Characteristics of Sensible Heat, Water Vapor, and CO2 Fluxes Over a Rice Paddy

An eddy-correlation system consisting of a sonic anemometer and an open-gas analyzer was used for understanding the characteristics of sensible heat, water vapor, and CO2 fluxes over a subtropical rice paddy in Taipei, Taiwan. The results showed that about 35-40 percent of net radiation was used for latent heat flux, 13 percent for sensible heat flux, and the rest (about 50 percent) was absorbed by the water and soil in the rice paddy. Based on the background measurements (where no rice was growing), it was found that CO2 emission from the soil surface was small, just about 0.074 micro mole per square meter per second. We also found that the relative turbulent transport efficiencies of heat to water and heat to carbon dioxide depended on Bowen ratio. However, in average, heat, water vapor, and carbon dioxide were transported with the same rate above this rice paddy.