Monthly Ri Report

:Issued: 2024 May 01 07:56 UTC
:Product: documentation at http://www.sidc.be/products/ri 
#-------------------------------------------------------------#
# MONTHLY TABLE OF THE INTERNATIONAL TOTAL SUNSPOT NUMBER     #
# AND 12-MONTH PREDICTIONS from the World Data Center SILSO   #
#-------------------------------------------------------------#

Provisional International monthly mean Sunspot Number for
April 2024 : 136.5 (one hundred and thirty-six point five)

Maximum : 266 on 23 // Minimum : 32 on 1

Provisional daily International Sunspot Numbers for April 2024 : 

      1.. 32    6.. 80   11.. 90   16..181   21..231   26..141
      2.. 39    7.. 84   12.. 86   17..209   22..265   27..139
      3.. 38    8.. 77   13..120   18..223   23..266   28..119
      4.. 48    9.. 55   14..148   19..240   24..251   29..100
      5.. 78   10.. 55   15..171   20..232   25..209   30.. 87

64 cooperating stations on May 1, 08 UT

Predictions of the monthly smoothed Sunspot Number using the last
provisional value, calculated for October 2023 : 124.8 (+-5%)

            SM    CM                 SM    CM                 SM    CM     

2023 Nov   123   125     2024 May   121   125     2024 Nov   111   133
     Dec   117   125          Jun   120   127          Dec   109   132
2024 Jan   115   126          Jul   118   130     2025 Jan   107   131
     Feb   118   126          Aug   117   133          Feb   105   129
     Mar   120   124          Sep   115   134          Mar   103   130
     Apr   121   124          Oct   113   134          Apr   101   130

SM : SIDC classical method : based on an interpolation of Waldmeier's
standard curves; the estimated error ranges from 7% (first month) to
35% (last month)
CM : Combined method : the combined method is a regression technique
coupling a dynamo-based estimator with Waldmeier's idea of standard
curves, due to K. Denkmayr.
ref. : K. Denkmayr, P. Cugnon, 1997 : "About Sunspot Number Medium-Term
Predictions", in "Solar-Terrestrial Prediction Workshop V", eds.
G. Heckman et al., Hiraiso Solar Terrestrial Research Center, Japan, 103



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