PASHA: regional long-term predictions of ionospheric parameters by ASHA

Abstract

In this paper it is shown that the adjusted spherical harmoníc analysis (ASFIA), previously used for the regional mapping of the monthly medians of the critical frequency of the F2 ionospheric layer (f0F2), can be adapted to obtain a regional Iong-term prediction model of the ionospheric parameters. By assuming that, at a fixed month, the monthly median value of f0F2 is a function of the geographic longitude lambda and colatitude teta and of the 12-month running mean value R12 of the Zurich sunspot number, i.e. f0F2 =f(lambda,teta, R12), PASHA (regional Iong-term predictions of ionospheric parameters by ASHA) is applied for mapping and modelling of this ionospheric parameter over Europe. Some examples are shown concerning the PASHA model results obtained for different solar activity conditions, seasons and geographic latitudes. The PC version of the FORTRAN 77 program is also available enabling the easy use of the PASHA model to obtain, as a final output, both a grid (2 x 2 degrees) of the predicted monthly medians of f0F2 in the European area and the 24 predicted monthly medians of the parameter at a given point in the region of interest.