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From July to September of 1990,CH_4 flux measurements were made in Lin’an rice paddies using gradient profiletechniques.Some characteristics of the turbulence structure under the stable conditions have been verified in the surfacelayer according to the in situ measurements.The semi-empirical turbulent parameters β_m,β_h and β_c and their changeswith the stability parameter Ri are given.Observed results indicate that CH_4 flux in the rice-paddy is mainly decided bythe methnogenesis and the process of CH4 transport from internal soils to the atmosphere,and that the CH_4 verticaltransfer is depressed in the stable surface layer.The CH_4 flux shows that its obvious diurnal changes,and the meanCH_4 flux are higher in nighttime and lower in daytime,and the peaks appear at about 2000 BST at night and 0300 BSTin the early morning,respectively.The mean value of CH_4 flux is about 4.18±2.3 mg/m~2 h.
From July to September of 1990, CH_4 flux measurements were made in Lin’an rice paddies using gradient profile techniques. Home characteristics of the turbulence structure under the stable conditions have been verified in the surface layer according to the in situ measurements. The semi-empirical turbulent parameters β_m, β_h and β_c and their changes with the stability parameter Ri are given .Observed results indicate that CH_4 flux in the rice-paddy is mainly decided by the methnogenesis and the process of CH4 transport from internal soils to the atmosphere, and that the CH_4 verticaltransfer is depressed in the stable surface layer. The CH_4 flux shows that its obvious diurnal changes, and the mean CH_4 flux are higher in nighttime and lower in daytime, and the peaks appear at about 2000 BST at night and 0300 BST in the early morning, respectively. The mean value of CH_4 flux is about 4.18 ± 2.3 mg / m ~ 2 h.