Skip to Content
ESA SSA SWE Service Page Mockup: TIO/for

Transionospheric Radio Link - Monitoring and Forecast of Ionospheric Disturbances

Equivalent Slabthickness at Pruhonice
Equivalent Slabthickness at Pruhonice (Czech Republic),
provided byIonosphere Monitoring and Prediction Center (IMPC), DLR.

The service "Transionospheric Radio Link - Monitoring and Forecast of Ionospheric Disturbances" aims to provide an estimate of the occurrence risk of ionospheric disturbances, including monitoring and detection of ionospheric phenomena causing local disturbances of electron density and detection of geomagnetic storms. This service is currently under development. The aim is to consider the following ionospheric phenomena:

  • trough,
  • Travelling Ionospheric Disturbances (TIDs),
  • patches,
  • depletions and
  • D-region absorption.

Currently, this service provides vertical TEC maps, URSI ionospheric parameters and ionospheric perturbation products like the equivalent slab thickness and Rate Of Change of TEC Index (ROTI).

This service is implemented through a combination of products, tools and alerts which can be found through the following tabs along with expert support provided by the teams constituting the SWE Network. Should you require further guidance in the use of this service, or have specific questions about any aspects of the service presented here, don’t hesitate to contact the Helpdesk.

The service is implemented through the following set of assets:

  • Ionosphere Monitoring and Prediction Center (IMPC) provided by the German Aerospace Center (DLR);
  • Real-Time Ionosphere Monitor (RTIM) provided by the Norwegian Mapping Authority (NMA);
  • European Ionosonde Service (EIS) provided by National Observatory of Athens (NOA);
  • Service Supporting Resource Exploitation System Operators (RESOSS) provided by he Tromsø Geophysical Observatory (UiT) and the Norwegian Mapping Authority (NMA);
  • GNSS Performance Indicator (GPI) provided by the Norwegian Mapping Authority (NMA);
  • Ionospheric determination and navigation based on Satellite And Terrestrial systems (IonSAT) provided by Universitat Politècnica de Catalunya (UPC);
  • Ionospheric Scintillation Monitoring (ISM) developed by Collecte Localisation Satellites (CLS) and IEEA;
  • Swarm Utilisation Analysis Ionosphere(SUA I) provided by the German Research Centre for Geosciences (GFZ).
  • Swarm Utilisation Analysis Geomagnetic conditions (SUA G) provided by the German Research Centre for Geosciences (GFZ).
  • ESA/ESOC Ionosphere Monitoring Facility, IONMON.

This service page is curated by the ESC Ionospheric Weather. For further information, please contact SSCC Help-desk


While quiet ionospheric conditions are considered in many applications, disturbed conditions limit the functionality and availability of most systems. Prominent ionospheric perturbations are e.g.

  • The ionospheric trough: an electron density depletion near the auroral region.
  • Ionospheric patches: very localised regions with strong electron density deviations. Patches occur predominantly in the polar regions.
  • Travelling Ionospheric Disturbances (TID): TIDs are signatures of atmospheric gravity waves. The atmospheric waves cause perturbations in the winds and density of the thermosphere, which is impacting the electron density.
  • Depletions: Electron density depletions in mid-latitudes often occur during high geomagnetic activity. They are related to mid-latitude spread-F plumes (or plasma bubbles).
  • D-region absorption: the D-region describes the lower ionosphere at about 80 km altitude. Enhancement of the D-region electron density can cause absorption of high frequency (HF) radio waves used for long-range communication. These D-region electron density enhancements can be primarily attributed to solar flares (X-ray) and radiation storms.


Many radiofrequency applications use models and assumptions of a quiet ionosphere. Sudden or dramatic changes in the electron density impact the functionality of these applications. E.g. ionospheric perturbations can disrupt or modify the radio communication used in aviation, military, emergency applications and by amateur radio operators. The forecasts of ionospheric perturbations can warn many users to take care of a limited functionality of their systems. The monitoring of ionospheric perturbations can be used to provide improved ionospheric corrections for some application.

Key Products

Equivalent Slab Thickness

The equivalent slab thickness is a measure of the width of the shape of the vertical electron density profile of the ionosphere. The equivalent slab thickness is defined by the ratio of the total electron content (TEC) and the peak electron density of the local ionosphere. To compute the peak electron density, vertical sounding data from the Pruhonice ionosonde stations is used. The corresponding TEC data are extracted from the TEC maps.


ROT (Rate of change of TEC) is derived from the first derivative of TEC with respect to time. It is proposed as useful tool to monitor small-scale variability. The Rate of change of TEC index (ROTI) is defined as standard deviation of ROT. In the service provided here, ROTI is generated from ground based real-time data streams. The calculated values are associated to the ionospheric pierce points. ROTI is a good indicator for scintillations.

ROTI maps are provided by IMPC and RTIM. Within the RESOSS application, ROTI at the ground is provided. This product shows ROTI for a specified ground receiver location, which is easier to apply for users.

Additionally, the SUA activity provides ROT along the flight paths' of the three Swarm satellites.

Current ionospheric conditions

A common measure for the quiet time ionosphere are median values of the ionosphere during one solar rotation period (27 days). The deviation of the ionosphere from the quiet values (median) are considered as ionospheric perturbations.

The service provides a map of Europe presenting the current level of ionospheric activity (perturbations of foF2). It shows the deviation of the observed foF2 parameter in respect to the running 30 days median. The maps are published with a latency of 15 min.

Solar Flare detectors SISTED

Solar flares cause plasma density enhancements in the ionosphere. These immediate electron density perturbations are detected by the following product.

SISTED is monitoring simultaneous sudden enhancements in the ionospheric Total Electron Content (TEC) using the drift rate (second time derivative) of the ionospheric carrier phase product (LI) which can be derived from the GNSS signal. LI is linearly related to the Slant TEC (STEC) along the satellite-receiver ray path under consideration. The drift rate is used to generate a set of three Impact Parameters (IP). An IP tells (in %) how many satellite-receiver pairs are affected by abrupt over ionisation.


For further information, please contact SSCC Help-desk

The following products are associated with this service:

Ionospheric Disturbances Nowcast

Ionospheric Disturbances
  • Equivalent slab thickness, Juliusruh
  • Equivalent slab thickness, Pruhonice
  • GIVE maps (Northern Europe)
  • ROTI maps (Northern Europe)
  • ROTI@Ground maps (Fennoscandia)
  • Alerts for ionospheric disturbances in the European sector
  • Current ionospheric conditions at each ionosonde location
  • SOLERA drift
  • SISTED warning
  • SOLERA warning
  • ROTI maps for Europe
  • ROTI at ground time series (Selected locations in northern Europe)
  • Swarm Rate Of change of TEC (ROT)
     SUA I
  • Swarm Ionospheric Bubble Index (IBI)
     SUA I
  • GNSS Performance Indicator

Ionosphere Nowcast and Forecast

Vertical Total Electron Content Map
  • TEC map (Europe), current
  • Magnetogrammes from North(West) Europe and Greenland
  • TEC map (Europe), 1hr forecast
  • TEC map (Global), current
  • TEC map (Global), 1hr forecast
  • VTEC maps (Northern Europe)
  • Near-real-time TEC maps for the European region
  • IONMON TEC maps
  • TEC and Err(TEC) nowcast modelled maps
  • TEC and Err(TEC) nowcast modelled values at a given location
3D Electron Density Grids
    URSI Ionospheric Parameters
    • European maps of foF2 long term predictions
    • Nowcast European maps of foF2
    • Maps of forecasted foF2 over Europe for the next 24 hours
    • Forecasted foF2 values for the next 24 hours over each ionosonde
    Riometer Data
    • Borowiec Riometer raw [V] and relative [dB]
    Scintillation Indices and Parameters
    • Local scintillation indices S4 & σφ Kiruna
    • Local scintillation indices S4 & σφ Neustrelitz
    • Local scintillation indices S4 & σφ Svalbard
    • Local scintillation indices S4 & σφ Tenerife
    • Local scintillation indices S4 & σφ Toulouse
    • S4 maps (Northern Europe)
    • σφ maps (Northern Europe)
    • S4 and Err(S4) nowcast modelled maps
    • SigmaPhi and Err(SigmaPhi) nowcast modelled maps
    • S4 and Err(S4) 6-hour forecast modelled maps
    • SigmaPhi and Err(SigmaPhi) 6-hour forecast modelled maps
    • S4 and Err(S4) nowcast modelled values at a given location
    • SigmaPhi and Err(SigmaPhi) nowcast modelled values at a given location
    • S4 and Err(S4) 6h forecast modelled values at a given location
    • SigmaPhi and Err(SigmaPhi) 6h forecast modelled values at a given location

    Solar indices Nowcast and Forecast

    Solar Flares
    • UGraz/KSO Solar flare detections
    • SIDC Solar flare forecast
    • UKMO Solar flare forecast
    • FLARECAST Solar flare forecast
    • SIDC Daily space weather bulletin
    • A-EFFort Solar flare forecast
    Smoothed Sunspot Number (SSN, R12)
    • SIDC/SILSO Latest sunspot number forecast
    Solar Microwave Index (F10.7)
    • F10.7 Index Forecast 27-day/BGS
    • F10.7 Index Forecast multi-year
    • F10.7 Index Forecast 27-day/SWPC
    • F10.7 Index Forecast 45-day
    • F10.7 Index Forecast 30-day Absolute
    • F10.7 Index Forecast 30-day Adjusted
    • SIDC 10.7cm Solar radio flux (F10.7) forecast
    Solar X-ray Flux
    Solar EUV Integrated Flux
      Solar UV Flux

        Geomagnetic indices Nowcast and Forecast

        Local External Magnetic Field on Ground
        • Magnetogrammes from North(West) Europe and Greenland
        • Forecasts of dB/dt
        • Real-time and historic geomagnetic activity plots and data files for geomagnetic surveying (total field)
        • Real-time and historic geomagnetic activity plots and data files for directional drilling (total field, declination and inclination)
        • LDiñ
        • LCiñ
        Local Geomagnetic Induced Geoelectric Field
        • Maps for power and pipeline operators
        • Table of modelled GIC
        • Pipe-to-soil voltage (PSV)
        • Horizontal electric field data

        Tools associated with this service:

        The GNSS Performance Indicator initial tool is an on-demand tool concept that provides a measure of space weather impacts on a specified Use Case, based on data from various products in the space weather portal. The indicator is given as a number, a color, and a text description. A machine-to-machine interface is also available.

        The AMDA system provides an archive of planetary, solar wind, Earth magnetosphere and ionosphere mission and ground based products. In addition it supports a range of standard models such as magnetic footprints, magnetic fields, solar wind propagation to planets and probes as well as access to external databases of observations and simulations. A key functionality of the system is its embedded plotting, data mining and cataloguing functionalities which are extremely useful in relation to posteriori analysis.

        Alerts associated with this service:

        Ionospheric Disturbance Detection

        Alerts for ionospheric disturbances in the European sector


        SISTED warning


        SOLERA warning


        This section provides links to web pages or resources that are not part of the SSA Space Weather Network or domain. These sites are not under ESA control and therefore ESA is not responsible for any of the information or links that you may find there.

        Other European Ionosphere Services

        Reference documents

          Choose Skin