Marine aerosol particles are an important part of the natural aerosol systems and have a significant impact on the global climate and biological cycle. Chemical and physical properties of remote-ocean marine aerosols are still less understood due to paucity of in-situ measurements, inducing uncertainties of global radiation budget prediction. We conducted a series of open-ocean aerosol measurements on board research vessel Polarstern during 4 transatlantic cruises covering around 100º of latitude. This study highlights main findings during these measurements, including chemical composition, sources, particle number size distribution (PNSD) as well as hygroscopic properties of the submicrometer aerosol over the Atlantic. Air masses originally from remote ocean or continent under prevailing winds and seasonal biological activities were also taken into consideration. Aerosol particles over the remote ocean were largely contributed by sulfate, sea salt and oceanic primary/secondary organic aerosols (63~79% of total particle mass concentration), showing mainly bimodal PNSD and high hygroscopicity (κ = 0.5~0.7). For aerosols influenced by continental transport, anthropogenic or biomass burning (BB) components, i.e., nitrate or BC and BB organic aerosols (BBOA), played a significant role (19~30% of total particle mass concentration), and a near monomodal PNSD as well as lower κ (mainly 0.3~0.5) were found. Markedly, particles measured between 30°S and 50°S in association with air masses passing the south end of South America exhibited pronounced contribution of marine primary organic aerosols, dominating mode of 30nm in PNSD while high hygroscopicity (κ = 0.8 at 300nm). Based on Polarstern measurements, meridional distribution of bimodal diameters of MBL aerosols were provided in high spatial resolution (1°). Additionally, new particle formation events over the remote ocean were identified and discussed preliminarily.