title: World Meteorological Organization's model simulations of the radionuclide dispersion and deposition from the Fukushima Daiichi nuclear power plant accident.
abstract: Five different atmospheric transport and dispersion model's (ATDM) deposition and air concentration results for atmospheric releases from the Fukushima Daiichi nuclear power plant accident were evaluated over Japan using regional (137)Cs deposition measurements and (137)Cs and (131)I air concentration time series at one location about 110 km from the plant. Some of the ATDMs used the same and others different meteorological data consistent with their normal operating practices. There were four global meteorological analyses data sets available and two regional high-resolution analyses. Not all of the ATDMs were able to use all of the meteorological data combinations. The ATDMs were configured identically as much as possible with respect to the release duration, release height, concentration grid size, and averaging time. However, each ATDM retained its unique treatment of the vertical velocity field and the wet and dry deposition, one of the largest uncertainties in these calculations. There were 18 ATDM-meteorology combinations available for evaluation. The deposition results showed that even when using the same meteorological analysis, each ATDM can produce quite different deposition patterns. The better calculations in terms of both deposition and air concentration were associated with the smoother ATDM deposition patterns. The best model with respect to the deposition was not always the best model with respect to air concentrations. The use of high-resolution mesoscale analyses improved ATDM performance; however, high-resolution precipitation analyses did not improve ATDM predictions. Although some ATDMs could be identified as better performers for either deposition or air concentration calculations, overall, the ensemble mean of a subset of better performing members provided more consistent results for both types of calculations.
authors.affiliation: National Oceanic and Atmospheric Administration, College Park, MD 20740, USA. Electronic address: Roland.Draxler@noaa.gov.
authors.forename: Roland
authors.initials: R
authors.lastname: Draxler
authors.affiliation: Zentralanstalt für Meteorologie und Geodynamik, Vienna, Austria.
authors.forename: Dèlia
authors.initials: D
authors.lastname: Arnold
authors.affiliation: Japan Atomic Energy Agency, Ibaraki, Japan.
authors.forename: Masamichi
authors.initials: M
authors.lastname: Chino
authors.affiliation: European Commission, Joint Research Centre, Ispra, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Galmarini
authors.affiliation: Met Office, Exeter, United Kingdom.
authors.forename: Matthew
authors.initials: M
authors.lastname: Hort
authors.affiliation: Met Office, Exeter, United Kingdom.
authors.forename: Andrew
authors.initials: A
authors.lastname: Jones
authors.affiliation: Met Office, Exeter, United Kingdom.
authors.forename: Susan
authors.initials: S
authors.lastname: Leadbetter
authors.affiliation: Canadian Meteorological Centre, Montréal, Canada.
authors.forename: Alain
authors.initials: A
authors.lastname: Malo
authors.affiliation: Zentralanstalt für Meteorologie und Geodynamik, Vienna, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Maurer
authors.affiliation: National Oceanic and Atmospheric Administration, College Park, MD 20740, USA.
authors.forename: Glenn
authors.initials: G
authors.lastname: Rolph
authors.affiliation: Japan Meteorological Agency, Ibaraki, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Saito
authors.affiliation: Canadian Meteorological Centre, Montréal, Canada.
authors.forename: René
authors.initials: R
authors.lastname: Servranckx
authors.affiliation: Japan Meteorological Agency, Ibaraki, Japan.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Shimbori
authors.affiliation: European Commission, Joint Research Centre, Ispra, Italy.
authors.forename: Efisio
authors.initials: E
authors.lastname: Solazzo
authors.affiliation: Zentralanstalt für Meteorologie und Geodynamik, Vienna, Austria.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Wotawa
mesh_terms: D002588:Cesium Radioisotopes / Q000032:analysis*; D062406:Fukushima Nuclear Accident; D055848:Nuclear Power Plants; D011868:Radioisotopes / Q000032:analysis*
chemical_list: D002588:Cesium Radioisotopes; D011868:Radioisotopes
keywords: ATDM; Air concentration; Cesium; Deposition; Fukushima; Iodine