1999 BRAVO Study

BRAVO, the Big Bend Regional Aerosol and Visibility Observational Study, is the more detailed study to follow the 1996 preliminary study. The United States and Mexico did not reach agreement on the BRAVO study design; as a result, BRAVO includes monitoring in the United States only.

The primary goals of the BRAVO are to understand the long-range, trans-boundary transport of visibility-reducing particles from regional sources in the U.S. and Mexico and to quantify the contributions of specific U.S. and Mexican source regions and source types responsible for poor visibility at Big Bend National Park.

In addition to determining impacts from individual sources, simultaneous assessment of all the important regional sources of haze at Big Bend National Park is desirable. This would allow for the formulation of more effective emissions control strategies in both countries that would ultimately result in the improvement of air quality in Big Bend National Park and throughout the region.

Other goals that are relevant to the BRAVO Study include:

• Determination of the chemical constituents of fine particles responsible for regional hazes along the U.S.-Mexico border, inclusive of Big Bend National Park;
• Determination of the effects of meteorology including moisture from the Gulf of Mexico on visibility-reducing particles.
• Evaluate and improve the accuracy of atmospheric models and source attribution methods through the use of atmospheric tracers and updated source emissions profiles.

The Final Program Plan for the Big Bend Regional Aerosol and Visibility Observational Study (BRAVO) describes in detail the reasons for the study, its objectives and goals, study design, tracer release, data gathering, data analysis, data management, and quality assurance. The BRAVO field measurements occurred during the four-month period July-October, 1999. Analysis of the field measurements is ongoing.