<pre><font face="Courier New" size="3">SUBJ: IPS MONTHLY SUMMARY - DECEMBER 2002<br />ISSUED BY IPS RADIO AND SPACE SERVICES<br />FROM THE AUSTRALIAN SPACE FORECAST CENTRE<br /><br />1. SOLAR-GEOPHYSICAL INDICES<br /><br /> SOLAR AUST AUST<br />Day 10 cm flux A-INDEX T INDEX<br />01-Dec 150 18 90<br />02-Dec 146 13 105<br />03-Dec 146 12 112<br />04-Dec 149 13 130<br />05-Dec 149 7 122<br />06-Dec 148 12 130<br />07-Dec 151 29 114<br />08-Dec 154 13 88<br />09-Dec 156 7 142<br />10-Dec 161 7 139<br />11-Dec 152 8 148<br />12-Dec 153 4 151<br />13-Dec 167 4 155<br />14-Dec 186 13 129<br />15-Dec 203 10 100<br />16-Dec 203 7 145<br />17-Dec 213 6 156<br />18-Dec 197 7 152<br />19-Dec 193 31 153<br />20-Dec 197 12 97<br />21-Dec 184 22 122<br />22-Dec 172 17 155<br />23-Dec 159 22 134<br />24-Dec 147 16 102<br />25-Dec 132 10 109<br />26-Dec 127 14 138<br />27-Dec 117 29 134<br />28-Dec 117 14 112<br />29-Dec 115 10 109<br />30-Dec 114 9 93<br />31-Dec 115 7 92<br /><br /> 10 CM SUNSPOT SUNSPOT AUST AUST No of<br /> FLUX NUMBER NUMBER A-INDEX T INDEX FLARES<br /> Monthly Monthly Yearly Monthly Monthly >M1.0 <br />Month Average Average Average Average Average <br />Dec 01 235.6 131.8 114.7 12.6 144.7 46<br />Jan 02 226.8 113.9 113.5 10.9 155.7 21<br />Feb 02 205.2 108.0 114.7 11.1 154.4 19<br />Mar 02 179.5 98.1 113.3 10.4 165.1 15<br />Apr 02 189.5 120.4 110.4 11.2 143.2 17<br />May 02 178.4 120.8 108.8 8.4 133.0 16<br />Jun 02 148.8 88.5 106.2 6.2 113.9 4<br />Jul 02 174.5 99.9 102.4p 8.8 108.6 35<br />Aug 02 184.0 116.4 99.2p 11.2 133.5 45<br />Sep 02 175.9 109.3 96.5p 9.8 137.7 12<br />Oct 02 167.0 97.5 93.0p 15.7 119.7 22<br />Nov 02 168.7 95.0 88.3p 14.5 121.1 11<br />Dec 02 157.2 81.6 84.8p 13.0 124.5 10<br /><br /> Monthly T indices<br /> Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec<br />1992 153 172 155 134 95 80 88 66 68 66 84 90 <br />1993 74 77 79 63 63 64 62 50 37 40 34 43 <br />1994 57 41 42 26 15 14 23 18 20 20 20 20 <br />1995 24 33 23 13 3 11 13 10 13 9 13 7 <br />1996 12 7 4 2 5 2 3 4 4 3 11 15 <br />1997 14 11 10 8 11 5 9 17 32 27 28 38 <br />1998 40 41 43 56 46 56 76 75 86 70 74 93 <br />1999 94 81 89 77 98 124 124 105 89 92 123 113 <br />2000 108 120 157 152 133 128 148 139 123* 129* 135* 141 <br />2001 129 129 135 123 111 131 111 112 143 151 154 160 <br />2002 167 172* 167* 137 129 111 105* 129* 132 113* 95^ 90^ <br />2003 86^ 81^ 74^ 68^ 64^ 61^ 58^ 55^ 52^ 50^ 47^ 45^ <br />2004 43^ 41^ 39^ 37^ 35^ 33^ 31^ 29^ 28^ 26^ 24^ 23^ <br />2005 21^ 20^ 19^ 17^ 16^ 15^ 14^ 13^ 12^ 11^ 10^ 9^ <br />2006 8^ 8^ 7^ 6^ 6^ 5^ 5^ 5^ 4^ 4^ 4^ 4^ <br />2007 4^ 5^ 5^ 6^ 7^ 8^ 9^ 11^ 13^ 16^ 18^ 21^ <br />2008 25^ 28^ 32^ 36^ 41^ 45^ 50^ 54^ 59^ 64^ 68^ 73^ <br />* = New data. T index may have changed.<br />^ = IPS predicted T index.<br /><br />The IPS Monthly T-index is derived from the observed monthly <br />median values of foF2 for each hour at up to 40 ionospheric <br />stations worldwide. These records become available from IPS <br />stations in Australia very soon after each month, but the <br />majority are received up to one year later. This means that <br />the exact observed value of the monthly T-index is not <br />available until some months later.<br /> <br />The predicted smoothed monthly T-indices are computed by <br />using a statistical analysis of the observed monthly T-indices <br />for all solar cycles since 1938. The IPS T-indices may not be <br />updated each month but only when sufficient new <br />data becomes available.<br /><br />===============================================================================<br /><br />2. FLARES AND SHORT-WAVE FADEOUTS <br />DATE CLASS M CLASS X FLARE FADEOUT POSSIBLE ON<br /> FLARES FLARES MAX DAYLIGHT HF CIRCUIT<br />04 Dec 02 M2.5/2N 2249UT<br />10 Dec 02 M1.1 1226UT<br />16 Dec 02 M2.5/1N 1115UT<br />16 Dec 02 M1.9/1N 2255UT<br />16 Dec 02 M1.3/SF 2336UT<br />17 Dec 02 M1.6/SF 2335UT<br />18 Dec 02 M2.4/1N 0642UT<br />19 Dec 02 M2.7/2N 2153UT<br />20 Dec 02 M6.8/SF 1318UT 1313-1320UT<br />22 Dec 02 M1.1/2F 0252UT<br /><br />2.1 Comments on Solar Activity.<br />Solar activity was at mostly low to moderate levels this month.<br />A total of 10 M class xray flare events were observed. No X class<br />flare activity was observed. High solar activity was observed <br />on 20 Dec due to an M6.8 flare at 1318UT on this day. This flare<br />was the largest xray event for the month.<br /><br />===============================================================================<br /><br />3. GEOMAGNETIC DISTURBANCES (for Australian Region)<br /><br />DATE COMMENTS<br />01 Dec 02: Mostly unsettled to active<br />07 Dec 02: Unsettled to Minor Storm<br />19 Dec 02: Unsettled to Minor Storm<br />21 Dec 02: Quiet to Major Storm<br />22 Dec 02: Quiet to Active<br />23 Dec 02: Unsettled to Active<br />24 Dec 02: Quiet to Active<br />27 Dec 02: Unsettled to Minor Storm<br />28 Dec 02: Unsettled<br /><br />Activity on 01,07,19-22,27-28 Dec are believed to be <br />associated with solar coronal holes. Activity during period<br />23-24 Dec is believed to be associated with weak coronal<br />mass ejection activity superimposed on a weak coronal<br />hole signature. The appearance of coronal holes on the <br />Sun has increased in recent months and is generally <br />considered a feature of the declining phase of a <br />solar cycle. <br /><br />===============================================================================<br /><br />4. IONOSPHERIC DISTURBANCES (for Australian Region)<br />08 Dec 02: Depressed 15% early in UT day.<br />15 Dec 02: Depressed 10-15% at some sites.<br />20 Dec 02: Depressed 10-15%<br />24 Dec 02: Depressed 15-30% early in UT day, southern Aus/NZ region.<br />30-31 Dec 02: Depressed 10-15% at some sites.<br /><br />Mild to moderate ionospheric MUF depressions, mostly <br />confined to southern Aus/NZ region, were observed on the <br />above days. The deepest depressions for the month<br />were observed early in the UT day, at southern <br />Aus sites, on 24 Dec.<br /><br />===============================================================================<br /><br />5. IPS WARNINGS AND ALERTS ISSUED<br /><br />WARNINGS:<br />HF RADIO WARNING:<br />ISSUE DATE NO BEGIN END<br />07 Dec 02 76 08 Dec 02 08 Dec 02<br />15 Dec 02 77 18 Dec 02 19 Dec 02<br />19 Dec 02 78 20 Dec 02 20 Dec 02<br />21 Dec 02 79 22 Dec 02 23 Dec 02<br />23 Dec 02 80 24 Dec 02 24 Dec 02<br />25 Dec 02 81 28 Dec 02 29 Dec 02<br /><br />GEOMAGNETIC WARNING:<br />ISSUE DATE NO BEGIN END<br />15 Dec 02 44 18 Dec 02 19 Dec 02<br />20 Dec 02 45 21 Dec 02 22 Dec 02<br />23 Dec 02 46 23 Dec 02 24 Dec 02<br />25 Dec 02 47 27 Dec 02 28 Dec 02<br /><br />ALERTS: <br />07 Dec 02: Geomagnetic<br />08 Dec 02: Geomagnetic<br />16 Dec 02: Flare Alert<br />17 Dec 02: Flare Alert<br />18 Dec 02: Flare Alert<br />19 Dec 02: Geomagnetic<br />19 Dec 02: Flare Alert<br />20 Dec 02: Geomagnetic<br />21 Dec 02: Geomagnetic<br />27 Dec 02: Geomagnetic<br /><br />SWF ALERTS AND DURATION REPORTS<br />DATE SWF BEGIN-END (UT)<br />None Issued.<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 </font></pre>