NAWDIC (North Atlantic Waveguide, Dry Intrusion, and Downstream Impact Campaign) is an international field campaign focusing on mid-latitude dynamics with the aim to provide required observations for understanding the tropopause structure and downstream high impact weather (HIW) in the eastern North Atlantic winter. NAWDIC will build directly on insights of the North Atlantic Wave guide and Downstream impact EXperiment (NAWDEX; Schäfler et al. 2018) and is scheduled to take place in the winter of 2024 or 2025.
To evaluate and improve NWP model representation of tropopause structure and PBL processes, observations of temperature and water vapor variations on the sub-grid scale are vital, but these are routinely not available. NAWDIC aims to systematically sample the near-tropopause structure with a particular focus on its sharpness in the vertical and horizontal directions in regions from where DIs originate. We complement this by following and probing the descending DI air streams from above until they reach and interact with the PBL in regions of exceptional surface heat and moisture fluxes. Finally, we plan probing with high spatio-temporal resolution in downstream regions prone to HIW related to strong winds and deep convection.
NAWDIC aims is to enhance our understanding of how extratropical HIW emerges downstream of particular large-scale environments and study the multi-scale mechanisms involved. Furthermore, NAWDIC will provide new observations in high resolution to evaluate NWP model performance. As such, NAWDIC lies at the heart of the Predictability and Processes theme. Two of the project leaders, Andreas Schäfler and Shira Raveh-Rubin, are members of the P&P task team.
For more information about NAWDIC, please visit https://internal.wavestoweather.de/campaign/projects/nawdic/wiki