In spring 2011, columns of bromine monoxide (BrO) were retrieved over Fairbanks, Alaska using a ground‐based multifunction differential optical absorption spectroscopy (MFDOAS) instrument. MFDOAS vertical column BrO is consistently lower than retrievals from the satellite‐based Ozone Monitoring Instrument (OMI), with a relative bias of 20 ± 14%. Numerous tropical‐based studies suggest that 5 ± 2 parts per trillion (ppt) of bromine from very short‐lived substances (VSLS) reaches the stratosphere. We evaluate upper limits on the contribution of VSLS to stratospheric bromine by treating the column retrievals of BrO as purely stratospheric and modeling the ratio of BrO to total inorganic bromine. The OMI and MFDOAS retrievals respectively present 8 and 5 ppt upper limits on the stratospheric injection of VSLS, and kinetic uncertainties in the daytime partitioning of bromine species decrease both values by ∼1.7 ppt. The OMI‐based estimate is in agreement with the 5 ppt tropical‐based value for stratospheric injection of VSLS if the tropospheric column of BrO is 1.5 × 10¹³ molecules cm⁻² over Fairbanks, which is within the range of uncertainty of a second ground‐based instrument that monitored tropospheric BrO during the campaign. Because our ground‐based instruments detected no BrO near the surface, this value for tropospheric BrO would originate from higher altitudes in the troposphere and is in agreement with previous retrievals of background tropospheric BrO. Our calculations of tropospheric BrO over Fairbanks are most sensitive to uncertainties in the stratospheric loading of VSLS, followed by the difference between the OMI and MFDOAS retrievals of BrO.

中文翻译：

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基于一氧化溴的色谱柱反演评估阿拉斯加费尔班克斯的平流层和对流层溴负担

2011年春季，使用地面多功能微分光吸收光谱仪（MFDOAS）在阿拉斯加的费尔班克斯（Fairbanks）上回收了一氧化溴（BrO）柱。MFDOAS垂直柱BrO始终低于卫星臭氧监测仪（OMI）的检索值，相对偏差为20±14％。许多基于热带的研究表明，来自极短寿命物质（VSLS）的溴每5万亿分之几（ppt）到达平流层。我们通过将BrO的色谱柱检索结果视为纯平流层并模拟BrO与总无机溴的比率来评估VSLS对平流层溴的贡献的上限。OMI和MFDOAS检索分别给出了平流层VSLS注入的8和5 ppt上限，溴种类在白天分配过程中的动力学不确定性和动力学不确定性将这两个值均降低了约1.7个百分点。如果BrO的对流层柱为1.5×10，则基于OMI的估算值与平流层VSLS的5 ppt热带值相符。费尔班克斯上空有^13个分子cm ^-2，这在竞选期间监测对流层BrO的第二台地面仪器的不确定性范围内。由于我们的地面仪器在地面附近未检测到BrO，因此对流层BrO的值将源自对流层较高的高度，并且与先前对流层背景BrO的取回一致。我们对费尔班克斯对流层BrO的计算对VSLS平流层载荷的不确定性最敏感，其次是BrO的OMI和MFDOAS取回之间的差异。