Water-air transfer resistance for ammonia from flooded rice

Abstract

Vertical flux densities of ammonia, water vapour and sensible heat were measured over a flooded rice field in China following the application of ammonium bicarbonate fertilizer. Aqueous and gaseous phase transfer resistances for ammonia were deduced from these measurements. The aqueous phase resistance was maximal in the morning and least in the afternoon. Stable stratification of the floodwater immediately adjacent to the air-water interface was observed during the morning when evaporation rates were low, and may be responsible for inhibiting the transfer of ammonia to the atmosphere.

Field observations of the ocean‐atmosphere exchange of ammonia: Fundamental importance of temperature as revealed by a comparison of high and low latitudes

“…Ammonia is a soluble gas and its transfer is generally considered to be under gas‐phase control [ Liss , 1983] . There is some evidence that under conditions of extreme surface water stability (such as those observed in stagnant, short fetch waters) there is a water‐phase component to the rate of transfer across the air‐water interface [e.g., Trevvit et al , 1988]. However, this is not thought to be applicable to the open ocean situation.…”