Journal of Nuclear Science, Engineering and Technology (JONSAT)
In cooperation with the Iranian Nuclear Society

Long-Term Variation of Atmospheric Beryllium-7 in Iran

Document Type : Research Paper

Authors

F Arkian
J Amidi
Abstract
Iran Radiological Air Monitoring Center has measured the concentration of atmospheric 7Be at two stations located in Iran: Tehran (35º 41'), and Zahedan (29º 28') for duration of 4 years. The gamma emitting nuclides have been collected by high-volume air samplers and measured by gamma spectrometry. The results of the measured gamma emitting nuclides have shown that the cosmogenic 7Be is the only nuclide found in the air of Iran. 7Be is one of radioactive products of the bombardment of atmosphere by the cosmic rays. The data for the two sampling sites show seasonal variations in the concentration of  7Be. The 7Be concentrations are the highest at each of these sites during the warm mid-year months. An important factor in producing the peak concentrations of 7Be during the warmer month is the increased rates of the vertical transport within the troposphere that occurs during the warm seasons. The concentration of 7Be in air shows some difference between the obtained data in Tehran and Zahedan stations, with the respective values of 10.41 ± 1.50E+00 mBqm-3 in Tehran and 17.10 ± 1.90E+00 mBqm-3 in Zahedan. But the seasonal variations of 7Be concentration behavior is the same. We believe that 7Be concentration decreases poleward from the middle latitudes, because of the stability of the tropospheric air is the highest toward the cold polar region and decreases in the rate of vertical mixing within the troposphere.

Highlights

        1.  J.R. Arnold and H.A. Al-Salih,  "7Be produced by cosmic reys,"Science, Vol. 121, 451-453 (1995).

           

          2.  W.B. Johnson and W. Viezee, "Stratospheric ozonein the lower troposphere – I. Presentation andinterpretation of aircraftmeasurements,"Atmos.Environ., Vol. 15, 1309-1323 (1981).

           

          3.  H.W. Feely, R.J. Larson, Sanderson, "Factors that cause seasonal variation in 7Be concentrations in surface air," J. Environ. Radioacivity., Vol. 9, 223-249 (1988).

           

           

           

           

           

           

          4.  W. Graustein, "7Be and Pb indicate an upper troposphere source for elevated ozone in the summertime subtropical free troposphere of the eastern North Atlantic,"Geophys. Res. Lett., Vol. 23, 539-542 (1996).

           

          5. K.B. Schnelle and R. Partha, "Atmospheric dispersion modeling complianceguide," New York: McGraw- Hill Companies Press, Ch., 1-24 (2000).  

Keywords

Beryllium-7
natural radioactivity
gamma spectroscopy
atmospheric dispersion

  1.  J.R. Arnold and H.A. Al-Salih,  "7Be produced by cosmic reys,"Science, Vol. 121, 451-453 (1995).

     

    2.  W.B. Johnson and W. Viezee, "Stratospheric ozonein the lower troposphere – I. Presentation andinterpretation of aircraftmeasurements,"Atmos.Environ., Vol. 15, 1309-1323 (1981).

     

    3.  H.W. Feely, R.J. Larson, Sanderson, "Factors that cause seasonal variation in 7Be concentrations in surface air," J. Environ. Radioacivity., Vol. 9, 223-249 (1988).

     

     

     

     

     

     

    4.  W. Graustein, "7Be and Pb indicate an upper troposphere source for elevated ozone in the summertime subtropical free troposphere of the eastern North Atlantic,"Geophys. Res. Lett., Vol. 23, 539-542 (1996).

     

    5. K.B. Schnelle and R. Partha, "Atmospheric dispersion modeling complianceguide," New York: McGraw- Hill Companies Press, Ch., 1-24 (2000).  

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