Advances in Earth Science ›› 2010, Vol. 25 ›› Issue (5): 492-504. doi: 10.11867/j.issn.1001-8166.2010.05.0492

• Articles • Previous Articles     Next Articles

210Pb and 7Be as Tracers for Aerosol Transfers at Center Guizhou,China:Ⅰ.The Explanation by Weekly Interval

Wan Guojiang 1,Zheng Xiangdong 2,Lee H N 3,Bai Z G 4,Wan Enyuan 1,Wang Shilu 1,Yang Wei 1,Su Fei 5,Tang Jie 2,Wang Changsheng 1,Huang Ronggui 1, Liu Peng 6   

  1. 1.State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang  550002, China;
    2.Chinese Academy of Meteorological Sciences, Beijing  100081, China;
    3.Environmental Measurements Laboratory, New York NY  10014-7447, USA;
    4.ISRIC-World Soil Information, Wageningen 6700 AJ, the Netherlands;
    5.Weather Bureau of Guizhou province,Guiyang  550002, China;
    6.China Global Atmosphere Watch Baseline Observatory,Xining  810001,China
  • Received:2009-09-24 Revised:2010-03-29 Online:2010-05-10 Published:2010-05-10
  • Contact: Wan Guojiang E-mail:wanguojiang@vip.skleg.cn
  • Supported by:

    万国江(1940),男,四川南溪人,研究员,主要从事区域环境演变、环境过程和核素示踪研究. E-mail:wanguojiang@vip.skleg.cn 

Wan Guojiang,Zheng Xiangdong,Lee H N,Bai Z G,Wan Enyuan,Wang Shilu,Yang Wei. 210Pb and 7Be as Tracers for Aerosol Transfers at Center Guizhou,China:Ⅰ.The Explanation by Weekly Interval[J]. Advances in Earth Science, 2010, 25(5): 492-504.

   It′s essential to measure air concentrations and depositional fluxes of environmental radionuclides in different regions for modeling global contamination transfer and validation, tracing deposition process and dating, referencing watershed erosion trace and assessing natural radiation of ecosystem. This study introduces the research background and methods and explains weekly variations of 210Pb and 7Be concentrations in surface air and precipitation at Mt. Guanfeng/Guiyang since 2001. The results indicate that 210Pb and 7Be concentrations in surface air fluctuate periodically at 2~6 week interval because of the meteorological condition changes. The annual trend in 210Pb air concentration is overall influenced by air temperature variation and periodical rainfall. 7Be air concentration varies up and down regualarly. The synchronization of low concentrations for both 210Pb and 7Be in surface air and high ratio (210Pb/7Be ≥ 0.8) indicate oceanic poor 210Pb-7Be air mass invasion. The synchronization of high concentrations of 210Pb and 7Be in surface air and low ratio (210Pb/7Be ≤ 0.7) implies rich 7Be air mass invasion from altostratus atmosphere. Weekly concentrations of 210Pb and 7Be in precipitation and the Kd coefficients are high in late Autumn to Spring, and low in late Spring to Autumn. Although 210Pb and 7Be concentrations vary seasonally, their weekly concentrations in precipitation increase with that of air concentration. The 210Pb and 7Be weekly concentrations for seasonal division is about 0.2 Bq/L and 1 Bq/L, respectively. However, the Kd coefficient decreases when 210Pb and 7Be air concentrations increase. Deposition of 210Pb and 7Be with precipitation mainly take place in Spring and Summer; The weekly fallout of 210Pb and 7Be increases with increasing precipitation; the increase of 7Be is triple of that of 210Pb and 2.5 when precipitation nears to zero. The weekly-high fallout of 210Pb and 7Be with precipitation corresponds with the dramatic decrease of their air concentrations within or vicinal weeks. The ratio of 210Pb to 7Be in rainfall is overall ≤ 0.5 and varies synchronously with the ratio in surface air, indicating that the two radionuclides are cleaned by precipitation from air at close speed. In the extreme freezing disaster in 2008, both 210Pb and 7Be air concentrations were low and coupling with coexist of low concentration of aerosol and high nuclides activities. Weekly concentration of 7Be in surface air at Mt. Guanfeng demonstrates the anticipated concentration level in the low-latitude and high-elevation region; the short-term fluctuations of 7Be concentration indicated the hysteresis was influcenced by the strong air current submersion and the low-elevation air mass rising differently at Mt. Guanfeng and Mt. Waliguan. 

No related articles found!
Viewed
Full text


Abstract