IPS Radio & Space Services

Observed And Predicted Sunspot Numbers

For many purposes it is important to estimate the value of the sunspot number up to a solar cycle in advance. For example, in planning High Frequency (HF) communication links, before making investment decisions, it is important to estimate what frequencies will be able to be supported by the ionosphere in the future. Predictions of sunspot number are also very important in planning space-related activities and NASA are very interested in such predictions.

In more detail, the table below shows observed sunspot numbers (12 month smoothed) from 1995, followed by predicted values up to the year 2009. The values listed in the table with a qualifier "e" means that the value is based partly on observed and partly on predicted values. Values in the table earlier than these values are totally observed; later values are totally predicted.

IPS also has a mailing list by which you can receive updated sunspot number predictions each month.

                 ISES OBSERVED AND PREDICTED SOLAR INDICES

                  Prepared by IPS Radio and Space Services
                         Issued on May 02  2001

------------------------ SMOOTHED SUNSPOT NUMBER ---------------------------
Year   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec
----------------------------------------------------------------------------
1995  24.2  23.0  22.1  20.6  19.2  18.2  17.0  15.4  13.4  12.1  11.3  10.8 
1996  10.4  10.1   9.7   8.4   8.0   8.5   8.4   8.3   8.4   8.8   9.8  10.4 
1997  10.5  11.0  13.5  16.5  18.3  20.3  22.6  25.0  28.3  31.8  35.0  39.0 
1998  43.7  48.9  53.4  56.5  59.4  62.5  65.5  67.8  69.5  70.5  73.0  77.9 
1999  82.6  84.6  83.8  85.4  90.4  93.0  94.4  97.5 102.3 107.7 110.9 111.0 
2000 112.8 116.6 119.8 120.7 118.9 118.6 119.6 118.4 116.1 114.4 113.5e112.9e
                                                                  ( 1)  ( 3)
2001 110.1e107.0e106.3e106.7e107.0e107.0e107.4e108.5e108.7e107.5e106.7 104.7 
      ( 5)  ( 7)  ( 9)  (11)  (13)  (15)  (17)  (19)  (21)  (23)            
2002 102.7 100.5  98.3  96.0  93.7  91.3  88.9  86.4  83.9  81.3  78.8  76.3 
2003  73.7  71.1  68.6  66.1  63.6  61.1  58.6  56.2  53.8  51.5  49.2  47.0 
2004  44.8  42.6  40.6  38.5  36.6  34.7  32.8  31.0  29.3  27.7  26.1  24.6 
2005  23.1  21.7  20.4  19.1  17.9  16.7  15.6  14.6  13.6  12.7  11.8  11.0 
2006  10.2   9.4   8.7   8.1   7.5   7.3   7.1   6.7   6.5   6.3   6.1   5.1 
2007   5.4   5.6   6.0   6.4   7.1   8.2   9.5  11.2  13.3  15.6  18.3  21.3 
2008  25.0  29.0  33.2  37.6  42.1  46.8  51.6  56.4  61.3  66.1  71.0  75.8 
2009  80.6  85.2  89.8  94.2  98.5 102.6 106.5 110.3 113.8 117.2 120.3 123.2 
============================================================================

-----------------  EQUIVALENT 10.7 CM SOLAR RADIO FLUX ---------------------
Year   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec
----------------------------------------------------------------------------
1995  81.3  80.5  79.9  78.9  78.0  77.3  76.6  75.6  74.3  73.6  73.1  72.8 
1996  72.6  72.4  72.2  71.4  71.2  71.5  71.4  71.4  71.4  71.6  72.2  72.6 
1997  72.6  72.9  74.4  76.2  77.4  78.7  80.2  81.9  84.2  86.8  89.2  92.3 
1998  96.1 100.4 104.3 107.0 109.6 112.4 115.1 117.3 118.9 119.8 122.2 126.9 
1999 131.5 133.4 132.7 134.2 139.2 141.8 143.2 146.4 151.2 156.8 160.0 160.1 
2000 162.0 165.9 169.2 170.1 168.2 167.9 169.0 167.7 165.4 163.6 162.7e162.1e
                                                                  ( 1)  ( 3)
2001 159.2e156.0e155.3e155.7e156.0e156.0e156.4e157.6e157.8e156.5e155.7 153.7 
      ( 5)  ( 7)  ( 9)  (11)  (13)  (15)  (17)  (19)  (21)  (23)            
2002 151.6 149.4 147.2 144.8 142.5 140.1 137.7 135.2 132.8 130.2 127.8 125.3 
2003 122.9 120.4 118.0 115.7 113.4 111.1 108.9 106.7 104.6 102.6 100.7  98.8 
2004  97.0  95.2  93.6  91.9  90.4  89.0  87.5  86.2  84.9  83.8  82.7  81.6 
2005  80.6  79.6  78.8  77.9  77.1  76.4  75.7  75.1  74.5  73.9  73.4  72.9 
2006  72.4  72.0  71.6  71.2  70.9  70.8  70.7  70.5  70.4  70.3  70.1  69.6 
2007  69.8  69.9  70.1  70.3  70.7  71.3  72.0  73.0  74.3  75.7  77.4  79.4 
2008  81.9  84.7  87.8  91.2  94.8  98.6 102.7 106.9 111.3 115.7 120.3 124.9 
2009 129.5 134.0 138.6 143.0 147.4 151.5 155.5 159.4 163.0 166.5 169.7 172.6 
============================================================================
This page is updated monthly using observed monthly sunspot numbers from
the Sunspot Index Data Center (http://www.oma.be/KSB-ORB/SIDC/).  Monthly
values are smoothed using a 13 monthly running filter and, where needed,
combined with a predicted sunspot number curve for Cycle 23/24. Values
which have an "e" next to them are based partly on observed and partly on
predicted values.  Values earlier in time to these are based entirely on
observed valued; values later in time are entirely predicted.  Observed
data are adjusted slightly at times to use the SIDC final monthly values
which are available several months later - SIDC preliminary monthly values
are used up to this time.
 
All Solar Radio Flux values, including the "observed" values, are
obtained from sunspot numbers using a statistical conversion.  They are
best described as equivalent solar flux values.
 
An estimate is made of the tolerance for the prediction for those values
marked 'e' and this is given in brackets below these values.
 
Prepared on behalf of the International Space Environment Service by
the Australian Space Forecast Centre, IPS Radio and Space Services. This
product is issued in the first few days of each month and is available
on the IPS Mailing List Server - http://www.ips.gov.au/mail-lists/
For more information please contact the centre at asfc@ips.gov.au
-----------------------------------------------------------------------------
                 OBSERVED MONTHLY SUNSPOT NUMBERS
1995  24.2  29.9  31.1  14.0  14.5  15.6  14.5  14.3  11.8  21.1   9.0  10.0
1996  11.5   4.4   9.2   4.8   5.5  11.8   8.2  14.4   1.6   0.9  17.9  13.3
1997   5.7   7.6   8.7  15.5  18.5  12.7  10.4  24.4  51.3  22.8  39.0  41.2
1998  31.9  40.3  54.8  53.4  56.3  70.7  66.6  92.2  92.9  55.5  74.0  81.9
1999  62.0  66.3  68.8  63.9 106.3 137.4 113.5  93.7  70.9 116.4 132.7  86.4
2000  90.2 112.3 138.2 125.3 120.8 124.9 169.1 130.5 109.9 100.1 106.5
  
Copyright © 1998 by Richard Thompson for IPS Radio & Space Services, Sydney, Australia. All rights reserved.

Comments or suggestions can be directed to richard@ips.gov.au

Background / Richard / Observed and Predicted SSN / 950503 / richard@ips.gov.au