ISS Observations of Mountain Waves and Rotors during T-REX

NCAR operated three ISS (Integrated Sounding System) stations for T-REX (Terrain induced Rotors EXperiment) in the lee of the High Sierras in the Owens Valley California during the spring of 2006. These systems include a surface meteorology station and wind profiler with RASS. One of the wind profilers was MAPR (Multiple Antenna Profiler Radar), which is capable of making very rapid wind measurements, and this ISS also hosted a radiosonde system, sodar, sky camera, and ceilometer. The MAPR ISS was located near the center of the valley; a second ISS was located part-way up the western slope. The third ISS was our mobile ISS (MISS) and this was moved around the valley for different IOPs.

All of the ISS observed interesting activity such as waves and possible rotors. For example the MISS system was sometimes positioned such that all three ISS were along a line across the valley and each observed different phases of waves that appeared to be trapped across the valley. At other times westerly flow aloft and reverse flow below was observed, suggesting rotors. Such features were also seen by other instruments in the valley, such as the REAL lidar scanning through and around the ISS locations. Examples of wave and rotors observations from the three ISS and REAL will be presented and discussed.