Less than 1 month after the successful NARVAL-II campaign in the Tropical Atlantic, the DLR HALO aircraft left for another campaign in the North Atlantic that has the potential to be as important and insightful for us as NARVAL-II. The NAWDEX: North Atlantic Waveguide and Downstream Impact Experiment was an international field experiment with the overarching scientific aim of to increase the physical understanding and to quantify the effects of diabatic processes on disturbances to the jet stream near North America, their influence on downstream propagation across the North Atlantic, and consequences for high-impact weather in Europe. NAWDEX ran from September 19 - October 16 2016 and besides HALO included the DLR Falcon, the French Falcon and the British FAAM; there was also some coordinated measurements with the US Global Hawk/SHOUT program. NAWDEX was able to accumulate a total of 15 Intensive Observation Periods that include a variety of highly interesting situations, for example the extratropical transition of tropical cyclone Karl.
NAWDEX has strong ties to to the German SFB Collaborative Research Center Waves to Weather that studies how diabatic processes impact the ability to forecast weather. For HD(CP)² the Science Team S6 plans to also make heavy use of the NAWDEX data as they provide unique measurements of cloud and precipitation processes and their link to the large-scale extratropical circulation. For example, North Atlantic ICON_LEM simulations are planned for the NAWDEX period, with the idea that these simulations will also be useful to researchers from Waves to Weather and thus help us to strengthen the link between weather and climate. More information about NAWDEX can be found on http://www.pa.op.dlr.de/nawdex/index.html and http://www.w2w.meteo.physik.uni-muenchen.de/cca/campaign-data/nawdex/index.html.