Ionosphere activity forecast map

Farmers in regions like South America are being impacted by increased ionospheric scintillation — the rapid fluctuation of GNSS signals — from Solar Cycle 25, but how can you know if the cause of positioning interruptions is scintillation?

Space and government agencies monitor the number of electrons present in the ionosphere over a region throughout the day. The number of electrons, measured by the total electron content (TEC), along with high rates of change in the electron levels, measured by the rate of change of TEC index (ROTI), help us predict when scintillation can occur, meaning possible impact to GNSS positioning accuracy and availability.

TEC fluctuates daily as the sun excites regions of the ionosphere. TEC also has a seasonal variation and is influenced by space weather. This causes the values to differ by location, season or solar cycles, which is why we see variations in ionospheric scintillation impacts depending on location and time of year.

Updated once a day at midnight UTC, the below map displays TEC and ROTI values from the past seven days and forecasts TEC values for the next 72 hours, to help identify regions that may be more likely to see scintillation impacting operations. You can view specific days or set a lower limit threshold by moving the upper or lower dial on the bottom, respectively. Toggle between TEC and ROTI values and 2D and 3D views using the buttons at the top.

The TEC data was obtained through the online archives of the Crustal Dynamics Data Information System (CDDIS), NASA Goddard Space Flight Center, Greenbelt, MD, USA. https://cddis.nasa.gov/archive/gnss/products/ionex/

The ROTI data was obtained from the Ionosphere Monitoring and Prediction Center (IMPC) operated by the German Aerospace Center (DLR). We thank the DLR who maintain the IMPC services. IMPC Website: Rate of Change of TEC Index (dlr.de)