The map above was generated using G7RAU’s Live MUF application. The map uses Great Circle projection centred on the central North Atlantic Ocean. The page is automatically refreshed approximately once per minute.
Radio propagation is reported by amateur radio operators via the DX Cluster network filtered to show only the digital modes (eg computer to computer FT4, FT8, WSPR etc). The Live MUF application plots the path on the map with the colour indicating the frequency of transmission according to the colour key. Map paths are plotted via the shortest Great Circle route, even if a contact was made via the “long path”.
The normal pattern is for the higher frequencies (above 7 MHz) to be active during daylight, and lower frequencies to be active during the night. Weekends tend to be a lot more active, especially during contest weekends where thousands of amateur operators chase contacts across the globe. The last 100 contacts reported on the DX Cluster can be seen here.
Solar flares can often cause intense bursts of X-rays to be blasted towards Earth. When they strike the atmosphere the ionosphere becomes highly ionized, which can cause severe radio blackouts due to noise on the HF frequencies. Blackouts can also affect VHF, UHF and higher frequencies.
Contact paths remain visible on the map for 30 minutes before being erased.