Assessing the impact of shipping emissions on air pollution in the Canadian Arctic and northern regions: current and future modelled scenarios
Assessing the impact of shipping emissions on air pollution in the Canadian Arctic and northern regions: current and future modelled scenarios
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DOI：
10.5194/acp-18-16653-2018
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发表时间：
2018-11-26
影响因子：
6.3
通讯作者：
Holt, Richard
中科院分区：
文献类型：
--
作者：
Gong, Wanmin;Beagley, Stephen R.;Holt, Richard
在这项研究中进行了第一次区域评估航运排放对加拿大北极和北方地区空气污染的影响。在有限区域上进行了模型模拟使用加拿大环境和气候变化在线空气质量预报模式GEM-MACH，（全球环境多尺度模拟空气质量和化学品），调查加拿大北极沃茨海运排放的贡献（在目前和预测的未来水平）与标准污染物（O-3、PM2.5、NO2和SO2）的环境浓度、硫（S）和氮（N）的大气沉积以及北极黑碳（BC）的大气负荷和沉积之间的关系。几个模型升级介绍了这项研究，包括海冰的干沉积参数化，化学横向边界条件，并列入北美野火排放的治疗。该模型被证明有类似的技能，在预测环境O-3和PM2.5浓度在加拿大北极和北方地区，目前在北美和欧洲的业务空气质量预测模型。特别是，该模型能够很好地模拟在加拿大高北极地区，警报观测到的O-3和PM成分。模型评估表明，在目前（2010年）的水平上，北极航运排放量对加拿大北极东部环境O-3浓度的贡献不到1%，对航运通道环境PM2.5浓度的贡献在1%到5%之间。北极航运排放对环境NO2和SO2浓度的贡献更大，分别为10%-50%和20%-100%。在预计的2030年一切照旧（BAU）水平上，北极航运排放的影响预计将增加到加拿大北极广大地区环境O3浓度的5%，并增加到航运通道环境PM2.5浓度的5%-20%。相比之下，如果在加拿大北极沃茨实施诸如目前北美排放控制区（NA ECA）实施的排放控制措施，则将大大减少航运对环境标准污染物的影响。例如，通过类似NA-ECA的控制措施，航运对SO2和PM2.5人口加权浓度的贡献将降低到目前的水平以下。加拿大北极航运对硫和氮的大气沉积的贡献在目前水平上很小，<5%，但在2030年“一切照旧”情景下，预计硫的贡献将增加到20%，氮的贡献将增加到50%。在目前的水平上，加拿大北极航运对BC柱负荷和BC沉积的贡献也很小，前者平均< 0.1%，在加拿大北极东部的局部高达2%，后者在航运通道上的贡献在0.1%和0.5%之间。在预计的2030年BAU水平上，预计影响将再次增加，特别是在巴芬岛和巴芬湾地区，以应对预计的船舶交通量增加，例如，BC柱负载高达15%，BC沉积局部超过30%。总的来说，研究表明，航运引起的大气成分和沉积物变化是在区域到地方的尺度上（特别是在北极），因此气候反馈可能在这些尺度上起作用，因此气候影响评估将需要以比现有辐射强迫和气候影响评估中使用的分辨率更精细的分辨率进行建模。
A first regional assessment of the impact of shipping emissions on air pollution in the Canadian Arctic and northern regions was conducted in this study. Model simulations were carried out on a limited-area domain (at 15 km horizontal resolution) centred over the Canadian Arctic, using the Environment and Climate Change Canada's on-line air quality forecast model, GEM-MACH (Global Environmental Multi-scale -Modelling Air quality and CHemistry), to investigate the contribution from the marine shipping emissions over the Canadian Arctic waters (at both present and projected future levels) to ambient concentrations of criteria pollutants (O-3, PM2.5, NO2, and SO2), atmospheric deposition of sulfur (S) and nitrogen (N), and atmospheric loading and deposition of black carbon (BC) in the Arctic. Several model upgrades were introduced for this study, including the treatment of sea ice in the dry deposition parameterization, chemical lateral boundary conditions, and the inclusion of North American wildfire emissions. The model is shown to have similar skills in predicting ambient O-3 and PM2.5 concentrations in the Canadian Arctic and northern regions, as the current operational air quality forecast models in North America and Europe. In particular, the model is able to simulate the observed O-3 and PM components well at the Canadian high Arctic site, Alert. The model assessment shows that, at the current (2010) level, Arctic shipping emissions contribute to less than 1% of ambient O-3 concentration over the eastern Canadian Arctic and between 1 and 5% of ambient PM2.5 concentration over the shipping channels. Arctic shipping emissions make a much greater contributions to the ambient NO2 and SO2 concentrations, at 10%-50% and 20%-100%, respectively. At the projected 2030 business-as-usual (BAU) level, the impact of Arctic shipping emissions is predicted to increase to up to 5% in ambient O3 concentration over a broad region of the Canadian Arctic and to 5 %-20% in ambient PM2.5 concentration over the shipping channels. In contrast, if emission controls such as the ones implemented in the current North American Emission Control Area (NA ECA) are to be put in place over the Canadian Arctic waters, the impact of shipping to ambient criteria pollutants would be significantly reduced. For example, with NA-ECA-like controls, the shipping contributions to the population-weighted concentrations of SO2 and PM2.5 would be brought down to below the current level. The contribution of Canadian Arctic shipping to the atmospheric deposition of sulfur and nitrogen is small at the current level, < 5 %, but is expected to increase to up to 20% for sulfur and 50% for nitrogen under the 2030 BAU scenario. At the current level, Canadian Arctic shipping also makes only small contributions to BC column loading and BC deposition, with < 0.1% on average and up to 2% locally over the eastern Canadian Arctic for the former, and between 0.1% and 0.5% over the shipping channels for the latter. The impacts are again predicted to increase at the projected 2030 BAU level, particularly over the Baffin Island and Baffin Bay area in response to the projected increase in ship traffic there, e.g., up to 15% on BC column loading and locally exceeding 30% on BC deposition. Overall, the study indicates that shippinginduced changes in atmospheric composition and deposition are at regional to local scales (particularly in the Arctic).Climate feedbacks are thus likely to act at these scales, so climate impact assessments will require modelling undertaken at much finer resolutions than those used in the existing radiative forcing and climate impact assessments.