Upper-layer ozone intrusion promotes wintertime secondary aerosol formation on the ground. - Wang, Yuzheng; Liu, Yongchun; Zheng, Feixue; Ma, Wei; Zhang, Yusheng; Hua, Chenjie; Chen, Xin; Xie, Jiali; Wang, Zongcheng; Ma, Pengkun (National Science Review, 2026)