Virtual Workshop: Warm Conveyor Belts – a challenge to forecasting
Session
Conveners
Session 10
- Frederic Vitart (ECMWF)
The physical and dynamical processes associated with warm conveyor belts (WCBs) have a major impact on the large-scale midlatitude dynamics and are important sources and magnifiers of forecast uncertainty. Most often, WCBs are defined as trajectories that ascend in a time interval of two days from the lower troposphere into the upper troposphere. Although this Lagrangian approach has been...
Subseasonal weather prediction bridges the gap between weather forecasting and climate projection and is receiving increasing attention across various socio-economic sectors. Predictability on subseasonal timescales is gained from slower climate modes such as the MJO or stratosphere. Thus synoptic-scale activity might project initially small error on the large-scale circulation and dilute...
During a one-week episode at the turn of the years 2015/2016, maximum surface air temperature in the Arctic reached record high values of more than 0°C, which led to pronounced, widespread sea-ice melting in the middle of the cold season. In this study, we adopt a Lagrangian perspective to investigate the origin of the warm air masses and the meteorological processes that allowed them to reach...
The link between cloud radiative forcing (CRF) and warm conveyor belts (WCBs), which are strongly ascending airstreams in extratropical cyclones, is investigated based on ERA-Interim reanalysis from 1979 to 2011. Clouds associated with WCBs can be liquid, mixed phase, or ice clouds. They interact with the longwave and shortwave radiation in different ways and thus strongly influence Earth’s...