The key to improving weather forecasts in the mid-latitudes is to get new measurements that are not already used to make the forecasts, especially in regions that are very sensitive to small disturbances. Therefore direct observations of wind in the Jetstream and moisture and clouds in the surrounding of low pressure systems over the Atlantic Ocean are required. In September and October 2016 researchers from the DLR Institute of Atmospheric Physics went to Iceland to conduct the ‚North Atlantic Waveguide and Downstream Impact Experiment‘ (NAWDEX). With the aid of modern remote sensing instruments onboard the research aircraft HALO and Falcon a unique data set of wind, moisture and cloud observations could be obtained. Data from special measurement sondes were used at the global weather centers. To complement the aircraft observations an increased measurement density was achieved by ground based observations over the North Atlantic and Europe. In total more than 30 international scientific partners were involved in NAWDEX.
NAWDEX was the first field experiment with HALO that focused on atmospheric dynamics. The large range and high flight altitude of HALO for the first time allowed flights over the dense air traffic routes over the North Atlantic Ocean. During the four week observation period the researchers observed a very active period. The predominant path from southwest towards Iceland allowed a series of flights to investigate the structure and intensification of low pressure systems as well as their interaction with the jet stream. For the first time it was possible to follow the entire track of a Hurricane from the tropics to the mid-latitudes with observations. Furthermore it was possible to obtain the first measurements of the structure of an arctic low pressure system at the tropopause. In the coming weeks a thorough analysis of the impact on the quality of the forecasts as well as a verification of weather models with the obtained measurements is planned that shall help to improve the predictability of weather in Europe.
During NAWDEX coordinated flights of the SAFIRE Falcon, the British BAE-146 and the NASA/NOAA GlobalHAWK with HALO and Falcon were performed. The coordinated flights between HALO, DLR and the SAFIRE Falcon that were possible for the first time during NAWDEX are of great interest for the DLR researchers as comparable radar and lidar instruments, that were deployed onboard the aircraft, will be operated on the future satellite missions ADM-Aeolous and EarthCARE of the European Space Agency (ESA). The NAWDEX data set is highly valuable to compare the different instruments, to investigate radar and lidar instrument synergies and to improve methods to derive satellite data products in the future.
The HALO and Falcon contribution to NAWDEX is a common project of DLR Institut für Physik der Atmosphäre, the Ludwig-Maximilians-Universität Munich, the Max-Planck-Institut für Meteorologie in Hamburg and the universities Köln, Hamburg and Leipzig, and the ETH Zürich. NAWDEX is a research initiative that is funded by the Deutsche Forschungsgemeinschaft (DFG) and the European Space Agency (ESA).
Dr. Andreas Schäfler
DLR press release
Satellite missions ADM-Aeolus and EarthCARE of the European Space Agency, ESA