Main Pages: [ SpaWx Indices Home | NWRA Home Page | ]
Graphics: [ X-ray | F10 | Ap | F10/Ap Forecasts | SSN Comparison | Kp+GOES+DSCOVR | Qe+GOES+DSCOVR ]
Listings/Reports: [ Indices Table | Events | RSGA | Discussion | SGAS | SRS | Predict | ]

Comparison of Sunspot-Number Indices


This plot illustrates the difference between the Estimated International Sunspot Number (EISN), which is calculated from optical observations of the sun and a sunspot number derived from the 10.7cm solar radio flux (SSNf). These indices are used as inputs to models of the ionosphere for use in communications-performance predictions.

The algorithm used to calculate the F10.7-derived SSN (SSNf) parameter is described here.

Note: The foF2-based effective sunspot number (SSNe) which had been included in this plot is no longer in production.

Home | About NWRA | Staff | Research Areas | Products ]

How to contact NWRA

Copyright © 1996-2024 NorthWest Research Associates, Inc.  All rights reserved.