A determination of the Dalton and Stanton numbers over a saturated barley field

Abstract

In order to determine the values of the Dalton and the Stanton numbers, an observational study was made over a saturated barley field in the Hachirogata. flat reclaimed land located in the northern part of Japan. The mean height of the barley was about 11 cm; the roughness height for momentum was determined from the mean wind profiles as 4.24 ? 0.18 cm and the zero-plane displacement height as 0 cm. Under neutral stratification and a saturated surface, ;he reciprocals of the Dalton and Stanton numbers, Da-' and St-', were estimated. The results show that the mean value of St-' is 12.1, and the ratio of the bulk transfer coefficient for heat to that for momentum, CHICw, is 0.53, which are not entirely incompatible with the few results available from past observations. The mean value of Da-' is 38.2. This value is larger than St-', and fits reasonably well with the semi-empirical equation proposed by Brutsaert (1975a,b).