UK Solar System Data Centre
Copyright WDC for STP at RAL.
This file contains provisional data of Sunspot Numbers from Meudon and Boulder, observed 10.7cm Radio Flux from Penticton and the Ap index. The Ap_1 to Ap_3 values represent forecasts of that days value from the three previous days. The data is taken from the Solar Daily Forecast (SESC) and the Meudon Ursigram.
From 20th December 2005, Meudon Sunspot Number, produced by SIDC (Solar Influences and Data analysis Centre, Belgium), is no longer available. Instead SIDC are providing a prompt International Sunspot Number estimated value, along with the number of observatories used to calculate it. It can be downloaded from the UKSSDC via the Geophysical data retrieval tool.