We now simulate methane concentrations at each sensor location during the events identified in the previous step. We run a separate simulation for all potential sources on the oil and gas site, which allows us to pick the most likely source for each event in the following step. The framework is not intrinsically tied to any atmospheric transport model, and for this paper we select the Gaussian puff model as a balance between simulation accuracy and computational expense, availability, and ease of use. This model approximates a continuous release of methane from a point source as a sequence of many small "puffs," each of which is modeled using a three-dimensional Gaussian-like function. This provides a reasonable approximation of atmospheric transport within a short time period after release and over short distances barring any major obstructions that would block the transport of methane (e.g., a large building), and hence we think it is suitable for use in our framework when applied to oil and gas production sites.