The Front Range Air Pollution and Photochemistry Experiment (FRAPPE) - an overview

Abstract:

The Front Range Air Pollution and Photochemistry Experiment (FRAPPÉ) was designed to quantify the factors controlling surface ozone in the Northern Front Range Metropolitan Area (NFRMA) and determine whether current and planned emission controls are sufficient to reduce ozone levels below standards. The experiment was conducted simultaneously with the 2014 DISCOVER-AQ (Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality) intensive, and employed a coordinated set of ground-based, aircraft-based and satellite measurements.

The NFRMA is subject to emissions from a wide variety of very diverse sources such as transportation, power generation, agriculture and livestock operations, oil and gas extraction activities, and natural emissions from vegetation. Inflow into the state can contain elevated ozone brought about from emissions originating from other Western states, Canada or Asia. Terrain-induced, complex mountain-valley circulation patterns, can, to some extent, recirculate polluted air and exacerbate high ozone events. This transport also contributes to high ozone, visibility degradation, and deposition of pollution into Rocky Mountain National Park and other pristine areas.

Fifteen flights were performed between July 26 and August 17, 2014, on board the NCAR/NSF C-130 research aircraft, which was equipped with a comprehensive gas phase photochemistry and aerosol payload. The C-130 flights covered much of the State of Colorado. Numerous ground sites and mobile labs were taking measurements simultaneously, and the NASA P3, B-200, and Falcon aircraft flight operations were concentrated on the NFRMA itself.

This presentation will summarize the FRAPPÉ activities and present first results with respect to emission characterization of the area and comparison with inventories, contributions of emission source types to ozone production and particle composition, transport and chemical evolution of air masses from the NFRMA into adjacent, remote areas such as rural mountain communities and Rocky Mountain National Park, as presented in detail later in this session by individual research groups.