Virtual Workshop: Warm Conveyor Belts – a challenge to forecasting

Different mechanisms for the influence of diabatic heating on the dynamics of the jet stream include: i) radiative maintenance of potential vorticity (PV) contrast across the tropopause, ii) sharpening of jet stream maximum wind by the “non-advective PV flux”, iii) amplification of baroclinic wave growth rate through lower “effective static stability” and iv) diabatic mass transport into...

Potential vorticity (PV) provides a conceptual stepping stone from diabatic heating rates in warm conveyor belts to their impact on the large-scale flow. Given the diabatic heating rates, the associated modification of the PV field can be computed and the resulting PV anomalies used to understand both the local intensification of the parent cyclone and any downstream impacts on the...

Tropopause folds are characterized by strong horizontal gradients of temperature, water vapor, and cloud. The two-stream radiation schemes used in almost all weather and climate models ignore this variability. Using the Monte Carlo code MYSTIC, we have computed thermal infrared heating rates for a two-dimensional cross-section of an upper-level front in a NAWDEX event, based on thermal and...