Multi-site tropospheric ozone measurements across the North Tropical Atlantic during the summer of 2010

► Higher tropospheric column ozone in the Eastern Atlantic relative to the Western Atlantic. ► Higher TCO values during (IOP I) rather than (IOP II) for Barbados and Cape Verde. ► Higher ozone mixing ratios are found in the 925-850 hPa layer in Cape Verde. ► Pre-trough conditions have higher ozone mixing ratios than post-trough conditions.