Nick Szapiro-April 4

On a world without TPVs: A currently broken experiment

Our predictions and understanding of the coupled, multi-scale Arctic are limited. Tropopause polar vortices (TPVs) are common, coherent upper-level potential vorticity anomalies with radii of 100 to 1000 km, intensities of 1 to 50 K, and lifetimes of days to months. What roles do TPVs play in the (predictability of the) Earth system? Case studies illustrate mechanisms for (the intensities of) TPVs to impact surface cyclones, Rossby wave breaking, and Arctic sea ice loss. Using a global, variable resolution, and coupled atmosphere-land-sea ice-ocean-river Earth system model (CESM-CAM-MPAS), sensitivity experiments were intended with localized tendencies to weaken and amplify TPVs to causally quantify their impacts, contextualized relative to variability in the CESM Large Ensemble model climate. Current software errors prevent the simulations but permit more time to reconsider the experimental design, which will be the focus of the discussion.