Impact of inertia-gravity waves (IGW) generated in the upper troposphere on precipitation events and the interaction of both phenomena

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The propagation of subtropical wet and warm air masses over the North Atlantic into the European region defines a Großwetterlage with intensive precipitation. The areas of precipitation, their intensity, time and duration are mainly determined by the nonlinear dynamics at planetary, synoptic and sub-synoptic (meso-) scales. The impact of these complex processes on precipitation events is not understood yet and will be studied in this project. The focus is on planetary poleward Rossby waves breaking events, because in this type of baroclinic lifecycles mesoscale low-frequency gravity waves, so-called inertia-gravity waves, are generated downstream of the jet streak. These waves may propagate from the upper troposphere down to the boundary layer. In potentially unstable situations these inertia-gravity waves may induce updrafts and subsequent deep convection leading to heavy precipitation events. For six selected cases high resolution model simulations should be performed to carry out process studies with explicit convection. The model results will be validated with observations and the problem of predictability will be examined.