[Ips-msgr] IPS Monthly Report - May 02

rwc rwc at ips.gov.au
Mon Jun 3 10:46:57 EST 2002


SUBJ: IPS MONTHLY SUMMARY - MAY 2002
ISSUED BY IPS RADIO AND SPACE SERVICES
FROM THE AUSTRALIAN SPACE FORECAST CENTRE

1.     SOLAR-GEOPHYSICAL INDICES

              SOLAR    AUST       AUST
Day      10 cm flux   A-INDEX   T INDEX
01-May         162        4      137
02-May         169        3      133
03-May         179        3      134
04-May         190        3      134
05-May         180        0      132
06-May         191        7      140
07-May         187        8      151
08-May         187        7      159
09-May         190        5      157
10-May         191       15      157
11-May         188       24      145
12-May         183       13      124
13-May         172        8      129
14-May         161       16      137
15-May         159       11      138
16-May         158        6      129
17-May         157        4      120
18-May         163       10      120
19-May         171        7      142
20-May         171        9      123
21-May         186        6      125
22-May         181        7      127
23-May         180       42      123
24-May         189        3      126
25-May         183        2      121
26-May         183        5      128
27-May         187       13      125
28-May         186        8      132
29-May         185        4      126
30-May         180        5      123
31-May         182        2      125

          10 CM    SUNSPOT  SUNSPOT  AUST     AUST     No of
          FLUX     NUMBER   NUMBER   A-INDEX  T INDEX  FLARES
          Monthly  Monthly  Yearly   Monthly  Monthly  >M1.0 
Month     Average  Average  Average  Average  Average 
May 01     148.7     97.3    108.7      7.1    118.0   11
Jun 01     173.7    134.0    109.8      5.9    135.8   13
Jul 01     131.3     82.2    111.7      6.5    113.6    2
Aug 01     163.2    106.8    113.6      8.0    113.3   23
Sep 01     233.3    150.7    114.1      9.3    146.8   48
Oct 01     208.2    125.6    114.0     15.8    149.8   36
Nov 01     212.7    106.5    115.6     16.1    156.1   47
Dec 01     235.6    131.8    114.8p    12.6    144.7   46
Jan 02     226.8    113.9    113.3p    10.9    155.7   21
Feb 02     205.2    108.0    112.7p    11.1    154.4   19
Mar 02     179.5     98.1    109.1p    10.4    165.1   15
Apr 02     189.5    120.4    104.5p    11.2    143.2   17
May 02     178.4    120.8    101.5p     8.4    133.0   16


               Monthly T indices
       Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec
1992   153   172   155   134    95    80    88    66    68    66    84    90  
1993    74    77    79    63    63    64    62    50    37    40    34    43  
1994    57    41    42    26    15    14    23    18    20    20    20    20  
1995    24    33    23    13     3    11    13    10    13     9    13     7  
1996    12     7     4     2     5     2     3     4     4     3    11    15  
1997    14    11    10     8    11     5     9    17    32    27    28    38  
1998    40    41    43    56    46    56    76    75    86    69    74    93  
1999    94    81    89    77    98   123   124*  105*   89    91   123   113* 
2000   108   120   158   154   133   133   147   140   124   130   137   140  
2001   133   127   137   122   113*  134*  112*  114*  143*  151*  158*  145* 
2002   155*  151*  159*  119^  113^  107^  100^   93^   86^   81^   78^   75^ 
2003    72^   69^   67^   64^   61^   59^   57^   54^   52^   49^   47^   45^ 
2004    43^   41^   39^   37^   35^   33^   31^   29^   28^   26^   24^   23^ 
2005    21^   20^   19^   17^   16^   15^   14^   13^   12^   11^   10^    9^ 
2006     8^    8^    7^    6^    6^    5^    5^    5^    4^    4^    4^    4^ 
2007     4^    5^    5^    6^    7^    8^    9^   11^   13^   16^   18^   21^ 
2008    25^   28^   32^   36^   41^   45^   50^   54^   59^   64^   68^   73^ 
* = New data. T index may have changed.
^ = IPS predicted T index.

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 
DATE             CLASS M    CLASS X     FLARE     FADEOUT POSSIBLE ON
                 FLARES     FLARES      MAX       DAYLIGHT HF CIRCUIT
07 May 02	 M1.4               	0346UT
08 May 02	 M1.4               	0346UT
11 May 02	 M1.4/SF            	1132UT
15 May 02	 M1.0/SF            	0813UT
17 May 02	 M1.5               	0123UT
17 May 02	 M1.5               	0754UT
17 May 02	 M2.9/SF            	1608UT
20 May 02	 M4.7               	1029UT    1014-1034UT
20 May 02	 M5.0               	1053UT    1049-1056UT
20 May 02	            X2.1 /2N    1527UT    1521-1531UT
21 May 02	 M1.5/2F            	2139UT
24 May 02	 M1.1               	0646UT
27 May 02	 M2.0/2F            	1810UT
30 May 02	 M1.3               	0532UT
30 May 02	 M1.6/SF            	1724UT
31 May 02	 M2.4               	0016UT

10 MeV Proton Events:
      Begin               End
22 05 2002 1820UT  24 05 2002 1400UT



2.1     Comments on Solar Activity.
Solar activity was at low to moderate levels for most of the month.
Activity became high on 20 May, due to an impulsive X2.1 event at 
1527UT. This was the largest flare for the month. A total of 16 xray 
events were observed for the month, 15 M class and 1 X class. A large 
solar filament rapidly erupted from the south-west quadrant of the 
solar disk on 22 May. The proton event 22-24 May is believed to be 
associated with this erupting solar filament and possibly an earlier M1.5 
flare/mass ejection on 21 May. 

===============================================================================

3.     GEOMAGNETIC DISTURBANCES              (for Australian Region)

DATE                     COMMENTS
10 May 02:     Active periods following weak sudden impulse in
	       IPS magnetometer data of 18nT at 1124UT.
11 May 02:     Isolated minor storm periods following weak sudden impulse
               in IPS magnetometer data of 18nT at 1015UT.
14 May 02:     Active periods.
18 May 02:     Weak sudden impulse of 23nT observed in IPS magnetometer 
	       data at 2009UT. No significant activity followed impulse.
20 May 02:     Weak sudden impulse of 16nT observed in IPS magnetometer
	       data at 0341UT. No significant activity followed impulse.
23 May 02:     Major Storm levels following weak sudden impulse of 36nT observed
	       at 1051UT, and moderate sudden impulse of 56nT observed at
	       1544UT.
27 May 02:     Active periods.

The most significant disturbance for the month was observed on
23 May, with the local A index reaching 42. This disturbance
is believed to be primarily due to the fast erupting solar filament
on 22 May. An earlier mass ejection on 21 May may have contributed
to this activity.

===============================================================================

4.     IONOSPHERIC DISTURBANCES              (for Australian Region)
   12 May 02 Southern region MUFs depressed 15-20% local day.
23-24 May 02 Degraded conditions local night hours 23 May.
	     Depressed regional MUFs 15-30% local day 24 May.

The strongest ionospheric disturbance for the month was observed
during interval 23-24 May. This disturbance followed geomagnetic 
storm activity on 23 May. High latitude/polar HF circuits were
degraded by proton event 22-24 May.

===============================================================================

5.     IPS WARNINGS AND ALERTS ISSUED

WARNINGS:
HF RADIO WARNING:
ISSUE DATE      NO       BEGIN           END
07 May 02	19	09 May 02	10 May 02
12 May 02	20	12 May 02	12 May 02
15 May 02	21	15 May 02	15 May 02
16 May 02	22	18 May 02	19 May 02
17 May 02	23	17 May 02	19 May 02
20 May 02	24	21 May 02	23 May 02
21 May 02	25	24 May 02	25 May 02


GEOMAGNETIC WARNING:
ISSUE DATE      NO       BEGIN           END
07 May 02	15	09 May 02	10 May 02
16 May 02	16	18 May 02	19 May 02
20 May 02	17	20 May 02	20 May 02
21 May 02	18	24 May 02	25 May 02
29 May 02	19	30 May 02	31 May 02


ALERTS: 
07 May 02: Flare Alert
11 May 02: Geomagnetic
17 May 02: Flare Alert
20 May 02: Flare Alert
21 May 02: Flare Alert
23 May 02: Geomagnetic
24 May 02: Geomagnetic
27 May 02: Flare Alert
30 May 02: Flare Alert
31 May 02: Flare Alert


SWF ALERTS AND DURATION REPORTS - None Issued.


IPS Radio and Space Services      | email: asfc at ips.gov.au
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