The Atmospheric Chemistry Studies in the Oceanic Environment (ACSOE) OXIdising Capacity of the Ocean Atmosphere (OXICOA) and Testing Atmospheric Chemistry in Anticyclone (TACIA) combined efforts to focus on continental plumes, mainly through in-situ measurements from on-board MRF C-130. Known affectionately as Snoopy, the C-130 research aircraft is a former transport aircraft operated by the Meteorological Research Flight (MRF), with a Royal Air Force crew. It has a range of 5,000 km and an endurance of up to 12 hours. It can reach a ceiling of 10 km, or can skim the wave-tops at fifty feet. During ACSOE it flew missions over the North Sea and North Atlantic from its home base at Boscombe Down, Wiltshire, and was also detached to the Azores, mainland Portugal, and Tenerife for experiments further afield. It was instrumented in a number of different configurations, depending on the experiment in progress, including a new fit of fast in-situ trace gas photochemistry instruments developed specifically for ACSOE. The aircraft has a central data acquisition system that logs data from all of the instruments and an on-board computer system called HORACE. The latter was configured to run various algorithms based on the real-time measurements.