Tropospheric N2O variability

作者：Hiram Levy II, Jerry D. Mahlman, W. J. Moxim · 发表于：Journal of Geophysical Research Atmospheres · 年份：1982 · DOI：10.1029/jc087ic04p03061 · 被引用次数：89 · 研究领域：Atmospheric Ozone and Climate、Atmospheric and Environmental Gas Dynamics、Atmospheric chemistry and aerosols

Tropospheric N2O climatologies are simulated with the GFDL general circulation/tracer model for three idealized source specifications: (1) a constant surface flux of 1.44×109 molecules cm−2 s−1 distributed uniformly over the earth's surface with a global source strength of 17 tg N2O yr−1 and an atmospheric lifetime of 131 yr; (2) a 13 month integration of the stable N2O field from experiment 1 with its N2O source removed; (3) a constant surface flux of 2.24×1010 molecules cm−2 s−1 over only those land areas with precipitation in excess of an arbitrary limit of 127 cm yr−1, but with the same global strength (17 tg N2O yr−1) and atmospheric lifetime (131 yr) as in experiment 1. In the boundary layer the model produces an interhemispheric gradient with a minimum in the northern hemisphere (N.H.). This is due to the greater downward transport in the N.H. which results in more dilution of N.H. boundary layer N2O mixing ratios by the N2O poor air from the lower stratosphere. The boundary layer distribution of N2O is also influenced by the distribution of the surface source. The lack of an N2O maximum in the model's N.H. boundary layer suggests that, unlike the model's idealized source, the true source has a large excess in the northern hemisphere. Above the boundary layer the north‐south gradient is controlled by the large‐scale vertical transport which produces a N.H. minimum in N2O mixing ratio. The impact of the surface source distribution is small. Current measurements at 500 m...