NATIONAL AERONAUTICS                   AND SPACE ADMINISTRATION

        The Space Environments Team in the Natural Environments Branch of the Engineering Directorate at Marshall Space Flight Center (MSFC) provides solar cycle predictions for NASA engineering programs and the aerospace community. The purpose of the predictions is to provide future statistical estimates of sunspot number, solar radio 10.7 cm flux (F10.7), and the geomagnetic planetary index, Ap, for input to various space environment models. For example, the F10.7 and Ap are required inputs to upper atmosphere (thermosphere) density computer models used for spacecraft operations such as orbital lifetime analysis and for the planning of future spacecraft missions.
        Each month the solar prediction is updated using historical and the latest month's observed solar indices to provide estimates for the balance of the current solar cycle and the next. The forecasted solar indices represent the 13-month smoothed values consisting of a best estimate value stated as a 50 percentile value along with approximate +/- 2 sigma values stated as 95 and 5 percentile statistical values. The F10.7 prediction also includes a 75 percentile value. The prediction method uses a statistical estimation technique which is descibed in NASA Technical Memorandum 4759 .
        The estimation technique is used to predict the remaining of the current cycle, but it is not able to predict the next solar cycle at this time. However, for engineering applications and mission planning an extended forcast for the next solar cycle is given below. The values shown for the next cycle are those of a mean cycle obtained from averaging previous cycles of 13-month smoothed indices along with the calculated statistical bounds.


Solar Cycle Progression & Forecast

  (Updated 4 Nov 2016)


                            Radio Flux (10.7 cm) Extended Forecast:     Plot     Table  (95 percentile)     Table  (75 percentile)

                            Radio Flux Recent Observations:   Table  (Monthly & 13-Month Smoothed)




                            Sunspot Number Extended Forecast:   Plot     Table

                            Sunspot Number Recent Observations:   Table  (Monthly & 13-Month Smoothed)




                          Geomagnetic Index Ap Extended Forecast:     Plot     Table

                          Geomagnetic Index Ap Recent Observations:   Table  (Monthly & 13-Month Smoothed)



Archived Predictions:     Tabular Data


Data Sources:
The monthly mean data presented above and used in generating the forecast products are obtained from the sources listed below.


Sunspot Number:
Sunspot Index and Long-term Solar Observations (SILSO) World Data Center (WDC), Royal Observatory of Belgium

Solar Radio Flux (10.7cm):
Solar Monitoring Program, Space Weather Canada

Ap Geomagnetic Index:
Indices of Geomagnetic Activity, Geophysics Department, GFZ Helmholtz Center Potsdam



Others Forecast:

Marshall Solar Physics

NOAA Space Weather Prediction Center

Related Links:

NASA Space Environment and Effects (SEE) Program