Black carbon over the South China Sea and in various continental locations in South China 1Institute of Tropical and Marine Meteorology, CMA, Guangzhou 510080, China
17 Dec 2013
2Division of Environment, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
3Atmospheric Research Centre, Fok Ying Tung Graduate School, Hong Kong University of Science and Technology, Nansha, Guangzhou, China
4Department of Chemistry, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
Received: 13 May 2013 – Published in Atmos. Chem. Phys. Discuss.: 01 Jul 2013 Abstract. Black carbon (BC) is an important atmospheric constituent as an air
pollutant and as a climate forcer. To our knowledge, field measurements of
BC have not been reported over the South China Sea. Observations of light-absorption coefficients (σabs) and BC concentrations by
Aethalometer were conducted on Yongxing Island in the South China Sea and at
five continental sites in the Pearl River delta (PRD) region, South China, in
two periods: 16 May–20 June 2008 in the rainy season and 12 December 2008–8
January 2009 in the dry season. At the oceanic site, the daily average BC
concentrations varied from 0.28 to 2.14 μg m−3 and variations of
BC were small between the two periods (0.67 in the dry season sampling
period and 0.54 μg m−3 in the rainy season sampling period).
Similarly, little difference in BC level was found at a rural site in PRD
between the two sampling periods (2.88 and 2.62 μg m–3). At the
PRD urban sites, the daily average concentration of BC ranged from 1.56 to
37.9 μg m−3, higher in the dry season sampling period (12.31 μg m–3) and lower in the rainy season sampling period (6.17 μg m–3).
The observed average σabs values in rainy vs. dry
season sampling periods are 119 vs. 62 Mm−1 at the PRD urban sites, 29
vs. 26 Mm−1 at the PRD background site, and 8.4 vs. 7.2 Mm−1 at
the marine site. At urban/suburban PRD sites, BC was observed to have a
diurnal pattern of higher concentrations at night and at the urban sites a
small peak in the early morning rush hour.
Revised: 25 Oct 2013 – Accepted: 07 Nov 2013 – Published: 17 Dec 2013
Citation: Wu, D., Wu, C., Liao, B., Chen, H., Wu, M., Li, F., Tan, H., Deng, T., Li, H., Jiang, D., and Yu, J. Z.: Black carbon over the South China Sea and in various continental locations in South China, Atmos. Chem. Phys., 13, 12257-12270, doi:10.5194/acp-13-12257-2013, 2013.