Shen Lu, Mickley Loretta J, Leibensperger Eric M, Li Mingwei
John A. Paulson School of Engineering and Applied Sciences Harvard University Cambridge MA USA.
Center for Earth and Environmental Science SUNY Plattsburgh Plattsburgh NY USA.
Geophys Res Lett. 2017 Dec 28;44(24):12527-12535. doi: 10.1002/2017GL075905. Epub 2017 Dec 26.
We find that summertime air quality in the eastern U.S. displays strong dependence on North Atlantic sea surface temperatures, resulting from large-scale ocean-atmosphere interactions. Using observations, reanalysis data sets, and climate model simulations, we further identify a multidecadal variability in surface air quality driven by the Atlantic Multidecadal Oscillation (AMO). In one-half cycle (~35 years) of the AMO from cold to warm phase, summertime maximum daily 8 h ozone concentrations increase by 1-4 ppbv and PM concentrations increase by 0.3-1.0 μg m over much of the east. These air quality changes are related to warmer, drier, and more stagnant weather in the AMO warm phase, together with anomalous circulation patterns at the surface and aloft. If the AMO shifts to the cold phase in future years, it could partly offset the climate penalty on U.S. air quality brought by global warming, an effect which should be considered in long-term air quality planning.
我们发现，美国东部夏季空气质量对北大西洋海表温度表现出强烈的依赖性，这是由大规模的海洋 - 大气相互作用导致的。利用观测数据、再分析数据集和气候模型模拟，我们进一步确定了由大西洋多年代际振荡（AMO）驱动的地表空气质量的多年代际变化。在AMO从冷相位到暖相位的半个周期（约35年）内，东部大部分地区夏季每日8小时最大臭氧浓度增加1 - 4 ppbv，颗粒物浓度增加0.3 - 1.0 μg/m。这些空气质量变化与AMO暖相位时更温暖、干燥和更稳定的天气有关，同时伴随着地表和高空的异常环流模式。如果未来几年AMO转变为冷相位，它可能部分抵消全球变暖给美国空气质量带来的气候惩罚，这一效应在长期空气质量规划中应予以考虑。
