Workshop: Stratospheric predictability and impact on the troposphere

Stratospheric changes, with a timescale of a few weeks, are associated with substantial effects on surface weather and climate, especially on the Northern Annular Mode (NAM) with associated long-lasting shifts in the jet streams, storm tracks, and precipitation. Despite unambiguous observations of this phenomenon, as well as numerical simulations, a quantitative physical explanation of this...

The two leading empirical orthogonal functions (EOFs) of zonal-mean zonal wind describe north–south fluctuations, and intensification and narrowing, respectively, of the midlatitude jet. Under certain circumstances, these two leading EOFs cannot be regarded as independent but are in fact manifestations of a single, coupled, underlying mode of the dynamical system describing the evolution in...

The ECMWF IFS (European Centre for Medium-Range Weather Forecasts – Integrated Forecasting System) and other numerical weather prediction models are known to be affected by a moist bias in the polar lowermost stratosphere. This results in an overestimation of long wave cooling and therefore to a cold bias. We use airborne GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere)...