Abstract
An eddy correlation method is usually used to measure latent and sensible heat fluxes above urban surfaces. This method needs to simultaneously measure the fluctuation of specific humidity, air temperature and vertical wind speed about lOHz frequency at the short path length with high accuracy. In the present study, a near-infrared hygrometer with two open optical paths is newly developed in order to measure the fluctuation of specific humidity in the field. The results of indoor experiments indicate the accuracy under 0.2g/kg. The results of field measurements show the necessity of the simultaneous measurement of solar radiation and specific humidity.
