Comparative analysis of nitrate evolution patterns during pollution episodes: Method development and results from
Yafei Li1, Yan Han2, Simeng Ma1
1State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control & Center for Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; CMA-NKU Cooperative Laboratory for Atmospheric Environment-Health Research, Tianjin 300000, China.
The Science of the Total Environment
|October 27, 2022
Summary
This study identifies three distinct patterns in particulate nitrate evolution during air pollution episodes. Understanding these patterns, driven by physical and chemical factors, is crucial for predicting pollution and developing mitigation strategies.
Area of Science:
- Atmospheric Chemistry
- Air Pollution Dynamics
- Environmental Science
Background:
- Particulate nitrate is a key component of air pollution, with complex formation mechanisms.
- Nitrate concentration changes are influenced by various factors across different pollution stages.
Purpose of the Study:
- To analyze typical nitrate evolution patterns during air pollution episodes.
- To identify the driving factors behind these patterns in different stages.
- To develop conceptual models for nitrate evolution.
Main Methods:
- An episode-based analysis was applied to twelve air pollution episodes.
- Nitrate evolution patterns were abstracted and categorized into distinct types.
- Conceptual models were constructed based on observed evolving shapes.
Main Results:
- Three typical nitrate evolution patterns were identified: "hump-shaped" (Type 1, 66.3%), "triangle-shaped" (Type 2, 24.3%), and "trapezoid-shaped" (Type 3, 9.4%).
- Type 1 is characterized by rapid growth linked to boundary layer height drops.
- Type 2 shows slower growth potentially driven by chemical processes, while Type 3 features a prolonged plateau influenced by high humidity and updrafts.
Conclusions:
- Pattern identification is essential for understanding nitrate evolution.
- The findings provide insights for improving air pollution prediction.
- This research supports the development of targeted scientific mitigation strategies for particulate nitrate.
