Tower at the Boulder Atmospheric Observatory
Tower at the Boulder Atmospheric Observatory, Credit: Shelby Frisch

Study begins at BAO to characterize vertical gradients of aerosol concentration


June 21, 2011

NOAA's Boulder Atmospheric Observatory (BAO) will host a month-long sampling study to be conducted by the National Center for Atmospheric Research (NCAR) Biosphere-Atmospheric Interactions Group and the University of Colorado's Mechanical Engineering Department. The goal of this study is to characterize the vertical gradients of aerosols near the earth's surface. Aerosols play a key role in visibility degradation, climate, as well as negatively impacting human health. Of particular interest is the vertical gradient of the larger mode of particles, termed coarse particulate matter (PM), which have a diameter between 10 and 2.5 micrometres (µm), in comparison to smaller PM. For coarse PM concentrations, comparison between ground level measurements and the Community Multi-scale Air Quality model output demonstrates that the regulatory model drastically under predicts the actual concentrations. One possible explanation is a poor description in the model of the vertical distribution in the lower atmosphere.

Located just east of Erie, CO, the BAO has been operated by ESRL's Physical Sciences Division since the mid-1970s and serves as a unique facility for monitoring the Earth's atmospheric boundary layer.

For this experiment, filters will be collected at five elevations on the BAO's 1000' research tower. Air pumped through these filters will capture PM in two size ranges; coarse mode and accumulation plus ultrafine modes. Filter sample collection will range from 24 to 72 hours. Students from CU's Mechanical Engineering department and NCAR's Significant Opportunities in Atmospheric Research and Science (SOARS) program will be involved in the setup, collection and analysis. Ancillary data collected at the BAO, including meteorological data, will be used to interpret the PM measurements.

Over the years, the BAO has hosted several large national and international experiments and numerous smaller ones. This study will investigate health impacts of the larger aerosol particles, and help improve understanding of their sources, transport and fate. Results will be used to assess and possibly improve the regulatory model.


Contact: Dan Wolfe More Information: