Source Apportionment of Sulfur and Light Extinction Using Receptor Modeling Techniques

Area of Science:

• Atmospheric chemistry and physics
• Environmental science
• Aerosol science

Background:

• Visibility impairment is primarily caused by sulfates, carbonaceous material, and soil.
• Source apportionment schemes must account for both secondary and primary aerosols.
• Chemical Mass Balance (CMB) is a common method for apportioning primary particles.

Purpose of the Study:

• To develop a semiquantitative apportionment of particulate sulfur, total sulfur, absorption, and extinction to source categories.
• To apply regressional techniques for a more comprehensive source apportionment of both primary and secondary species.
• To refine source profile extraction and verification within CMB analysis.

Main Methods:

• Utilized regressional techniques with unique tracer species to apportion secondary and primary aerosols.
• Applied Chemical Mass Balance (CMB) formalism to attribute aerosols to specific sources.
• Integrated regression models with CMB analysis to link trace elements to source categories.

Main Results:

• Approximately 50% of measured particle sulfur is attributed to coal-fired power plants year-round.
• In winter, about 50% of particle sulfur may originate from primary emissions due to burning activities and urban sources.
• Light extinction (babs) is significantly influenced by burning activity (winter) and burning, transportation, and soil (summer).

Conclusions:

• Regressional techniques offer a robust method for source apportionment of both primary and secondary aerosols.
• Coal-fired power plants are a major contributor to particle sulfur.
• Understanding source contributions is crucial for developing effective visibility management strategies.