An Intercomparison of Aircraft Air-Motion Measurement Systems During the TRACE-P and ACE-ASIA Formation Flights

Intercomparison flights were flown in the spring of 2001 between the NASA-Wallops P-3B and NCAR C-130Q aircraft. These research aircraft were participating in overlapping Tropospheric missions, the Global Tropospheric Experiment's (GTE) Transport and Chemical Evolution in the Pacific (TRACE-P) and Aerosol Characterization Experiment's ACE-ASIA mission, respectively. Both aircraft were equipped with similar air-motion measurement systems and in situ meteorology sensors designed to measure the eddy-correlation fluxes of momentum, heat, and water vapor. This paper presents the results of the informal intercomparison flights performed over the Sea of Japan. Data from intercomparison flight legs flown at several different altitudes within the atmospheric boundary layer in a "pacer aircraft" scenario have been analyzed. The variances and spectra of the three-dimensional winds, temperature, and humidity are presented along with the cospectra of the vertical velocities and various parameters. The results show good consistency in the measurements obtained from the two aircraft during the intercomparison periods. Discrepancies in the data are analyzed and discussed.