SavedAdd your journal

Journals / Atmospheric Pollution Research / 2018 / Cilt: 9 - Sayı: 6

Boundary-layer features and regional transport process of an extreme haze pollution event in Nanjing, China

Duanyang Liu
Wenlian YAN
Zhiming KANG
Anning LİU
Yi ZHU
Pages
1088–1099
DOI
—
🏛️Bibliographic metadata and full text access for this article are provided via DergiPark.
DergiPark Record ↗
✨

AI Summary & Key Takeaways

AI Insight
⚡ TL;DR(Too Long; Didn't Read)

The results showed that this haze event was associated with weak cold front activity under relatively stable weather conditions, including weak surface wind speed.

📌 3 Key Takeaways

🎯
Objective & Hypothesis:Extreme haze pollution event is a major environmental concern in East China.
📊
Key Findings & Data:In this study, we aim at elucidating the relationships among boundary-layer features, regional transportation and low-visibility event of haze pollution in Nanjing in December 2013.
💡
Conclusion & Impact:The results showed that this haze event was associated with weak cold front activity under relatively stable weather conditions, including weak surface wind speed.
🔬Design:Research Article
📍Scope:2013 Verileri
⚙️Variables:Domain Parameters

Özet

Extreme haze pollution event is a major environmental concern in East China. In this study, we aim at elucidating the relationships among boundary-layer features, regional transportation and low-visibility event of haze pollution in Nanjing in December 2013. The results showed that this haze event was associated with weak cold front activity under relatively stable weather conditions, including weak surface wind speed. Local pollutant accumulation was the main cause during the whole haze process, the surface wind speed was under 2 m/s, and the irradiance 24-hour change (IR24) had negative values. The higher the pollutants' concentrations, the greater the change of IR24. Most of the pollution was circulating and trapped within 130-km range around the observing site. Based on the cluster analysis, the circling trajectory presented the highest PM2.5, and the long-distance pollutant transformation from North China also made the pollutants' concentration higher. Multilayer inversions, lower mixed layer height and thick lower wind speed zone promoted extreme haze maintenance. Both inversion and relative humidity (RH) had obvious diurnal variation. During the serious pollution period (visibility < 2000 m), the wind speed below 500 m was under 2 m/s all the time. Surface inversion (SI), low-hanging inversion and multi-layer inversion all occurred. The lower the inversion bottom (IB), the lower the visibility. Many multi-layer inversions had intensity greater than 1°C/100 m, and corresponded to the increase of pollutants concentrations on the ground. Although the low-hanging inversion intensity (LHII) was only 0.32°C/100 m and the low-hanging inversion bottom (LHIB) rose to 420.0 m, the multi-layer and large thickness (124.9 m) of inversions sustained surface pollutants concentrations at high levels. The downward momentum transport by the weak cold front increased surface wind speeds destroyed the inversions and ended the haze event.

🔖

Cite This Article

Liu, D., YAN, W., KANG, Z., LİU, A., ZHU, Y. (2018). Boundary-layer features and regional transport process of an extreme haze pollution event in Nanjing, China. Atmospheric Pollution Research, Cilt: 9 - Sayı: 6, 1088–1099. https://ajindex.com/articles/209840

📄 Full Text PDF Viewer

📄

PDF görüntüleyici hazırlanıyor...

References (6)

  1. Allwine, K.J., Whiteman, C.D., 1994. Single-station integral measures of atmospheric stagnation, recirculation and ventilation. Atmos. Environ. 28 (4), 713–721.
  2. Aruna, K., Kumar, T.V.L., Rao, D.N., Murthy, B.V.K., Babu, S.S., Moorthy, K.K., 2013. Black carbon aerosols in a tropical semi-urban coastal environment: effects of boundary layer dynamics and long range transport. J. Atmos. Solar-Terrestrial Phys. 104, 116–125.
  3. Chen, H., Wang, H., 2015. Haze Days in North China and the associated atmospheric circulations based on daily visibility data from 1960 to 2012. J. Geophys. Res. Atmos. 120, 2015JD023225. Chen, Z.H., Cheng, S.Y., Su, F.Q., Gao, Q.X., Yu, T., Ren, Z.H., 2007. Analysis of large- scale weather pattern during heavy air pollution process in Beijing. Res. Environ. Sci. 20, 99–105 (In Chinese). Cheng, S.Y., Xi, D.L., 1997. Several kinds of methods on determining atmospheric mixed layer. Adv. Environ. Sci. 2 (04), 64–68 (In Chinese). Cheng, S.Y., Xi, D., Zhang, B.N., Hao, R.X., Zheng, Z.B., Han, T.Y., 1997. Study on the determination and calculating method of atmospheric mixing layer height. China Environ. Sci. 17, 512–516 (In Chinese). Cui, H., Chen, W., Dai, W., Liu, H., Wang, X., He, K., 2015. Source apportionment of PM 2.5 in Guangzhou combining observation data analysis and chemical transport model simulation. Atmos. Environ. 116, 262–271.
  4. Dai, Z.J., Liu, D.Y., Wang, H.B., Wei, J.S., Jiang, Y.S., 2016. The classification study of the heavy haze during autumn and winter of Jiangsu. Acta Meteorol. Sin. 74, 133–148. (In Chinese). Ding, Y., Liu, Y., 2014. Analysis of long-term variations of fog and haze in China in recent 50 years and their relations with atmospheric humidity. Sci. China Earth Sci. 57, 36–46.
  5. Ding, G.A., Chan, C.Y., Gao, Z.Q., Yao, W.Q., Li, Y., Cheng, X.H., Meng, Z.Y., Yu, H.Q., Wong, K., Wang, S.F., Miao, Q.J., 2005. Vertical structures of PM 10 and PM 2.5 and their dynamical character in low atmosphere in Beijing urban areas. Sci. China, Ser. D. 48 (S2), 38–54.
  6. Ding, A.J., Huang, X., Nie, W., Sun, J.N., Kerminen, V.M., Petäjä, T., Su, H., Cheng, Y.F., Yang, X.Q., Wang, M.H., Chi, X.G., Wang, J.P., Virkkula, A., Guo, W.D., Yuan, J., Wang, S.Y., Zhang, R.J., Wu, Y.F., Song, Y., Zhu, T., Zilitinkevich, S., Kulmala, M., Fu, C.B., 2016. Black carbon enhances haze pollution in megacities in China. Geophys. Res. Lett. 2016, GL067745. Draxler, R.R., 2003. Evaluation of an ensemble dispersion calculation. J. Appl. Meteorol. 42, 308–317.