Home The field Campaign Current activities Publications Links Internal use


Diabatic processes during the North Atlantic Waveguide and Downstream impact EXperiment

Modeling studies and comparison with observational datasets:

  • Stalactite cyclone (29 Sep - 3 Oct 2016):
            Figure 1: (Left) Flights tracks on 2 Oct 2016. (Upper right) Simulated reflectivity by a Meso-NH simulation (2.5-km resolution) forced by Arpege operational analysis along the flight F7. (Lower right) Measured reflectivity by the radar RASTA along the flight F7.             

The Flight F7 was dedicated to the observation of the warm conveyor belt ascending regions of the Stalactite cyclone. Different simulations are performed with the Meso-NH mesoscale model to assess the skills of the different parametrizations of the model, in particular cloud microphysics, and its impact on synoptic-scale dynamics.
  • Scandinavian blocking (3 - 16 Oct 2016):

Figure 2: (Left) Spatial correlations between the geopotential anomaly at a given time provided by the Arpege operational analysis and the geopotential anomalies of the 4 weather regimes. (Right) geopotential anomaly of each weather regime.

Early October 2016 was marked by a transition toward the Scandinavian blocking that last until the end of the field campaign. This transition is closely related to the development of the Stalactite cyclone. The ridge building downstream of the cyclone allowed to bring low potential vorticity values over Scandinavian region.

                                                                   Figure 3: Spatial correlations between the geopotential anomalies of the 10 members of the Arpege ensemble forecasts and the geopotential anomalies of the 4 weather regimes.                                                             

Even though the transition toward blocking can be anticipated by the ensemble forecasts 5 days in advance, the intensity of the anticyclonic anomaly is underestimated.
  • Cut-off Sanchez (9 - 15 October 2016):