Monthly Ri Report

:Issued: 2022 May 01 08:16 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 2022 : 84.0 (eighty-four point zero)

Maximum : 135 on 28 // Minimum : 11 on 11

Provisional daily International Sunspot Numbers for April 2022 : 

      1..128    6.. 74   11.. 11   16.. 64   21..114   26..132
      2..121    7.. 58   12.. 14   17.. 85   22..110   27..132
      3..118    8.. 52   13.. 33   18..101   23..128   28..135
      4.. 81    9.. 38   14.. 41   19.. 96   24..127   29..107
      5.. 86   10.. 21   15.. 47   20.. 99   25..118   30.. 51

73 cooperating stations on May 1, 08 UT

Predictions of the monthly smoothed Sunspot Number using the last
provisional value, calculated for October 2021 :  45.0 (+-5%)

            SM    CM                 SM    CM                 SM    CM     

2021 Nov    49    50     2022 May    95    84     2022 Nov   154   111
     Dec    55    57          Jun   104    89          Dec   168   113
2022 Jan    59    63          Jul   113    95     2023 Jan   184   115
     Feb    67    69          Aug   122   100          Feb   202   117
     Mar    76    73          Sep   132   103          Mar   219   119
     Apr    85    79          Oct   143   107          Apr   235   120

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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