A year of H2 measurements at Weybourne Atmospheric Observatory, UK
A year of H2 measurements at Weybourne Atmospheric Observatory, UK
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英国韦伯恩大气观测站一年的 H2 测量
DOI：
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发表时间：
2012
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通讯作者：
Stefan Emeis
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作者：
G. Forster;W. Sturges;Z. Fleming;B. Bandy;Stefan Emeis
本文介绍了2008年3月至2009年2月在英国北海海岸测量的长达一年的大气分子氢（H2）高精度时间序列。H2季节循环明显，冬末/早春的平均值比夏末/早秋的平均值高约40 ppb。背景减去的摩尔H2/CO比（ΔH2/ΔCO）在所有数据组合时平均为0.35±0.002，当ΔH2高于10 ppb时平均为0.25±0.002。ΔH2/ΔCO比值在夏季最高，可能是光化学产量较大的结果。通过同时测量臭氧，我们估计夜间逆温事件期间H2的沉积速度在2008年6月平均为3.5±0.7×10−4 m s−1，在2008年7月平均为1.9±1×10−4 m s−1，与其他报道的估计结果很好地一致。2008年5月，我们观察到一段异常清洁的空气从热带输送而来，但从北方到达，其中H2略有升高，表明地表损失最小。在另一个东南风向的情况下，我们认为我们检测到了近大陆H2生产设施的排放，其特征是H2混合比达到1450 ppb。
ABSTRACT We present a year-long high precision time series of atmospheric molecular hydrogen (H2) measured at the UK North Sea coast from March 2008 to February 2009. We observed a pronounced seasonal cycle in H2 with mean values in late winter/early spring~40 ppb higher than those in late summer/early autumn. Background-subtracted molar H2/CO ratios (ΔH2/ΔCO) averaged 0.35±0.002 for all data combined and 0.25±0.002 when ΔH2 was above 10 ppb. The ΔH2/ΔCO ratio was highest in summer, possibly as a result of larger photochemical production. Using simultaneous measurements of ozone, we estimated the deposition velocity of H2 during nocturnal inversion events to average 3.5±0.7×10−4 m s−1 for June 2008 and 1.9±1×10−4 m s−1 for July 2008, in good agreement with other reported estimates. In May 2008, we observed an episode of exceptionally clean air being transported from the tropics but arriving from the north, in which H2 was slightly elevated indicating minimal surface loss. On another occasion with south-easterly winds, we believe we detected emissions from H2 production facilities in the near-continent characterised by H2 mixing ratios reaching 1450 ppb.