Long-Term Variation of Stratospheric Aerosols Observed With Lidar from 1982 to 2014 Over Tsukuba, JapanTetsu Sakai, Osamu Uchino, Tomohiro Nagai, Toshifumi Fujimoto and Isao TabataEPJ Web of Conferences, 119 (2016) 23011DOI: https://doi.org/10.1051/epjconf/201611923011