Enhanced heating rate of black carbon above the planetary boundary layer over megacities in summertime
Enhanced heating rate of black carbon above the planetary boundary layer over megacities in summertime
复制标题
夏季超大城市行星边界层上方黑碳的加热速率增强
DOI：
10.1088/1748-9326/ab4872
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发表时间：
2019
影响因子：
6.7
通讯作者：
Deping Ding
中科院分区：
文献类型：
--
作者：
Dantong Liu（通讯）;Delong Zhao（通讯）;Zhenzhen Xie;Chenjie Yu;Ying Chen;Ping Tian;Shuo Ding;Kang Hu;Douglas Lowe;Quan Liu;Wei Zhou;Fei Wang;Jiujiang Sheng;Shaofei Kong;Dawei Hu;Zhenzhu Wang;Mengyu Huang;Deping Ding
抽象的。夏季，在东亚的大城市上空观测到了次级气溶胶层的快速发展。在三个小时内，从中午到下午早些时候，行星边界层(PBL)上的二次气溶胶的贡献增加了三到五倍，黑炭(BC)表面的涂层也增加了，并使其吸收效率提高了50%。这往往是由于在PBL上方接收到的强烈光化通量促进了光化学反应。通过边界层云顶对太阳辐射的强烈反射，可以进一步放大BC的吸收。由强太阳辐射、二次形成和云反射等综合过程引入的BC的这种增强加热效应可能会显著增加边界层以上的逆温。在评估BC的辐射影响时，特别是对于受到强烈太阳辐射的污染地区，应该考虑这一机制。
Abstract. The fast development of a secondary aerosol layer was observed over megacities in eastern Asia during summertime. Within three hours, from midday to early afternoon, the contribution of secondary aerosols above the planetary boundary layer (PBL) increased by a factor of three to five, and the coatings on black carbon (BC) also increased and enhanced its absorption efficiency by 50%. This tended to result from the intensive actinic flux received above the PBL which promoted photochemical reactions. The absorption of BC could be further amplified by the strong reflection of solar radiation over the cloud top across the PBL. This enhanced heating effect of BC introduced by combined processes (intensive solar radiation, secondary formation and cloud reflection) may considerably increase the temperature inversion above the PBL. This mechanism should be considered when evaluating the radiative impact of BC, especially for polluted regions receiving strong solar radiation.