SILAM CTM simulations for the arrival of an invasive ladybird (Harmonia axyridis) to the UK for years 2004 and 2005

The first Harlequin ladybirds (<em>Harmonia axyridis</em>) arrived to the UK in 2004 and 2005. The dataset presents the SILAM atmospheric chemical transport model (CTM) simulatios of the arrival of<em> H. axyridis</em> to the UK in 2004 and 2005 and inverse CTM simulations from the first<em> H. axyridis</em> recods in 2004. These SILAM simulations are theoretical. They are intended to help assess whether it was possible for ladybirds to fly over the English Channel. <strong>LadybirdsSILAMforward.tar </strong>includes SILAM CTM forward simulation for 2004 and 2005. PM10 and PM2.5 particles represent ladybirds. The source is daily 5 -18 UTC from some cities in France, Belgium and Netherlands. The fileformat is GrADS. <strong>HarlequinsFootprintsFirstObsUK.tar</strong> includes the inverse simulations of <em>H. axyridis</em> from the first records in the UK in 2004. PM10 and PM2.5 particles represent ladybirds. Fileformat is GrADS. Ctl-files are examples for the grads-file, and they also describe output resolution and output timesteps for the SILAM model simulations.