July 15, 2015

Wind-Lidar-Campaign in preparation of the ADM-Aeolus Mission

For accurate weather forecasts for Europe it is crucial to capture the winds over the North Atlantic as precisely as possible. Scientists at the DLR Institute of Atmospheric Physics have developed an airborne prototype of a wind lidar (light detection and ranging) that is scheduled for deployment on a new European Space Agency (ESA) satellite for launch by end 2016. In May 2015, DLR was using its Falcon research aircraft to test an aircraft-based version of the wind lidar technology. From their base in Iceland, the researchers were flying over the ice sheets of southern Greenland. Another wind lidar that was used over Iceland to take volcanic ash measurements during the eruption of Eyjafjallajökull in 2010 was used as a reference instrument on board the Falcon. The flights were performed in cooperation with ESA and NASA, which provided two other wind lidars on NASA's research aircraft DC-8. For the first time worldwide, four wind lidar instruments on two aircraft were taking measurements at the same time. In addition 100 sondes were dropped from the DC-8 aircraft to measure wind and temperature profiles with in-situ sensors. Another wind lidar from the University of Leeds (UK) was specifically deployed for this campaign on the Greenland summit station to measure surface winds.

The wind-lidar technology that was tested and calibrated on the aircraft is an important step towards ESA's Atmospheric Dynamics Mission ADM-Aeolus. This will be the first wind lidar in space capable of measuring the altitude profile of the atmospheric wind from ground up to 30 km. This satellite will use a Doppler wind lidar to measure wind, cloud and aerosol profiles along its path and provide data in near real time. These profiles will be used for improving the weather forecast and fill a crucial gap in the global observing system of the World Meteorological Organization (WMO). Researchers at the DLR Institute of Atmospheric Physics and the DLR Remote Sensing Technology Institute will process data from the satellite.

All objectives for the campaign could be achieved during the coordinated flights from the DLR Falcon and NASA DC-8: calibration flights over the Greenland ice sheet, a flight towards the US research station at an altitude of 3200 m at Greenland summit, flights towards the southern tip of Greenland with high surface winds and an underpass of the MetOP-B satellite. During the 3-weeks campaign period, the weather situation offered two times the possibility to fly above a jet stream in the North Atlantic in the southwest of Iceland with wind speeds up to 70 m/s in 10 km altitude. The unique dataset from 4 airborne Wind-Lidar instruments, from 100 dropsondes, and from the ground-based measurements of the Greenland Summit Station are being analysed by scientists at DLR, NASA and ESA to ensure an optimal preparation of the future satellite mission ADM-Aeolus.