Parallel emissions inventories were prepared for dispersion and chemical transport modeling in the Permian Basin. In both inventories, routine emissions of light alkanes from oil and gas sources were estimated with hourly resolution. Emissions were spatially aggregated based on their distance from a centralized air quality monitor and model input requirements. Several tools and datasets including, among others, the Methane Emissions Estimation Tool (MEET), the U.S. EPA Non-Point Oil and Gas Tool, the U.S. EPA Greenhouse Gas Reporting Program (GHGRP), and the U.S. EPA Inventory of Greenhouse Gas Emissions and Sinks (GHGI), were used to develop the emissions estimates. Predictions from a puff dispersion model (CALPUFF) and a chemical transport model (CAMx) with source-tagging capabilities were combined to predict ambient hydrocarbon concentrations at a centrally-located air quality monitor operated by the Texas Commission on Environmental Quality (TCEQ) in Midland TX. Time-matched measurements from the ambient air quality monitor were used to evaluate the model predictions and the relative contribution of near ( ≤ 50km away) and distant (> 50 km) sources. The impact of reactive losses were also evaluated. The framework was further applied to evaluate potential sources of seasonal emissions patterns.