Uncertainty Due to Hygrometer Sensor in Eddy 1 Covariance Latent Heat Flux Measurements
چکیده
9 Half-hour latent heat flux (LE) was measured over an early-maturing peach orchard 10 (Prunus persica L.) by two different hygrometers: 1) infrared gas analyzer (IRGA) (Li11 COR, model Li-7500); and 2) ultraviolet hygrometer (Campbell, KH20). A good 12 agreement between LE obtained with the IRGA (LEIRGA) and the KH20 (LEKH20) 13 hygrometers was observed. During rainy periods, LEIRGA and LEKH20 were not reliable 14 due to failure of the instruments caused by water drops standing over the sensors 15 heads. Filtering out rainy periods improved the similarity between LEIRGA and LEKH20: 16 mean estimation error, 6.2 W m; root mean square error, 21.3 W m; and refined 17 index of agreement, 0.919. Even though the IRGA hygrometer is generally 18 recommended, when economic constraints exist, the KH20 hygrometer can be used 19 with similar confidence. 20 21 22