Электродинамические процессы в высоких широтах: материалы междунарордного симпозиума «Полярные геомагнитные явления», 25-31 мая 1986 г., Суздаль, СССР / Междунар. геодез. и геофиз. союз, Междунар. ассоц. геомагнетизма и аэрономии ; Акад. наук СССР, Кол. фил. им. С. М. Кирова, Поляр. геофиз. ин-т ; [редкол.: О. М. Распопов (отв. ред.). и др.]. - Апатиты : Кольский филиал АН СССР, 1988.

PROTON FLUXES AND IONIZATIOH PRODUCTION RATES. The proton fluxes were measured on GOBS-5 in 7 energy bands and their variations between 0915 and 1 6 ЗО UT are shown in Figure 6. A marked energy dependence! implying a change of spectrum, is evident. The flux peaked soonest at the highest energies ( > 3 9 MeV), and considerably later at the lower ones ( < 8 . 7 MeV). The neutron monitor at Oulu registered an enhanced flux fr o m 0905 to about 1000 UT, peaking at 0915-0920 UT (Kananen, private communication), wh i c h is about the time w h e n the PCA began. Though this was not an intense ground-level event, the-enhancement shows that proton energies exceeded 8- M e V at the onset. B y comparing the shape of the absorption variation at Ramfjord (plotted as log(absorption) ) w i t h the flux variations i n Pig. 6, it is immediately possible to identify the bands 8.7-14.5 M e V an d 15-44 Me V as the principal ones for absorption production throughout moat of the event, though the highest energies appeared to contribute enough in the early part to fo r m the absorption peak near 1000 UT. Ion-electron production rates were calculated at selected altitudes using the computer p rogram PROTON (Reid, private communication); Figure 7 shows these computed values for every 5 k m between 35 and 90 km. The production rate was greatest at 60 km after 1030 UT, but lower altitudes were strongly affected during the first ho u r of the event, and at the onset (at 0 9 1 5 UT) the production rate maximized as low as 25 km. EFFECTIVE RECOMBINATION COEFFICIENTS. Values of p et e=q/Ng were calculated for every 5 k m between 65 and 90 k m and for each half-hour between 1030 and ІЗЗО UT, except for 1130 UT w h e n the antenna was pointed away from the zenith. As a general compari son, averages over all times are in Figure 8 super imposed on a summary of previous determinations (after Figure 9 of Re a g a n an d W a t t , 1976). Most of these average values fall w i t h i n the range of the previous estimates though towards the hig h e r extre m e s below 85 km. Values for 85, 80 and 75 k m are close to those of Megill et al.(1971), and for 70 and 6 5 k m to those of Adams and Masley (1965). The presence of a contribution to the production rate from solar UV malcea our values at 90 k m too low by about 4 %, and those at 85 % too low b y about 2 %. These errors are less than the 10 % random error due to the uncertainty (of 5 %) in the electron density measurements, and are not significant in the present context. A n interesting feature of the present ot measurements is that the values decrease progressi vely during the day (Figure 9) between 70 and 85 km; the variation over 3 hours exceeds a factor of two over this height range. Reagan and Watt (1976) F i g . 6» Proton -reported a similar effect during the event of August fluxes measured on GOES-5 in seven energy 1972 at heights b etween 59 end 89 k m except for an b a n d s . Il