Observations of Airborne Pollutants and Deposition During the 2006 Rocky Mountain
Airborne Nitrogen and Sulfur (RoMANS) Study

J. Collett, C. Gorin, S. Raja, C. Carrico, T. Lee1, F. Schwandner,
Atmospheric Science Department, Colorado State University, Fort Collins, COw

D. Day,
National Park Service/CIRA, Colorado State University, Fort Collins, CO

A. Sullivan, G. McMeeking, K. Beem, S. Kreidenweis
Atmospheric Science Department, Colorado State University, Fort Collins, CO

J. Hand, B. Schichtel, W. Malm
National Park Service/CIRA, Colorado State University, Fort Collins, CO

Recent ecological studies have shown a number of deleterious effects due to elevated and increasing deposition of nitrogen compounds in Rocky Mountain National Park (RMNP). The Rocky Mountain Airborne Nitrogen and Sulfur (RoMANS) study was conducted to improve our understanding of the sources and transport of airborne nitrogen and sulfur species within RMNP as well as their deposition pathways. Two field campaigns were conducted, in spring and summer 2006, to characterize pollutant transport and deposition during seasons with historically high nitrogen deposition inputs. Several measurements sites were operated within the park, at locations to the west and east of the park boundaries, and at locations near the northeastern, northwestern, and southeastern boundaries of the state of Colorado. Measurements at several sites included 24- hour integrated gas concentrations (ammonia, nitric acid, sulfur dioxide) PM2.5 composition, and wet deposition. A core measurement site in the park included more detailed and higher time resolution chemical, optical, and size distribution measurements. Measurements here included 15 min measurements of PM2.5 composition using a Particle Into Liquid Sampler (PILS), a Micro Orifice Uniform Deposition Impactor (MOUDI), a suite of 5 minute gas measurements, a nephelometer, and measurement of particle size distributions over the range 40 nm to 15 micrometers. An overview of study findings will be presented including the inorganic composition of collected PM2.5, concentrations of key trace gas species, and observations of wet deposition composition and fluxes. We will also examine variability in composition between sites, compare relative inputs from dry vs. wet deposition for various nitrogen species, and illustrate relationships between transport patterns and pollutant concentrations and deposition in the park.