Seasonal Changes of Turbulent Fluxes at a Typical Agricultural Site in the Chengdu Plain Based on Quality-Controlled Data

抄録

Land surface pattern and the quality of turbulent data exert important influences on calculations of surface momentum and heat fluxes. This article assesses the excellence of quality-controlled data, which are at Wenjiang station in April, July, and September 2007 and January 2008, and uses high-quality data to analyze the seasonal changes of flux footprint and calculate the aerodynamic roughness length z₀. We use total flux data to analyze the seasonal changes of fluxes for different underlying surfaces. Footprint analyses show that the distribution of flux contribution in source regions is related to not only wind directions but also underlying surfaces. An estimate of z₀ is near 0.9, but the value of z₀ is close to 0.05 when wind direction is near NNW. There are obvious seasonal changes in heat fluxes, but not in momentum flux.