Decreased nitrogen deposition in Beijing over the recent decade and its implications

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Ecosystem Sustainability

Background:

• Human activities like agriculture and fossil fuel combustion significantly alter atmospheric reactive nitrogen (Nr) deposition.
• Understanding Nr deposition changes is crucial for ecosystem functionality and sustainability.

Purpose of the Study:

• To report long-term measurements of wet and dry Nr deposition in Beijing from 1999 to 2022.
• To analyze the relationship between Nr deposition trends and China's air pollution control policies.

Main Methods:

• Long-term ground-based measurements of wet Nr deposition (1999-2022) and dry Nr deposition (2010-2022).
• Analysis of deposition data in relation to the "Action Plan for Prevention and Control of Air Pollution (APCP)" and fertilizer use policies.

Main Results:

• Total Nr deposition in Beijing decreased by 34% between 2010 and 2022.
• Dry N deposition saw a substantial reduction of 54.27%, with reduced and oxidized N decreasing by 29.93% and 72.05%, respectively.
• These reductions correlate with the implementation of the APCP and "Zero Growth in Fertilizer Use by 2020" policy.

Conclusions:

• Ground-based measurements provide evidence of successful air pollution control in Beijing.
• The findings offer a reference for other regions in China and globally for mitigating Nr pollution.