Contrasting annual variation of organic and elemental carbon in the Pearl River Delta: Insights from three years of continuous observations and the unique conditions of the COVID-19 lockdown - Haoxin Sui; Jisheng Zhang; Chenglei Pei; Jing Yu; Li Fang; Chunyue Miao; Yifan Zhang; Yongpan Liu; Yanxia Li; Zheng Zong; Dawei Lu; Likun Xue (Journal of Environmental Management, 2026)