TY JOUR TI Comparison between seasonal variations in tidal and internal gravity wave activity as derived from observations at Maimaga and Tiksi KW high-latitude mesopause KW hydroxyl emission KW internal gravity waves KW tidal waves JO Solnechno-Zemnaya Fizika AU Sivtseva, V.I. AU Ammosov, P.P. AU Gavrilieva, G.A. AU Koltovskoi, I.I. AU Ammosova, A.M. PY 2018 IS 4 PB Institute of Solar-Terrestrial Physics SB RAS