Department of Meteorology and Atmospheric Science, Pennsylvania State University, University Park, PA 16802.
Department of Chemistry and Biochemistry, University of Alaska, Fairbanks, AK 99775.
Proc Natl Acad Sci U S A. 2022 Sep 13;119(37):e2201213119. doi: 10.1073/pnas.2201213119. Epub 2022 Sep 6.
Atmospheric electrical discharges are now known to generate unexpectedly large amounts of the atmosphere's primary oxidant, hydroxyl (OH), in thunderstorm anvils, where electrical discharges are caused by atmospheric charge separation. The question is "Do other electrical discharges also generate large amounts of oxidants?" In this paper, we demonstrate that corona formed on grounded metal objects under thunderstorms produce extreme amounts of OH, hydroperoxyl (HO), and ozone (O). Hundreds of parts per trillion to parts per billion of OH and HO were measured during seven thunderstorms that passed over the rooftop site during an air quality study in Houston, TX in summer 2006. A combination of analysis of these field results and laboratory experiments shows that these extreme oxidant amounts were generated by corona on the inlet of the OH-measuring instrument and that corona are easier to generate on lightning rods than on the inlet. In the laboratory, increasing the electric field increased OH, HO, and O, with 14 times more O generated than OH and HO, which were equal. Calculations show that corona on lightning rods can annually generate OH that is 10-100 times ambient amounts within centimeters of the lightning rod and on high-voltage electrical power lines can generate OH that is 500 times ambient a meter away from the corona. Contrary to current thinking, previously unrecognized corona-generated OH, not corona-generated UV radiation, mostly likely initiates premature degradation of high-voltage polymer insulators.
大气放电现在被认为会在雷暴砧中产生大量的大气主要氧化剂羟基（OH），其中的放电是由大气电荷分离引起的。问题是“其他放电是否也会产生大量氧化剂？”在本文中，我们证明了在雷暴下接地金属物体上形成的电晕会产生大量的 OH、过氧羟（HO）和臭氧（O）。在 2006 年夏季休斯顿空气质量研究期间，有 7 次雷暴经过屋顶站点，在这些雷暴期间，我们测量到了数百到数十亿分之几的 OH 和 HO。对这些现场结果和实验室实验的分析表明，这些极端氧化剂是由 OH 测量仪器入口处的电晕产生的，并且电晕在避雷针上比在入口处更容易产生。在实验室中，增加电场会增加 OH、HO 和 O，其中 O 的生成量比 OH 和 HO 多 14 倍，它们是相等的。计算表明，避雷针上的电晕每年可在距避雷针几厘米处产生比环境浓度高 10-100 倍的 OH，并在距电晕 500 倍的距离处产生环境浓度的 OH。与当前的思维方式相反，以前未被识别的电晕产生的 OH，而不是电晕产生的紫外线辐射，很可能会引发高压聚合物绝缘子的过早降解。
