These are Hourly Area Predictions (HAP) of communication frequencies based on current observed conditions in the Australasia ionosphere. Because of the variability of the ionosphere this type of prediction can only be made for the current hour.

HAP Charts for Australasia Select one.... Adelaide Aitape Alice Springs Auckland Brisbane Cairns Canberra Charleville Charleville2MHz Charleville4MHz Charleville6MHz Charleville8MHz Charleville10MHz Charleville12MHz Charleville14MHz Charleville16MHz Charleville18MHz Charleville20MHz Darwin Denpasar Dili East Sale Fiji Hobart Honiara Jakarta Learmonth Melbourne Niue Norfolk Island Perth Rabaul Shoalwater Bay Sydney Tikopia Tonga Townsville Wagga Wagga Wiluna Wiluna2MHz Wiluna4MHz Wiluna6MHz Wiluna8MHz Wiluna10MHz Wiluna12MHz Wiluna14MHz Wiluna16MHz Wiluna18MHz Wiluna20MHz

During daylight hours the absorption limiting frequency is increased by solar xray flares. The near real time hourly HAP charts will show an empirical model estimate of the flare increased ALF, during the local day, if there is a flare in progress at the time the chart was created. Click here to see an example HAP chart for Darwin with a prediction of flare enhanced absorption limiting frequencies overplotted. The ALF prediction was made for a solar xray flare of X1 magnitude, shown as dashed white line contours over the HAP chart.