*Prabir Patra^1,2、Tazu Saeki¹、Edward J Dlugokencky⁴、Kentaro Ishijima¹、Taku Umezawa³、Akihiko Ito³、Shuji Aoki²、Shinji Morimoto²、Eric A Kort⁵、Andrew Crotwell⁴、Ravi Kumar Kunchala⁶、Takakiyo Nakazawa² (1.Department of Environmental Geochemical Cycle Research, JAMSTEC, Yokohama, Japan、2.CAOS, Graduate School of Science, Tohoku University, Sendai, Japan、3.National Institute for Environmental Studies, Tsukuba, Japan、4.NOAA Earth System Research Laboratory, Colorado, USA、5.University of Michigan, Michigan, USA、6.Arctic GRENE, National Institute of Polar Research, Tachikawa, Japan)