Ammonia emissions are associated with many agricultural operations including animal and poultry operations, waste and wastewater treatment operations, fertilizer and manure land applications. The fate of ammonia released to the atmosphere is affected by interaction with other gases, aerosols, and fine particles. These interactions affect the gas-to-particle conversion. This process alters ammonia concentrations downwind from agricultural operations.

However, experimental research and modeling of the gas-to-particle conversion processes in ammonia rich environment is generally limited. This white paper will summarize the state-of-the-art knowledge related to gas-to-particle conversion of ammonia. The white paper will be focused on the implications the gas-to-particle conversion has for agricultural sources of ammonia emissions including swine, beef cattle, dairy operations and land applications. Specific gaps in the knowledge related to implications of the gas-to-particle conversion of ammonia released from agricultural operations will be identified.