Ionospheric Summary and Forecast

Ionospheric Summary

(last updated 13 Dec 2025 23:30 UT)

Date T index 13 Dec 28 Observed Australian Regional MUFs Cocos Island Region: Depressed by 50% during local day. Depressed by 35% during local night. Depressed by 20% after local dawn. Niue Island Region: Near predicted monthly values during local day. Enhanced by 30% during local night. Enhanced by 20% after local dawn. Northern Australian Region: Depressed by 35% during local day. Near predicted monthly values during local night. Southern Australian Region: Depressed by 30% during local day. Near predicted monthly values during local night. Depressed by 25% after local dawn. Antarctic Region (Casey/Davis/Mawson): Depressed by 25% over the UT day. Monthly T index: Month T index Nov 103 Dec 89 Jan 89

Ionospheric Forecast

(last updated 13 Dec 2025 23:30 UT)

Date T index MUFs 14 Dec 70 Depressed 15 to 20%/near predicted monthly values 15 Dec 85 Near predicted monthly values 16 Dec 85 Near predicted monthly values COMMENT: Maximum usable frequencies (MUFs) in the Australian region on UT day 13-Dec were 35% depressed to near predicted monthly values, with depressed conditions observed during the local day. Sporadic E was observed during local night hours. MUFs in the southern Australian region are 20% depressed after local dawn this morning. MUFs are expected to be initially 15-20% depressed on 14-Dec then gradually recovering and near predicted monthly values. MUFs are expected to be near predicted monthly values on 15-16 Dec.