NAWDEX
Final Report Abstract
The North Atlantic Waveguide and Downstream Impact Experiment (NAWDEX) was an international measurement campaign over the North Atlantic Ocean in the autumn of 2016. HALO and three other aircraft made detailed observations of intensifying storms, with the goal of improving weather forecasting systems. The focus was on structures called warm conveyor belts, where air rises rapidly and small errors in the forecast amplify quickly. The campaign was very successful, and provided an unprecedented data set with detailed observations of many weather systems. The measurements confirmed a key hypothesis of the campaign, that the outflow from warm conveyor belts at the tropopause is a primary area of uncertainty for downstream weather forecasts. The results were even more dramatic than expected, and included the first-ever observations of negative potential vorticity – a condition that indicates strong instability in the air flow. The many detailed observations of storm structure from NAWDEX are being used to evaluate different aspects of weather prediction models in collaboration with the weather services in different countries.
Publications
- 2018: The North Atlantic Waveguide and Downstream Impact Experiment, Bull. Amer. Meteor. Soc., 99, 1607–1637
Schäfler, A., G. Craig, H. Wernli, P. Arbogast, J.D. Doyle, R. McTaggart-Cowan, J. Methven, G. Rivière, F. Ament, M. Boettcher, M. Bramberger, Q. Cazenave, R. Cotton, S. Crewell, J. Delanoë, A. Dörnbrack, A. Ehrlich, F. Ewald, A. Fix, C.M. Grams, S.L. Gray, H. Grob, S. Groß, M. Hagen, B. Harvey, L. Hirsch, M. Jacob, T. Kölling, H. Konow, C. Lemmerz, O. Lux, L. Magnusson, B. Mayer, M. Mech, R. Moore, J. Pelon, J. Quinting, S. Rahm, M. Rapp, M. Rautenhaus, O. Reitebuch, C.A. Reynolds, H. Sodemann, T. Spengler, G. Vaughan, M. Wendisch, M. Wirth, B. Witschas, K. Wolf, and T. Zinner
(See online at https://doi.org/10.1175/BAMS-D-17-0003.1) - 2019: Aircraft-based stereographic reconstruction of 3-D cloud geometry. Atmos. Meas. Tech., 12, 1155-1166
Kölling, T., T. Zinner, and B.Mayer
(See online at https://doi.org/10.5194/amt-12-1155-2019) - 2019: The impact of dropsonde and extra radiosonde observations during NAWDEX in autumn 2016. Mon. Wea. Rev., 148, 809–824
Schindler, M., M. Weissmann, A. Schäfler, and G. Radnoti
(See online at https://doi.org/10.1175/MWR-D-19-0126.1) - 2020: Observation of jet stream winds during NAWDEX and characterization of systematic meteorological analysis error, Monthly Wea. Rev.
Schäfler, A., B. Harvey, J. Methven, J. D. Doyle, S. Rahm, O. Reitebuch, F. Weiler, and B. Witschas
(See online at https://doi.org/10.1175/MWR-D-19-0229.1)
