00591naa#a2200181#i#450# EN\\bibl\46507 20240504210622.6 1681-1208 20200225b2020####ek#y0engy0150####ca ENG RU Electron density in the polar F region ionosphere during solar minimum: modeling, radar and ionosonde observations Journal article Moscow Geophysical Center of the Russian Academy of Sciences 2020 15 с. Journal article local Lukianova Renata Kozlovsky Alexander rjes.ru