurately measure the magnetic field and electron density at high frequency, as the NanoMagSat mission should be able to, will be necessary to extend the reliability of the results to ever smaller spatio-temporal scales.

 

 

How to cite: De Michelis, P.: The project “Characterization of Ionospheric Turbulence Level by Swarm Constellation”: Results and Prospects, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11583, https://doi.org/10.5194/egusphere-egu23-11583, 2023.

11:40–11:50
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EGU23-5696
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ECS
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On-site presentation
Alessio Pignalberi, Fabio Giannattasio, Michael Pezzopane, Igino Coco, and Tommaso Alberti

Electron density (Ne) and electron temperature (Te) observations collected by Langmuir Probes (LPs) on board the European Space Agency’s Swarm satellites are used to characterise the NeTe correlation in the topside ionosphere. The large dataset of Swarm LPs in-situ observations at 2-Hz rate, covering the years 2014−2021, allowed us to investigate the correlation properties of the topside ionospheric plasma for different diurnal and seasonal conditions, with a coverage and a detail never reached before. Spearman correlation coefficients (RSpearman) are calculated on joint probability distributions between Ne and Te for specific conditions. Results are given as maps of RSpearman as a function of the Quasi-Dipole (QD) magnetic latitude and magnetic local time (MLT) coordinates, for different seasons. This study highlights, for the first time, the NeTe correlation at high latitudes, and provides a global description of the corresponding diurnal trend for different seasons. A negative correlation is found at the equatorial morning overshoot, during daytime at mid latitudes, and during night-time at subauroral latitudes (ionospheric trough). Conversely, a positive correlation dominates the night-time sector at mid and low latitudes, and to a minor extent the low latitudes from 09:00 MLT onwards. A seasonal dependence of the correlation is visible only at very high latitudes where the general pattern of anti-correlation is broken around ±75° QD latitude in the summer season.

How to cite: Pignalberi, A., Giannattasio, F., Pezzopane, M., Coco, I., and Alberti, T.: On the correlation between electron density and temperature in the topside ionosphere through Swarm satellites data, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5696, https://doi.org/10.5194/egusphere-egu23-5696, 2023.

11:50–12:00
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EGU23-5123
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ECS
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On-site presentation
Giulia Lovati, Paola De Michelis, Giuseppe Consolini, Michael Pezzopane, Alessio Pignalberi, and Francesco Berrilli

Swarm enabled researchers to investigate the disturbing phenomena that have affected spacecraft transiting in the F-region ionosphere over the last ten years, in addition to the mission's primary scientific goals. Indeed, plasma density irregularities in the ionospheric region traversed by Swarm satellites can affect both the phase and amplitude of electromagnetic waves propagating through it. As a result, the accuracy and reliability of the Global Navigation Satellite System's (GNSS) performance may be compromised. In the worst-case scenario, a GNSS signal interruption could occur while a Loss of Lock (LoL) event is taking place. This type of events appears to be important in the space weather framework, as it is favored by increased solar activity and disturbed geomagnetic conditions. The high-latitude ionospheric region is particularly impacted by these GNSS signal interruptions.

Here, we look into how the orientation of the interplanetary magnetic field affects the growth of the plasma irregularities that give rise to GPS LoL events. We use LoL events recorded between July 15, 2014, and December 31, 2021, onboard two of the three Swarm satellites, and examine how the orientations of the interplanetary magnetic fields affect the GPS LoL events distribution in magnetic local time and magnetic latitude, in both hemispheres. The results show that there is a clear dependence on the IMF orientation in the y-z plane. The effect of the IMF x component on the LoL distribution is found to be linked to the IMF y component, mainly due to the IMF spiral structure. The results are discussed considering the ionospheric convection patterns as reconstructed by SuperDARN radar observations. The capacity provided by Swarm to track these events and study their dependence on solar, interplanetary, and geophysical parameters may pave the way for a further development of LoL hazard maps at high-latitudes, and thus significantly contribute to space weather effect mitigation.

How to cite: Lovati, G., De Michelis, P., Consolini, G., Pezzopane, M., Pignalberi, A., and Berrilli, F.: The relation between GPS loss of locks and the Interplanetary Magnetic Field orientation: Swarm observations, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5123, https://doi.org/10.5194/egusphere-egu23-5123, 2023.

12:00–12:10
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EGU23-6558
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On-site presentation
M. Mainul Hoque, Norbert Jakowski, Juan Andres Cahuasqui Llerena, Stephan C. Buchert, Martin Kriegel, Paul David, Dmytro Vasylyev, Jens Berdermann, and Klaus Nielsen

The Swarm data products are well-suited to address a number of crucial topics for space weather science and monitoring, such as investigating spatial and temporal characteristics of ionospheric irregularities or improving topside approaches in ionospheric models for monitoring and forecasting the dynamics of the geo-plasma environment. Precision and safety of life applications using trans-ionospheric signals require key information on space weather conditions in particular on the perturbation degree of the ionosphere. Such applications are particularly vulnerable against severe spatial gradients and rapid changes of the electron density (Ne) as well as the total electron content (TEC) measured along different satellite‐receiver links. Here, we propose two new Swarm products 1) the TEC Gradient Ionosphere indeX (TEGIX) and 2) the Ne Gradient Ionosphere indeX (NEGIX). The TEGIX estimates spatial TEC gradients in the topside ionosphere (Swarm up to GNSS orbit) using GNSS Precise Orbit Determination (POD) measurements whereas the NEGIX estimates spatial Ne gradients using Swarm onboard Langmuir probe (LP) measurements (2 Hz sampled).  The approach takes benefit from the coordinated flight of satellites A and C at an orbit height of about 460 km. We will present a first version of both products and will explore their potential impact, utility, and use through case studies.

Acknowledgement:

The work is funded by the MIGRAS (Monitoring of Ionospheric Gradients At SWARM) project under the Swarm DISC Subcontract Doc. no: SW‐CO‐DTU‐GS‐133, Rev: 1.

How to cite: Hoque, M. M., Jakowski, N., Cahuasqui Llerena, J. A., Buchert, S. C., Kriegel, M., David, P., Vasylyev, D., Berdermann, J., and Nielsen, K.: Monitoring ionospheric gradients using SWARM satellite data, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6558, https://doi.org/10.5194/egusphere-egu23-6558, 2023.

12:10–12:20
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EGU23-1889
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On-site presentation
Loredana Perrone and Andrey Mikhailov

European and North American near-noontime ionosonde observations along with CHAMP and Swarm neutral density measurements were used during a major Arctic SSW in January  2009 and a minor Antarctic SSW in September 2019 to retrieve variations of thermospheric parameters (neutral composition, temperature, winds) related to these SSW events. Neutral density observations were used in the retrieval process as a fitted parameter. The main effect of SSW 2009 event is a strong decrease of the atomic oxygen [O] abundance in the thermosphere which is confirmed by satellite neutral gas density observations. Along with this no thermosphere cooling effects were revealed.

The duration of [O] decrease related to SSW is around 3-5 days in the vicinity of the SSW peak. The decrease of [O] depends on the intensity of SSW. The minor Antarctic SSW event in September 2019 manifested no pronounced thermospheric effects in the Northern Hemisphere.

 

How to cite: Perrone, L. and Mikhailov, A.: The thermospheric effects of SSWs observed in 2009 and 2019 at mid latitudes of the Northern Hemisphere, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1889, https://doi.org/10.5194/egusphere-egu23-1889, 2023.

12:20–12:30
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EGU23-10157
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ECS
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On-site presentation
Ashley Smith, Constantinos Papadimitriou, Georgios Balasis, Sebastian Käki, Theresa Hoppe, and Heikki Vanhamäki

SwarmPAL is a new Python package under development with support from Swarm DISC (Data, Innovation, and Science Cluster). This project aims to provide the research community with a suite of tools to rapidly access, analyse, and visualise data from Swarm (and related data sources). By relying on the VirES system [1] for data access and other utilties, this greatly reduces the complexity required within SwarmPAL. By making use of HAPI [2], we can also connect to many other data sources to retrieve data from beyond Swarm. This is part of an overall strategy for integrating with the wider Python (and Jupyter) ecosystem, while being cognisant of the particular scientific landscape occupied by Swarm [3].

SwarmPAL is developed by researchers and research software engineers: this ensures a close fit between the development process and the needs of researchers, as well as fostering software skills within the research community. Through several other DISC activities we bring different research teams together, working on different areas of Swarm science, to collaboratively work on the SwarmPAL system. Namely, these activities currently include the TFA (time frequency analysis), and DSECS (dipolar spherical elementary current systems) toolboxes. These toolboxes provide tools to rapidly and configurably apply analyses to Swarm data, while the SwarmPAL package provides the home for these, together with all the maintenance and documentation that this implies. The development process is made with a strong focus on sustainability and open source [4].

[1] https://vires.services
[2] https://hapi-server.org
[3] https://doi.org/10.3389/fspas.2022.1002697
[4] https://github.com/Swarm-DISC/SwarmPAL

How to cite: Smith, A., Papadimitriou, C., Balasis, G., Käki, S., Hoppe, T., and Vanhamäki, H.: Developing the SwarmPAL Python package, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10157, https://doi.org/10.5194/egusphere-egu23-10157, 2023.

Lunch break
Chairpersons: Gauthier Hulot, Georgios Balasis
14:00–14:05
14:05–14:15
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EGU23-5288
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On-site presentation
David Knudsen and Johnathan Burchill

The Swarm mission concept is innovative in its recognition that high-quality measurements of the geomagnetic field from LEO require accurate knowledge of Earth’s plasma environment, and furthermore that combined, precision measurements of fields, plasmas and neutral density from polar orbit provide a new window into ionosphere-thermosphere-magnetosphere (ITM) coupling and science. During the first decade of operations, event-based studies have led to new discoveries such as extreme plasma flows associated with the Birkeland current systems, the electrodynamic structure of multiple auroral arcs, the sub-auroral “STEVE” phenomenon, and the existence of standing Alfvén waves at equatorial latitudes. At the same time, the mission has accumulated an extensive database of measurements at high spatial resolution collected over a wide range of condition covering nearly a full solar cycle; these data have been used in longer-term statistical studies of plasma properties, high-latitude convection and ITM coupling via Poynting flux. As we enter the next decade of operations, the Swarm data are increasingly being used to inform empirical and physics-based models of the ionosphere; these in turn will comprise an important part of the long-term legacy of the Swarm mission. This talk will highlight scientific discoveries from the first decade of EFI operations, centred on observations of ion flows and associated electric fields from the EFI’s Thermal Ion Imagers, and made possible by a large and active community of collaborators. 

How to cite: Knudsen, D. and Burchill, J.: Swarm Electric Field Instruments' Thermal Ion Imagers: A Decade of Discovery, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5288, https://doi.org/10.5194/egusphere-egu23-5288, 2023.

14:15–14:25
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EGU23-3621
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On-site presentation
Malcolm Dunlop, Xiangcheng Dong, Xin Tan, Junying Yang, Dong Wei, and Chao Xiong

We review a number of studies, undertaken during the 10 years of Swarm, using distributed, multi-scale measurements arising from the combination with Cluster, MMS and ground based arrays. The scaling, coherence and correlation of field-aligned current sheets (FACs) connecting different regions of the magnetosphere have been explored with associated analysis techniques using these multi-point measurements at both low (LEO) and high altitudes, and in relation to (R1/R2) auroral boundaries. Individual events can map to conjugate current density distributions at the magnetopause and ring current and regions in between; as well as to associated  ground signatures, driven by the external conditions. Large and small-scale (MLT) trends in FAC orientation can be inferred from dual-spacecraft (e.g. the Swarm A&C spacecraft). Conjugate effects seen in ground (dH/dt), ionospheric and magnetospheric magnetic signals show that intense, coherent FA currents can take place in the polar cusp during the main phase of a geomagnetic storm and at near tail local times during substorm activity, at different altitudes. In the former event the mesoscale FACs show vertical scaling and a corresponding geomagnetic disturbance, driven by unsteady magnetic reconnection at the magnetopause. In the latter event, the most intense dH/dt is shown to be associated with FACs driven into the ionosphere by the arrival of bursty bulk flows BBFs at geosynchronous orbit (linked via a modified sub-storm current wedge, SCW). In situ ring current morphology can also be investigated by MMS, THEMIS and Cluster during the Swarm era, and can be compared to distributions of R2-FACs.

How to cite: Dunlop, M., Dong, X., Tan, X., Yang, J., Wei, D., and Xiong, C.: Review of coordinated measurements with Swarm and Cluster : multi-scale magnetospheric and ground currents, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3621, https://doi.org/10.5194/egusphere-egu23-3621, 2023.

14:25–14:35
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EGU23-12663
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ECS
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On-site presentation
Christina Toldbo, Matija Herceg, Julia Sushkova, Troelz Denver, Jesper Henneke, Mathias Benn, Peter S. Jørgensen, José M.G. Merayo, Enkelejda Qamili, Berta Hoyos Ortega, Roger Haagmans, Pierre Vogel, Anja Strømme, Seth Shulman, and John L. Jørgensen

The three spacecraft which constitute the Swarm mission are equipped with the Micro Advanced Stellar Compass (μASC) provided by the Technical University of Denmark (DTU) for attitude determination. Each μASC is comprised of three Camera Head Units (CHUs) for a total of nine cameras on the mission. The CCD sensor inside the CHUs are sensitive to energetic particle irradiation which appear as transient bright pixels dubbed ’Energetic Particle Detections’ (EPDs) on the star field images.

For more than five years the μASCs on-board Swarm have transmitted the occurrence of EPDs to ground and thereby effectively added high energy radiation monitoring capabilities to the Swarm mission. The high sensitivity, high sample rate (1-2 Hz), orientation of the camera heads, simultaneous measurements from all three spacecraft and near-polar orbits at an altitude of 450-510 km and allows for continuous and real-time monitoring of the high energy (>65 MeV) proton environment in LEO. This data uncover short and long term changes in particle flux in e.g. the South Atlantic Anomaly (SAA) of relevance for future mission planning.

The same radiation monitoring capability exists on NASA’s Magnetospheric Multiscale Mission (MMS) which, due to its highly elliptical orbit, survey the Van Allen radiation belts and detect enhanced radiation levels in the belts associated with geomagnetic storms. Combining data from the μASCs onboard Swarm and MMS provides unique insight into the injection mechanisms and dynamics of very high energy particles which is currently poorly understood. This work presents observations and results using high energy radiation data obtained from the μASC on board ESA’s Swarm mission, from February 2018 to February 2023, in combination with μASC data from MMS.

 

How to cite: Toldbo, C., Herceg, M., Sushkova, J., Denver, T., Henneke, J., Benn, M., Jørgensen, P. S., Merayo, J. M. G., Qamili, E., Hoyos Ortega, B., Haagmans, R., Vogel, P., Strømme, A., Shulman, S., and Jørgensen, J. L.: The High Energy Particle Populations of Earth Mapped by Swarm and MMS, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12663, https://doi.org/10.5194/egusphere-egu23-12663, 2023.

14:35–14:45
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EGU23-6437
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ECS
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On-site presentation
Dario Sabbagh, Alessandro Ippolito, Dedalo Marchetti, Loredana Perrone, Angelo De Santis, Saioa A. Campuzano, Gianfranco Cianchini, and Alessandro Piscini

In this work, a new method to define a background for the topside ionospheric electron density from satellite in-situ measurements is proposed as a useful tool for analysis of plasma density variations at LEO satellites heights. The method is applied to the data acquired by the Langmuir Probes onboard CHAMP satellite during the years 2004 and 2009, and the three Swarm satellites during 2016 and 2017 in the 15°-wide mid-latitudinal belt from 35°N to 50°N, and any longitude. CHAMP/Swarm in-situ measurements have also been used to check and compare such a new defined background with the one computed directly from IRI-2016 electron density output at satellite altitude. A general overestimation of the electron density from IRI during noon hours is highlighted, despite an underestimation of IRI with respect to Swarm-derived background for Swarm 2017 data is found as well, while the two backgrounds result more in agreement during night-time. Finally, the analysis of 2004 plasma data suggests that the IRI-2016 model could be used as a background during periods characterized by high levels of geomagnetic activity under high solar activity conditions.

How to cite: Sabbagh, D., Ippolito, A., Marchetti, D., Perrone, L., De Santis, A., Campuzano, S. A., Cianchini, G., and Piscini, A.: Ionospheric mid-latitude electron density background definition from CHAMP and Swarm satellite measurements under different solar conditions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6437, https://doi.org/10.5194/egusphere-egu23-6437, 2023.

14:45–14:55
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EGU23-6172
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Virtual presentation
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Gianfranco Cianchini, Angelo De Santis, Massimo Calcara, Saioa A. Campuzano, Serena D'Arcangelo, Mariagrazia De Caro, Domenico Di Mauro, Cristiano Fidani, Adriano Nardi, Martina Orlando, Loredana Perrone, Dario Sabbagh, and Maurizio Soldani

The Swarm three-satellite mission by ESA was initially designed with its original configuration to monitor and study the geomagnetic field and the state of the ionosphere and magnetosphere. For the first time, in 2017, the Swarm satellites detected some pre- and post-earthquake magnetic field anomalies on occasion of the 2015 Nepal M7.8 earthquake. Interestingly, the cumulative number of satellite anomalies and the cumulative number of earthquakes behaved similarly with the so-called S-shape, providing an empirical proof on the lithospheric origin of the satellite anomalies (De Santis et al., 2017; doi:10.1016/j.epsl.2016.12.037). Following the same approach, other promising results were obtained for 12 case studies in the range of 6.1-8.3 earthquake magnitude, in the framework of the SAFE (SwArm For Earthquake study) project funded by ESA (De Santis et al., 2019a; doi:10.3390/atmos10070371). In 2019, almost five years of Swarm magnetic field and electron density data were analysed with a Superposed Epoch and Space approach and correlated with major worldwide M5.5+ earthquakes (De Santis et al. 2019b; doi:10.1038/s41598-019-56599-1). The analysis verified a significant correlation between satellite anomalies and earthquakes above any reasonable doubt, after a statistical comparison with random simulations of anomalies. The work also confirmed the Rikitake (1987) law, initially proposed for ground-based data: the larger the magnitude of the impending earthquake, the longer the precursory time of anomaly occurrence in ionosphere from satellite. A more recent investigation (Marchetti et al. 2022; doi:10.3390/rs1411264) over a longer time series of data, i.e. 8 years, confirmed the same results. Furthermore, we demonstrated in several case studies (e.g., Akhoondzadeh et al. 2019; doi: 10.1016/j.asr.2019.03.020; De Santis et al. 2020; doi:10.3389/feart.2020.540398) that the integration of Swarm satellite data with other kinds of measurements from ground, atmosphere and space (e.g., CSES-01 satellite data) reveals a chain of processes before the mainshocks of many seismic sequences. 

How to cite: Cianchini, G., De Santis, A., Calcara, M., A. Campuzano, S., D'Arcangelo, S., De Caro, M., Di Mauro, D., Fidani, C., Nardi, A., Orlando, M., Perrone, L., Sabbagh, D., and Soldani, M.: The great potentiality of Swarm three-satellite mission for detecting pre-earthquake ionospheric anomalies, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6172, https://doi.org/10.5194/egusphere-egu23-6172, 2023.

14:55–15:05
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EGU23-7914
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ECS
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Virtual presentation
Rayan Imam, Luca Spogli, Lucilla Alfonsi, Claudio Cesaroni, Yaqi Jin, Lasse Clausen, Alan Wood, and Wojciech Miloch

The 16 Hz plasma density measurements provided by the high-resolution faceplate onboard Swarm satellites can be utilized to reconstruct the one-dimensional spectral slope (p) of the power spectrum of the plasma density irregularity. The 16 Hz sampling rate at Swarm orbital features (speed of ~7.5 km/s on quasi-polar orbits) allows modelling spatial scales of about 500 m along the flight trajectory, which are slightly above the first Fresnel zone, the upper limit of the scale sizes of the irregularities causing scintillation on Global Navigation Satellite Systems (GNSS) signals. 

The p-value is a key parameter in estimating the scintillation strength and thus a Swarm ionospheric scintillation (SWIS) proxy is investigated. Such approach, once consolidated, will benefit the scientific community in studying, monitoring and modelling the small-scale irregularities; specially in contexts where ground based GNSS scintillation monitoring is not available, for example over the oceans.

In this work, p-value from Swarm, combined with the reconstruction of the irregularity layer , are ingested to compute the amplitude scintillation index (S4) using Rino’s theory of weak scattering. In this work, the model formulation and sample results of S4 estimation from Swarm are demonstrated. Results of validating SWIS S4 against S4 from ground based GNSS scintillation for selected key ionospheric sectors are also shown. The results demonstrate that the model can capture the amplitude scintillation index inflation both at low and high latitudes, demonstrating the capability of detecting the equatorial and the (rare) polar amplitude scintillation from Swarm measurements. 

How to cite: Imam, R., Spogli, L., Alfonsi, L., Cesaroni, C., Jin, Y., Clausen, L., Wood, A., and Miloch, W.: Determining the L-band amplitude scintillation index from Swarm faceplate plasma measurements, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7914, https://doi.org/10.5194/egusphere-egu23-7914, 2023.

15:05–15:15
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EGU23-14565
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Virtual presentation
Natalia Gomez Perez and Ciaran Beggan
The Swarm mission, launched in November 2013, consists of three identical satellites in near polar orbit dedicated to measuring the Earth's magnetic field to very high accuracy. Two satellites fly at a lower altitude in close orbital proximity while the third flies at a higher altitude producing a steady local time drift. The unique configuration allows a wide set of new models of the various sources of the field to be created from core to magnetosphere. In this study, we separate the magnetic field sources measured at satellite altitude and produce a model of the night-side magnetosphere. This model can be used to study the magnetosphere during storm time to see how it responds to external forcing. Additionally, we observe seasonal variations of the quiet-time configuration. We find good agreement with previous studies during both quiet and storm periods, and we are able to produce these complete models in a timely fashion, making a high-resolution and near real-time characterisation of the magnetosphere configuration possible.

How to cite: Gomez Perez, N. and Beggan, C.: A Swarm-only night-side magnetospheric model to degree and order 3, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14565, https://doi.org/10.5194/egusphere-egu23-14565, 2023.

15:15–15:25
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EGU23-15810
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Virtual presentation
Peter Kovacs, Balazs Heilig, Zsófia Bebesi, and Andrea Opitz

The almost one decade of operation of ESAs Swarm mission provides an unprecedented opportunity to investigate the appearance of small-scale nonlinear magnetic field irregularities in the topside ionosphere in terms of various climatological and solar-cycle conditions. Within the framework of the EPHEMERIS project supported by ESA we have developed an index for the characterization of the intermittent status of the compressional and tangential (i.e., parallel and perpendicular to the mean background field, respectively) magnetic field fluctuations along the orbits of the Swarm spacecraft triplet. The index is called intermittency index, in short IMI. IMIs are computed for consecutive overlapping segments of Swarm’s magnetic field records by evaluating the deviation of their statistical distribution from the Gaussian distribution. By portraying the global spatial distribution of IMIs, it turns out that the most intensive intermittent fluctuations appear in the polar and equatorial regions, due to auroral field-aligned currents (FAC) and equatorial spread F and plasma bubble phenomena, respectively. Making use of the Adjusted Spherical Cap Harmonic (ASHA) expansion of IMIs, we model the distribution of the intermittent transverse magnetic fluctuations in the polar region in terms of geomagnetic latitude and magnetic local time (MLT), for different geomagnetic activities. We show that the most intermittent fluctuations at high latitudes are distributed about two oval regions that adjoin in the night sector. The ovals expand towards the equator with increasing geomagnetic activity. We argue that the boundaries of the poleward oval coincide with the locations of FACs, while the equatorward oval of intermittent fluctuations (separating from the poleward oval in the noon sector) corresponds to the ionosphere footprint of the plasmasphere boundary, i.e. the plasmapause. These findings are reinforced by independent aurora oval and plasmapause models.

How to cite: Kovacs, P., Heilig, B., Bebesi, Z., and Opitz, A.: Modelling the distribution of intermittent magnetic field fluctuations recorded by the Swarm mission in the polar area, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15810, https://doi.org/10.5194/egusphere-egu23-15810, 2023.

15:25–15:35
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EGU23-4333
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Virtual presentation
Chao Xiong and Yuyang Huang

The equatorial ionization anomaly (EIA) is one of the most important phenomena at equatorial and low latitudes, which is caused by the daytime eastward electric field via E×B effect. The well-developed EIA at dayside is thought to be a quite large structure with two crests extending to ±15° magnetic latitude, and the plasma density distributes quite smooth along the magnetic fluxtube. However, an additional density peak at poleward of the EIA crests is sometimes observed from the high-resolution plasma density measurements of Swarm. The additional peak is observed at the poleward of EIA crest only in the summer hemisphere, and shows a local time preference between 09:00 and 24:00. From a global view, the additional peak has relatively large occurrence at the norther hemisphere in the pacific longitudes. From the perspective of constellation, the Swarm B can revisit the same longitude of Swarm A/C, though with a certain time day. The delay time gradually increases from a few minutes to a few hours. By comparing the location of the additional peak observed by Swarm B and Swarm A/C, we found the peak keeps at a rather constant latitude irrespective of the delay time between Swarm satellites. Possible drivers for causing such additional peak have been further discussed.

How to cite: Xiong, C. and Huang, Y.: An additional plasma density peak at poleward of the equatorial ionization anomaly crests observed by Swarm, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4333, https://doi.org/10.5194/egusphere-egu23-4333, 2023.

15:35–15:45
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EGU23-6799
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Highlight
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On-site presentation
Klaus Nielsen, Nikolai Linden-Vørnle, Clemens Kloss, and Chris Finlay

In October 2022 an audio installation using Data Sonification methods premiered in Copenhagen. The project was a sonic representation of Earth’s magnetic field played on a 32-channel speaker system dug into the ground of a public square. The project was a massive success – particularly online with close to a million plays on ESA’s SoundCloud and thus proved a great opportunity to showcase the important work in Earth Observation done within the Swarm community.

The audio installation is an artistic representation controlled by magnetic field data through a sonification method called parameter mapping. The output of the 32 speakers was controlled individually by fluctuations in the magnetic field strength at 32 locations on the globe. Data was taken from the GGF100k – a global field model going back 100.000 years – and condensed into a 5-minute sequence composed of 32 different tracks running simultaneously. Six different parameters were mapped to various qualities of the audio playback (volume, pitch, filter, sample playback speed); these included the three components of the magnetic field at the core mantle boundary, the rate of change, and the field average at surface level.

The soundtrack was meant to give the listener an impression of a living planet in constant flux and is build up from recordings of natural sounds in various combinations. This presentation will describe the approach and give a demonstration of the results. In addition, it will briefly discuss data sonification as a method for inclusion and science outreach.

How to cite: Nielsen, K., Linden-Vørnle, N., Kloss, C., and Finlay, C.: Eerie sounds of Earth’s magnetic field, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6799, https://doi.org/10.5194/egusphere-egu23-6799, 2023.

Posters on site: Wed, 26 Apr, 14:00–15:45 | Hall X2

Chairpersons: Georgios Balasis, Anja Stromme
X2.252
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EGU23-12093
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Highlight
Anja Stromme

The three satellite Swarm constellationon is on a mission to unravel our planets invisible shield - the Earths magnetic field, and Swarm is after almost 10 years in orbit still in excellent shape and is still contributing to a wide range of scientific studies  from the core of our planet via the mantle, the lithosphere and out to the ionosphere and the interaction with the Solar wind.

 

In this talk we will present an update on the status of the Swarm mission, including the health and quality of the spacecrafts , instruments and data products, examples from scientific studies  and outline our plans for the future.

How to cite: Stromme, A.: Swarm - status after almost 10 years in orbit and the way forward, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12093, https://doi.org/10.5194/egusphere-egu23-12093, 2023.

X2.253
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EGU23-6672
Enkelejda Qamili, Roberta Forte, Nicola Comparetti, Lars Tøffner-Clausen, Stephan Buchert, Johnathan Burchill, Christian Siemes, Anna Mizerska, Jonas Bregnhøj Nielsen, Thomas Nilsson, Maria Eugenia Mazzocato, María José Brazal Aragón, Lorenzo Trenchi, Jerome Bouffard, Anja Stromme, Pierre Vogel, and Berta Hoyos Ortega

Launched by the European Space Agency (ESA) in November 2013, the three-satellite Swarm constellation continues to provide very high-quality measurements of the Earth's magnetic field and associated plasma environment. After around 10 years in space the Swarm mission has achieved remarkable scientific results, opening the door for many innovating applications largely beyond its original scope. With this paper, the authors would like to provide a broad overview of the Swarm mission status and Swarm instruments performance. Moreover, the many improvements obtained from the new Swarm data processing baseline together with other innovative Swarm-based data products and services will be presented.

How to cite: Qamili, E., Forte, R., Comparetti, N., Tøffner-Clausen, L., Buchert, S., Burchill, J., Siemes, C., Mizerska, A., Bregnhøj Nielsen, J., Nilsson, T., Mazzocato, M. E., Brazal Aragón, M. J., Trenchi, L., Bouffard, J., Stromme, A., Vogel, P., and Hoyos Ortega, B.: Instruments performance and data quality after 10 years of Swarm in orbit, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6672, https://doi.org/10.5194/egusphere-egu23-6672, 2023.

X2.254
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EGU23-16622
Roberta Forte, Stephan Buchert, Thomas Nilsson, and Enkelejda Qamili

The three-satellite SWARM constellation is a mission by the ESA Earth Observation directorate to provide very high-quality measurements of the
Earth's magnetic field. Also the plasma environment in the topside ionosphere is monitored with Langmuir Probes which together with thermal ion imagers, TIIs, comprise the EFI (electric field instrument). Over ten years the LPs have delivered with near 100 % coverage estimates of ion and electron densities, and electron temperature in the global ionosphere. We present summaries of selected results and scientific achievements, point out some caveats of the data and give an outline of planned enhancements of the LP data products.

How to cite: Forte, R., Buchert, S., Nilsson, T., and Qamili, E.: The Swarm Langmuir Probes, Ten Years in Space, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16622, https://doi.org/10.5194/egusphere-egu23-16622, 2023.

X2.255
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EGU23-5709
Gauthier Hulot, Pierdavide Coïsson, Louis Chauvet, Jean-Michel Léger, and Thomas Jager

ESA Swarm satellites carry a magnetometry payload consisting of an absolute scalar magnetometer (ASM), a relative flux gate vector magnetometer (VFM), and a set of star trackers (STR). The primary role of the ASM is to provide precise 1 Hz absolute field intensity measurements, while the VFM and STR provide the additional data needed to accurately reconstruct the vector field. This magnetometry payload has provided a remarkable set of nominal vector data, which has extensively been used for multiple investigations, as illustrated by the many results presented in this session. Each ASM instrument, however, can also produce its own self-calibrated 1 Hz experimental vector data, or, when requested, 250 Hz scalar burst mode. Self-calibrated 1 Hz experimental vector data have routinely been produced ever since launch, and substantial amount of scalar burst mode sessions have now also been run, mostly since 2019, when the decision was made to run such sessions one week per month on both the Alpha and Bravo satellites. In this presentation, we will illustrate the added value both these datasets brought to the Swarm mission, with the self-calibrated 1 Hz experimental vector data contributing to improvement and validation of the nominal dataset, and the burst mode data bringing new science opportunities. We will also discuss the lessons learnt from operating the ASM instruments on Swarm and how these led to the development of an appropriate miniaturized magnetometry payload for the NanoMagSat nanosatellite constellation. This constellation project is currently under development in the context of the ESA Scout program, and aims at a launch in the near future for complementing and enhancing the science return of the Swarm mission.

How to cite: Hulot, G., Coïsson, P., Chauvet, L., Léger, J.-M., and Jager, T.: Ten years of operation of Swarm's absolute magnetometers, lessons learnt and prospect for the NanoMagSat nanosatellite constellation project, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5709, https://doi.org/10.5194/egusphere-egu23-5709, 2023.

X2.256
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EGU23-17261
Lars Tøffner-Clausen

The ESA Swarm DISC (Data, Innovation, and Science Cluster), a consortium of several research institutions, has been established with a goal of deriving science products by combination of data from the three ESA Swarm spacecraft as well as other spacecraft. Here we present the results of the Comprehensive Inversion (CI) magnetic field modelling by the Swarm DISC team at DTU Space and NASA Goddard. The CI chain takes full advantage of the Swarm constellation by doing a comprehensive co-estimation of the magnetic fields from Earth's core, lithosphere, ionosphere, and magnetosphere together with induced fields from Earth's mantle and oceans using single and dual satellite gradient information from Swarm supplemented by scalar data from the Chinese CSES (China Seismo-Electromagnetic Satellite), the platform magnetometers onboard CryoSat-2, as well as data from ground based magnetic observatories.

How to cite: Tøffner-Clausen, L.: Earth's Magnetic Field Models from Comprehensive Inversion of 9 Years of Swarm, CSES, and CryoSat Data, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17261, https://doi.org/10.5194/egusphere-egu23-17261, 2023.

X2.257
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EGU23-4397
Nils Olsen

The sensitivity of magnetic measurements taken by satellites in elliptical orbits to the lithospheric magnetic field is studied by comparing the formal error variances of the lithospheric Gauss coefficients for various satellite orbital constellations.

We compare the results obtained using a satellite in a near-polar circular orbit at 350 km altitude with those from a satellite in an elliptical orbit with perigee at 140 km (and apogee at 1500 km) and find that the latter leads to Gauss coefficient variances at spherical harmonic degree n = 180 (corresponding to a horizontal wavelength of λ= 220 km) that are 104 times smaller compared to those derived from a similar number of data measured at 350 km altitude. These findings are supported by an analysis of synthetic magnetic data along simulated satellite orbits from which the lithospheric Gauss coefficients are estimated and compared with the original ones used to generate the synthetic data.

The analysis demonstrates that low-altitude magnetic data collected by satellites in low-perigee elliptical orbits - although only available for a fraction of each orbit - enable improved global lithospheric field modelling at spatial wavelengths well beyond what is currently possible with data from satellites in circular orbits that do not reach such low altitudes. We applied the approach to the orbital configuration proposed for the Daedalus satellite mission (140 km perigee); the method will however also help in the preparation for other satellite missions in near-polar low-perigee elliptical orbits like the Macau Science Satellite pair MSS-2A and MSS-2B (perigee of 200 km or lower).

How to cite: Olsen, N.: Modelling Earth's lithospheric magnetic field using satellites in low-perigee elliptical orbits, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4397, https://doi.org/10.5194/egusphere-egu23-4397, 2023.

X2.258
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EGU23-8490
Erwan Thebault and Gauthier Hulot

Detailed mapping of the Earth's magnetic field brings key constraints on the composition, dynamics, and history of the crust. Satellite and near-surface measurements detect different length scales and are complementary. However, direct global inversion of a design matrix built with magnetic field measurements locations of near surface and satellite data is numerically intractable at high spatial resolutions.

We apply a procedure developed during the Swarm mission satellite preparation phase to bypass this severe computing issue. We first select the magnetic field measurements during magnetically quiet days of the German CHAMP satellite up to year 2010 and of the ESA Swarm satellites from January 2014 to 31st August 2022. We then build a a complete dataset by combining the selected satellite measurements with the second version of the World Magnetic Anomaly Map; the most globally complete grid of airborne and marine data.

We follow a regional approach for the modelling of the full vector, scalar and gradient dataset. We compute a series of spherical cap harmonic models within 700 overlapping spherical caps tiling the Earth’s sphere. This regional strategy allows us to perform linear inverse problems in parallel using robust procedures, to deal with the Backus effect in equatorial regions, and to assess independently each regional model. The complete procedure is described in Thébault, Erwan, et al. "A Spherical Harmonic Model of Earth's Lithospheric Magnetic Field up to Degree 1050." Geophysical Research Letters 48.21 (2021): e2021GL095147).  We finally transform the series of regional models into a unique set of spherical harmonic (SH) Gauss coefficients. This produces the first global model to SH degree 1300. The new model agrees with previous satellite-based models at large wavelengths and fits the CHAMP and Swarm satellite data down to expected noise levels. Further assessment in the geographical and spectral domains show that the model is stable when downward continued to the Earth's surface.

How to cite: Thebault, E. and Hulot, G.: A lithospheric magnetic field model to spherical harmonic degree 1300, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8490, https://doi.org/10.5194/egusphere-egu23-8490, 2023.

X2.259
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EGU23-4523
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ECS
Martin Fillion, Gauthier Hulot, Patrick Alken, and Arnaud Chulliat

We present a new empirical model of quiet-time F-region ionospheric currents and associated magnetic fields. This model is designed to accurately represent these currents and fields at low and mid latitudes. It is built by taking advantage of the unprecedented space-time data coverage provided by the Swarm satellite constellation. For each individual Swarm satellite, the preprocessed data is represented as a non-potential toroidal magnetic field using the Mie representation in a thin-shell and spherical harmonic expansions. This approach allows to fully separate spatial and climatological variations as well as to assess the robustness of the model with respect to both measurement errors and data sampling with local time. The obtained model describes the toroidal magnetic fields and the associated radial poloidal electric currents at two distinct altitudes in the ionosphere F region. Clear signatures of low- and mid-latitude interhemispheric field-aligned currents (IHFACs) are identified. The model reproduces well-known characteristics of the climatology of IHFACs and provides new insights, for example on the average daily variations of IHFACs during winter in the northern hemisphere. It also well recovers the variations of IHFACs with longitude. The potential driving mechanisms of these variations, such as longitudinal variations of the main field and modulation by upward propagating atmospheric tides, are discussed. The new model can be used to analyze the relationship between atmospheric tides and IHFACs. It can also be used to investigate the connection between the magnetic fields and electric currents from the ionospheric E and F regions in order to improve the separation of these fields as well as our understanding of the overall ionospheric electric current system.

How to cite: Fillion, M., Hulot, G., Alken, P., and Chulliat, A.: Modelling the climatology of low- and mid-latitude F-region ionospheric currents using the Swarm constellation, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4523, https://doi.org/10.5194/egusphere-egu23-4523, 2023.

X2.260
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EGU23-15406
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Roberta Tozzi, Tommaso Alberti, Igino Coco, Paola De Michelis, Fabio Giannattasio, Michael Pezzopane, and Alessio Pignalberi

Besides the high resolution of measurements, one feature that distinguishes ESA Swarm mission from previous ones, also aimed at monitoring the Earth's magnetic field at Low Earth Orbit altitudes, is its configuration. We here take advantage of the nine years of geomagnetic field observations from Swarm satellites, to estimate the ionospheric F region current density. Specifically, we estimate the current density between Swarm A and B satellite altitudes, of about 510 and 460 km respectively, by calculating the curl of their Earth's magnetic field components.

This technique was first used in 2015 on a dataset of only seven months of vector magnetic data; because it was not possible to cover the entire local time range at the time, the corresponding mapping of ionospheric current density  was limited to two local nighttime intervals: before and after midnight. Seven years after the first application of this technique, we now use it on a more reliable and larger dataset and map the amplitude of the radial, meridional, and zonal components, as well as the total intensity of the ionospheric current density at all local times.

How to cite: Tozzi, R., Alberti, T., Coco, I., De Michelis, P., Giannattasio, F., Pezzopane, M., and Pignalberi, A.: Using nine years of Swarm magnetic field observations to estimate ionospheric electric current density through the curl-B technique, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15406, https://doi.org/10.5194/egusphere-egu23-15406, 2023.

X2.261
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EGU23-15262
Lorenzo Trenchi and Nicola Plutino

Field-aligned currents (FACs) flowing from Earth’s outer magnetosphere to the high latitude ionosphere along the geomagnetic field lines, are driven by solar wind and interplanetary magnetic field and allow a direct coupling of Earth’s ionosphere with outer plasma regions. This coupling is strongly enhanced during geomagnetic storms, when the energy transfer from solar wind to inner magnetosphere increases significantly and the ionospheric convection / currents are enhanced as well.

In addition to geomagnetic indexes computed from magnetic perturbations measured from ground-based observatories, also the behaviour of FACs can provide relevant information on energy transfer and coupling mechanisms during geomagnetic storms.

In this work we use data from Swarm satellites, which include very accurate measures of field-aligned currents, to characterize the geomagnetic storm that occurred between the 3rd and the 4th of November 2021.

In particular, we investigated the behaviour of FACs at different spatial scales as a function of solar wind conditions, and in comparison with the main geomagnetic indexes (e.g. the Dst and SYM-H indices). We discuss our findings in the context of main results reported in previous literature.

How to cite: Trenchi, L. and Plutino, N.: Behaviour of Field Aligned Currents during a geomagnetic storm: Swarm observations, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15262, https://doi.org/10.5194/egusphere-egu23-15262, 2023.

X2.262
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EGU23-3991
Georgios Balasis, Constantinos Papadimitriou, Adamantia Zoe Boutsi, Georgios Vasalos, Alexandra Antonopoulou, Omiros Giannakis, and Ashley Smith

The ongoing Swarm mission of the European Space Agency (ESA) provides an opportunity for a better knowledge of the near-Earth electromagnetic environment, including investigations of ultra-low frequency (ULF) wave events. The Time-Frequency Analysis (TFA) tool is a processing tool established for deriving Pc1 (0.2–5 Hz) and Pc3 (20–100 mHz) wave indices. The tool includes both a graphical interface as well as a dedicated back-end that can be used to perform wavelet analysis and visualize the results for both Pc1 and Pc3 waves, using both Swarm magnetic Level 1b 50 Hz and 1 Hz data. Following recommendations from the Advisory Board of the Swarm Data, Innovation and Science Cluster (Swarm DISC) the tool has been further developed and generalized so as to accommodate analysis of other types of time series from both satellite and ground station measurements. In particular, the resulting TFA toolbox provides users with the capabilities of studying different wave types (e.g. compressional waves, Alfvén waves, etc.), various magnetic field components (e.g. in Mean Field Aligned – MFA coordinates), and other geophysical measurements (e.g. electric field, plasma parameters). The TFA toolbox is also able to detect external source signals, e.g. due to plasma instabilities, and artificial disturbances (anomalies), e.g. spikes, jumps. It is possible also to use data from ground stations in a consistent format, e.g. 1 Hz magnetic observatory data as available in the virtual research service - VirES for Swarm. Moreover, integration of the TFA toolbox into the VirES platform is currently under development. This presentation aims to demonstrate the unique capabilities of the Swarm DISC TFA toolbox.

How to cite: Balasis, G., Papadimitriou, C., Boutsi, A. Z., Vasalos, G., Antonopoulou, A., Giannakis, O., and Smith, A.: The Time-Frequency Analysis (TFA) toolbox: a versatile processing tool for the recognition of magnetospheric and ionospheric signals in Swarm time series, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3991, https://doi.org/10.5194/egusphere-egu23-3991, 2023.

X2.263
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EGU23-12138
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ECS
Alexandra Antonopoulou, Georgios Balasis, Constantinos Papadimitriou, Adamantia Zoe Boutsi, Ioannis A. Daglis, and Omiros Giannakis

Ultra-low frequency (ULF) magnetospheric plasma waves play a key role in the dynamics of the Earth’s magnetosphere and, therefore, their importance in Space Weather phenomena is indisputable. Magnetic field measurements from recent multi-satellite missions (e.g., Cluster, THEMIS, Van Allen Probes and Swarm) are currently advancing our knowledge on the physics of ULF waves. In particular, Swarm satellites, one of the most successful missions for the study of the near-Earth electromagnetic environment, have contributed to the expansion of data availability in the topside ionosphere, stimulating much recent progress in this area. Coupled with the new successful developments in artificial intelligence (AI), we are now able to use more robust approaches devoted to automated ULF wave event identification and classification. The goal of this effort is to use a popular machine learning method, widely used in Earth Observation domain for classification of satellite images, to solve a Space Physics classification problem, namely to identify ULF wave events using magnetic field data from Swarm. We construct a Convolutional Neural Network (ConvNet) that takes as input the wavelet spectrum of the Earth’s magnetic field variations per track, as measured by Swarm, and whose building blocks consist of two alternating convolution and pooling layers, and one fully connected layer, aiming to classify ULF wave events within four different possible signal categories: (1) Pc3 wave events (i.e., frequency range 20–100 MHz), (2) background noise, (3) false positives, and (4) plasma instabilities. Our preliminary experiments show promising results, yielding successful identification of more than 97% accuracy. The same methodology can be easily applied to magnetometer data from other satellite missions and ground-based arrays.

How to cite: Antonopoulou, A., Balasis, G., Papadimitriou, C., Boutsi, A. Z., Daglis, I. A., and Giannakis, O.: Convolutional Neural Networks for Automated ULF Wave Classification in Swarm Time Series, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12138, https://doi.org/10.5194/egusphere-egu23-12138, 2023.

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EGU23-17550
Comparative Study on Generating and Predicting Swarm Satellite Data by Deep Neural Networks
(withdrawn)
Yaxin Bi
X2.265
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EGU23-8989
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ECS
Kuldeep Pandey, Robert G. Gillies, E. Ceren Kalafatoglu Eyiguler, Glenn C. Hussey, Donald W. Danskin, and Andrew W. Yau

The Radio Receiver Instrument (RRI) on-board the Swarm-E satellite is used to determine the full polarisation state of transionospheric radio waves. Co-ordinated experiments between ground transmitters and RRI have shown that the detected radio waves can have ellipticity that varies from linearly to circularly polarised when observed poleward of the transmitter at low elevations. Circular polarisation states are expected for waves propagating traverse to the local geometric field; however, these circular states were observed over a much wider range of aspect angles than expected. The present study compares the results of radio transmissions from the Saskatoon SuperDARN radar with a transionospheric radio wave model to estimate the relative strengths of received O- and X-mode waves along the satellite track. At selected low elevations, the X-mode of the radio wave dominates over the O-mode, resulting in a circular ellipticity, although the propagation is not transverse to the magnetic field. This work presents new ways to utilize ellipticity polarisation observations of radio waves to better understand the structure of the ionosphere, complementing Faraday rotation observations which have been extensively used.

How to cite: Pandey, K., Gillies, R. G., Kalafatoglu Eyiguler, E. C., Hussey, G. C., Danskin, D. W., and Yau, A. W.: The polarisation state of transionospheric radio waves detected by RRI on Swarm-E, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8989, https://doi.org/10.5194/egusphere-egu23-8989, 2023.

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EGU23-15082
Martin Pačes, Daniel Santillan, and Ashley Smith

The VirES service can be described as an ecosystem: the VirES server provides robust API-based access to both data and models derived from Swarm measurements; the VirES web interface provides visual point-and-click access [1]; the viresclient Python package provides the basis for a programmatic workflow and connection to the scientific Python landscape [2]; the Virtual Research Environment (VRE) provides a ready-to-code Jupyter environment to empower researchers to quickly start writing and running code using the latest Python packages [3].

In tandem with the evolution of the Swarm product portfolio, VirES evolves to provide access to and visualisation of new data products as they are published. Beyond this, Swarm activities are shifting away from static data products and toward on-demand processing and tools. We support development and dissemination of such tools in a scientist-led way through the VRE. These take the form of both computational notebooks and of Python packages.

With a growing number of data sources, both Earth-bound and orbital, it is critical to enable easier multi-dataset scientific workflows. At the same time, there is a multiplicity of research software projects, complex to navigate and make use of. We are tackling these issues through adoption of the Heliophysics API specification (HAPI [4, 5]), and coordination with the Python in Heliophysics Community.

[1] https://vires.services
[2] https://viresclient.readthedocs.io
[3] https://notebooks.vires.services
[4] https://hapi-server.org
[5] https://vires.services/hapi

How to cite: Pačes, M., Santillan, D., and Smith, A.: VirES for Swarm & Virtual Research Environment: Disseminating Swarm data, models, and tools, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15082, https://doi.org/10.5194/egusphere-egu23-15082, 2023.