Study of intercontinental transport of air pollutants by means of coordinated flights over the East coast of North America, the Azores and the West coast of Europe. ITOP was a component of ICARTT, an international initiative which coordinates the efforts of various American and European groups who have developed plans for field campaigns in the summer of 2004, with the aim of improving our understanding of the factors determining air quality over the two continents and over remote regions of the North Atlantic. The British contribution to ITOP, referred to as ITOP-UK, was funded by NERC through the UTLS-Ozone Directed Research Programme.

The ITOP-UK dataset includes forecast trajectories and other products to support ICARTT flight plans of the Summer 2004 (computed using ECMWF wind fields) and data collected aboard the FAAM Bae-146 aircraft in July and August 2004.