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Volume 80 (2018)
- Issue 6 Pages 515-
- Issue 5 Pages 427-
- Issue 4 Pages 277-
- Issue 3 Pages 213-
- Issue 2 Pages 103-
- Issue 1 Pages 3-
Volume 80, Issue 2
Displaying 1-7 of 7 articles from this issue
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Keisuke SUZUKI2018 Volume 80 Issue 2 Pages 103-113
Published: 2018
Released on J-STAGE: March 01, 2023
JOURNAL OPEN ACCESSThe Japanese Alps experience exceptionally heavy snowfall, extreme even by global standards, and in spring and summer the melting snow becomes a valuable water resource. The snow effectively acts as a natural dam when it accumulates in watersheds during winter. However, there have been no observations of the amount of snow in high-altitude regions of Japan. Therefore, we cannot discuss the effect of global warming on the change in the amount of snow in these regions based on direct observation data. We were, however, able to obtain climatic and hydrologic data for high-altitude sites in the Japanese Alps, and discuss the variations in these conditions in the Kamikochi region (altitude 1490m‒3190m) of the Japanese Alps over a 68-year period using these observed data. No long-term trends are observed in the annual mean, maximum, or minimum temperatures at Taisho-ike from 1945 to 2012; the total annual precipitation shows a statistically significant decreasing trend. The annual total snowfall at Taisho-ike from 1969 to 2012 shows a statistically significant increasing trend. The annual total runoff of the Azusa River from 1945 to 2012 shows a statistically significant increasing trend, as does the snowmelt runoff to the river (which occurs from May to July). We can thus conclude that the annual snowfall in the Azusa River catchment has increased in recent years.View full abstractDownload PDF (3691K) -
Kentaro ARAKI2018 Volume 80 Issue 2 Pages 115-129
Published: 2018
Released on J-STAGE: March 01, 2023
JOURNAL OPEN ACCESSTo improve forecasts of snowfall events, a better understanding of the microphysical properties of snow clouds is needed. TheMeteorological Research Institute conducted the “#KantoSnowCrystal Project” to collect images of snow crystals from citizens during snowfall events in the Kanto and Koshin regions in Japan. Smartphone cameras were used to capture the images, which were mainly collected through social networking services. Through the campaign in the 2016-2017 winter season, we confirmed the availability of snow crystal observations by citizen science, and tried understanding the snowfall characteristics in these metropolitan areas. Through the project, we were able to establish an easy method for snow crystal observation and data collection. More than 10,000 snow crystal images were gathered throughout the 2016-2017 winter, of which 73% were analyzable. The #KantoSnowCrystal Project thereby realized spatiotemporally ultra-dense observations of snow crystals in these metropolitan areas, and the observation dataset should contribute to investigations of snowfall mechanisms in these areas and the verification and improvement of numerical weather models, etc. The amount of data, however, varied considerably between heavily populated central urban areas and less-populated inland areas. Collaboration with local autonomous bodies and educational organizations, and effective outreach and dissemination activities are needed to expand the network of snow crystal observation by citizen science.View full abstractDownload PDF (12060K) -
Kentaro ARAKI2018 Volume 80 Issue 2 Pages 131-147
Published: 2018
Released on J-STAGE: March 01, 2023
JOURNAL OPEN ACCESSOn 27 March 2017, a heavy snowfall associated with cyclones caused a surface avalanche in Nasu, Tochigi Prefecture, Japan. Although it is known that large amounts of snowfall in a short time are important for surface avalanches, understanding of snowfall characteristics in mountainous regions during heavy snowfall events is lacking. We conducted a case study of this event and also performed a statistical analysis of snowfall events in Nasu from 1989 to 2017, where we investigated the snowfall characteristics and meteorological conditions of each event. In the March 2017 event, low-level supercooled water clouds were formed by orographically forced updrafts in mountainous regions in Nasu as moist northerly and easterly flows intensified due to the cycloneʼs approach. Localized snowfall intensification and short-duration heavy snowfalls were produced by the Seeder-Feeder mechanism associated with the low-level clouds and snow from the upper clouds of the cyclone. The statistical analysis revealed that similar heavy snowfall events occur about once every 3 years, but only once every 19 years in March. The surface pressure patterns in heavy snowfall cases in Nasu were about 63% in the typical winter monsoon pattern and about 30% in cyclones. Although snowfall amounts became larger as snowfall duration increased in both patterns, some short-duration heavy snowfalls exceptionally occurred in cases where occluded cyclones passed near the Kanto region.View full abstractDownload PDF (10746K) -
Osamu ABE, Satoru YAMAGUCHI, Masamitsu ONO2018 Volume 80 Issue 2 Pages 149-157
Published: 2018
Released on J-STAGE: March 01, 2023
JOURNAL OPEN ACCESSIn this study, we estimate the snow water equivalent on Mt. Gassan (1984m a. s. l.) using historical data. We collated data for late March in 1954, 1955, 2003 and 2004, and derived a linear equation based on snow depth and elevation, and an empirical equation to convert snow depth to snow water equivalent. A square area of 400km2 was selected with the peak of Mt. Gassan at the center. The total snow water equivalent is estimated to be 5.2×10 8t, and the average snow water equivalent is estimated as 1300mm. This study confirms that the area around Mt. Gassan has one of the heaviest snowfalls in Japan.View full abstractDownload PDF (4523K) -
Kazuyuki SAITO, Junko MORI, Hirokazu MACHIYA, Shin MIYAZAKI, Takeshi I ...2018 Volume 80 Issue 2 Pages 159-174
Published: 2018
Released on J-STAGE: March 01, 2023
JOURNAL OPEN ACCESSAn Arctic terrestrial model intercomparison project (GTMIP), designed for enhanced collaborations between modeling and field scientists, and for assessment of uncertainty and variations in current terrestrial models to improve, was carried out with 21 domestic and international participants, ranging from physical to biogeochemical to hybrid models. Metrics of the project covers energy-water budget, snowpack, phenology, subsurface regimes, and carbon budget. This paper reports the results on energy-water budget between the atmosphere, surface and subsurface, of the 34-year site simulations (1980-2013) for four GRENE-TEA sites with different eco-climate background (i.e., Fairbanks, Kevo, Tiksi, and Yakutsk). Models were driven by common, statistically fitted data created through model‒field collaborations with use of the site observations. Energetic and hydrological balances between the atmosphere showed no systematic differences that result from disciplines that models are oriented to, but individual modelsʼ specifics. Modelsʼ performance at different sites were less associated with the types or complexity of the models than with the ecological and subsurface characteristics of the sites. The model ensemble proved to be a robust estimate to represent the observed values in general. However, snowpack and subsurface hydrological-thermal states, which greatly affect surface-subsurface exchanges, demonstrated large differences in performance and biases among models, which implies needs for special attention at future developments.View full abstractDownload PDF (6383K) -
Shinji MATSUMURA2018 Volume 80 Issue 2 Pages 175-184
Published: 2018
Released on J-STAGE: March 01, 2023
JOURNAL OPEN ACCESS -
Kazuyoshi SUZUKI2018 Volume 80 Issue 2 Pages 185-192
Published: 2018
Released on J-STAGE: March 01, 2023
JOURNAL OPEN ACCESS
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