International NAWDIC “Dry Run”

In less than a year from now, the international “North Atlantic Waveguide, Dry Intrusion and Downstream Impact Campaign” (NAWDIC) will take place in North Atlantic-European region.

In less than a year from now, the international “North Atlantic Waveguide, Dry Intrusion and Downstream Impact Campaign”(NAWDIC) will take place in North Atlantic-European region (https://www.nawdic.kit.edu/). The overarching goal of the campaign, which is coordinated by IMKTRO, is to advance our understanding of dynamical and physical processes across scales in extratropical cyclones leading to high impact weather events, such as gale-force winds or heavy precipitation. The research campaign incorporates measurements from three European research aircraft, which will be based in Ireland and France and from KITcube (https://www.kitcube.kit.edu/), which will be deployed at the Western coast of France. Many German and international research institutions contribute to the research campaign. Such a large-scale research campaign requires substantial preparation in terms of coordination of measurement strategies and flight plans. Therefore, the hybrid, so-called NAWDIC “Dry Run” took place at the end of January 2025 for a two-week period (https://www.nawdic.kit.edu/24.php).

During the Dry Run, all participants mimic realistic campaign conditions, which includes setting up detailed flight plans across the North Atlantic for the respective weather conditions. Challenges in the flight mission planning arise due to several reasons. These includeuncertainties in the weather forecast, air traffic restrictions, instrument limitations, as well as coordination of the three aircraft.

To practice mission planning under realistic conditions, real weather forecast data from the European Centre for Medium-Range Weather Forecasts were employed and used for the visualisation of weather conditions along the virtual flight tracks (Fig. 1). Figure 1a illustrates one mission option for the long-range German research aircraft HALO. In that scenario, the goal is to observe the mesoscale structure of the cold front as well as the structure of the upper-level jet using remote sensing instruments and the KITsonde dropsonde system. A typical (virtual) campaign day consisted of a General Planning meeting in the morning to discuss and coordinate upcoming missions, break-out groups for individual aircraft missions during the day, as well as detailed weather forecast discussions in the afternoon.

Thanks to the great engagement of all participants, the two weeks were successful - the Dry Run resulted in lots of gained experience, a large number of different mission scenarios, and increased motivation of all participants. We are now looking forward to January 2026 and the start of the NAWDIC campaign.

(a) Example of a virtual flight track (blue line) planned during the NAWDIC Dry Run to observe the structure of the cold front (way points 1-2, 3-4), processes in the cold sector (way points 2-3), as well as atmospheric conditions in the jet stream region (way points 5-6, 7-8). Shown are equivalent potential temperature and geopotential height (white contours) in the lower troposphere. (b) Virtual vertical cross-section along the flight track showing cloud cover and wind speed (red contours). The blue line displays the altitude of the aircraft.