Recent measurements of momentum and heat flux between 5.66 and 22.6 meters on a tower over a flat uniform site indicate that both fluxes are constant with height to within ±20%. Some important aspects of instrument performance relevant to flux measurement, e.g., sonic anemometer array configuration, alignment and leveling of the axes, and errors in sonic thermometry, are discussed. The large variations observed in the vertical momentum flux gradient during unstable conditions appear to be the result of intermittent bursts in the momentum transport. Some characteristics of these bursts are described. Long averaging periods, of the order of an hour, are needed for meaningful estimates of flux gradients under such conditions.
If you can't find a tool you're looking for, please click the link at the top of the page to "Go to old article view". Alternatively, view our Knowledge Base articles for additional help. Your feedback is important to us, so please let us know if you have comments or ideas for improvement.