Robert W Portmann¹, Eric A Ray², John S Daniel¹, Pengfei Yu^3,4, Stephen A Montzka⁵ and Geoffrey S Dutton⁶, (1)NOAA Boulder, Boulder, CO, United States, (2)NOAA/CIRES, Boulder, United States, (3)CIRES, Boulder, CO, United States, (4)Jinan University, Guangzhou, China, (5)NOAA/ESRL Global Monitoring Division, Boulder, CO, United States, (6)NOAA/ESRL GMD, Boulder, CO, United States