On 15th November 2021, the online Young Scientist School (YSS) on \u201cMulti\u2013Scales and \u2013Processes Integrated Modelling, Observations and Assessment for Environmental Applications\u201d in the Memory of Sergej Zilitinkevich has been opened with a series of lectures. These included \u2013 the introduction into the PEEX programme and its research and educational activities, the Finnish Flagship \u2013\u00a0Atmosphere and Climate Competence Center<\/a>\u00a0as well as the Earth System, hydrological, numerical weather prediction and atmospheric chemical transport modelling and their specific challenges \u2013 and were delivered by scientists from Finland, Russia and Switzerland. During the entire week, in total 25 lectures will be delivered to participants of the school (see detailed programme at:\u00a0https:\/\/megapolis2021.ru<\/a>)<\/a>.<\/p>\n The school includes both the theoretical lectures and practical exercises (to be accomplished by groups of participants-\u201cstudents\u201d) as\u00a0small-scale research projects<\/a>\u00a0(SSRPs) ending with presentation of the project results on 3rd December 2021. The remote work in\u00a09 groups\/<\/a>\u00a0teams on SSRPs will start on 16th November. The developed SSRPs are based on the EC-Earth, Enviro-HIRLAM and ARCA-Box models (see more details at:\u00a0https:\/\/megapolis2021.ru\/ssrp)<\/a>.<\/p>\n Text by Sergey Chalov, Anatolii Tsyplenkov (Moscow State University), Alexander Mahura (University of Helsinki)<\/p>\n<\/div><\/div>