中国物理B ›› 2016, Vol. 25 ›› Issue (5): 50701-050701.doi: 10.1088/1674-1056/25/5/050701

• GENERAL • 上一篇    下一篇

Daily variation of radon gas and its short-lived progeny concentration near ground level and estimation of aerosol residence time

M Mohery, A M Abdallah, A Ali, S S Baz   

  1. 1. Physics Department, Faculty of Science, University of Jeddah, Saudi Arabia;
    2. Physics Department, Faculty of Science, Sohag University, Sohag, Egypt;
    3. Astronomy Department, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia;
    4. Astronomy Department, Faculty of Science, Cairo University, Cairo, Egypt;
    5. Physics Department, Girls Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
  • 收稿日期:2015-11-26 修回日期:2016-01-02 出版日期:2016-05-05 发布日期:2016-05-05
  • 通讯作者: M Mohery E-mail:mmohery@hotmail.com,mohery@yahoo.com,mmohery@kau.edu.sa
  • 基金资助:
    Project supported by the Deanship of Scientific Research (DSR), King Abdulaziz University, Jeddah (Grant No. 291/965/1434).

Daily variation of radon gas and its short-lived progeny concentration near ground level and estimation of aerosol residence time

M Mohery1,2, A M Abdallah1, A Ali3,4, S S Baz5   

  1. 1. Physics Department, Faculty of Science, University of Jeddah, Saudi Arabia;
    2. Physics Department, Faculty of Science, Sohag University, Sohag, Egypt;
    3. Astronomy Department, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia;
    4. Astronomy Department, Faculty of Science, Cairo University, Cairo, Egypt;
    5. Physics Department, Girls Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
  • Received:2015-11-26 Revised:2016-01-02 Online:2016-05-05 Published:2016-05-05
  • Contact: M Mohery E-mail:mmohery@hotmail.com,mohery@yahoo.com,mmohery@kau.edu.sa
  • Supported by:
    Project supported by the Deanship of Scientific Research (DSR), King Abdulaziz University, Jeddah (Grant No. 291/965/1434).

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摘要： Atmospheric concentrations of radon (222Rn) gas and its short-lived progenies 218Po, 214Pb, and 214Po were continuously monitored every four hours at the ground level in Jeddah city, Kingdom of Saudi Arabia. The measurements were performed three times every week, starting from November 2014 to October 2015. A method of electrostatic precipitation of positively charged 218Po and 214Po by a positive voltage was applied for determining 222Rn gas concentration. The short-lived 222Rn progeny concentration was determined by using a filter holder connected with the alpha-spectrometric technique. The meteorological parameters (relative air humidity, air temperature, and wind speed) were determined during the measurements of 222Rn and its progeny concentrations. 222Rn gas as well as its short-lived progeny concentration display a daily and seasonal variation with high values in the night and early morning hours as compared to low values at noon and in the afternoon. The observed monthly atmospheric concentrations showed a seasonal trend with the highest values in the autumn/winter season and the lowest values in the spring/summer season. Moreover, and in parallel with alpha-spectrometric measurements, a single filter-holder was used to collect air samples. The deposited activities of 214Pb and the long-lived 222Rn daughter 210Pb on the filter were measured with the gamma spectrometric technique. The measured activity concentrations of 214Pb by both techniques were found to be relatively equal largely. The highest mean seasonally activity concentrations of 210Pb were observed in the autumn/winter season while the lowest mean were observed in the spring/summer season. The mean residence time (MRT) of aerosol particles in the atmospheric air could be estimated from the activity ratios of 210Pb/214Pb.

关键词: daily variation, radon progeny concentration, meteorological variables

Abstract: Atmospheric concentrations of radon (222Rn) gas and its short-lived progenies 218Po, 214Pb, and 214Po were continuously monitored every four hours at the ground level in Jeddah city, Kingdom of Saudi Arabia. The measurements were performed three times every week, starting from November 2014 to October 2015. A method of electrostatic precipitation of positively charged 218Po and 214Po by a positive voltage was applied for determining 222Rn gas concentration. The short-lived 222Rn progeny concentration was determined by using a filter holder connected with the alpha-spectrometric technique. The meteorological parameters (relative air humidity, air temperature, and wind speed) were determined during the measurements of 222Rn and its progeny concentrations. 222Rn gas as well as its short-lived progeny concentration display a daily and seasonal variation with high values in the night and early morning hours as compared to low values at noon and in the afternoon. The observed monthly atmospheric concentrations showed a seasonal trend with the highest values in the autumn/winter season and the lowest values in the spring/summer season. Moreover, and in parallel with alpha-spectrometric measurements, a single filter-holder was used to collect air samples. The deposited activities of 214Pb and the long-lived 222Rn daughter 210Pb on the filter were measured with the gamma spectrometric technique. The measured activity concentrations of 214Pb by both techniques were found to be relatively equal largely. The highest mean seasonally activity concentrations of 210Pb were observed in the autumn/winter season while the lowest mean were observed in the spring/summer season. The mean residence time (MRT) of aerosol particles in the atmospheric air could be estimated from the activity ratios of 210Pb/214Pb.

Key words: daily variation, radon progeny concentration, meteorological variables

中图分类号:  (Instruments for environmental pollution measurements)

  • 07.88.+y
06.90.+v (Other topics in metrology, measurements, and laboratory procedures) 23.90.+w (Other topics in radioactive decay and in-beam spectroscopy) 92.05.Df (Climate and inter-annual variability)