Intercomparison of Airborne Water Vapour DIAL Measurements with Ground Based Remote Sensing and Radiosondes within the Framework of LUAMI 2020

Abstract

Within the framework of the 'Lindenberg campaign regarding an Upper-Air Methods Intercomparison' (LUAMI), an intercomparison of water vapour profile measurements between ground based lidars and radiosondes with an airborne differential absorption lidar (DIAL) were performed. On 17. October 2008 the DLR Falcon aircraft carried out a flight over middle Europe with overpasses of the ground based observatories located at Payerne (MeteoSwiss, Switzerland), Bilthoven (RIVM, Netherlands), Lindenberg (DWD, Germany) and Zugspitze (IMK, Germany). The aircraft was equipped with DLR's new four-wavelength water-vapour DIAL WALES and a coherent wind lidar operating at 2 μm wavelength. On this day the water vapour field over the probed region showed a highly non-standard vertical distribution with a very dry layer at about 3 km altitude, most probably originating from a stratospheric intrusion. This gave an excellent opportunity to compare RAMAN lidar, DIAL, and radiosonde measurements under conditions far from the standard profile. The results of this effort will be shown together with a critical analysis of the relative benefits and deficits of the different probing methods which were applied.