%0 Dataset
%T Data and codes for the paper "Chloramine chemistry as a missing link in atmospheric chlorine cycling"
%J National Cryosphere Desert Data Center
%I National Cryosphere Desert Data Center(www.ncdc.ac.cn)
%U http://www.ncdc.ac.cn/portal/metadata/873a775f-8280-417a-ae11-1ccf638db83f
%W NCDC
%R 10.12072/ncdc.atmosphere.db7322.2026
%A Jiang Jingkun
%A Chen Yijing
%A Xia Men
%A Zhang Jinghui
%A Epameinondas Tsiligiannis
%A Wu Cheng
%A Yan Chao
%A Cai Runlong
%A Zheng Guangqing
%A Li Yuyang
%A Guo Junchen
%A An Zhaojin
%A Li Yiran
%A Zhao Xinyan
%A Qu Qipeng
%A Hua Chenjie
%A Wang Zongcheng
%A WANG Shuxiao
%A Liu Yongchun
%A Cao Lina
%A He Kebin
%A Markku Kulmala
%A Mattias Hallquist
%A Wang Tao
%A Douglas Worsnop
%K Chloramine chemistry;urban air pollution;atmospheric chemistry
%X Chlorine radicals (Cl·) profoundly affect atmospheric oxidation capacity. Chloramines, especially trichloramine, are emerging precursors of Cl·. However, their sources and roles in the atmosphere remain elusive. This study presents field evidence of primary emissions and explicit secondary production pathways of atmospheric trichloramine in Beijing, supplemented by observations from New Delhi and reanalysis of measurements in Toronto. We demonstrate that the sequential chlorination reactions initiated by molecular chlorine and ammonia in atmospheric aerosols are a major source of trichloramine. The trichloramine produced in aerosols is a source of gaseous trichloramine and serves as an intermediate during the conversion from molecular chlorine to Cl·, while direct trichloramine emissions constitute a previously overlooked source of Cl·. Overall, chloramine chemistry alters the Cl· production mechanism and represents a crucial missing pathway to Cl· worldwide.