“…The mixing ratios at the lower boundary are adopted as 0.1, 0.2, 0.1 and 0.5 ppbV for CFCl3, CF2Cl2, CCl4 and CH3Cl, respectively. These values are based on measurements in the non-urban troposphere by Lovelock (1971Lovelock ( , 1972Lovelock ( , 1974Lovelock ( , 1975, Lovelock et al (1973), Wilkniss et al (1973Wilkniss et al ( , 1975a, Su and Goldberg (1973), Simmonds et al (1974), Hester et al (1974Hester et al ( , 1975a, Grimsrud and Rasmussen (1975a, b), Zafonte et al (1975), and Cox et al (1976).…”