NAWDEX aims at quantifying errors of the thermodynamic structure near Rossby waves and their relation to diabatic processes. The aim is to obtain a comprehensive and unprecedented data set in a region that, so far, was not accessible with smaller research platforms.
HALO and Falcon with instrumentation for NAWDEX
HALO provides the required flight range to reach the central and eastern North Atlantic and Europe and the altitude to perform remote sensing observations from above cloud systems. With the help of the established instrument combination of the WALES differential absorption lidar, the cloud radar of the Hamburg Microwave Package (HAMP), different radiometers and the dropsonde device the three-dimensional structure of water vapour, wind, temperature and cloud properties will be observed. Additionally to HALO, DLR will deploy its research aircraft Falcon with a wind lidar payload which allows a detailed observation of jet-level winds. The collected data inside and outside clouds allows to investigate the relevance of different diabatic processes and related weather systems for the Rossby wave evolution by validating different numerical models. Beside upper-level observations, the humidity structure in the lower troposphere is of interest for diabatic processes.
|HAMP (HALO Microwave Package)||HALO|
|HALO-SR||HALO||Univ. Leipzig||spectral nadir radiance, actinic flux densities
|specMACS||HALO||LMU Munich||spectral nadir radiance, actinic flux densities
||Dropsondes||HALO||DLR-PA||profiles of relative humidity, temperature and horizontal wind|
|BAHAMAS||HALO||DLR-FX||In-situ obervations of T,q, u, v, w, 100 Hz data, GPS|
|A2D||FALCON||DLR-PA||20 degree off nadir LOS velocity profiles|
|2-Ám Doppler Wind Lidar||FALCON||DLR-PA||profiles of the horizontal wind vector|
|in-situ instruments||FALCON||DLR-FX||In-situ obervations of T,q, u, v, w, 100 Hz data, GPS|
Overview of the NAWDEX instrumentation. For a detailed information about the instruments, resolution and accuracy please refer to the NAWDEX CIP
HALO and Falcon will operate over the eastern North Atlantic with the operation base in Iceland to guarantee optimal flight range and proximity to the regions of interest. The observation period in September and October is chosen as the above described weather systems characterized by strong diabatic activity and forecast busts are likely to occur. 100 flight hours from Iceland are envisaged with HALO. 50 flight hours are planned with the DLR Falcon. For a three-dimensional characterization of wind, temperature and moisture at jet level elongated high-level cross-sections across the jet stream and in regions where diabatically modified air masses interact with the wave-guide will be designed depending on the flow field.
For the first time it will be possible to follow the evolution of Rossby waves along the wave guide and to observe weather systems ranging from synoptic to cloud scales. Lagrangian tracking of diabatically modified air masses is planned. This will be tried with consecutive HALO/Falcon flights and by coordinating flights with the international partners. French colleagues applied for the use of the French Safire Falcon to perform measurements in downstream developing weather systems. Additionally, ground-based observations will be performed over Europe.