Timo Pitkänen^1,2, Maria Hamrin², Ramon E Lopez³, Herbert Gunell^2,4, Alexandre De Spiegeleer², Oleksandr Goncharov², Linus Norenius² and Ghai Siung Chong², (1)Shandong University, Weihai, China, (2)Umeå University, Umeå, Sweden, (3)University of Texas at Arlington, Arlington, TX, United States, (4)Belgian Institute for Space Aeronomy, Brussels, Belgium