SOLAR-RADIATION FLUXES IN THE 10-30 NM RANGE FROM STUDYING THE E-REGION AND E-F VALLEY

For the 10-30 nm interval within the extreme UV region of the solar sp ectrum, there are no commonly accepted views on the spectral compositi on and absolute magnitudes of the radiation intensity due to the lack of reliable data. This region is connected with characteristics of the ionosphere heat regime, photoelectron spectrum parameters and E-F val ley characteristics. For estimating the solar radiation flux by the in direct route within the spectral region from 10 to 30 nm, which is dif ficult for direct measurements, it is suggested to use data on the ele ctron concentration in the E-region maximum and E-F valley. Taken from empirical models, the data on these parameters were correlated with t heoretical calculations of height profiles of electron concentration i n the ionosphere. Based on the proportion between electron concentrati on in the E-layer maximum and E-F valley minimum, the solar radiation flux within the 10-30 nm region was shown to be 2.5 times greater than that obtained in measurements on board the 'AE-E' and 'AE-C' satellit es, The results are used for correcting model spectra of the extreme U V radiation.