The Aerosol Direct Radiative Impact Experiment (ADRIEX) was a joint UK Met Office/Natural Environment Research Council (NERC)/UK Royal Society/University of Oslo project aiming at improving our understanding of the radiative effects of anthropogenic aerosol and gases (ozone and methane) in the troposphere.

This dataset contains backward trajectories arriving over Europe from the TOMCAT model.

“Chemical attributes” are found by interpolating chemical distributions (in space and time) from a global chemical transport model to the origin of each trajectory (using its full length). During the ICARTT campaign the TOMCAT global CTM is being run in near-real time (about 19 hours behind present) driven by wind analyses from the ECMWF. The back trajectories are sufficiently long that a TOMCAT chemical analysis exists even at the origin of forecast trajectories. For example, the longest forecast lead time for the Azores domain is 5 days but the back trajectories are 7 days long so that the TOMCAT fields dating from 2 days before the latest meteorological analysis are used to find the attributes. For the US East Coast domain the back trajectories are shorter (3 days long) but the longest lead time is also 3 days so that the chemical attributes can be calculated as soon as TOMCAT has been brought up to date with the latest ECMWF analyses.