Last updated 15 May 2008 14:03 UT IPS OBSERVED AND PREDICTED SOLAR INDICES CYCLE 24 Prepared by IPS Radio and Space Services Issued on May 01 2008 ------------------------ SMOOTHED SUNSPOT NUMBER --------------------------- Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ---------------------------------------------------------------------------- 2000 113.0 116.9 120.0 120.9 119.0 118.8 119.8 118.7 116.3 114.5 112.7 112.1 2001 108.7 104.0 104.8 107.5 108.6 109.8 111.7 113.6 114.1 114.0 115.5 114.6 2002 113.5 114.6 113.3 110.5 108.8 106.2 102.7 98.7 94.6 90.5 85.3 82.1 2003 81.0 78.6 74.2 70.4 67.9 65.3 62.1 60.3 59.8 58.4 57.0 55.0 2004 52.1 49.4 47.2 45.6 43.9 41.7 40.2 39.3 37.6 35.9 35.4 35.2 2005 34.6 34.0 33.6 31.7 28.9 28.8 29.1 27.5 25.9 25.6 25.0 23.0 2006 20.8 18.7 17.4 17.1 17.4 16.4 15.3 15.6 15.6 14.2 12.7 12.1 2007 12.0 11.6 10.8 9.9 8.7 7.7 7.0 6.1 5.9 6.1 5.8e 5.3e 2008 4.8e 4.6e 4.7e 5.2e 5.8e 6.1e 6.3e 7.1e 7.6e 8.3e 9.2 9.6 2009 10.7 11.9 13.4 14.7 16.3 18.1 20.2 22.6 25.2 29.6 34.5 39.8 2010 44.2 48.8 53.8 59.4 64.5 68.8 72.8 79.0 85.5 91.3 94.7 98.0 2011 101.4 105.2 109.1 112.6 116.6 120.2 122.4 125.4 127.1 127.9 129.2 130.9 2012 131.8 133.9 134.7 134.7 133.9 131.8 131.3 130.0 130.0 129.6 129.6 130.0 2013 130.0 129.2 129.2 127.9 125.0 122.0 119.3 116.6 113.5 110.0 107.7 105.7 2014 104.1 102.2 100.1 97.4 94.3 89.3 84.2 79.4 76.3 73.5 70.9 68.5 2015 66.0 63.2 60.1 57.7 56.0 55.2 54.3 53.1 51.4 49.1 46.4 43.6 2016 41.3 39.4 37.5 35.3 33.0 30.9 29.2 27.9 26.6 25.3 23.9 22.8 2017 21.8 21.1 20.6 20.0 19.3 18.2 17.3 16.8 16.5 15.9 14.9 14.2 2018 14.1 14.3 14.3 14.0 14.0 14.2 14.2 14.1 14.1 14.0 13.6 12.9 ============================================================================ ----------------- EQUIVALENT 10.7 CM SOLAR RADIO FLUX --------------------- Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ---------------------------------------------------------------------------- 2000 162.2 166.2 169.4 170.3 168.3 168.1 169.2 168.0 165.6 163.7 161.9 161.2 2001 157.8 153.0 153.7 156.6 157.7 158.9 160.8 162.8 163.3 163.2 164.8 163.9 2002 162.7 163.9 162.5 159.6 157.9 155.2 151.6 147.6 143.4 139.3 134.1 131.0 2003 129.9 127.6 123.4 119.7 117.4 114.9 112.0 110.4 109.9 108.7 107.4 105.6 2004 103.2 100.8 98.9 97.6 96.2 94.4 93.3 92.5 91.2 89.9 89.5 89.4 2005 88.9 88.4 88.1 86.7 84.7 84.6 84.8 83.6 82.5 82.3 81.9 80.5 2006 79.0 77.6 76.8 76.7 76.8 76.2 75.5 75.7 75.7 74.8 73.9 73.6 2007 73.5 73.3 72.8 72.3 71.6 71.0 70.6 70.1 70.1 70.1 70.0e 69.7e 2008 69.5e 69.4e 69.4e 69.6e 70.0e 70.1e 70.3e 70.7e 71.0e 71.4e 71.9 72.1 2009 72.7 73.4 74.3 75.1 76.1 77.3 78.6 80.2 82.0 85.2 88.8 92.9 2010 96.5 100.3 104.6 109.6 114.2 118.2 122.0 128.0 134.3 140.1 143.5 146.9 2011 150.3 154.2 158.2 161.8 165.9 169.6 171.8 174.9 176.6 177.4 178.8 180.5 2012 181.4 183.5 184.3 184.3 183.5 181.4 180.9 179.6 179.6 179.2 179.2 179.6 2013 179.6 178.8 178.8 177.4 174.5 171.4 168.6 165.9 162.7 159.1 156.8 154.7 2014 153.1 151.1 149.0 146.3 143.1 138.1 133.1 128.4 125.3 122.7 120.2 117.9 2015 115.6 113.0 110.2 108.1 106.5 105.8 105.1 104.0 102.5 100.6 98.3 96.0 2016 94.1 92.6 91.1 89.4 87.7 86.1 84.9 83.9 83.0 82.1 81.1 80.4 2017 79.7 79.2 78.9 78.5 78.0 77.3 76.8 76.4 76.2 75.9 75.2 74.8 2018 74.8 74.9 74.9 74.7 74.7 74.8 74.8 74.8 74.8 74.7 74.5 74.0 ============================================================================ This page is updated monthly using observed monthly sunspot numbers from the Solar Influences Data Analysis Center (http://sidc.oma.be). Monthly values are smoothed using a 13 monthly running filter and, where needed, combined with a predicted sunspot number curve for Cycle 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. 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/mailman/listinfo/ For more information please contact the centre at asfc@ips.gov.au PLEASE NOTE: The technique used to make these predictions was changed for the predictions issued from early November 2003. The revised technique is more appropriate to the situation of a declining solar cycle -----------------------------------------------------------------------------

Last updated 15 May 2008 14:03 UT 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 63.7 106.4 137.7 113.5 93.7 71.5 116.7 133.2 84.6 2000 90.1 112.9 138.5 125.5 121.6 125.5 170.1 130.5 109.7 99.4 106.8 104.4 2001 95.6 80.6 113.5 107.7 96.6 134.0 81.8 106.4 150.7 125.5 106.5 132.2 2002 114.1 107.4 98.4 120.7 120.8 88.3 99.6 116.4 109.6 97.5 95.0 81.6 2003 79.5 46.2 61.5 60.0 55.2 77.4 85.0 72.7 48.8 65.6 67.2 47.0 2004 37.2 46.0 48.9 39.3 41.5 43.2 51.0 40.9 27.7 48.4 43.7 17.9 2005 31.3 29.2 24.5 24.4 42.6 39.6 39.9 36.4 22.1 8.5 18.0 41.2 2006 15.4 5.0 10.8 30.2 22.2 13.9 12.2 12.9 14.5 10.4 21.5 13.6 2007 16.9 10.6 4.8 3.7 11.7 12.0 10.0 6.2 2.4 0.9 1.7 10.1 2008 3.4 2.1 9.3 2.9

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. To subscribe to this mailing list click here

Below is a graph of sunspot numbers:

Last updated 15 May 2008 14:03 UT FORECAST SOLAR CYCLE 24 ------------------------------------------------------------------------------- Cycle Sol. Min Sol. Max Max SSN Length Rise to Max Max to End Year Mth Year Mth Yr Mth Year Mth Year Mth ------------------------------------------------------------------------------- 24 2008 Oct 2012 Apr 134.7 10.8 129 3.5 42 7.3 87 Description of Prediction Technique The prediction is based on the average of the last 8 solar cycles (Cycles 15 to 23). IPS will adjust this average cycle as the new cycle unfolds. To do this IPS has developed software for manipulating this predicted cycle. The difficulty is ensuring that adjustments are not made for short term variation, only for longer term cycle variation.

A solar cycle viewing tool (zip file) is available for ftp download here.