地学雑誌 Journal of Geography（Chigaku Zasshi） 128（1）1⊖4 2019 doi:10.5026/jgeography.128.1

Overview of the Special Issue on “Investigation of Weather and Climate Changes in the Region”

＊ ＊＊ Kenichi UENO , Hiroaki KAWASE , ＊＊＊ ＊＊＊＊ Takashi HAMADA and Hiroyuki MURAOKA

Mountains foster an ecosystem and supply surrounding mountains. Elevation dependencies water necessary for human life. Recently, there on climate between the southern Yakushima have been concerns that transformations in the island and Daisetsuzan Volcanic Group in mountain environment due to global warming Hokkaido are quite different, and they cannot may threaten various systems that depend on be unambiguously defined using the same em- mountains（ Watanabe and Ueno, 2017）. Over- pirical functions. Extreme weather frequently seas, temperature warming trends at high elev- causes disasters between mountains （at the ations have been identified（ Mountain Research feet of mountains）. As global warming has Initiative EDW Working Group, 2015）. A progressed, synoptic scale fields surrounding shrinking mountainous cryosphere with topo- mountain areas have been modulated, and sur- graphical and ecological changes that affect face temperatures in the mountains have not tourism and water resources has been revealed simply increased. When an overseas researcher by in-situ observations and modeling analyses. asks whether the impacts of global warming An international conference to share knowledge are also being manifest in Japanese mountains, and discuss the challenges of ongoing mountain- it is difficult to give a clear answer because of related issues has been held once every five the diversity of weather and climate among the years（ Ueno and Watanabe, 2016）, and a work- mountains. shop named the International Mountain Confe- An interuniversity cooperative project named rence（ IMC） is planned for 2019 in Innsbruck, JALPS was conducted over five years in central Austria. When comparing such research trends . That climate study group summarized with those in Japan, we notice that weather the challenges of study topics in the past, pres- and climate variability in mountain studies is ent, and future（ See details in Vol. 122, No. 4, very distinctive worldwide. Originally, the cli- Journal of Geography（ Chigaku Zasshi））. One mate of Japan was maritime and strongly influ- important recognition was that studies in rela- enced by Asian monsoons. Backbone mountain tion to weather and climate variability in Japa- ranges play a major role in dividing climate nese mountains cover quite a range of interdis- zones, such as the Pacific side, inland, and Sea ciplinary topics from long term, such as climate of Japan side. On the other hand, weather in reconstruction by geology/dendrochronology, to basins and plains, where major cities are locat- short term, such as weather nowcasting to mit- ed, is controlled by thermodynamic effects of igate hazards caused by extreme weather. Re-

＊ Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, 305-8572, Japan ＊＊ Meteorological Research Institute, Japan Meteorological Agency, Tsukuba, 305-0052, Japan ＊＊＊ Nagano Environmental Conservation Research Institute, Nagano, 381-0075, Japan ＊＊＊＊ River Basin Research Center, Gifu University, Gifu, 501-1193, Japan

― 1 ― search studies in multiple fields, such as those Global Precipitation Mission （GPM） satellite relating to water cycle, biodiversity, and forest/ estimates depending on synoptic disturbance land management, are underway in a country types. Discrepancies due to the structure of the composed of islands. Topics are not limited precipitation system are discussed, such as an to “mountain meteorology” as categorized in overestimation that tends to appear on a wider atmospheric science. On the other hand, spa- scale with extra-tropical cyclones and an under- tiotemporal scale and target mountains differ estimation that tends to appear in the meso- among research groups, and it is difficult to dis- scale with shallow, warm convections. Yasue et cuss and summarize what the ongoing changes al. （2019） reconstruct summer temperatures are in relation to common scientific configura- since 1774 based on ring width, maximum den- tions. This is one reason it has been difficult sity, and δ 18O chronologies of Tsuga diversifolia to respond to questions raised by overseas re- and Picea jezoensis var. hondoensis growing searchers, as previously mentioned. The goal of in the Akaishi Mountains, and compare them this special issue is to compare efforts related to records in ancient documents. Those papers to ongoing climate/weather-change research indicate that an analysis of “weather variabil- in various fields and to promote an integrated ities” requires different methods depending on understanding and cross-sectional knowledge the time scale, and interpretation of the results exchanges. An open call for submissions of depends on the scientific point of view. Mon- papers was made through the JAPLS commu- itoring and future predictions of snow-cover nity, and we collected 11 papers from various variability are especially important research fields on state-of-art research trends. We asked themes with regard to mountains, and the fol- the authors to include basic reviews of target lowing two topics demonstrate the matching of topics so that other specialists could more in-situ observation with model outputs. Nishi- easily understand the contents. This issue was mura et al. （2019） conducted 15-year heat- planned in August 2017, and it took one and a budget observations in the Norikura highlands. half years to prepare for publication. The edito- Albedo effects on the short-wave radiation bud- rial board would like to thank the contributors get during the melting season were revealed by for their efforts given such a short period. a comparison of melting ratios using bulk and An outline of this special issue is as follows: degree-day methods. Kawase et al.（ 2019） com- The first four papers are about weather moni- pare snow-depth observations to non-hydrostatic toring, trends in variability, and climate recon- numerical simulations in high mountainous struction. Suzuki and Sasaki （2019） analyze areas, and confirm good model performance in the year-to-year variability of temperature and the year-to-year variabilities of a high-resolution snow depths observed at 14 mountain weather model, although there are discrepancies in pre- stations that have been independently main- cipitation amounts in cases with a poor model tained since 2003. They represent very import- resolution. ant observational signals at high elevations in Relationships between long-term climate central Japan and are expected to reveal cor- change and vegetation changes in the mountains responding large-scale climate variability and are another important research topic. Oguma verify simulation results. Kuribayashi et al. et al.（ 2019） monitor year-to-year variability in （2019） focus on the altitudinal dependence of the timing of snow cover extinction with Alpine annual change rates of precipitation in Nagano plant activities by analyzing images from an Prefecture since 1979, and show that temporal automatic monitoring camera network. Large trends at high-elevation points contributed to year-to-year and point-by-point variabilities the significance of altitudinal dependencies. are identified in both snow cover and phenology Ueno et al.（ 2019） compare daily base surface conditions; however, significant temporal trends gauge precipitation, including JALPS data to are not identified for the 16 years observed. A

― 2 ― horizontal analysis of mountain vegetations, standing and research collaboration. We expect together with geographical information, is anti- subsequent special issues to be published re- cipated. Shimono et al.（ 2019） observed vegeta- lated to mountain studies. We thank all the tion changes in a ten-year plot survey at Koma- authors and reviewers who contributed to this ga take in the Central Japanese Alps. Although special issue. no change in species number was detected, the References total plant count significantly increased with Kawase, H., Iida, H., Aoki, K., Shimada, W., Nosaka, the increase in effective cumulative soil tem- M., Murata, A. and Sasaki, H.（ 2019）: Comparison perature. Sasaki et al.（ 2019） monitored seven of snow cover observations along the Tateyama- years of changes in land-surface conditions Kurobe Alpine route with snow cover simulations after a forest fire. The diurnal cycle of melting- using the non-hydrostatic regional climate model freezing was accelerating due to the reduction （NHRCM） with different horizontal resolutions. Journal of Geography（ Chigaku Zasshi）, 128, 77⊖ of the forest canopy, but no obvious surface 92.（ in Japanese with English abstract） topography changes were identified. Muraoka Kenta, T.（ 2019）: The life-history evolution of plants et al.（ 2019） summarize the outlooks of cross- and its relevance to climate. Journal of Geography cutting studies to reveal and predict carbon, （Chigaku Zasshi）, 128, 147⊖154.（ in Japanese with water, and material cycles in the mountain English abstract） Kuribayashi, M., Yamato, H. and Hamada, T.（ 2019）: forest ecosystem. They propose the importance Altitude dependence of trends of summertime pre- of long-term observations focusing on photo- cipitation during 1979⊖2015 in . synthetic production and its seasonal changes Journal of Geography（ Chigaku Zasshi）, 128, 21⊖ in mountain forests with a combination of 30.（ in Japanese with English abstract） Mountain Research Initiative EDW Working Group ecohydrology and biogeochemical studies in a （2015）: Elevation-dependent warming in mountain forested watershed ecosystem. Kenta （2019） regions of the world. Nature Climate Change, 5, discuss the possible evolution of a plant’s life 424⊖430. history depending on global climate changes Muraoka, H., Maruya, Y. and Nagai, S.（ 2019）: Long- based on life-history theory and experimental term and multidisciplinary research on carbon cycl- ing and forest ecosystem functions in a mountain- studies. ous landscape: Development and perspectives. Jour-­ It is very important to compare and sum- nal of Geography（ Chigaku Zasshi）, 128, 129⊖146. marize the results of each paper, especially to （in Japanese with English abstract） identify the consistency of discussions about Nishimura, M., Sasaki, A. and Suzuki, K. （2019）: weather/climate variability in each time scale Long-term fluctuations, modelling and predictions of the snow accumulation and ablation process in and how they interact. Researchers tend to Norikura highland: Study using an energy balance identify with their own mountains, and some- analysis and ablation models. Journal of Geogra- times avoid conflicts of research topic in the phy （Chigaku Zasshi）, 128, 61⊖75. （in Japanese same observation fields. Mountain studies are with English abstract） Oguma, H., Ide, R., Amagai, Y. and Hamada, T. an interdisciplinary science, and multi-angular （2019）: Using a time-lapse camera network to moni- focuses on and interests in the ongoing envi- tor alpine vegetation phenology and snowmelt times. ronmental changes are welcome. On the other Journal of Geography（ Chigaku Zasshi）, 128, 93⊖ hand, as proposed by Ueno et al.（ 2013） and 104.（ in Japanese with English abstract） Muraoka et al.（ 2019）, establishing super sites Sasaki, A., Kariya, Y. and Suzuki, K.（ 2019）: Geo- environmental changes on Post-fire alpine slopes of for comprehensive observations by renovat- Mt. Shirouma-dake, northern Japanese Alps. Jour- ing or associating existing facilities/functions nal of Geography（ Chigaku Zasshi）, 128, 115⊖127. or creating a research flamework for climate- （in Japanese with English abstract） change assessments strategically focusing on Shimono, A., Makino, J., Muromura, A., Nakamura, H., Sobazhima, N. and Oguma, H.（ 2019）: Vegeta- specifically protected or development areas of tion changes during last decade at Mt. Komagatake. mountains, such as the UNESCO Biosphere Re- Journal of Geography（ Chigaku Zasshi）, 128, 105⊖ serves（ ecopark）, will promote mutual under-

― 3 ― 113.（ in Japanese with English abstract） Ueno, K., Mito, W., Kanai, R., Ueji, Y., Inami, A., Suzuki, K. and Sasaki, A.（ 2019）: Meteorological ob- Suzuki, K., Kobayashi, H., Tamagawa, I., Yamamoto, servations in the Japanese Alps Region. Journal of M.K. and Shige, S.（ 2019）: Distribution of precip- Geography（ Chigaku Zasshi）, 128, 9⊖19.（ in Japa- itation depending on synoptic scale disturbances nese with English abstract） with satellite estimate comparisons in the Japanese Ueno, K. and Watanabe, T.（ 2016）: International tre- Alps area during warm seasons. Journal of Geogra- nds in mountain studies, “Perth III: Mountains of phy（ Chiaku Zasshi）, 128, 31⊖47.（ in Japanese with our future earth”. Journal of Geography（ Chigaku English abstract） Zasshi）, 125, 291⊖298.（ in Japanese with English Watanabe, T. and Ueno, K.（ 2017）: Sangaku, Science abstract） Pallet（ Translation of “Mountains” by M. F. Price）. Ueno, K., Isono, J., Imaizumi, F., Inami, A., Kanai, R., Maruzen, 176p.（ in Japanese） Suzuki, K., Kobayashi, H., Tamagawa, I., Saitoh, Yasue, K., Kubo, N., Akao, M., Sano, M. and Naka- T.M. and Kondo, H.（ 2013）: Data archive of mete- tsuka, T.（ 2019）: Dendroclimatic reconstruction of orological data created through the Japanese Alps summer temperature at the Akaishi Mountains inter-university cooperative project. Journal of Geo­ since A.D. 1774. Journal of Geography （Chigaku graphy（ Chigaku Zasshi）, 122, 638⊖650.（ in Japa- Zasshi）, 128, 49⊖59.（ in Japanese with English ab- nese with English abstract） stract）

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