DOAS-observation of halogen radical-catalysed arctic boundary layer ozone destruction during the ARCTOC-campaigns 1995 and 1996 in Ny-Ålesund, Spitsbergen
DOAS-observation of halogen radical-catalysed arctic boundary layer ozone destruction during the ARCTOC-campaigns 1995 and 1996 in Ny-Ålesund, Spitsbergen
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DOI：
10.3402/tellusb.v49i5.16005
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发表时间：
1997-11
期刊：
影响因子：
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通讯作者：
M. Tuckermann;R. Ackermann;C. Gölz;H. Lorenzen-Schmidt;T. Senne;J. Stutz;B. Trost;W. Unold;U. Platt
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文献类型：
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作者：
M. Tuckermann;R. Ackermann;C. Gölz;H. Lorenzen-Schmidt;T. Senne;J. Stutz;B. Trost;W. Unold;U. Platt
在1995年和1996年春季的两次现场活动中，利用差分光学吸收光谱（DOAS）以优于1.5h的时间分辨率观测了BrO、ClO、IO、SO 2、NO 2、HNO 2、CH 2 O和O3的边界层浓度水平。高达30 ppt的BrO和ClO都被发现与低臭氧事件（LOE）相吻合。在正常臭氧期间，BrO和ClO的平均水平接近于零。LOE期间的平均ClO水平在1995年（21 ppt）比1996年（3.3 ppt）高得多。一般情况下，只能给出50 ppt的NO 2和SO 2的上限，然而，观察到的一系列浓度峰值（高达几ppb）的情况下，NO 2最有可能是由于本地污染，而SO 2峰值的来源仍然不清楚。对数据的分析表明，臭氧损失最有可能是由BrO x（= Br + BrO）-和BrO x + ClO x −催化的臭氧破坏（BrO自身反应和ClO + BrO反应分别是速率限制步骤）的组合引起的。IO的含量不太可能超过1-2 ppt，因此其对臭氧破坏的贡献不大，但也不能完全排除。观察到的BrO和ClO水平足够高，每小时破坏1-2 ppb的O3，从而在1-2天内完全消除40 ppb的初始O3。然而，气团动力学也可能是重要的，特别是观察到的O 3下降率高达7 ppb/h，只能归因于平流的空气已经耗尽臭氧。Cl-原子和Br-原子浓度推导出ClO和BrO测量和ClO/CL和BrO/Br比的估计，来自“碳氢化合物时钟”观测在北极的数据进行了比较。虽然这两套数据是兼容的溴和1996年的ClO数据，在1995年的DOAS ClO数据表明更高的氯原子水平比碳氢化合物时钟观测。DOI：10.1034/j.1600-0889.49.issue5.9.x
During two field campaigns in spring 1995 and 1996, boundary layer concentration levels of BrO, ClO, IO, SO 2 , NO 2 , HNO 2 , CH 2 O and O 3 , were observed at a time resolution of better than 1.5 h by Differential Optical Absorption Spectroscopy (DOAS). Up to 30 ppt of both, BrO and ClO, were found to coincide with low ozone events (LOE). During periods of normal ozone, average levels of BrO and ClO were close to zero. Average ClO levels during LOE were considerably higher in 1995 (21 ppt) than in 1996 (3.3 ppt). Generally, only upper limits for NO 2 and SO 2 of 50 ppt can be given, however, a series of concentration spikes (up to a few ppb) observed are in the case of NO 2 most likely due to local pollution, while the origin of the SO 2 spikes remains unclear. Analysis of the data suggests that the ozone loss is most likely caused by a combination of BrO x (= Br + BrO)- and BrO x + ClO x − catalysed ozone destruction (with the BrO self reaction and ClO + BrO reaction being the rate limiting steps, respectively). The presence of IO at levels exceeding 1–2 ppt and thus its contribution to ozone destruction is unlikely, but cannot be completely excluded. The observed levels of BrO and ClO are sufficiently high to destroy 1–2 ppb O 3 per hour, thus completely eliminating 40 ppb of initial O 3 within 1–2 days. However airmass dynamics is also likely to be important, in particular observed O 3 decrease rates of up to 7 ppb/h can only be attributed to advection of air already depleted in ozone. The Cl-atom and Br-atom concentrations deduced from ClO and BrO measurements and estimates of ClO/CL and BrO/Br ratios, are compared with data derived from “hydrocarbon clock” observations in the arctic. While both sets of data are compatible for BrO and 1996 ClO data, in 1995 the DOAS ClO data indicate much higher Cl-atom levels than seen by hydrocarbon clock observations. DOI: 10.1034/j.1600-0889.49.issue5.9.x