20 January 2025

The Sustainable Nitrogen Management Seminar 2025 – Accumulation of Nitrogen Data in EANET was held online on December 22, 2025 bringing together 58 participants. Organized under the EANET Project Fund Activity 2025-04 by the Network Center for the EANET, the seminar focused on strengthening the accumulation, analysis, and utilization of nitrogen-related data to address growing regional and global nitrogen pollution challenges.

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Addressing Nitrogen Beyond Planetary Boundaries

The seminar opened with remarks underscoring nitrogen as a pollutant that has transgressed planetary boundaries, posing serious risks to ecosystems, human health, and climate. Speakers referred to the 2022 United Nations Environment Assembly (UNEA) Resolution on Sustainable Nitrogen Management that calls for sustainable nitrogen management worldwide. Against this backdrop, EANET’s role as a long-term regional monitoring network in East Asia was positioned as increasingly critical for evidence-based policymaking.

Moderated by Dr. Hiroyuki Sase of the Asia Center for Air Pollution Research (ACAP), serving as the Network Center for the EANET, the session highlighted how EANET’s Medium-Term Plan (MTP) 2026–2030 places nitrogen management as one of the core objectives. Dr. Toshimasa Ohara, Director General of ACAP, emphasized that EANET’s extensive datasets on atmospheric concentration and deposition offer a strong foundation for advancing sustainable nitrogen strategies and supporting international environmental cooperation.

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Advancing Nitrogen Monitoring Science

The technical session showcased cutting-edge research and monitoring approaches. Professor Kazuhide Matsuda from Tokyo University of Agriculture and Technology presented an assessment of atmospheric nitrogen deposition using EANET data. He drew attention to the growing significance of reduced nitrogen (ammonia) and the challenges of accurately measuring it, particularly the artifact problems associated with traditional filter-pack methods. He proposed passive samplers as a practical, cost-effective option for expanding ammonia monitoring across rural and forested areas.

Complementing this, Dr. Yongjoo Choi from Hankuk University of Foreign Studies demonstrated how CrIS satellite data, combined with in-situ measurements and machine learning bias correction, can map ammonia concentrations with high spatial and temporal resolution. His findings revealed elevated ammonia levels over agricultural and livestock-intensive regions in Republic of Korea, especially during summer, illustrating the value of integrating satellite and ground-based observations.

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Focus on Ammonia and Deposition Complexity

A major discussion theme was the complexity of ammonia (NH₃) deposition, particularly its bidirectional exchange between the atmosphere and ecosystems. Depending on environmental conditions, ammonia can be either deposited or re-emitted, complicating net flux estimates. Participants stressed the need for improved models, enhanced measurement techniques, and hybrid data approaches to better understand ammonia’s ecological impacts.

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Strengthening Collaboration for the Future

In closing, Dr. Fan Meng, Deputy Director General of ACAP, thanked the speakers and participants for their active engagement. The seminar concluded with a shared understanding that enhanced monitoring, innovative data analysis, and international collaboration will be essential for managing reactive nitrogen pollution effectively across the EANET region.

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Find out more about the EANET Project Fund.

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Useful Resources:

–Event Summary

-Presentations:

• Introductory remarks: EANET’s potential for contributing to sustainable nitrogen management (by Dr. Hiroyuki Sase)
• Regional assessment of atmospheric nitrogen deposition using EANET monitoring data (by Prof. Kazuhide Matsuda)
• Spatio-temporal distribution of ammonia over Korea using CrIS satellite (by Dr. Yongioo Choi)

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Photo credits: Japan (2019) by Nomadic Julien.