title: Spatial and temporal variations of atmospheric 85Kr observed during 1995-2001 in Japan: estimation of atmospheric 85Kr inventory in the Northern Hemisphere.
abstract: Atmospheric 85Kr concentrations have been continuously monitored since 1995 at the Meteorological Research Institute (MRI) in Tsukuba, Japan. They have also been observed once a year at several stations over the Japanese islands since 1995. The annual growth rate of the background atmospheric 85Kr concentrations in Tsukuba was 0.03 Bq x m(-3) x yr(-1) during 1996-2001. The atmospheric 85Kr concentrations at several stations over Japan were within the range of the annual variations in Tsukuba. However, higher and lower 85Kr concentrations in early winter, compared with those in Tsukuba (36.1 degrees N, 140.1 degrees E), occurred in Sapporo (43.1 degrees N, 141.3 degrees E) and Ishigaki (24.3 degrees N, 124.2 degrees E), respectively. The reason for this is that Sapporo is covered by a continental air mass, some from European sources, whereas Ishigaki is still covered by a subtropical air mass. The Northern Hemispheric background 85Kr concentrations from 1994 to 2001 was calculated from the 85Kr inventory and the release rate of 85Kr from the nuclear fuel reprocessing plants in Europe. Calculated 85Kr concentrations in surface air were in good agreement with annual average observed values at the MRI, Tsukuba. The global atmospheric inventory of 85Kr in December 2001 was also estimated to be approximately 5 EBq by using observed data in Tsukuba.
authors.affiliation: Meteorological Research Institute, Ibaraki, Japan. mhirota@met.kishou.go.jp
authors.forename: Michio
authors.initials: M
authors.lastname: Hirota
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Nemoto
authors.forename: Akira
authors.initials: A
authors.lastname: Wada
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Igarashi
authors.forename: Michio
authors.initials: M
authors.lastname: Aoyama
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Matsueda
authors.forename: Katsumi
authors.initials: K
authors.lastname: Hirose
authors.forename: Hartmut
authors.initials: H
authors.lastname: Sartorius
authors.forename: Clemens
authors.initials: C
authors.lastname: Schlosser
authors.forename: Sabine
authors.initials: S
authors.lastname: Schmid
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Weiss
authors.forename: Kenji
authors.initials: K
authors.lastname: Fujii
mesh_terms: D000396:Air Pollutants, Radioactive / Q000032:analysis*; D005060:Europe; D007564:Japan; D007727:Krypton Radioisotopes / Q000032:analysis*; D009688:Nuclear Reactors; D012621:Seasons; D013997:Time Factors
chemical_list: D000396:Air Pollutants, Radioactive; D007727:Krypton Radioisotopes