SUBJ: IPS WEEKLY SOLAR AND GEOPHYSICAL REPORT <br />ISSUED ON 25 OCTOBER 2002, BY IPS RADIO AND SPACE SERVICES,<br />FROM THE AUSTRALIAN SPACE FORECAST CENTRE<br /><br />1. SUMMARY (18 OCTOBER - 24 OCTOBER)<br />Date 18 19 20 21 22 23 24<br />10cm 173 180 180 183 169 164 160<br />AFr 9 9 8 7 10 6 ( 30)<br />Aaus 13 16 9 7 12 9 ( 28)<br />T 141 136 115 143 133 113 112<br /><br />Solar: Solar flare activity<br />Geomagnetic: Geomagnetic activity observed for Australian Region.<br />Frequencies: Australian Ionospheric F2 critical frequencies<br /><br />18 Oct <br />Solar: very low<br />Geomagnetic: Quiet to Active <br />Frequencies: <br /> Equatorial PNG Region:<br /> Enhanced by 20% during local day,<br /> Enhanced by 65% during local night.<br /> Northern Australian Region:<br /> Enhanced by 15-20%.<br /> Southern Australian and New Zealand Region:<br /> Near predicted monthly values during local day,<br /> Enhanced by 20% during local night.<br /> Antarctic Region (Casey/Scott Base):<br /> Enhanced by 15% over the UT day.<br /><br />19 Oct <br />Solar: low<br />Geomagnetic: Quiet to Unsettled <br />Frequencies: <br /> Equatorial PNG Region:<br /> Enhanced by 25-40%.<br /> Northern Australian Region:<br /> Enhanced by 15-25%.<br /> Southern Australian and New Zealand Region:<br /> Enhanced by 20%.<br /> Antarctic Region (Casey/Scott Base):<br /> Near predicted monthly values over the UT day.<br /><br />20 Oct <br />Solar: moderate, with an M1/1F at 0045UT, an M1/2N at <br /> 0339UT, an M1/1N at 0514UT, and an M1/1B at 1428UT<br />Geomagnetic: Quiet to Unsettled <br />Frequencies: <br /> Equatorial PNG Region:<br /> Enhanced by 15-35%.<br /> Northern Australian Region:<br /> Enhanced by 20-30%.<br /> Southern Australian and New Zealand Region:<br /> Depressed by 15% during local day,<br /> Near predicted monthly values during local night.<br /> Antarctic Region (Casey/Scott Base):<br /> Near predicted monthly values over the UT day.<br /><br />21 Oct <br />Solar: low<br />Geomagnetic: Quiet <br />Frequencies: <br /> Equatorial PNG Region:<br /> Enhanced by 20-50%.<br /> Northern Australian Region:<br /> Near predicted monthly values during local day,<br /> Enhanced by 35% during local night.<br /> Southern Australian and New Zealand Region:<br /> Enhanced by 15-30%.<br /> Antarctic Region (Casey/Scott Base):<br /> Near predicted monthly values over the UT day.<br /><br />22 Oct <br />Solar: moderate, with an M1/SF at 1535UT<br />Geomagnetic: Quiet to Active <br />Frequencies: <br /> Equatorial PNG Region:<br /> Enhanced by 20-50%.<br /> Northern Australian Region:<br /> Enhanced by 15%.<br /> Southern Australian and New Zealand Region:<br /> Enhanced by 15-20%.<br /> Antarctic Region (Casey/Scott Base):<br /> Enhanced by 15% over the UT day.<br /><br />23 Oct <br />Solar: very low<br />Geomagnetic: Quiet to Unsettled <br />Frequencies: <br /> Equatorial PNG Region:<br /> Near predicted monthly values during local day,<br /> Enhanced by 20% during local night.<br /> Northern Australian Region:<br /> Near predicted monthly values.<br /> Southern Australian and New Zealand Region:<br /> Near predicted monthly values.<br /> Antarctic Region (Casey/Scott Base):<br /> Enhanced by upto 20% with some periods of<br /> depressions and degradations.<br /><br />24 Oct <br />Solar: low<br />Geomagnetic: Unsettled to Minor Storm <br />Frequencies: <br /> Equatorial PNG Region:<br /> Near predicted monthly values during local day,<br /> Enhanced by 25% during local night.<br /> Enhanced by 20% after local dawn.<br /> Northern Australian Region:<br /> Near predicted monthly values.<br /> Southern Australian and New Zealand Region:<br /> Mostly near predicted monthly values,<br /> Depressed by 30% after local dawn.<br /> Antarctic Region (Casey/Scott Base):<br /> Near predicted monthly values over the UT day.<br /><br />COMMENT: An earlier than expected rise in the geomagnetic <br />activity to minor storm level was observed late on 24 Oct <br />(UT day). This seems to have been due to the coronal hole<br />effect and a sustained period of Bz staying southwards.<br />Depressions in MUFs have been observed in the high latitude<br />regions early 25 October (after local dawn) due to this <br />rise in the geomagnetic activity. MUFs did not show any <br />significant variation due to this activity at low latitudes. <br />This effect is expected to continue for the next 2 days and <br />is expected to decline gradually thereafter.<br /><br />2. FORECAST (25 OCTOBER - 31 OCTOBER)<br />Solar: Low to moderate<br /><br />Geomagnetic: Mostly Unsettled to Active with Active to<br /> Minor storm intervals possible.<br /><br />Frequencies: Depressions from 5 to 15% may be observed on <br />mid- to high latitude circuits- especially during the first <br />half of the period. MUFs are expected to remain mostly normal<br />for most of the period on low latitudes. SWFs probable early <br />in week.<br /><br />PEASE NOTE: <br />At this time of the solar cycle, space weather conditions<br />are frequently determined by short timescale events, not<br />able to be forecasted a week in advance.<br /><br />IPS Radio and Space Services | email: asfc@ips.gov.au<br />PO Box 1386 | WWW: http://www.ips.gov.au<br />Haymarket NSW 1240 AUSTRALIA | FTP: ftp://ftp.ips.gov.au <br />tel: +61 2 9213 8010 | fax: +61 2 9213 8060 <br />_______________________________________________