Lagrangian particle dispersion models are indispensable tools to study atmospheric transport processes. Lagrangian transport models simulate the dispersion of trace gases and aerosols by means of trajectory calculations for large sets of infinitesimally small air parcels or `particles’. In contrast to Eulerian models, in Lagrangian models the particles are distributed on an irregular grid following the fluid flow. A major advantage of this approach is that it is less affected by numerical diffusion and well capable of representing small-scale features of the atmosphere, such as filaments of tracers associated with long-range transport. Because of their distinct advantages, Lagrangian transport models found various operational and research applications.

At the Jülich Supercomputing Centre, we are developing the Lagrangian particle dispersion model MPTRAC. Compared with other models, MPTRAC is particularly suited for use on supercomputers because of its efficient MPI/OpenMP hybrid parallelization. MPTRAC found first applications in studying the dispersion of trace gases and aerosols related to volcanic eruptions (Hoffmann et al., 2016), inverse transport modeling to estimate volcanic emissions (Heng et al., 2016), and transport of aerosols associated with the Asian summer monsoon (Wu et al., 2017). More recently, the model has been carefully validated by means of superpressure balloon observations (Hoffmann et al., 2017) and the accuracy and efficiency of different numerical schemes has been assessed (Roessler et al., 2018). This presentation summarizes the main findings of the first Lagrangian transport studies with MPTRAC and gives an outlook to future work.

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