Publication Date:
2013-07-07
Description:
[1] Observations of tropospheric N 2 O mixing ratio show significant variability on inter-annual timescales (0.2 ppb, 1 standard deviation). We found that inter-annual variability in N 2 O is weakly correlated with that in CFC-12 and SF 6 for the northern extra-tropics and more strongly correlated in the southern extra-tropics suggesting that inter-annual variability in all these species is influenced by large-scale atmospheric circulation changes and, for SF 6 in particular, inter-hemispheric transport. N 2 O inter-annual variability was not, however, correlated with polar lower stratospheric temperature, which is used as a proxy for stratosphere to troposphere transport in the extra-tropics. This suggests that stratosphere to troposphere transport is not a dominant factor in year-to-year variations in N 2 O growth-rate. Instead, we found strong correlations of N 2 O inter-annual variability with the Multivariate ENSO Index. The climate variables, precipitation, soil moisture and temperature were also found to be significantly correlated with N 2 O inter-annual variability, suggesting that climate-driven changes in soil N 2 O flux may be important for variations in N 2 O growth rate.
Print ISSN:
0094-8276
Electronic ISSN:
1944-8007
Topics:
Geosciences
,
Physics
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