One of the goals of the Trans-Atlantic Saharan Dust Aerosol and Ocean Science Expedition (AEROSE) is to estimate the impact of Saharan dust on regional air quality and its ecosystem impacts in the Caribbean and US eastern seaboard. An AEROSE cruise aboard the NOAA ship Ronald H. Brown was again conducted in summer 2007. A report on trace gas measurements of surface level ozone (O3) and carbon monoxide (CO) were obtained throughout this cruise. O3 is a reactive oxidant gas produced naturally in trace amount in the Earth's atmosphere. Major sources of CO in the tropical marine boundary layer (MBL) include technological processes (combustion and industrial processes), biomass burning, and the oxidation of hydrocarbons. CO and O3 chemistry is strongly linked, but previous studies have indicated that this linkage is disrupted in the presence of significant atmospheric loading of Saharan dust aerosols. These measurements were taken from May 6 to May 24, 2007 along a cruise track that included encounters with both light and heavy Saharan dust episodes, a cross section of the intertropical convergence zone, and a cross section of the continental outflow from West Africa.