10Be/7Be implies the contribution of stratosphere-troposphere transport to the winter-spring surface O3 variation observed on the Tibetan Plateau.

¹⁰Be/⁷Be is a stratospheric sensitive tracer. In this paper, measurements of ¹⁰Be/⁷Be and surface O₃ from October 2005 to May 2006 at Mt. Waliguan (hereafter WLG, 100.898°E, 39.287°N, 3810 m, a.s.l.), China global atmospheric watch (GAW) observatory, are introduced and used to investigate the stratosphere-troposphere transport (STT) and its impact on surface O₃ on the Tibetan Plateau. The results show that the magnitude of STT is weak in winter, followed by strengthening from the end of winter to 10 7 10 7 the middle of spring (from mid February to mid April) with large increases in Be, Be, Be/ Be and surface O₃. At the end of spring (from the end of April to mid May in this paper), the STT weakened, and the continuous increase of surface O₃ at WLG is produced by tropospheric photochemistry reactions. [ABSTRACT FROM AUTHOR]