[Application of inverse Lagrangian dispersion analysis in simulating forest evapotranspiration]

Based on the localized near field (LNF) theory and coupled with the distribution of vertical velocity standard deviation (sigma(w)(z)) and Lagrangian integral time scales (T(L)(z)) within the canopy proposed by Raupach, the relationship between water vapor source/sink distribution and its mean concentration profile was constructed. The estimation of forest evapotranspiration was also conducted by the inverse Lagrangian dispersion analysis, which can calculate the water vapor source/sink distribution from its mean concentration profile. The calculated forest evapotranspiration was compared with the measured values. It was concluded that the simulated precision of the daily daytime evapotranspiration could reach 87.3%, the calculated results was 15 %-25% higher than the measured one, the nighttime evapotranspiration was about 70% of the daily value, and the total monthly evapotranspiration from June to August was higher than that in May and September.