Aerosol scavenging: model application and sensitivity analysis in the Indian context

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Ecology

Background:

• Sulfate aerosols are primary drivers of precipitation acidity.
• Acidic precipitation poses long-term ecological risks to aquatic ecosystems.
• Understanding sulfate scavenging is crucial for environmental impact assessment.

Purpose of the Study:

• To apply the layer-averaged aerosol-scavenging model for predicting wet scavenging coefficients and sulfate concentrations in Indian cities.
• To analyze the sensitivity of the scavenging coefficient to precipitation intensity.
• To validate model predictions against measured data from selected Indian urban areas.

Main Methods:

• Utilized the layer-averaged aerosol-scavenging model (Okita et al., 1996).
• Performed sensitivity analysis (Pandey et al., 1997) to determine key influencing factors.
• Collected and compared model predictions with measured sulfate concentrations and scavenging coefficients in precipitation samples.

Main Results:

• The wet scavenging coefficient is highly sensitive to precipitation intensity.
• Model predictions for sulfate concentrations and scavenging coefficients were generated for Delhi, Mumbai, Calcutta, and Chennai.
• Comparison with measured data provided validation of the model's applicability.

Conclusions:

• The aerosol-scavenging model effectively predicts sulfate levels in precipitation.
• Precipitation intensity is a critical factor in the wet deposition of sulfate aerosols.
• The study provides valuable insights for managing acid rain impacts in Indian urban environments.