Measurements of Po214 at Sao Jose dos Campos and Cachoeira Paulista: correlation with meteorological data
Description
PO214, a short life daughter product of RN222, was measured by alpha-ray spectrometry of a atmospheric particles sampled on Millipore filters (0.8 μm pore) at Sao Jose dos Campos (23012'S, 45051'W) and Cachoeira Paulista (22041'S, 45000'W). The infleunce of rainfall on the atmospheric Po214 was studied at Sao Jose dos Campos. The mean activity was 98 pCi/m3 for dry days (without rain during the preceding two days). On the contrary a low mean activity of 35 pCi/m3 was observed for high pluviometry days from 08/30 to 10/26 for which total rainfall was 365.5 mm. At Cachoeria Paulista the Po214 activity was correlated with the stability of the air (measured by the Richardson number), showing an accumaltion of natural radioactive aerosols during periods of higher stability of the lower atmosphere. (author)
Abstract (Portuguese)
Mediu-se o Po214, descendente de curta meia-vida do RN222, coletando os aerossois atmosfericos sobre filtros de membrana (diametro de poro 0,8 μm), que sao posteriormente analisados por espectrometria alfa. Foram feitas medidas em Sao Jose dos Campos (23012'S, 45051'W) e Cachoeira Paulista (22041'19''S, 45000'22''W). En Sao Jose dos Campos analisou-se a influencia da pluviometria na concentracao do PO214 atmosferico. Verificou-se uma alta atividade com media de 98 pCi/m3 para dias secos, isto e, dois dias apos haver chovido, e, inversamente, uma baixa atividade correspondente a alto indice pluviometrico com media de 35 pCi/m3 por dia no periodo de 30/08 a 26/10 onde o total de precipitacao foi de 365,5 mm. Em Cachoeira Paulista estudou-se a variacao na concentracao de Po214 atmosferico em correlacao com a estabilidade do ar, atraves do numero de Richardson, evidenciando a acumulacao de aerossois radioativos naturais no periodo de maior estabilidade nas camadas inferiores da atmosfera. (autor)Files
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Additional details
Additional titles
- Original title (Portuguese)
- Medidas de Po
Publishing Information
- Imprint Pagination
- 30 p.
- Report number
- INPE--3725
INIS
- Country of Publication
- Brazil
- Country of Input or Organization
- Brazil
- INIS RN
- 19076129
- Subject category
- S54: ENVIRONMENTAL SCIENCES;
- Descriptors DEI
- AEROSOLS; ALPHA SPECTROMETERS; ALPHA SPECTROSCOPY; ATMOSPHERIC PRECIPITATIONS; METEOROLOGY; PARTICLES; POLONIUM 214; RADIATION MONITORING; RADIOACTIVITY
- Descriptors DEC
- ALPHA DECAY RADIOISOTOPES; COLLOIDS; DISPERSIONS; EVEN-EVEN NUCLEI; HEAVY NUCLEI; ISOTOPES; MEASURING INSTRUMENTS; MICROSEC LIVING RADIOISOTOPES; MONITORING; NUCLEI; POLONIUM ISOTOPES; RADIOISOTOPES; SOLS; SPECTROMETERS; SPECTROSCOPY
Optional Information
- Secondary number(s)
- PRE--857.