Paris Observatory
Print Preview

Warning: the forecasts are not updated anymore !
Index long-term forecast:
The sunspot index and the 10-centimeter flux lend themselves well to long-term forecast. During a given cycle one can either forecast the evolution of the current cycle (what is done here) or the profile and maximum of next cycle.

Modulation parameters:
The solar wind magnetic field, which varies with the 11 year solar cycle, interacts with the high energy particules coming from outside the heliosphere. It has been shown by Gleeson & Axford (1967) that "except at low energy, the solar modulation of galactic cosmic rays is rather well represented by a single parameter which can be interpreted as being the potential at Earth corresponding to a hypothetical heliocentric electric field". Three different potentials are frequently used : the heliocentric potential (O'Brien, 1971), the modulation potential (Nymmik et al., 1996) and the deceleration potential (Badhwar and O'Neill 1996). See also the recent potentials page.

Chosen flight dose forecast:
The radiation doses received during flights are mostly due to galactic cosmic rays coming from the massive stars explosions called supernovae. Significant additional doses received from solar particles are rare. As the solar activity modulates the galactic cosmic ray intensity, the sunspot index, used to predict the modulation potentials, leads to estimates of the doses received on board aeroplanes in function of the solar cycle. The flight dose predicted here are typical of the routes starting from Europe. The calculations are based on actual flight plans from Air France.