著者

Hideo Shiogama Noriko N. Ishizaki Naota Hanasaki Kiyoshi Takahashi Seita Emori Rui Ito Toshiyuki Nakaegawa Izuru Takayabu Yasuaki Hijioka Yukari N. Takayabu Ryosuke Shibuya

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

vol.17, pp.57-62, 2021 (Released:2021-04-03)

参考文献数

20

被引用文献数

1 18

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Climate change impact assessment studies often use future projections of only a few global climate models (GCMs) due to limited research resources. Here we develop a novel method to select a small subset of GCMs that widely capture the uncertainty range of large ensemble. By applying this method, we select a subset of five GCM projections from the Coupled Model Intercomparison Project Phase 6 (CMIP6) ensemble for impact and adaptation studies in Japan. At first, we omit GCMs whose global warming projections have been evaluated to be overestimated in the recent literature. Then, we select a subset of five GCMs that widely captures the uncertainty ranges for 8 climate variables and have good performances in present-climate simulations. These selected GCM simulations will be used to provide better climate scenarios for impact and adaptation studies than those in the previous impact assessment project.

著者

Hideo Shiogama Rui Ito Yukiko Imada Toshiyuki Nakaegawa Nagio Hirota Noriko N. Ishizaki Kiyoshi Takahashi Izuru Takayabu Seita Emori

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

vol.16, pp.75-79, 2020 (Released:2020-05-01)

参考文献数

22

被引用文献数

7

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The ensemble average projections of the Coupled Model Inter-comparison Project Phase 5 (CMIP5) ensemble show future increases in shortwave radiation at the surface (SW) in Japan. We reveal that the Arctic Oscillation-like atmospheric circulation trends cause cloud cover decreases around Japan, leading to increases in the SW.In many cases, impact assessment studies use the outputs of only a few models due to limited research resources. We find that the four climate models used in the Japanese multisector impact assessment project, S-8, do not sufficiently capture the uncertainty ranges of the CMIP5 ensemble regarding the SW projections. Therefore, the impact assessments using the SW of these four models can be biased. We develop a novel method to select a better subset of models that are more widely distributed and are not biased, unlike the S-8 models.

著者

Hiroaki Kawase Akihiko Murata Ken Yamada Tosiyuki Nakaegawa Rui Ito Ryo Mizuta Masaya Nosaka Shunichi Watanabe Hidetaka Sasaki

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

pp.2021-001, (Released:2020-12-18)

被引用文献数

12

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We investigate regional characteristics of future changes in snowfall in Japan under two emission scenarios—RCP2.6 and RCP8.5—using a high-resolution regional climate model with 5 km grid spacing and discuss the influence of changes in atmospheric circulation. The high-resolution model can simulate details of changes in distributions of total snowfall in Japan. Under RCP2.6, the annual total snowfall decreases in most parts of Japan except for Japan's northern island, Hokkaido. In Hokkaido, the winter snowfall increases even under RCP8.5, especially in January and February. The snowfall peak is delayed from early December to late January in Hokkaido. Along the Sea of Japan in eastern Japan, the winter-total snowfall decreases even if the winter mean temperature is below 0°C in the future climate. The different snowfall changes in Hokkaido and on the Sea of Japan side of eastern Japan are caused by precipitation changes in each region. Future changes in atmospheric circulation related to the Aleutian low cause the enhancement and the inhibition of winter precipitation in Hokkaido and the Sea of Japan side of eastern Japan, respectively, contributing to changes in the regional characteristics of snowfall and snow cover in addition to moistening due to atmospheric and ocean warming.

著者

Hideo Shiogama Noriko N. Ishizaki Naota Hanasaki Kiyoshi Takahashi Seita Emori Rui Ito Toshiyuki Nakaegawa Izuru Takayabu Yasuaki Hijioka Yukari N. Takayabu Ryosuke Shibuya

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

pp.2021-009, (Released:2021-02-16)

被引用文献数

18

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Climate change impact assessment studies often use future projections of only a few global climate models (GCMs) due to limited research resources. Here we develop a novel method to select a small subset of GCMs that widely capture the uncertainty range of large ensemble. By applying this method, we select a subset of five GCM projections from the Coupled Model Intercomparison Project Phase 6 (CMIP6) ensemble for impact and adaptation studies in Japan. At first, we omit GCMs whose global warming projections have been evaluated to be overestimated in the recent literature. Then, we select a subset of five GCMs that widely captures the uncertainty ranges for 8 climate variables and have good performances in present-climate simulations. These selected GCM simulations will be used to provide better climate scenarios for impact and adaptation studies than those in the previous impact assessment project.

著者

Hiroaki Kawase Akihiko Murata Ken Yamada Tosiyuki Nakaegawa Rui Ito Ryo Mizuta Masaya Nosaka Shunichi Watanabe Hidetaka Sasaki

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

vol.17, pp.1-7, 2021 (Released:2021-01-27)

参考文献数

29

被引用文献数

12

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We investigate regional characteristics of future changes in snowfall in Japan under two emission scenarios—RCP2.6 and RCP8.5—using a high-resolution regional climate model with 5km grid spacing and discuss the influence of changes in atmospheric circulation. The high-resolution model can simulate details of changes in distributions of total snowfall in Japan. Under RCP2.6, the annual total snowfall decreases in most parts of Japan except for Japan's northern island, Hokkaido. In Hokkaido, the winter snowfall increases even under RCP8.5, especially in January and February. The snowfall peak is delayed from early December to late January in Hokkaido. Along the Sea of Japan in eastern Japan, the winter-total snowfall decreases even if the winter mean temperature is below 0°C in the future climate. The different snowfall changes in Hokkaido and on the Sea of Japan side of eastern Japan are caused by precipitation changes in each region. Future changes in atmospheric circulation related to the Aleutian low cause the enhancement and the inhibition of winter precipitation in Hokkaido and the Sea of Japan side of eastern Japan, respectively, contributing to changes in the regional characteristics of snowfall and snow cover in addition to moistening due to atmospheric and ocean warming.

著者

Hideo Shiogama Rui Ito Yukiko Imada Toshiyuki Nakaegawa Nagio Hirota Noriko N. Ishizaki Kiyoshi Takahashi Izuru Takayabu Seita Emori

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

pp.2020-013, (Released:2020-03-30)

被引用文献数

7

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The ensemble average projections of the Coupled Model Inter-comparison Project Phase 5 (CMIP5) ensemble show future increases in shortwave radiation at the surface (SW) in Japan. We reveal that the Arctic Oscillation-like atmospheric circulation trends cause cloud cover decreases around Japan, leading to increases in the SW. In many cases, impact assessment studies use the outputs of only a few models due to limited research resources. We find that the four climate models used in the Japanese multisector impact assessment project, S-8, do not sufficiently capture the uncertainty ranges of the CMIP5 ensemble regarding the SW projections. Therefore, the impact assessments using the SW of these four models can be biased. We develop a novel method to select a better subset of models that are more widely distributed and are not biased, unlike the S-8 models.

著者

Tetsuya Takemi Rui Ito Osamu Arakawa

出版者

Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

雑誌

Hydrological Research Letters (ISSN:18823416)

巻号頁・発行日

vol.10, no.3, pp.81-87, 2016 (Released:2016-11-12)

参考文献数

23

被引用文献数

7 19

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Typhoon Mireille (1991) caused devastation over Japan. Assessing the impacts of such an extreme typhoon under global warming is an important task to prevent and mitigate future natural disasters. This study investigated the influences of global warming on the strong winds of Typhoon Mireille by conducting pseudo-global warming (PGW) experiments with a regional model. Since significant damages to forest areas occurred in Kyushu and Tohoku, we compared the typhoon impacts in these two regions. It was demonstrated that on average the mean wind speeds induced by Typhoon Mireille become stronger in Kyushu and weaker in Tohoku under the PGW conditions than under the September 1991 conditions. The difference between the two regions in the future is due to the simulated typhoons under PGW being stronger at lower latitudes and weakening more rapidly at higher latitudes. Thus, the impacts of Typhoon Mireille under a warmed climate are considered to be more severe at a lower latitude and weaker at a higher latitude.

著者

Shiori Sugimoto Rui Ito Koji Dairaku Hiroaki Kawase Hidetaka Sasaki Shingo Watanabe Yasuko Okada Sho Kawazoe Takeshi Yamazaki Takahiro Sasai

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

vol.14, pp.46-51, 2018 (Released:2018-04-01)

参考文献数

32

被引用文献数

7

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To evaluate the influence of spatial resolution in numerical simulations on the duration of consecutive dry days (CDDs) and near-surface temperature over the central mountains in Japan, a regional climate model was used to conduct two experiments with horizontal resolutions of 5 and 20 km. Compared with observations, the spatial and temporal features of the CDDs were simulated well in the 5 km experiment, whereas in the 20 km simulation they were overestimated over the mountains and underestimated in the surrounding regions. The accuracy in the simulated CDDs affected the near-surface temperature in the model. In years with a difference of more than five days in the CDDs between the 5 and 20 km experiments, near-surface temperatures over the mountains were 0.2-0.3 K lower in the 5 km simulation compared with the 20 km simulation. This was due to the lower number of CDDs in 5 km simulation causing active cloud convection and reduced net radiation at the ground, resulting from a large decrease in the solar radiation at the ground. In addition, a land surface wetness controls a spatial heterogeneity of temperature difference between two experiments.

著者

Rui Ito Tetsuya Takemi Osamu Arakawa

出版者

(公社)日本気象学会

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

vol.12, pp.100-105, 2016 (Released:2016-04-22)

参考文献数

23

被引用文献数

5 38

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Typhoon Songda (2004), while undergoing an extratropical transition and reintensification over the Sea of Japan, spawned serious damages over forest areas in the northern part of Japan. To clarify influences of anticipated global warming on the typhoon hazard in high-latitude regions, we carried out numerical experiments on Typhoon Songda in a current climate and a pseudo global warming climate and examined the impacts of climate change on the typhoon intensify and windstorms for the region. The typhoon intensity at its maturity becomes stronger in a warming climate, and the typhoon while passing over the Sea of Japan weakens more rapidly in the warming climate. Thus the strong wind over the northern part of Japan in the warming climate also becomes weaker. We examined atmospheric environmental factors in the higher-latitude region: sea surface temperature, vertical shear, and meridional gradient of temperature. It was found that the environmental meridional gradient of temperature at the 500 hPa level is smaller in the warming climate than in the current climate, which indicates that the baroclinicity becomes weak under global warming. The weak baroclinicity makes the typhoon environment unfavorable for the extratropical transition, and therefore, possibly reduces the severity of typhoon wind in northern Japan.