Nitrous oxide and methane in the Atlantic Ocean between 50 1 N and 52 1 S : Latitudinal distribution and seato-air flux
Nitrous oxide and methane in the Atlantic Ocean between 50 1 N and 52 1 S : Latitudinal distribution and seato-air flux
复制标题
大西洋 50 1 N 至 52 1 S 之间的一氧化二氮和甲烷：纬度分布和海气通量
DOI：
--
复制
发表时间：
2009
期刊：
影响因子：
--
通讯作者：
E. Woodward
中科院分区：
文献类型：
--
作者：
G. Forster;R. Upstill‐Goddard;N. Gist;C. Robinson;G. Uher;E. Woodward
我们讨论了大西洋子午线(AMT)计划(AMT巡航12和13)期间沿北纬501N和南纬521两条13500公里断面上的49个垂直剖面上一氧化二氮(N2O)和甲烷(CH4)的分布。N2O垂直分布可以根据与朗赫斯特省一致的共同特征进行分析。相比之下，CH4则没有表现出这种模式。纬度深度分布的最显著特征是一个明确的“羽流”，其N2O浓度极高，而CH4水平很低，位于23.51N和23.51S之间；这一特征反映了含有硝化作用产生的N2O的深水上升流，通过对N2O、表观氧利用率(AOU)和NO3的分析，推测其在CH4中被细菌氧化耗尽。相当于大西洋表面积42%的区域的海-气排放通量在0.40-0.68Tg-N2O年和0.81-1.43Tg-CH4年之间。根据当代对全球大气N2O和CH4海洋来源强度的估计，大西洋可能分别占这些来源总数的6%-15%和4%-13%。考虑到大西洋约占全球海洋表面的20%，按单位面积计算，大西洋似乎是大气N2O的一个略弱于其他海洋区域的来源，但它对海洋大气CH4的贡献可能比之前认为的要大一些。皇冠版权所有&2008由爱思唯尔有限公司出版。保留所有权利。
We discuss nitrous oxide (N2O) and methane (CH4) distributions in 49 vertical profiles covering the upper 300 m of the water column along two 13,500 km transects between 501N and 521S during the Atlantic Meridional Transect (AMT) programme (AMT cruises 12 and 13). Vertical N2O profiles were amenable to analysis on the basis of common features coincident with Longhurst provinces. In contrast, CH4 showed no such pattern. The most striking feature of the latitudinal depth distributions was a welldefined ‘‘plume’’ of exceptionally high N2O concentrations coincident with very low levels of CH4, located between 23.51N and 23.51S; this feature reflects the upwelling of deep waters containing N2O derived from nitrification, as identified by an analysis of N2O, apparent oxygen utilization (AOU) and NO3 , and presumably depleted in CH4 by bacterial oxidation. Sea-to-air emissions fluxes for a region equivalent to 42% of the Atlantic Ocean surface area were in the range 0.40–0.68 Tg N2O yr 1 and 0.81–1.43 Tg CH4 yr . Based on contemporary estimates of the global ocean source strengths of atmospheric N2O and CH4, the Atlantic Ocean could account for 6–15% and 4–13%, respectively, of these source totals. Given that the Atlantic Ocean accounts for around 20% of the global ocean surface, on unit area basis it appears that the Atlantic may be a slightly weaker source of atmospheric N2O than other ocean regions but it could make a somewhat larger contribution to marine-derived atmospheric CH4 than previously thought. Crown Copyright & 2008 Published by Elsevier Ltd. All rights reserved.