The main scientific objective of T-REX is a comprehensive study of the coupled mountain-wave--rotor--boundary-layer system. Complimentary scientific issues include stratospheric-tropospheric exchange (STE) and structure and evolution of the complex-terrain boundary layer in the absence of rotors. Resulting from the need to document atmospheric conditions and processes from the Earth surface up to the upper-tropospheric/lower-stratospheric altitudes, the T-REX field campaign had both a comprehensive ground-based and an airborne observing program. The ground-based observing platforms were located on both sides of the high Sierra Nevada, with the majority of instrument platforms positioned near the town of Independence in Owens Valley in the Sierra Nevada lee. These include Doppler and aerosol lidars, wind profilers, sodars, networks of automatic weather stations, soil moisture and temperature sensors, flux towers, and radiosonde operations. The three aircraft involved in the airborne program were NSF/NCAR HIAPER, UK FAAM BAe146, and the University of Wyoming King Air, which were involved in a number of two- and three- aircraft coordinated missions.
Fifteen Intensive Observing Periods that documented the coupled rotor and boundary layer system were carried out during the two-month field campaign. In addition, five Enhanced Observing Periods were conducted to observe the quiescent boundary layer evolution in the absence of rotors. The comprehensive T-REX data sets afford us with a unique opportunity to address basic scientific questions motivated by T-REX, and provide crucial observations for numerical model validation. In this talk we will summarize the integrated observing system deployed in T-REX, discuss the key observations, and illustrate how the observations from the integrated observing system are being used to address basic T-REX scientific questions