Lagrangian analysis of convective rainfall under different synoptic forcing

Precipitation is commonly analysed from an Eulerian perspective, in which rainfall is considered at a fixed location. Lagrangian analysis of precipitation represents an alternative approach. Here, precipitation objects – for example, convective cells – are identified in a precipitation field and are then tracked through space and time, allowing object properties over the whole life of a convective cell to be collected. This approach offers additional insights into the mechanisms by which convective cells develop and behave across their lifecycle, which would not be evident from standard analysis methods.

In this study, we perform Lagrangian analysis of convective cells under different large-scale circulation regimes. Tracking is based on convection-permitting simulations with the COSMO-CLM at 0.025° resolution over central Europe. All identified precipitation objects are tracked through space and time, collecting cell characteristics for each object, e.g. cell area, intensity, distance travelled, etc. Here we associate precipitation objects with categorical synoptic-scale circulation patterns and compare the cell properties between the different categories.