A case study of a transported bromine explosion event in the Canadian high arctic
A case study of a transported bromine explosion event in the Canadian high arctic
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DOI：
10.1002/2015jd023711
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发表时间：
2016-01
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通讯作者：
Xiaoyi Zhao;Kimberly Strong;Colin E. Adams;Robyn Schofield;Xin Yang;Andreas Richter;U. Friess;A. Blechschmidt;Ja Ho Koo
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文献类型：
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作者：
Xiaoyi Zhao;Kimberly Strong;Colin E. Adams;Robyn Schofield;Xin Yang;Andreas Richter;U. Friess;A. Blechschmidt;Ja Ho Koo
极地对流层中的臭氧消耗事件与极高浓度的溴有关，称为溴爆炸事件(BEE)。然而，发生这些事件的最佳气象条件仍然不确定。2011年4月4日至5日，在加拿大尤里卡(86.4°W，80.1°N)的一只蜜蜂期间，观察到了飘雪和稳定的浅边界层的组合。用多轴差示吸收光谱仪进行了测量，提取了BrO轮廓和部分柱子。在这次事件中，近地表的溴体积混合比以体积计增加到约20ppbv，而表面的臭氧被消耗到~1ppbv至700m。反向轨迹和全球臭氧监测实验2卫星对流层BRO柱证实，这次事件源于波弗特海的一次溴爆炸。3月30日至31日，气象数据显示，波弗特海上空风速高(24m/S)，边界层高度升高(约800m)。向尤里卡的长途运输(5天内约1800公里)表明，溴羽流中的溴有很强的再循环。这一事件通常被全球化学-气候模型捕捉到，当时包括了来自吹雪的海盐溴来源。模式敏感性研究表明，尤里卡的表面BRO受局地光化学和边界层动力学共同控制。模型结果与地面和卫星测量结果的比较证实，在尤里卡观察到的蜜蜂是在稳定的大气浅边界层条件下从波弗特海输送增强的BRO，然后在当地生产/再循环引发的。
Ozone depletion events in the polar troposphere have been linked to extremely high concentrations of bromine, known as bromine explosion events (BEE). However, the optimum meteorological conditions for the occurrence of these events remain uncertain. On 4–5 April 2011, a combination of both blowing snow and a stable shallow boundary layer was observed during a BEE at Eureka, Canada (86.4°W, 80.1°N). Measurements made by a Multi‐Axis Differential Optical Absorption Spectroscopy spectrometer were used to retrieve BrO profiles and partial columns. During this event, the near‐surface BrO volume mixing ratio increased to ~20 parts per trillion by volume, while ozone was depleted to ~1 ppbv from the surface to 700 m. Back trajectories and Global Ozone Monitoring Experiment‐2 satellite tropospheric BrO columns confirmed that this event originated from a bromine explosion over the Beaufort Sea. From 30 to 31 March, meteorological data showed high wind speeds (24 m/s) and elevated boundary layer heights (~800 m) over the Beaufort Sea. Long‐distance transportation (~1800 km over 5 days) to Eureka indicated strong recycling of BrO within the bromine plume. This event was generally captured by a global chemistry‐climate model when a sea‐salt bromine source from blowing snow was included. A model sensitivity study indicated that the surface BrO at Eureka was controlled by both local photochemistry and boundary layer dynamics. Comparison of the model results with both ground‐based and satellite measurements confirmed that the BEE observed at Eureka was triggered by transport of enhanced BrO from the Beaufort Sea followed by local production/recycling under stable atmospheric shallow boundary layer conditions.