In:
Journal of Geophysical Research: Atmospheres, American Geophysical Union (AGU), Vol. 94, No. D8 ( 1989-08-20), p. 11106-11116
Abstract:
Atmospheric depositional fluxes of 7 Be and 210 Pb were measured simultaneously in wet‐only and bulk deposition over a 29‐month period (October 1982 through February 1985) in Norfolk, Virginia (36°53′N, 76°18′W). Total precipitation accumulation during 1983 and 1984 was 134 and 129 cm, respectively, slightly above the normal yearly accumulation. The volume‐weighted average concentrations of 7 Be in bulk deposition for 1983 and 1984 were 90 and 100 dpm/L, while those for 210 Pb were 5.9 and 6.6 dpm/L, respectively. The annual depositional fluxes of 7 Be and 210 Pb in bulk deposition in 1983 and 1984 were 12.0 and 12.9 dpm/cm 2 (for 7 Be) and 0.79 and 0.85 dpm/cm 2 (for 210 Pb), respectively. There was a high degree of correlation between 7 Be and 210 Pb concentrations in wet‐only deposition. This was not anticipated, considering that the sources of these two radionuclides are different. These results suggest that 7 Be and 210 Pb cannot be used as two independent tracers for materials originating in the stratosphere versus those from the troposphere. Dry depositional fluxes for both radionuclides, estimated from differences in the wet‐only and bulk fluxes, were calculated to be a maximum of 12 and 11% of the bulk 7 Be and 210 Pb fluxes, respectively. On an annual average the washout ratio for 7 Be in bulk deposition was 370, while that for 210 Pb was 215. The annual average total deposition velocities for 7 Be and 210 Pb were estimated to be 1.3 and 0.7 cm/s, respectively. It is suggested that the apparent differences in the depositional characteristics (that is, total deposition velocity, washout ratio) for these radionuclides are mere artifacts of the manner in which they are calculated and do not necessarily reflect differential behavior in the atmospheric deposition of 7 Be and 210 Pb.
Type of Medium:
Online Resource
ISSN:
0148-0227
DOI:
10.1029/JD094iD08p11106
Language:
English
Publisher:
American Geophysical Union (AGU)
Publication Date:
1989
detail.hit.zdb_id:
2033040-6
detail.hit.zdb_id:
3094104-0
detail.hit.zdb_id:
2130824-X
detail.hit.zdb_id:
2016813-5
detail.hit.zdb_id:
2016810-X
detail.hit.zdb_id:
2403298-0
detail.hit.zdb_id:
2016800-7
detail.hit.zdb_id:
161666-3
detail.hit.zdb_id:
161667-5
detail.hit.zdb_id:
2969341-X
detail.hit.zdb_id:
161665-1
detail.hit.zdb_id:
3094268-8
detail.hit.zdb_id:
710256-2
detail.hit.zdb_id:
2016804-4
detail.hit.zdb_id:
3094181-7
detail.hit.zdb_id:
3094219-6
detail.hit.zdb_id:
3094167-2
detail.hit.zdb_id:
2220777-6
detail.hit.zdb_id:
3094197-0
SSG:
16,13
Permalink