INTERCOMPARISON AMONG 4 FLUX AIRCRAFT AT BOREAS IN 1994

Four airplanes measured fluxes of momentum, heat, water vapor, and car bon dioxide in 1994, during the intensive field campaigns of the Borea l Ecosystem-Atmosphere Study (BOREAS): the NOAA/ATDD Long-EZ, the NRC Twin Otter, the University of Wyoming King Air, and the NCAR Electra. This paper presents the results of wing-towing formation flights compa ring the flux measurements from these airplanes. Comparisons of the sp ectra of wind components, air temperature, water vapor concentration, and carbon dioxide concentration along with the cospectra of these qua ntities with vertical velocity showed numerous instructive differences . However, among the three airplanes using established techniques, the fluxes and variances of these quantities generally did not differ by more than one would expect, given the separation of the airplanes. Sta tistics computed from the Long-EZ data, based on a still evolving appl ication of the Global Positioning System, often differed more strongly .