This dataset provides AutoMObile trace Gas Surveyor (AMOG) in situ relevant datasets collected during the CO2 and Methane EXperiment (COMEX) field campaign and afterwards. COMEX was conducted in the summer and fall 2014 to study strong methane, CH4, sources in S. California including animal husbandry, fossil fuel industrial (FFI) production, petroleum refining, landfills, and natural geological formations. The AMOG Surveyor is a mobile air quality laboratory built into a passenger car. AMOG Surveyor uses an asynchronous logging system based on a NMEA tagging protocol, termed a tagstream. Analyzers provide data at rates from 5 Hz to 0.016 Hz. Tagstream data are timestamped based on the time of the analyzer measurement, which does not take into account the air sample travel time in sample tubes and analyzers, termed layback time. This dataset contains Level 0 (L0) and Level 1 (L1) data. L0 data were analyzed and sensor data interpolated to a uniform timebase of 5 Hz, correcting for the layback time, the time of flight for air samples in the sample tube and analyzers. L1 data include true winds (corrected for vehicle velocity), with filtering of outliers, non-physical data, and gap filling. The data files are in HDF-5 (.h5) format.