Yuri Knyazikhin¹, Xiaojun She^1,2, Matti Mottus³, Miina Rautiainen⁴ and Jan Pisek⁵, (1)Boston University, Earth and Environment, Boston, MA, United States, (2)Southwest University, School of Geographical Sciences, Chongqing, China, (3)VTT Tech Research Centre, Espoo, Finland, (4)Aalto University, Aalto, Finland, (5)University of Tartu, Tartu Observatory, Tartu, Estonia