1. Variations of atmospheric nitrous oxide concentration in the northern and western Pacific.
- Author
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ISHIJIMA, K., NAKAZAWA, T., and AOKI, S.
- Subjects
ATMOSPHERE ,CONTAINER ships ,EMISSIONS (Air pollution) - Abstract
Atmospheric N
2 O concentration was observed in the Pacific for the period 1991–2006, using commercial container ships sailing between Japan and North America and between Japan and Australia or New Zealand. The N2 O concentration showed a secular increase and interannual variations at all sampling locations, but a seasonal cycle was detectable only at northern high latitudes. The annual mean N2 O concentration showed little longitudinal variations (within ± 0.3 ppb) in the northern Pacific, but showed a clear north-south gradient of about 0.8 ppb, with higher values in the Northern Hemisphere. The annual mean N2 O was also characterized by especially high values at 30°N due to strong local N2 O emissions and by a steep latitudinal decrease from the equator to 20°S due to the suppression of interhemispheric exchange of air by the South Pacific Convergence Zone. The N2 O growth rate showed an interannual variation with a period of about 3 yr (high-values in 1999 and 2000), with a delayed eastward and poleward phase propagation in the northern and western Pacific, respectively. The interannual variations of the N2 O growth rate and soil water showed a good correlation, suggesting that the N2 O emission from soils have an important causative role in the atmospheric N2 O variation. [ABSTRACT FROM AUTHOR]- Published
- 2009
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