Trace gas maps retrieved from satellite measurements show enhanced levels of the atmospheric volatile organic compounds formaldehyde (HCHO) and glyoxal (CHOCHO) over the Atlantic Ocean. To validate the spatial distribution of this continental outflow, ship-based measurements were taken during the Continental Outflow of Pollutants towards the MArine tRoposphere (COPMAR) project. A Multi-AXis Differential Optical Absorption Spectrometer (MAX-DOAS) was operated aboard the research vessel (RV) Maria S. Merian during cruise MSM58/2. This cruise was conducted in October?2016 from Ponta Delgada (Azores) to Cape Town (South Africa), crossing between Cabo Verde and the African continent. The instrument was continuously scanning the horizon, looking towards the African continent. Enhanced levels of HCHO and CHOCHO were found in the area of expected outflow during this cruise. The observed spatial gradients of HCHO and CHOCHO along the cruise track agree with the spatial distributions from satellite measurements and the Model for OZone and Related chemical Tracers version 4 (MOZART-4) model simulations. The continental outflow from the African continent is observed in an elevated layer, higher than 1000m, and probably originates from biogenic emissions or biomass burning according to FLEXible PARTicle dispersion model (FLEXPART) emission sensitivities.
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机译:从卫星测量中检索的痕量气体图显示出在大西洋上的大气挥发性有机化合物甲醛(HCHO)和乙二醛(Chocho)的增强水平。为了验证这一大陆流出的空间分布,在污染物的大陆流出过程中朝向海洋对流层(共和党)项目的情况下采取了基于船舶的测量。在Cruise MSM58 / 2期间,在研究容器(RV)Maria S. Merian中,运营多轴差动光学吸收光谱仪(MAX-DOAs)。这次巡航在10月份进行了2016年从Ponta Delgada(Azores)到Cape Town(南非),在Cabo Verde和非洲大陆之间穿过。该仪器连续扫描地平线,朝向非洲大陆。在此巡航期间的预期流出领域发现了增强的Hcho和Chocho水平。观察到的Hcho和Chocho的空间梯度沿着巡航轨道与卫星测量的空间分布以及臭氧和相关化学示踪剂版本4(Mozart-4)模型模拟的空间分布。非洲大陆的大陆流出在高于1000米的升高层中观察到,并且根据柔性颗粒分散模型(Flexpart)发射敏感性,可能起源于生物发射或生物量燃烧。
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