EPATAN-NEAREX 2016 : a Franco-Norwegian contribution to the NAWDEX campaign in Iceland

The NAWDEX experiment (North Atlantic Waveguide Downstream and impact Experiment) took place from mid-September to mid-October 201. It is the most important international campaign dedicated to the study of atmospheric perturbations in the North Atlantic that has been organized since nearly 20 years, with the FASTEX campaign in 1997. NAWDEX studies the small scale thermodynamical processes inside these perturbations, particularly inside the “warm-air conveyor belts” which are not necessarily well described in the models, leading to uncertainties in the short- and medium-range weather forecasts.
The French airborne component has participated from 28th September to 17th October 2016, when the Safire Falcon 20, based in Iceland at Keflavik Airport, performed 14 flights for the benefit of French (LATMOS, LA, LaMP, LMD et Météo-France) and Norwegian (Norwegian met, Univ. Bergen, Univ. Oslo) scientific teams. DLR from Germany was engaging 2 aircrafts, one Falcon 20 and one Gulfstream 5 “HALO” in the NAWDEX campaign. The British BAE146 from FAAM also participated to a coordinated flight with French and German aircraft, preparing forthcoming space missions (on MetOp – Eumetsat).
Measurements made during flights of the SAFIRE F20 were aiming to deal with the goals of two projects. On one side, EPATAN, funded by ESA and CNES, is preparing the “Earthcare” space mission (clouds and aerosol radiative forcing), and ADM-Aeolus (atmospheric dynamics), notably by providing a unique dataset of active teledetection measurements with the instruments RASTA (radar 95 GHz) and LNG (lidar 355 nm). On the other side, the project NEAREX that was selected by EUFAR and led by a Norwegian team, aims at a better understanding of air masses called” atmospheric rivers”, which transport heat and moisture from subtropical areas to higher latitudes and may cause intense precipitations over lands. Releasing of dropsondes completed the dataset by in-situ measurements, which were directly sent to the global telecommunication system (GTS).
As a synergy with the NAWDEX campaign, a wide set of clouds and mid-latitude typical situations have been sampled. Comparisons can also be made with measurements of similar instruments on-board other participating aircrafts.
Thanks to the excellent reliability of aircraft and instruments, as well as involvement of people, the French team could perform the whole program of flights, even during severe conditions.

The movie shown below was directed by Arnaud Mansat for SAFIRE.