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Dispersion characteristics of radioactive materials estimated by wind patterns

The radioactive materials are generally concentrated downwind of their origins when the prevailing winds blow continuously in one direction. If this principle determined the pattern of dispersion in all cases, dispersion directions could be estimated by wind patterns. However, this hypothesis has no...

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Autores principales: Yoshikane, Takao, Yoshimura, Kei
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6028445/
https://www.ncbi.nlm.nih.gov/pubmed/29967386
http://dx.doi.org/10.1038/s41598-018-27955-4
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author Yoshikane, Takao
Yoshimura, Kei
author_facet Yoshikane, Takao
Yoshimura, Kei
author_sort Yoshikane, Takao
collection PubMed
description The radioactive materials are generally concentrated downwind of their origins when the prevailing winds blow continuously in one direction. If this principle determined the pattern of dispersion in all cases, dispersion directions could be estimated by wind patterns. However, this hypothesis has not been sufficiently verified because of the complexity of dispersion processes and weather systems. Here, we show that dispersion directions, which are divided into four ranges, can be estimated by wind patterns using a machine learning approach. The five-year average hit rates of the directions of dispersion estimated using near-surface winds exceed 0.85 in all months. The dispersion directions can be estimated up to 33 hours in advance using forecast winds. In particular, high hit rates exceeding 0.95 are achieved in January and March, when large-scale weather systems dominate. These results indicate that the dispersion directions are determined by the wind patterns that correspond to large-scale weather systems and diurnal circulation patterns in most cases. Our findings also provide more reliable information on dispersion patterns with reduced uncertainties, given that reasonable skill is achieved at a sufficient lead time for evacuation.
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spelling pubmed-60284452018-07-09 Dispersion characteristics of radioactive materials estimated by wind patterns Yoshikane, Takao Yoshimura, Kei Sci Rep Article The radioactive materials are generally concentrated downwind of their origins when the prevailing winds blow continuously in one direction. If this principle determined the pattern of dispersion in all cases, dispersion directions could be estimated by wind patterns. However, this hypothesis has not been sufficiently verified because of the complexity of dispersion processes and weather systems. Here, we show that dispersion directions, which are divided into four ranges, can be estimated by wind patterns using a machine learning approach. The five-year average hit rates of the directions of dispersion estimated using near-surface winds exceed 0.85 in all months. The dispersion directions can be estimated up to 33 hours in advance using forecast winds. In particular, high hit rates exceeding 0.95 are achieved in January and March, when large-scale weather systems dominate. These results indicate that the dispersion directions are determined by the wind patterns that correspond to large-scale weather systems and diurnal circulation patterns in most cases. Our findings also provide more reliable information on dispersion patterns with reduced uncertainties, given that reasonable skill is achieved at a sufficient lead time for evacuation. Nature Publishing Group UK 2018-07-02 /pmc/articles/PMC6028445/ /pubmed/29967386 http://dx.doi.org/10.1038/s41598-018-27955-4 Text en © The Author(s) 2018 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Yoshikane, Takao
Yoshimura, Kei
Dispersion characteristics of radioactive materials estimated by wind patterns
title Dispersion characteristics of radioactive materials estimated by wind patterns
title_full Dispersion characteristics of radioactive materials estimated by wind patterns
title_fullStr Dispersion characteristics of radioactive materials estimated by wind patterns
title_full_unstemmed Dispersion characteristics of radioactive materials estimated by wind patterns
title_short Dispersion characteristics of radioactive materials estimated by wind patterns
title_sort dispersion characteristics of radioactive materials estimated by wind patterns
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6028445/
https://www.ncbi.nlm.nih.gov/pubmed/29967386
http://dx.doi.org/10.1038/s41598-018-27955-4
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