Arctic haze is a seasonal phenomenon with high concentrations ofaccumulation-mode aerosols occurring in the Arctic in winter and earlyspring. Chemistry transport models and climate chemistry models struggle toreproduce this phenomenon, and this has recently prompted changes in aerosolremoval schemes to remedy the modeling problems. In this paper, we show thatshortcomings in current emission data sets are at least as important. Weperform a 3 yr model simulation of black carbon (BC) with the Lagrangianparticle dispersion model FLEXPART. The model is driven with a new emissiondata set ("ECLIPSE emissions") which includes emissions from gas flaring.While gas flaring is estimated to contribute less than 3% of global BCemissions in this data set, flaring dominates the estimated BC emissions inthe Arctic (north of 66° N). Putting these emissions into ourmodel, we find that flaring contributes 42% to the annual mean BC surfaceconcentrations in the Arctic. In March, flaring even accounts for 52% of allArctic BC near the surface. Most of the flaring BC remains close to thesurface in the Arctic, so that the flaring contribution to BC in the middleand upper troposphere is small. Another important factor determiningsimulated BC concentrations is the seasonal variation of BC emissions fromresidential combustion (often also called domestic combustion, which is usedsynonymously in this paper). We have calculated daily residential combustionemissions using the heating degree day (HDD) concept based on ambient airtemperature and compare results from model simulations using emissions withdaily, monthly and annual time resolution. In January, the Arctic-meansurface concentrations of BC due to residential combustion emissions are150% higher when using daily emissions than when using annually constantemissions. While there are concentration reductions in summer, they aresmaller than the winter increases, leading to a systematic increase of annualmean Arctic BC surface concentrations due to residential combustion by 68%when using daily emissions. A large part (93%) of this systematic increasecan be captured also when using monthly emissions; the increase iscompensated by a decreased BC burden at lower latitudes. In a comparison withBC measurements at six Arctic stations, we find that using daily-varyingresidential combustion emissions and introducing gas flaring emissions leadsto large improvements of the simulated Arctic BC, both in terms of meanconcentration levels and simulated seasonality. Case studies based on BC andcarbon monoxide (CO) measurements from the Zeppelin observatory appear toconfirm flaring as an important BC source that can produce pollution plumesin the Arctic with a high BC / CO enhancement ratio, as expected for thissource type. BC measurements taken during a research ship cruise in theWhite, Barents and Kara seas north of the region with strong flaringemissions reveal very high concentrations of the order of200–400 ng m?3. The model underestimates these concentrationssubstantially, which indicates that the flaring emissions (and probably alsoother emissions in northern Siberia) are rather under- than overestimated inour emission data set. Our results suggest that it may not be "verticaltransport that is too strong or scavenging rates that are too low" and"opposite biases in these processes" in the Arctic and elsewhere in currentaerosol models, as suggested in a recent review article (Bond et al.,Bounding the role of black carbon in the climate system: a scientificassessment, J. Geophys. Res., 2013), but missing emission sources and lackingtime resolution of the emission data that are causing opposite model biasesin simulated BC concentrations in the Arctic and in the mid-latitudes.
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机译：北极雾霾是一种季节性现象，在冬季和早春时，北极地区会出现高浓度的累积模式气溶胶。化学迁移模型和气候化学模型难以重现这种现象，最近这促使气雾去除方案发生变化，以弥补建模问题。在本文中，我们表明当前排放数据集的缺陷至少同样重要。使用拉格朗日粒子分散模型FLEXPART对黑碳（BC）进行3年模型模拟。该模型由一个新的排放数据集（“ ECLIPSE排放量”）驱动，其中包括气体燃烧产生的排放。虽然该数据集中估计气体燃烧产生的总BC排放量不到全球BC排放量的3％，但燃烧产生了北极估算的BC排放量（以北66°N）。将这些排放量放入我们的模型中，我们发现扩口对北极年平均BC表面浓度的贡献为42％。 3月，喇叭口甚至占地表附近所有BC省的52％。在北极，大部分扩张的BC保持靠近地表，因此对流层中上层对BC的扩张贡献很小。决定模拟的BC浓度的另一个重要因素是居民燃烧（通常也称为家庭燃烧）中的BC排放的季节变化。我们已经根据环境气温使用日热度（HDD）的概念计算了每日的住宅燃烧排放量，并将使用排放量的模型仿真结果与每日，每月和每年的时间分辨率进行了比较。 1月份，使用每日排放量时，由于居民燃烧排放而导致的北极卑鄙地表BC浓度比使用年度恒定排放量高150％。夏季虽然浓度降低，但小于冬季增加的浓度，由于使用每日排放量时，居民燃烧导致北极卑诗省平均年表面浓度系统性增加68％。使用月度排放量时，也可以捕获到这一系统增加中的很大一部分（93％）;在低纬度地区，BC负担的减少可以补偿增加的费用。通过与六个北极站的BC测量进行比较，我们发现，使用日变化的居民燃烧排放并引入气体燃烧排放，无论是在平均浓度水平还是在季节性方面，都可以极大地提高模拟北极BC的水平。齐柏林飞艇天文台基于BC和一氧化碳（CO）测量的案例研究似乎证实了火炬燃烧是重要的BC源，可以在北极产生具有高BC / CO增强比的污染羽流，正如对此源类型的预期。在研究船在该区域以北的怀特，巴伦支和卡拉海航行的过程中进行的BC测量表明，其强烈的火炬发射表明浓度很高，约为200-400 ng m ？3 。该模型显着低估了这些浓度，这表明爆发式排放（以及西伯利亚北部的其他排放）也被低估了而不是高估了我们的排放数据集。我们的结果表明，在北极和当前气溶胶模型的其他地方，这可能不是“垂直传输太强或清除率太低”和“这些过程中的相反偏差”，正如最近的一篇评论文章所建议的（Bond等人，“限制黑碳在气候系统中的作用：一项科学评估，J。Geophys。Res。，2013），但是缺少排放源，并且缺乏排放数据的时间分辨率，这导致了北极和北极地区模拟BC浓度的模型偏差。在中纬度地区。
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