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Shown here are daily updated backtrajectories for ICOS atmosphere stations and some other stations. The trajectories go backwards in time for 6 days (144 hours) and arrive every hour from today 0:00 until 5 days ahead at 23:00. Time between each square in the backtrajectory is 6 hours. The backtrajectories give an indication of the expected atmospheric flow arriving at the arrival time at the station at the measurement height. As most ICOS towers measure at several heights and the air masses can be quite different with height we calculate backtrajectories for every available measurement height, in total 120 receptor points.
Please beware that backtrajectory positions have a large uncertainty that grows with time backwards and with forecast time. After several days of travel backwards in time the position is just an indication. Also forecasted trajectories calculated more than 3 days in advance should be treated as just an indication. This data is updated daily, the update occurs around 12:00 AM.
Provenance: Meteorological data from the ECMWF operational IFS model, retrieved at 1x1 degree global and 3 hour time resolution, using FlexExtract V7.1.1 software. Backtrajectories are calculated using Flextra V5.0, the downloadable files are gzipped text output files from Flextra. Trajectories are plotted by a small python3 program using matplotlib and BaseMap; the plots are glued into a movie using ffmpeg.