In the past decades, intensive human agricultural activities have caused a significant increase in ammonia (NH3) emissions to the atmosphere, which have led to serious environmental and public health problems. Accurate quantification of NH3 emissions from agricultural ecosystems is essential for the understanding of NH3 budgets at regional to global scales as well as for the control and mitigation strategies on air pollution.
Scientists at the Institute of Atmospheric Physics of the Chinese Academy of Sciences and their collaborators from Ningbo HealthyPhoton Co., Ltd. have developed a portable and solar-powered open-path NH3 analyzer (model: HT8700). This analyzer is specifically designed for NH3 flux measurement based on the eddy covariance (EC) method, the most direct and effective way to measure NH3 exchanges between terrestrial ecosystems and the atmosphere. The team investigated the analyzer's suitability to measure NH3 fluxes through laboratory and field experiments and published their study in Agricultural and Forest Meteorology.
A flux system based on the EC method requires an NH3 analyzer with high sensitivity and fast response. For the conventional closed-path NH3 instruments, the surface adsorption effect of NH3 causes longer response time and therefore introduce measurement bias. Meanwhile, the sampling pumps for the closed-path systems usually require high power consumption, which makes them not feasible in field deployments particularly in places where grid power is not readily available.
Read more at: Institute of Atmospheric Physics, Chinese Academy of Sciences
Eddy covariance flux measuring system for ammonia (Photo Credit: Kai Wang)