Xref: news.cs.tut.fi aus.radio:451 rec.radio.amateur.misc:52697 rec.radio.info:5191 Newsgroups: aus.radio,ips.solar.activity,rec.radio.amateur.misc,rec.radio.info Path: news.cs.tut.fi!news.cc.tut.fi!news.funet.fi!sunic!trane.uninett.no!nac.no!ifi.uio.no!wabbit.cc.uow.edu.au!news.ci.com.au!metro!ipso!rwc From: rwc@icarus.syd.ips.oz.au (Regional Warning Centre) Subject: IPS Monthly Report - May 94 Message-ID: <1994Jun2.024953.29533@ips.oz.au> Followup-To: aus.radio,rec.radio.amateur.misc Sender: news@ips.oz.au (Usenet News) Nntp-Posting-Host: icarus.syd.ips.oz.au Organization: IPS Radio and Space Services. Sydney, Australia. Date: Thu, 2 Jun 1994 02:49:53 GMT Approved: rec-radio-info@ve6mgs.ampr.ab.ca Lines: 209 SUBJ: IPS MONTHLY REPORT - MAY 1994 ISSUED BY IPS RADIO AND SPACE SERVICES FROM THE REGIONAL WARNING CENTRE (RWC), SYDNEY. 1. SOLAR-GEOPHYSICAL INDICES SOLAR MAGNETIC AUST Day 10 cm flux A-INDEX T INDEX May 01 075 25 27 May 02 076 41 -5 May 03 074 29 49 May 04 073 20 19 May 05 073 33 16 May 06 074 29 13 May 07 074 30 17 May 08 074 33 10 May 09 077 24 -10 May 10 080 24 11 May 11 082 25 22 May 12 087 12 15 May 13 089 08 22 May 14 090 19 36 May 15 091 28 44 May 16 091 26 33 May 17 095 14 41 May 18 094 20 48 May 19 091 15 48 May 20 090 07 44 May 21 088 05 46 May 22 085 08 39 May 23 081 10 41 May 24 078 25 51 May 25 074 24 49 May 26 071 11 38 May 27 070 05 25 May 28 070 21 15 May 29 069 33 10 May 30 069 35 23 May 31 069 28 17 10 CM FLUX SUNSPOT NUMBER A INDEX AUST FLARES INDEX Monthly Monthly Yearly Monthly Monthly >M1.0 Month Average Average Average Average Average May 94 79.8 18.2 21.5 27.5 0 April 94 79.0 16.7 21.0 34.7 0 March 94 90.5 31.7 17.5 36.9 0 February 94 99.5 35.9 22.5 38.0 2 January 94 115.0 58.8 12.4 60.2 11 December 93 104.9 49.4 10.4 56.4 8 November 93 95.8 34.8 41.0 11.7 50.0 3 October 93 100.2 55.4 44.7 11.6 31.3 3 September 93 86.3 21.7 48.2 12.3 33.6 2 August 93 93.7 42.0 52.1 11.0 48.7 1 July 93 99.0 57.3 54.4 10.6 59.6 4 June 93 109.4 49.1 55.8 13.0 62.6 13 May 93 112.4 61.2 59.6 11.0 64.3 5 IPS Predicted (Yearly Smoothed) Sunspot Numbers for December 1993-November 1994 Month Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov SSN 38.3 36.0 33.9 33.3 32.0 30.1 28.3 25.4 23.0 21.6 21.0 20.9 Latest T-Indices for IPS Advanced Stand-Alone Prediction System-(ASAPS) Last update: April 1994 Solar-Geophysical Summary Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 1988 45 43 58 74 72 84 84 95 115 132 116 128 1989 147 164 135 140 141 157 162 149 143 159 164 152 1990 150 128 135 129 126 138 136 138 141 136 122 133 1991 142 176 172 164 136 118 141 128 136 131 121 130 1992 152 172 156 134 95 79 89 66 68 67 85 89 1993 75 78 80 65 63 63 55 47 34 31 37 58 1994 39* 37* 36* 35* 34* 31* 28* 26* 24* 22* 21* 19* 1995 18* 18* 17* 16* 15* 14* 14* 13* 12* 11* 11* 10* 1996 10* 9* 9* 8* 8* 8* 8* 9* 9* 10* 11* 12* 1997 13* 15* 17* 19* 21* 23* 26* 30* 33* 38* 43* 48* Asterisk indicates predicted value. For information concerning ASAPS for an IBM PC (or compatible) contact IPS. The IPS Monthly T-index is derived from the observed monthly median values of foF2 for each hour at up to 40 ionospheric stations worldwide. These records become available from IPS stations in Australia very soon after each month, but the majority are received up to one year later. This means that the exact observed value of the monthly T-index is not available until some months later. The predicted smoothed monthly T-indices are computed by using a statistical analysis of the observed monthly T-indices for all solar cycles since 1938. The IPS T-indices may not be updated each month but only when sufficient new data becomes available. =============================================================================== 2. FLARES AND SHORT-WAVE FADEOUTS All M flares with an energy greater than or equal to M1 are tabulated under class M flares. However, times of fade-outs are shown only for flares with an energy greater than X-ray class M3. DATE CLASS M CLASS X FADEOUT POSSIBLE FLARES FLARES ON DAYLIGHT CIRCUIT NO FLARES. 2.1 Comments on Solar Activity. Solar activity continued at very low to low levels during May. Little variation was observed in the daily 10cm flux values throughout the month. A peak for the month of 95 occurred on 17 May, with a minimum value of 69 recorded on 31 May. The monthly sunspot number of 18.2 was the second lowest since the decline of the cycle - April 1994 was the lowest. The most interesting feature was the sequence of six days at the end of the month when the sun was without spots at all. This is the longest such sequence yet observed in this declining phase of the cycle. May is now the third month consecutive month with no M class flares observed (the most recent M-class solar flare was observed on February 27th). =============================================================================== 3. GEOMAGNETIC DISTURBANCES (for Learmonth, WA) DATE COMMENTS May 1-11 The major pattern of recurrent geomagnetic activity observed over the past 3-4 months continued during this interval. Active to minor storm levels were observed at times on May 1-3, 7-8 and 11, with unsettled to active levels recorded at other times over this period. May 15 Active to minor storm levels were observed, as part of another long standing pattern of recurrent activity. May 24-25 Active to minor storm periods observed in the northern hemisphere, during this interval. Unsettled levels were observed at Learmonth. May 28-31 Active to minor storm periods observed during this interval. This activity is again the return of the major pattern of recurrent geomagnetic activity which was last observed May 1-11. Active to minor storm periods are expected to continue until June 8. 3.1 Comments on Geomagnetic Activity. Lengthy periods of recurrent activity were observed during May. The most disturbed days of the month were May 2 and 30, with an A indices of 41 and 35 respectively. Recurrent activity began again on May 28 and is currently in progress, and is expected to decline after June 8. =============================================================================== 4. IONOSPHERIC DISTURBANCES (for Sydney) DATE MUFs May 2-3 Depressions of 30% were observed for most of May 2. Enhancements of around 30% then followed for most of May 3. May 4 Depressions of 30% were observed 10-14UT. May 5 Depressions of 15-30% were observed 11-17UT. May 6 Depressions of 15-30% were observed 04-07UT and 10-11UT. May 8-10 Depressions of 15-30% were observed from 08/15UT - 09/07UT. Depressions of 50% were observed 09/10-17UT, with depressions of 15-30% then observed until 10/03UT. May 11 Depressions of 40% were observed 16-20UT. May 28-31 Depressions of 15-20% were observed at times during this interval. Spread F was observed during local night. 4.1 Comments on Ionospheric Conditions. Depressions were observed during the first half of the month and towards the end of the month. Spread F was commonly observed during local night-time hours. The most significant depressions were those observed May 8-10. =============================================================================== 5. IPS WARNINGS AND ALERTS ISSUED WARNINGS: NO ISSUE TIME ISSUE DATE BEGIN END COMMENTS 12 2337 UT 25 04 1994 29 04 1994 11 05 1994 Magnetic and Ionospheric 13 2313 UT 09 05 1994 12 05 1994 16 05 1994 Magnetic and Ionospheric 14 2333 UT 21 05 1994 24 05 1994 25 05 1994 Magnetic and Ionospheric 15 0234 UT 26 05 1994 28 05 1994 07 06 1994 Magnetic and Ionospheric SIGNIFICANT EVENT SUMMARY NO TIME DATE COMMENTS NONE ISSUED. SWF WARNING NO TIME DATE NONE ISSUED. ALERTS: DATE OF ISSUE TYPE OF ALERT 03 May Magnetic 04 May Magnetic 07 May Magnetic 08 May Magnetic 09 May Magnetic 16 May Magnetic 17 May Magnetic 30 May Magnetic 31 May Magnetic DATE SWF BEGIN-END (UT) NONE ISSUED. -- IPS Regional Warning Centre, Sydney |IPS Radio and Space Services email: rwc@ips.oz.au fax: +61 2 4148331 |PO Box 5606 RWC Duty Forecaster tel: +61 2 4148329 |West Chatswood NSW 2057 Recorded Message tel: +61 2 4148330 |AUSTRALIA