This study proposes to observe high-elevation aerosol at the Mountain Lulin(2,862 m regional/transboundary) atmospheric background station for the next year.The observation scope includes physical and chemical characteristics of atmosphericaerosols during the regional background and event (influenced by long-rangetransport of Indochina biomass burning smoke and Asian haze) periods. In addition,this study will collaborate with general project to participate in 2017~2018 post-7-SEAS international activities including the construction of long-term monitoringnetwork, regional collaborations with scientists in Southeast Asia, and collaborationswith Northeast Asian (Japan, Korea, Taiwan, Hong Kong) scientists on theobservation of pollution outflow from Asian Continent. Daily aerosol chemicalproperties will be observed by manual collection and automated monitoring at bothMountain Lulin and Bamboo sites (1,103 m a.s.l.) in the international intensivemeasurement campaign scheduled during October~November 2017 andMarch~April 2018.The detailed PM2.5 observation items contain mass concentration, water-solubleinorganic ions, carbonaceous content, water-soluble organic carbon, humic likesubstance, anhydrosugars, and aerosol water content in this study. Measurements oftrace gases, aerosol physical properties, and meteorological factors at the MountainLulin site will also be incorporated into data analysis. The observation results willcontrast the differences of mountain aerosol characteristics between event (biomassburningsmoke transport, cloud/fog occurrence, and Asian haze) and non-event(regional background) periods. In addition to the traditional manually-collected bulkphase aerosol chemical properties, the combination of particle-into-liquid ionchromatograph (PILS-IC) and the in-situ water content analyzer assembled inprevious years will facilitate this study to evaluate the integrated short-intervalrelationship among aerosol water content, aerosol size spectra, and water-solubleinorganic ions. The short time-interval aerosol characteristics can also provide abasis for examining aerosol dynamic characteristics between event and non-eventperiods, and that from various air mass trajectories during the study periods. Insummary, this study will utilize the acquired comprehensive data to investigateaerosol characteristics of background air in the East Asia, transported BB air masses,and pre- and post-cloud event at the various sites. The observed data combining withprevious findings can further provide long-term aerosol chemical characteristics formodelers to validate model simulations and assess aerosol-cloud-radiationinteraction in the East Asia.