Boise Valley Inversion and Air Pollution Study

EPA Grant Number: R829425E01
Title: Boise Valley Inversion and Air Pollution Study
Investigators: Dawson, Paul
Current Investigators: Dawson, Paul , Crawford, Ronald L. , Greeley, Joseph N.
Institution: Boise State University
EPA Project Officer: Hunt, Sherri
Project Period: September 1, 2002 through August 31, 2004
Project Amount: $517,650
RFA: EPSCoR (Experimental Program to Stimulate Competitive Research) (2001) RFA Text |  Recipients Lists
Research Category: EPSCoR (The Experimental Program to Stimulate Competitive Research)


The Boise valley (Treasure Valley), which has been experiencing a high rate of growth in the last decade, is particularly susceptible to prolonged winter valley inversion events. Atmospheric inversions often trap polluted air in the Treasure Valley and make it unhealthy to breathe. The dominant atmospheric pollutant in winter valley inversions consists of particulate matter (PM).

The objectives of the research are the following: (1) to monitor, model, and analyze winter inversion events in the Treasure Valley, including the meteorology and the three-dimensional airflow; and (2) to collect, measure, and analyze meteorological and PM data over space and time. The focus of the research is to accurately simulate the three-dimensional windfields. The windfields are necessary to develop accurate airshed modeling, a key component to Airshed Management and one of the highest Air Quality priorities in the Idaho Department of Environmental Quality (IDEQ).


The Fifth-Generation NCAR/Penn State Mesoscale Model (MM5) will be used to numerically simulate the meteorology of valley inversion events. Data from IDEQ?s air pollution monitoring sites and meteorological station, from the National Weather Service, and from various other meteorological sites in the Treasure Valley will be collected and analyzed for all of the multi-day winter inversion events. In addition, two portable sodar systems will be rented and used to analyze the inversion events and to validate the numerical modeling. These phased array Doppler sodar systems continuously measure wind speed and direction, vertical motions, turbulence, thermal structure, and mixing depth at heights ranging from 20 m up to 2000 meters.

The numerical modeling approach and the sodar system are novel and innovative techniques to study airflow in the Treasure Valley. All of the project components will be coordinated with personnel from the Air Quality Program Office of IDEQ.

Expected Results:

The research is expected to complement and support an air quality maintenance plan for PM in the Treasure Valley. It will provide a better understanding of the meteorology of winter valley inversion meteorology and will develop a local technology that can be used at other times and at other locations. The research will also provide educational incentives for valley residents about hazards, sources, and solutions of air pollution problems.

Supplemental Keywords:

mountain valley inversions, cool air pools, mesoscale modeling, particulate matter monitoring, air quality episodes., RFA, Scientific Discipline, Air, Geographic Area, Ecosystem Protection/Environmental Exposure & Risk, particulate matter, Ecology, State, Monitoring/Modeling, atmospheric dispersion models, atmospheric particulate matter, atmospheric measurements, Boise Valley, particulate, Idaho (ID), three dimensional air flow modeling, air quality models, airborne particulate matter, air pollution, Boise Valley Inversion, particulate matter mass, atmospheric inversion

Progress and Final Reports:

  • 2003 Progress Report
  • Final