3rd HyMeX workshop 1-4 June 2009 Heraklion (Gournes), Crete-Greece
T-NAWDEX - The THORPEX North Atlantic Waveguide and Downstream Impact Experiment: Outline of scientific backgroundHeini Wernli (University of Mainz); Andreas Dörnbrack(DLR Oberpaffenhofen, Germany), George Craig(DLR Oberpaffenhofen, Germany), Sarah Jones (University and Research Centre Karlsruhe, Germany)
T-NAWDEX is a THORPEX field experiment tentatively scheduled for autumn 2012. The scientific goal is to investigate the triggering of waveguide disturbances, their subsequent evolution over the North
Atlantic and the associated downstream impacts over Europe, the Mediterranean and Northern Africa. This new field experiment is motivated by the following concerns: Errors in medium-range forecasts for Europe originate mainly due to a small number of "busts", caused by the inaccurate representation of events such as extra-tropical transitions of tropical cyclones, warm conveyor belts and diabatic Rossby waves. Forecast errors in extratropical cyclones reveal typical patterns, for example, the downstream side of the trough in developing cyclones should often be sharper in the forecasts compared to the analysis. It is one of the underlying hypotheses of T-NAWDEX that these deviations are associated with latent heat release, which is the most poorly understood and modeled part of the dynamics. Therefore, the observational strategy of T-NAWDEX will be guided by the need to have novel and detailed insight in key thermo-dynamical processes occurring in (rapidly) developing weather systems. In T-NAWDEX, this will be facilitated by advanced observing technologies as satellite platforms, active/passive remote sensing, in-situ sensors, and others instruments.
This presentation will provide an outline of the scientific basis of T-NAWDEX and of the current status of the campaign planning, including the connection with the Mediterranean HYMEX experiment.