A13B-3163:
Modeling Spatial and Temporal Variability in Ammonia Emissions from Agricultural Fertilization in China
Monday, 15 December 2014
Chuchu Chen and Qiang Zhang, Tsinghua University, Beijing, China
Abstract:
Ammonia (NH
3) is a key precursor to atmospheric fine particulate matter (PM
2.5) and an important component of the reactive nitrogen cycle, with strong implications for both regional air quality and ecosystems. Due to limited parameterization of the complex interactions between fertilizer usage, farm practices, soil and meteorological conditions, ammonia emission estimates for agricultural fertilization over China, one of the most important ammonia emission sources, are usually based on time-averaged emission factors and temporal profiles. Here we develop a process-based ammonia emission model for fertilize use at fine spatial and temporal scales in support of air quality models. The model estimates NH
3 emissions based on the parameterization of crop acreages, fertilizer application rates, plant growth period, fertilizer use patterns, soil processes, and meteorological conditions. Preliminary results show that the total ammonia fertilizer emission in China was approximately 3.8 Tg in 2006 with peak emissions during April to June. The regions with the highest emission rates are located in Central China. We also examine the sensitivities of different parameters on NH
3 emission estimates. We found that the magnitude of NH
3 emissions is most sensitive to fertilizer application rates while the seasonality of emissions is more sensitive to fertilization time.
