Nitrous oxide measurements in the eastern tropical Pacific Ocean

作者：David Pierotti, R. A. Rasmussen · 发表于：Tellus · 年份：1980 · DOI：10.1111/j.2153-3490.1980.tb01722.x · 被引用次数：93 · 研究领域：Marine and coastal ecosystems、Ocean Acidification Effects and Responses、Atmospheric chemistry and aerosols

In March 1976 the first N 2 O measurements were made in the sea water and marine air of the eastern tropical Pacific Ocean during a cruise from San Diego, California, to San Martin, Peru. Continuous measurements of N 2 O in the marine atmosphere were made throughout the duration of the cruise. The tropospheric mixing ratio was 332 ± 9 p.p.b. v/v N 2 O. The concentration of N 2 O in the marine air appeared to show a direct relationship to the N 2 O concentration in the surface sea water, with the highest N 2 O mixing ratios over regions which were highly supersaturated, off the coasts of Baja California and Peru, and in the equatorial upwelling region. The surface sea water samples were generally supersaturated with N 2 O, with an average saturation of 145% relative to the marine atmosphere. The average flux of N 2 O from the surface sea water into the atmosphere was 0.5 × 10 -12 g N 2 O cm -2 s -1 . Only one surface sea water sample showed significant undersaturation; the other 28 surface water samples were approximately saturated or supersaturated. Water samples were also collected down to depths of 300 m during seven hydrocast stations. The stations showed two distinct distribution patterns for N 2 O concentration versus depth for the region between the surface and 300 m. At five of the seven stations the N 2 O concentration increased rapidly from the surface to a depth of 100 m, and then remained relatively constant down to the maximum depth of 300 m. At the other two stat...