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DISC Activities

Swarm DISC (the Data, Innovation and Science Cluster) is a consortium of expert partners with a project office at DTU Space.


The aurora is a unique manifestation of plasma processes in the near-Earth space environment. Swarm-Aurora was designed to facilitate and drive the use of Swarm in situ measurements in auroral science. Swarm-Aurora will build a bridge between the Swarm and auroral science communities. Swarm-Aurora ( is a web-based tool which provides access to quick-look summary data for a large array of ground-based instruments, as well as Swarm in situ measurements. This web interface allows researchers to quickly and efficiently browse Swarm and ASI data sets to identify events of interest. Swarm-Aurora drastically lowers the barrier of entry to optical and swarm data, reducing the time needed to do a survey of Swarm and ground-based instruments for investigating auroral phenomena. We expect this project to form the basis of the next generation of data viewers and access protocols for auroral science. The platform is built to be scalable (to other instruments, both ground and in situ) and useable for decades to come.

More information about this project can be found at
Project duration: November 2015 - March 2017. This project is funded by ESA via the Swarm DISC, Sub-Contract No. SW-CO-DTU-GS-016.

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AuroraX-DISC activities is building directly on the Swarm-Aurora framework. The team will continue to evolve the metadata and summary data from the satellites and the ground-based (and ultimately space-based) imagers in response to suggestions by users. The motivation for these activities is to bring as much auroral data to the Swarm mission as is possible, to provide better and faster identification of interesting events, and to provide connections between the Swarm mission and citizen scientists who are interested in the aurora. This is meant to compliment for example SuperDARN and SuperMag which provide fairly quick access to summaries of data from the global HF radar and magnetometer networks operated by more than a dozen nations. There is at present no such system for the auroral observations, and AuroraX will become that system.

More information about this project can be found at and
Project duration: June 2018 - December 2020. This project is funded by ESA via the Swarm DISC, Sub-Contract No. SW-CN-DTU-GS-023.

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Multi-Approach Gravity Field models from Swarm GPS data (MAGF)

Although the knowledge of the gravity of the Earth has improved considerably with CHAMP, GRACE and GOCE satellite missions, the geophysical community has identified the need for the continued monitoring of its time-variable component with the purpose of estimating the hydrological and glaciological yearly cycles and long-term trends. Currently, the GRACE-FO satellites are the sole provider of this data, while previously the GRACE mission collected these data for 15 years. Between the GRACE and GRACE-FO data periods lies a gap spanning from July 2017 to May 2018, while the Swarm satellites have collected gravimetric data with its GPS receivers since December 2013.
This project aims at providing high-quality gravity field models from Swarm data that constitute an alternative and independent source of gravimetric data, which could help alleviate the consequences of the 10-month gap between GRACE and GRACE-FO, as well as the short gaps in the existing GRACE and GRACE-FO monthly time series.
The geodetic community has realized that the combination of the different gravity field solutions is superior to any individual model. This project exploits this fact and delivers to the highest quality monthly-independent gravity field models, resulting from the combination of 4 different gravity field estimation approaches. All solutions are unconstrained and estimated independently from month to month.
Preliminary comparison with GRACE data has demonstrated that the signal in the Swarm gravity field models is restricted to degrees 12-15 and below, while the temporal correlations decrease considerably above degree 10. The 750km smoothed models are suitable to retrieve the global annual temporal variations of Earth's gravity field and the agreement with GRACE over large basins (e.g. Amazon, Congo-Zambezi, Ganges-Brahmaputra) is within 1cm RMS in terms of Equivalent Water Height. The global RMS relative to a bias, trend, an annual and semi-annual model derived from GRACE over deep ocean areas (those roughly 1000km from shorelines) is under 1mm geoid height during periods of low geomagnetic activity.

Project documentation:

More information about this project can be found at
This project was funded in 2017 by ESA via Swarm DISC, Sub-Contract No. SW-CO-DTU-GS-111.

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Auroral Electrojet and auroral Boundaries estimated from Swarm observations (Swarm-AEBS)

The Swarm mission provides an excellent opportunity for studies related to the ionospheric currents, aurora, magnetosphere-ionosphere coupling, and space weather especially at high latitudes.
In the Swarm-AEBS project, a set of new Swarm data products that characterize the auroral electrojets and auroral oval boundaries will be derived from Swarm magnetic field measurements. These include the electrojet sheet current density as well as the total horizontal sheet and associated large-scale field-aligned current density along the Swarm orbit ionospheric footprints at auroral latitudes, estimated using the Spherical Elementary Current System (SECS) method. The electrojet sheet current density will also be estimated using the Line Current (LC) method as this method allows extending the analysis to cover the polar cap region as well. The electrojet boundaries and peaks will also be provided, the latter characterized in terms of peak current density and peak magnetic field disturbance at ground level. The set of products is completed by auroral oval boundaries, associated with auroral precipitation, that are estimated from the presence of small-scale (<150 km) field-aligned currents.

More information about this project can be found at
Project duration: January 2018 - January 2020. This project is funded by ESA via the Swarm DISC, Sub-Contract No. SW-CO-DTU-GS-112.

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The Average Magnetic field and Polar current System model (AMPS)

The outcome of this project is a new climatological model of polar ionospheric currents, based on magnetic field measurements from the CHAMP and Swarm satellites. The model is a representation of the global disturbance magnetic field associated with ionospheric currents, as a function of solar wind speed, the interplanetary magnetic field, the tilt angle of the Earth's magnetic dipole, and the F10.7 solar flux index. The ionospheric current system, and an estimate of the magnetic disturbances on ground, can be derived from the model coefficients. This is an advancement compared to earlier empirical models because the full horizontal current density can be derived directly from magnetic field measurements, without any assumption about conductivity or electric fields. The AMPS model is valid in both hemispheres, and no assumptions about hemispheric symmetries have been applied. For this reason, and since we have corrected for variations in Earth's magnetic field, the model can be used to do precise comparisons of the ionospheric current system in the two hemispheres.

The AMPS forward code, pyAMPS, is available at This code can be used to calculate model magnetic field and currents for a given set of input parameters. The documentation for the code can be found at

A web-interface for the model can be found at Here you can plot the model current system or magnetic field disturbances on polar maps in the two hemispheres. The model output can be changed using drop-down menus, and the input can be changed by adjusting sliders or by clicking a plot of the solar wind conditions from the previous 24 hours.

Useful model information:

Even more detailed documentation:

Project duration: September 2017 - August 2018. This project was funded by ESA via the Swarm DISC, Sub-Contract No. SW-CO-DTU-GS-113.

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Ionospheric Plasma IRregularities characterised by the Swarm satellites (IPIR)

Ionospheric plasma is often characterised by irregularities and fluctuations in its density. They are the result of various plasma instabilities, reflecting complex interactions in the near-Earth space environment. Plasma density irregularities and fluctuations can influence the propagation of trans-ionospheric radio waves and are thus of importance for ground based operations that rely on precise positioning with Global Navigation Satellite Systems (GNSS). Understanding ionospheric plasma irregularities and fluctuations is thus of both scientific and practical interest.
Through the IPIR project we will develop a high-level, global product based on Swarm measurements that will characterize ionospheric irregularities and fluctuations, and address the needs of scientific community and operational users. The product will provide characteristics of plasma density structures in the ionosphere and will assign them to predominant plasma processes and regions in the ionosphere. This result will open possibilities for extensive, global studies of plasma irregularities and fluctuations. IPIR will also provide indication, in the form of a numerical value index, on their severity of the plasma fluctuations for the integrity of trans-ionospheric radio signals and hence the accuracy of GNSS precise positioning.

More information about this project can be found at
Project duration: November 2017 - November 2018. This project is funded by ESA via the Swarm DISC, Sub-Contract No. SW-CO-DTU-GS-114.

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Geomagnetic Virtual Observatories (GVO)

In this project, Geomagnetic Virtual Observatories (GVO) data series are derived from Swarm data collected around target locations. The GVO data product consists of time series of vector magnetic field values at fixed locations, on a uniform grid at satellite altitude. Such data, regularly distributed in space and time are suitable for modelling the main geomagnetic field, for core flow inversion studies, and for data assimilation studies of the core dynamo process. GVOs are designed to make Swarm data more accessible to researchers studying the physics of the core dynamo process, and related phenomenon such are secular variation, geomagnetic jerks and rapid core dynamics. The GVOs data product also provide valuable information to those interested in investigating magnetospheric and ionospheric magnetic signals on timescales of months and longer. GVO time series including all field contributions, and those processed to isolate the core field, are available along with estimated errors.

More information about this project can be found at
Project duration: June 2019 – June 2020. This project is funded by ESA via the Swarm DISC, Sub-Contract No. SW-CO-DTU-GS-121.

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Plasmapause Related boundaries in the topside Ionosphere as derived from Swarm Measurements (PRISM)

The position of the plasmapause (PP) is a key parameter in space weather. The plasmapause is defined as the outer boundary of the Earth-corotating plasma (the plasmasphere) characterised by steep plasma density gradients. The variation of the PP location is a very sensitive indicator of geomagnetic activity. There are many space phenomena (e.g., cold plasma and energetic particle populations, etc.) separated spatially by the PP, as well as several space processes (e.g., high-latitude magnetosphere-ionosphere coupling processes, etc.) that are dynamically linked to the location of the plasmapause.
In this project, Plasmapause Related boundaries in the topside Ionosphere as determined from Swarm Measurements (PRISM), we develop products that characterize PP related phenomena in the topside ionosphere. These are the mid-latitude ionospheric trough (MIT) based on electron density and temperature measurements of the Langmuir probe onboard and also from GPS TEC estimates, as well as the equatorward boundary of small-scale field-aligned currents leading to an index that can be used as an estimate of the midnight position of the plasmapause. The MIT equatorward/poleward edge is closely related to the ionospheric footprint of the PP/the auroral oval, respectively. The midnight PP index based on small-scale FAC signatures observed at low Earth orbit (LEO) altitudes. Both Swarm products, the MIT location and the midnight PP index, will be provided separately for the three individual Swarm satellites.
PRISM is a collaborative project between Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences, Germany and the Mining and Geological Survey of Hungary (Magyar Bányászati és Földtani Szolgálat, MBFSZ), Hungary.

More information about this project can be found at
Project duration: November 2019 – November 2020. This project is funded by ESA via the Swarm DISC, Sub-Contract No. SW-CO-DTU-GS-122.

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Swarm Ion Temperature Estimation (SITE)

Ion temperature is one of the key parameters that provides insight into the thermal balance of the coupled ionosphere-thermosphere system. Together with the temperatures of neutral and electron gases, it controls various physical and chemical processes in the upper atmosphere. These include the ion-neutral collision frequencies, chemical reaction rates and plasma scale height, all of which affect the variation and distribution of the electron density. The Swarm satellites carry out continuous measurements of ionospheric electron temperatures and densities using the Langmuir probes (LP) which are part of the electric field instrument (EFI). Ion temperature measurements, however, are not currently available. The main objective of this project is to estimate ion temperatures along the orbits of Swarm satellites using available LP electron density and temperature measurements, and numerical models. To accomplish this task, it is planned to develop a physics-based, data-driven model of the ion temperature along the orbits of the Swarm satellites from equator to high latitudes, evaluate the validity of the model under different geophysical conditions, and validate estimated ion temperatures against independent measurements. This new data product, which will be available to the scientific community, is expected to enhance the ability of the Swarm mission to provide more complete information about the ionospheric plasma, and thus, will enhance the overall scientific return of the mission.

More information about this project can be found at
Project duration: January 2020 – April 2021. This project is funded by ESA via the Swarm DISC, Sub-Contract No. SW-CO-DTU-GS-123.

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Swarm LP Ion Drift and Effective Mass (SLIDEM)

The Swarm electric field instruments (EFI) comprise a pair of thermal ion imagers (TII) for measuring properties of the ionospheric thermal ions (drift and temperature), a pair of Langmuir probes (LP) for measuring electron temperature and ion (practically, electron) density, and a fixed-bias planar Langmuir probe (faceplate) for measuring ion density. Using data from these instruments, the Swarm LP Ion Drift and Effective Mass (SLIDEM) project will augment Swarm's ability to measure the along-track component of ion drift, and assess the composition of ionospheric ions. This project develops the framework for implementing a Level 2 along-track ion drift and effective ion mass data product for the Swarm PDGS data processing chain. Methods will be refined for deriving the data products, validating the product using independent datasets, models, and particle-in-cell simulations, and delivering a first release of the data based on historical Swarm EFI measurements. An operational Level 2 scheme will be demonstrated for routine processing of the latest EFI data and reprocessing of the entire mission dataset when needed. The new dataset has the potential to benefit scientific investigations of ionospheric ion drift, electric field, ion composition, and related studies (e.g., mass and energy conservation), as well as for validating the TII along-track drift estimates.

Project duration: June 2020 – July 2022. This project is funded by ESA via the Swarm DISC, Sub-Contract No. SW-CO-DTU-GS-124.

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Topside Ionosphere Radio Observations from multiple LEO-missions (TIRO)

LEO (Low Earth Orbit) satellites are indispensable when it comes to gaining/acquiring information on the electron content of the upper ionosphere. This region is otherwise not accessible neither on a continuous basis, nor on a global scale. Investigating electron density variations is crucial in particular because they cause ionospheric effects on radio communication and navigation signals, such as Global Navigation Satellite Systems (GNSS). TIRO will provide two measurements from onboard instruments of LEO satellite missions: TEC (Total Electron Content) derived from GNSS signals, and electron density derived from KBR (K-Band Ranging) system observations.

The main goal of TIRO is to extend the existing TEC data set of Swarm with topside TEC products derived from other LEO missions, e.g. CHAMP, GRACE, and GRACE-FO. Another goal of TIRO is to extend the existing Swarm data sets for in situ plasma density by adding similar products derived from inter-satellite K-Band radio links between the two GRACE and GRACE-FO satellites, respectively.

The benefit of combining observations from multiple satellites is to extend the spatial and local time coverage of ionospheric sounding. At the completion of TIRO, electron content and density data of the topside ionosphere will be available for nearly two solar cycles from 2000 up to present.

More information about this project can be found at
Project duration: August 2020 – February 2022. This project is funded by ESA via the Swarm DISC, Sub-Contract No. SW-CO-DTU-GS-126.

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