Year: 2026
Type: article
Abstract: Organic carbon in precipitation represents an important pathway linking atmospheric processes with terrestrial and aquatic carbon cycling, yet data from rapidly urbanizing tropical and subtropical cities remain scarce. This study investigated total organic carbon (TOC) concentrations in 264 rainwater samples collected from 21 wards across Hanoi, Vietnam, between May 2023 and December 2025. TOC concentrations ranged from 0.41 to 17.72 mgC.L-1, with an average of 3.75±2.94 mgC.L-1, exceeding mean values previously reported for Asia and global continental regions. Significant seasonal variability was observed, with TOC concentrations consistently higher during the dry season than the rainy season, reflecting the dominant influence of rainfall dilution and atmospheric washout processes. The study also detected an upward trend in annual mean TOC concentrations over the study period, suggesting increasing contributions from anthropogenic emissions. Despite Hanoi receiving relatively high annual rainfall, elevated TOC concentrations indicate that urban activities remain an important source of atmospheric organic carbon available for wet deposition. This study provides critical baseline data to improve regional and global estimates of wet organic carbon deposition, advance understanding of carbon cycling in urban environments, and support strategies for air quality management and sustainable rainwater use.
Institutions: Graduate University of Science and Technology, Viện Hóa học, Vietnam Academy of Science and Technology, Vietnam National University, Hanoi, VNU University of Science, Hanoi University of Industry, Centre National de la Recherche Scientifique, Université Paris-Est Créteil, Sorbonne Université, Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement, Institut d'écologie et des sciences de l'environnement de Paris, Seoul National University, Hanoi University of Natural Resources and Environment, Electric Power University, Viện Khoa học công nghệ Năng lượng và Môi trường
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W7222932465