Contributions to DEEPWAVE from the DLR Dassault Falcon 20 Draft April 17, 2013 by RBS Additions April 23 2013 by AD If the DLR Falcon is able to join the DEEPWAVE campaign in New Zealand in 2014, there are a number of contributions it could make to the program. A preliminary list is given below. Hopefully the Falcon would have its new data acquisition system by then. The Principle Investigators would be Markus Rapp and Andreas Dornbrack. They would be invited to join the DEEPWAVE steering committee. There would be a meeting of the steering committee in advance of the project to finalize flight tracks and other details of the project. Falcon Contributions 1. Additional flight level measurement of vertical momentum and energy flux. (Note that energy flux requires differential GPS and accurate static pressure, along with gust probe vertical velocity measurements.) a. At altitudes from 4 to 11 km, below the NGV b. On parallel tracks to the NGV tracks c. On shorter tracks than the long 400 km NGV tracks 2. Disturbed wind field and gravity waves over the S. Alps terrain using the 2 μm Doppler wind lidar system1. The instrument performs a conical step-and-stare scan around the vertical axis with a nadir angle of 20°. The horizontal resolution of the wind profiles (5–10 km) is determined by the time needed for one scanner revolution (24 times 1 or 2 s as accumulation time per scan position, plus 6 s for the scanner motion) and the aircraft velocity (160–240 m s-1). The vertical resolution of 100 m is determined by the pulse length of 400 ns of the laser. The dominant horizontal scale of airflow over the S. Alps is probably between 10 and 200 km. So the horizontal resolution of the Doppler wind lidar might capture the wave structures larger than 30 km. A faster in-plane scan strategy will improve the spatial resolution. Nadir observations in high resolution are possible to measure the vertical wind component alone. During a flight switching between the different observing strategies is possible. 3. 3-D surveys of ambient and disturbed wind and temperature profiles over the sea, below the aircraft, upwind and downwind of New Zealand. This can be done using dropsondes and the Lidar Wind system. This is important for observing how the airflow approaches and flows around the mountains. 1 Weissmann, M., R. Busen, A. Dörnbrack, S. Rahm, and O. Reitebuch, 2005: Targeted Observations with an airborne wind lidar, J. Atmos. Ocean. Techn., 22, 1706-1719. 4. Mapping out the cloud field over the S. Alps using the backscatter intensity of the down-looking lidar. As the DEEPWAVE flights will be done at night, we will have no other observations of clouds over New Zealand. Cloud mapping is important as clouds may alter the generation of vertically propagating gravity waves. Expected cloud types include a. Lenticular (liquid or ice) clouds b. Undulating alto-stratus c. Shallow convective clouds Airborne Doppler wind lidar observations in the lee of Greenland during a so-called tip jet event which occurred on November 23 2003. Upper two panels: wind direction and speed from gust probe (uppermost rows) and Doppler wind lidar from analyzing one-scanner revolution data. Middle panel: vertical wind from gust probe. Lower two panels: horizontal wind analyzed from four scanner revolution data and backscatter intensity. Black areas mark either clean air or regions of low signal-to-noise ratio, e.g. below clouds.