The trans-Atlantic Aerosol and Ocean Science Expeditions (AEROSE) are a series of intensive field experiments conducted aboard the NOAA Ship Ronald H. Brown during the northern hemisphere spring and summer. The ongoing AEROSE mission focuses on providing a set of critical measurements that characterize the impacts and microphysical evolution of aerosols from the African continent during their transport across the Atlantic Ocean. The three central scientific questions that guide the missions are: (1) What is the extent of change in the mineral dust and smoke aerosol distributions as they evolve physically and chemically during trans-Atlantic transport? (2) How do Saharan and sub-Saharan aerosols affect the regional atmosphere and ocean during trans-Atlantic transport? 3) What is the capability of satellite remote sensing and numerical models for resolving and studying the above processes? While there have been a variety of aerosol campaigns that have encountered mineral dust or smoke, few have focused on both Saharan dust and sub-Saharan smoke, and none have sought to characterize the evolution of these aerosols during long-range transport as a function of season. The combined atmospheric and oceanic sampling also constitutes a unique aspect of the mission that will enable an unparalleled view of the thermodynamic influence of these African aerosols in the Atlantic marine environment. A comprehensive suite of aerosol measurements and size-segregated sampling is performed during each cruise to characterize the evolution of the mineral dust mass distribution with respect to number density, chemical composition, and biological content. This paper will focus primarily on data obtained from the recent AMMA-AEROSE-II cruise conducted during May–July 2006.