Estimating regional climate change uncertainty in Japan at the end of the 21st century with mixture distribution
February 18th, 2017
Shunya Wakamatsu, Kenji Oshio, Koji Ishihara, Hirokazu Murai, Takuya Nakashima, Tsuyoshi Inoue
Received 2016/08/01, Accepted 2016/12/24, Published 2017/02/18
Shunya Wakamatsu1), Kenji Oshio2), Koji Ishihara2), Hirokazu Murai2), Takuya Nakashima3), Tsuyoshi Inoue3)
1) Ministry of Education, Culture, Sports, Science and Technology
2) Japan Meteorological Agency
3) Mitsubishi Research Institute Inc.
To facilitate accurate assessments of the regional impacts of global warming, and make informed decisions about appropriate measures to mitigate them, detailed global warming projections with uncertainties are needed. The Ministry of Environment of Japan and the Japan Meteorological Agency performed 21 different multi-scenario and multi-ensemble experiments in Japan using the regional climate model MRI-NHRCM with a horizontal resolution of 20 km. To estimate the total range of uncertainty due to natural fluctuations and the variety of experimental runs by a single climate model with multi-physics and multi-SST ensembles under each greenhouse gas emission scenario, a unique statistical method that combined a mixture distribution and bootstrap resampling was adopted. Based on three models that adopted the Yoshimura scheme as a cumulus convection parameterization, annual mean temperatures in Japan were projected to rise significantly by 1.1 ± 0.4°C, 2.0 ± 0.4°C, 2.6 ± 0.6°C, and 4.4 ± 0.6°C under the RCP2.6, RCP4.5, RCP6.0, and RCP8.5 scenarios, respectively, at the end of the 21st century relative to the end of the 20th century (ensemble means ± standard deviations). In contrast, changes in future annual precipitation over Japan were projected to be statistically insignificant.
Copyright (c) 2017 The Author(s) CC-BY 4.0