Tropospheric, stratospheric and tropopause dynamics as well as related transports

Tropopause dynamics and cross-tropopause transport

The midlatitude dynamical tropopause (i.e. the 2 pvu surface) is typically richly structured and reveals mesoscale features like jet streaks, tropopause folds, streamers and cut offs. They correspond to the upper-level signatures of baroclinic waves and are often associated with significant cross-tropopause exchange. Our studies include the diagnostic case study analysis of the dynamical evolution of these mesoscale features, a climatological analysis of jets, PV cutoffs and PV streamers, and a comprehensive Lagrangian analysis of cross-tropopause transport.

Lower stratosphere dynamics

The dynamics of the lower stratosphere are of supreme importance for the coupling between the statosphere and the troposphere. Potential vorticity anomalies in the region have the dynamical potential to instigate cyclogenesis at
the surface.

Tropospheric transport

Understanding the pathways of tropospheric dust and water is an important clue in the process of unravelling the misteries of  the ice cores from the

Alps and Greenland. Lagrangian and high resolution climate models are used to shed light on these transport processes.

• Understanding the dynamical factors and phenomena leading to very cold temperatures in polar vortices. (Sandro Buss)
  

• Lagrangian analysis of moisture transport and sources:

    This project applies a novel back-trajectory based moisture transport diagnostic
    to investigate the link between moisture sources and transport and the stable
    isotope signal in ice cores. Current target areas include Greenland and the
    Swiss Alps (Harald Sodemann).

• Water transport in a regional climate model:

    This project uses the CHRM (Climate High Resolution Model) to simulate the
    transport of water vapour tracers. Current research focus is on understanding
    the premises of extreme precipitation events in central Europe
    (Harald Sodemann).

• Origin and characteristics of upper-level potential vorticity anomalies

    These are explored using tracking and backward trajectories. Contour dynamics
    simulations are used to examine the stability and interactions of vorticity 
    structures (Sarah Kew)

• idealized, full-physics model simulations of cyclogenesis in a
       moist baroclinic atmosphere (Rich Moore)
•  idealized, full-physics model simulations and detailed case study
       analyses investigating the role of diabatic processes in explosive
       cyclogenesis (Rich Moore)
  

• Concluded research