Atmospheric Science and Technology Directorate, Science and Technology Branch, Environment Canada, 4905 Dufferin Street, Toronto, Ontario M3H 5T4 Canada.
Environ Sci Technol. 2012 May 1;46(9):4819-28. doi: 10.1021/es2033845. Epub 2012 Feb 28.
Measurements of black carbon (BC) with a high-sensitivity laser-induced incandescence (HS-LII) instrument and a single particle soot photometer (SP2) were conducted upwind, downwind, and while driving on a highway dominated by gasoline vehicles. The results are used with concurrent CO(2) measurements to derive fuel-based BC emission factors for real-world average fleet and heavy-duty diesel vehicles separately. The derived emission factors from both instruments are compared, and a low SP2 bias (relative to the HS-LII) is found to be caused by a BC mass mode diameter less than 75 nm, that is most prominent with the gasoline fleet but is not present in the heavy-duty diesel vehicle exhaust on the highway. Results from both the LII and the SP2 demonstrate that the BC emission factors from gasoline vehicles are at least a factor of 2 higher than previous North American measurements, and a factor of 9 higher than currently used emission inventories in Canada, derived with the MOBILE 6.2C model. Conversely, the measured BC emission factor for heavy-duty diesel vehicles is in reasonable agreement with previous measurements. The results suggest that greater attention must be paid to black carbon from gasoline engines to obtain a full understanding of the impact of black carbon on air quality and climate and to devise appropriate mitigation strategies.
利用高灵敏度激光诱导白炽（HS-LII）仪器和单颗粒 soot 光度计（SP2）对高速公路上以汽油车为主的上风、下风及行驶过程中的黑碳（BC）进行了测量。将同时进行的 CO(2)测量结果用于分别推导出实际平均车队和重型柴油车辆的基于燃料的 BC 排放因子。比较了两种仪器得出的排放因子，发现 SP2 存在偏低（相对于 HS-LII）的情况，这是由于 BC 质量模态直径小于 75nm 造成的，这种情况在汽油车队中最为明显，但在高速公路上的重型柴油车辆尾气中不存在。LII 和 SP2 的结果均表明，汽油车的 BC 排放因子至少比以前的北美测量值高 2 倍，比加拿大目前使用的 MOBILE 6.2C 模型衍生的排放清单高 9 倍。相反，测量的重型柴油车辆的 BC 排放因子与以前的测量值基本一致。研究结果表明，必须更加关注汽油发动机产生的黑碳，以全面了解黑碳对空气质量和气候的影响，并制定适当的缓解策略。
