Effects of boundary layer dynamics and meteorology on ultrafine particle formation and growth
Effects of boundary layer dynamics and meteorology on ultrafine particle formation and growth
复制标题
DOI：
10.1016/j.atmosenv.2023.119952
复制
发表时间：
2023-07
影响因子：
5
通讯作者：
Zachary Watson;L. Tiszenkel;Arastoo Pour Biazar;K. Knupp;Shan‐Hu Lee
中科院分区：
文献类型：
--
作者：
Zachary Watson;L. Tiszenkel;Arastoo Pour Biazar;K. Knupp;Shan‐Hu Lee
目前还没有很好地了解行星边界层（PBL）动力学如何影响大气中超细颗粒的形成和生长，因为有限的同位气溶胶粒径分布和激光雷达测量。在这里，我们显示，从长期的原位观测，边界层过程和表面气溶胶动力学之间的明确联系。2016年、2017年和2022年，在亚拉巴马大学亨茨维尔校区使用扫描迁移率粒度仪（SMPS）测量了7至300 nm直径范围内的气溶胶粒度分布。较大的气溶胶的后向散射测量使用一个共同定位的激光雷达云高计。气象地面参数，包括温度，相对湿度，站压，风速和风向，太阳辐射和降水量也进行了测量。新粒子形成（NPF）和长期增长（超过12小时）的事件发生在冬季最频繁，不像许多其他地方的NPF事件更频繁地发生在春季和秋季，表明较低的温度在温暖的亚热带环境中的超细粒子形成中发挥重要作用。在夏季太阳辐射较强时，短时间增长事件（小于6 h）较多，可能与边界层内的对流有关。我们的观测结果还表明，冷锋影响测得的气溶胶粒径分布，因为降水清除和清洁空气的结合可以提供有利于NPF和气溶胶生长的热力学条件。这些结果突出了气象学对气溶胶形成和增长的重要性。
It is currently not well understood how the planetary boundary layer (PBL) dynamics affects the formation and growth of ultrafine particles in the atmosphere, because of the limited co-located aerosol size distributions and lidar measurements. Here we show, from long-term in-situ observations, a clear link between boundary layer processes and surface aerosol dynamics. Aerosol size distributions in the diameter range from 7 to 300 nm were measured with a scanning mobility particle sizer (SMPS) at the University of Alabama Huntsville campus in 2016, 2017, and 2022. The backscatter of larger aerosols was measured using a co-located lidar ceilometer. Meteorological surface parameters including temperature, relative humidity, station pressure, wind speed and direction, solar radiation, and precipitation were also measured. New particle formation (NPF) and long growth (over 12 h) events occurred most frequently during the winter, unlike many other locations where NPF events occur more frequently in spring and fall, indicating that cooler temperatures play important roles in ultrafine particle formation in the warm subtropical environment. During the summer with strong solar radiation, there were more short-time growth events (less than 6 h), likely associated with convection within the boundary layer. Our observations also show cold fronts affect the measured aerosol size distributions because the combination of precipitation scavenging and cleaner air can provide thermodynamic conditions favorable for NPF and aerosol growth. These results highlight the importance of meteorology on aerosol formation and growth.