The Budget of Turbulent Energy Measured at the ERC 30-m Meteorological Tower

[摘要] Turbulence measurements of wind and temperature were made by sonic anemometerthermometers in the first thirty meters of the atmosphere. Turbulent statistics obtained by direct measurements were analyzed, using the Monin-Obukhov similarity theory.The behaviors of the terms in the turbulent energy budget were examined, together with the relation of turbulent statistics to the measured parameters such as mean wind speed, stability and height. A model of the turbulent energy budget was derived from the results. Under near neutral conditions, mechanical production and viscous dissipation are dominant and essentially in balance, while turbulent transport and buoyant production are not important. In unstable conditions, each term in the budget is important. Buoyant production is a gain and turbulent transport is a loss. In stable conditions, all terms except turbulent transport are significant. Mechanical production and the imbalance are the sources of turbulent energy and the others energy sinks. For both stable and unstable conditions, the imbalance increases with the magnitude of stability.

[学科分类] 大气科学