Measurement Errors in Vertical Wind Velocity at the Boulder Atmospheric Observatory

Abstract

This paper describes an effort to identify instrumental and flow-related contributions to the mean vertical velocity offsets observed by sonic anemometers on the Boulder Atmospheric Observatory's 300 m tower. A simple technique to remove these offsets, which typically range from 0.1 to 0.2 m s?1, is presented. The correction yields 20 min averaged vertical velocities with good temporal and spatial continuity. Corrections for the vertical velocity standard deviation and the temperature flux are negligible. For momentum flux, the correction could be important when that flux is very small.