Kenichi Ueno

University of Tsukuba · School of Life and Environmental Sciences

This paper is an attempt to bring forth situations of UV radiation levels or UV index (UVI) and effects affecting different causes to concerned living beings and on environment in the Himalayas. It has analyzed solar radiation data observed at different locations, covering the elevation range of 2735 meters (m) above sea level (a.s.l.) to 4355 m a....

Based on 15 years of snow pit observation data in Sugadaira Highland, the year-to-year variations of weather patterns influencing the snowpack properties were examined. A significant relation between the snow depth in mid-February and the total precipitation after persistent snow cover was found. The ratio of the total thickness of melt forms in th...

Long-term hourly data records of the Automated Meteorological Data Acquisition System (AMeDAS) with snow depth measurements at three high elevation sites were analyzed in central Japan to assess the decadal scale winter climate variabilities with the effects of observation biases. Year-to-year variations of persistent snow cover periods (PSCPs) did...

Mountains comprise complex relief roughness with various land surface conditions, and regional weather/climate and orographic landscapes, including formation of glaciers, are characterized by land–atmosphere dynamic interactions. In the first half of this chapter, we introduce important rules of atmospheric boundary layer and water cycles by means...

Nocturnal temperature inversion (NTI) is an important factor characterizing the local climate in mountainous areas. In central Japan, most of the mountain slopes are covered by forests, but the effects of their leaf expansion/fall on the NTI variations in basins have not been clarified. According to a three-year leaf area index (LAI) observation in...

Few studies have revealed the statistical tendencies of occurrences for cloud, fog, heavy rain or snowfall that characterizes mountain weather variabilities in Japan. Characteristics of seasonal and diurnal variations in fog and mist discriminated by visibility, precipitation types and precipitation intensity were clarified using data from November...

Intra-seasonal variation of surface air temperature observed by the automatic weather station at Syangpoche in Khumbu region, Nepal Himalayas, is analyzed. In the monsoon season, temperature was nearly constant with large decrease in insolation due to monsoon clouds. On the other hand, large intra-seasonal variation existed in the winter with incre...

A numerical experiment with a 2-km resolution was conducted using the Weather Research and Forecasting (WRF) model to investigate physical processes driving nocturnal precipitation over the Himalayas during the mature monsoon seasons between 2003 and 2010. The WRF model simulations of increases in precipitation twice a day, one in the afternoon and...

Heavy precipitation events were identified during the cold seasons of 2014-2019 using two-day accumulated precipitation data at 137 stations of the Japan Meteorological Agency. The mechanisms for producing heavy precipitation regarding the structure of an occluding extratropical cyclone were analyzed using the products of the Dual-frequency Precipi...

This article provides insights from a survey of education programs for sustainable mountain development (ESMD) and comments on the findings from the perspective of United Nations Educational, Scientific and Cultural Organization's.(UNESCO) Education for Sustainable Development (ESD) for 2030 framework. Twenty-eight programs implemented by universit...

This paper is an attempt to bring forth situations of UV radiation levels or UV index (UVI) and effects affecting different causes to concerned living beings and on environment in the Himalayas. It has analyzed solar radiation data observed at different locations, covering the elevation range of 2735 meters (m) above sea level (a.s.l.) to 4355 m a....

A fifth highest event of two-day accumulation precipitation in Honsyu area (Jan. 17-18, 2016) was nominated during the 10 winters since 2006 (Anzai and Ueno, 2018). Then, using Global Precipitation Measurement (GPM) dual-frequency precipitation radar (DPR) products, a case study was conducted to reveal the three-dimensional and synoptic scale struc...

The Third Pole (TP) is experiencing rapid warming and is currently in its warmest period in the past 2,000 years. This paper reviews the latest development in multidisciplinary TP research associated with this warming. The rapid warming facilitates intense and broad glacier melt over most of the TP, although some glaciers in the northwest are advan...

Gauge-based hourly precipitation data during the 2015-2016 warm seasons in central Japan observed with the Japan Meteorological Agency AMeDAS network and the Japanese Alps Inter-University Cooperation Project (JALPS) mountain observation network are archived. Gauge data are compared to satellite precipitation data (GSMaP_MVK and GPM/DPR) produced b...

Sediment transport activities in periglacial environments are controlled by microclimate conditions (i.e., air and ground temperatures, throughfall), which are highly affected by vegetation cover. Thus, there is the possibility that forest harvesting, the most dramatic change to vegetation cover in mountain areas, may severely impact sediment trans...

Relations between the diurnal change of the radar echo areas and surface condition were examined at the central Tibetan Plateau during the monsoon season in 1998. During the late June, under the synoptic conditions of prevailing surface heat low with Tibetan anticyclone, a weekly time scale modulation was clearly observed in the diurnal changes of...

Sediment transport activities in the periglacial environment are controlled by hillslopes micrometeorological conditions (i.e., air and ground temperatures, ground water content), which are highly affected by vegetation cover. Thus, there is a possibility that forest harvesting, which is the most dramatic change to vegetation cover in mountain area...

Seasonal and diurnal variation of temperature profile in mountain forest was observed for a year, and relation to forest phenology was discussed.

Changes in precipitation distribution associated with a surface temperature rise in the late 1980s, which accompanied a climatic regime shift, are investigated using Automated Meteorological Data Acquisition System (AMeDAS) data of the Japan Meteorological Agency, and their relations with the variability of surface pressure patterns are revealed. A...

The international conference “Perth III: Mountains of Our Future Earth” was held in Perth, Scotland on Oct. 4-8, 2015. International trends in mountain studies observed at the meeting are examined, following a brief history of recent international mountain studies. Field trips and educational activities associated with the meeting are also introduc...

The locations of initiating Mesoscale Convective Systems (MCSs) in southwest (SW) China were examined using the Chinese geosynchronous satellite of China, and differences in synoptic-scale conditions were analyzed with Japanese objective analysis data. MCSs tended to occur along western mountainous margins in the evening, and those in the central S...

The top 30 days of two-day rainfall total amounts or snowfall depths from Dec. to Mar. from 1981 to 2014 were counted at 28 AMeDAS stations located in the inland district of Japan as “heavy precipitation days” (HPD) or “heavy snowfall days” (HSD). Long-term trends of HPD/HSD frequency and geographical distribution were examined. In the analysis, li...

Freezing and thawing processes play an important rule for the gravitational transport of surface materials on steep mountain slopes in Japan. The effects of deforestation on frost heave activity were observed through the 2012/13 winter season in Ikawa University Forest, a southern mountainous area in central Japan (1180–1310 m above sea level). Dur...

Diurnal variations of surface wind speeds during fair weather in the summer were revealed in central Japan, including data at Automated Meteorological Data Acquisition System (AMeDAS) and mountain station data above 2000 m above the mean sea level (a.s.l.) archived by an inter-university cooperative project, in relation to the altitude and concave-...

The distribution of weather divides in Japanese winters was identifi ed using 30-year data of the Automated Meteorological Data Acquisition System AMeDAS operated by the Japan Meteorological Agency. Two kinds of weather divide were defined, one is a cloudy weather divide CWD determined by the high-frequency grids of large gradients in the sunshine...

The temporal tendency of winter rain events in the Sugadairakogen Highlands was investigated using 33 years daily records of rainfall/snowfall discrimination at the Sugadaira Montane Research Center, University of Tsukuba, and the characteristics of atmospheric circulation in relation to the precipitation-phase changes were analyzed for 12 precipit...

An intensive field observation was implemented for the Tibetan Plateau from early spring to the mature season of the Asian summer monsoon in 2008. Atmospheric conditions in the early spring and the pre-monsoon season are investigated in detail using radiosonde observation data. In early spring, atmospheric profiles show unstable stratification, whi...

The one-dimensional structure of a daytime planetary boundary layer (PBL) with shallow cloud development was captured by intensive sonde observation during the late winter season at the central Tibetan Plateau (TP), and its relationship to patchy snow cover conditions was revealed. The diurnal change of potential temperature was evident in the atmo...

In this study, we revealed and discussed the role of mesoscale convective systems (MCSs) in the eastward expansion of an upper tropospheric high (UH, that is South Asian High or Tibetan High) with a timescale of a few days over the Asian monsoon region in the summers of 1999–2008. The MCSs was extracted using hourly satellite images. The distributi...

A 12 year archive of the Tropical Rainfall Measuring Mission (TRMM) rain rate is used to document the regionality of diurnal rainfall cycle in the Yangtze River Valley (YRV). The regional rain peaks, local phase shifts, rain event's behavior, and related seasonal change from March to August are examined. In the middle reach of YRV, rainfall appears...

Rain gauge data for the period of 1998–2004 from the Syangboche Automated Weather Station (S-AWS) site in the Nepal Himalayas were compared with multi-satellite precipitation products for the period of 2003–2005, employing several retrieval algorithms: the Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA), the...

The generation processes of mesoscale convective systems (MCSs) that occurred over the Sichuan Basin in China were revealed in the early 2008 monsoon season. MCS occurrences detected in METEOSAT geostational satellite images are associated with the traveling of midlatitude troughs after the onset of the Indian monsoon. Three episodes of large-scale...

The Qinghai - Tibet Plateau is characterized by a significant intra-annual variability and spatial heterogeneity of surface conditions. Snow and vegetation cover, albedo, surface temperature and wetness change very significantly during the year and from place to place. The influence of temporal changes on convective events and the onset of the mons...

This study revealed the formation processes of mesoscale convective systems (MCSs) over the eastern Tibetan Plateau (TP), associated with the establishment of subplateau-scale convergences affected by the longitudinal surface wetness gradient. Composites of reanalysis data and satellite infrared images showed that large MCSs occurred in the afterno...

In the 1998 monsoon season, precipitation from midnight through early morning was frequently observed in the central Tibetan Plateau (TP). It occurred on several successive days and tended to be accompanied by low-level easterly winds. Global Energy and Water Cycle Experiment (GEWEX) Asian Monsoon Experiment (GAME) reanalysis data also showed easte...

The passing of a synoptic trough is expected to contribute strongly to water vapor (WV) transport processes from the Indian Ocean to the Tibetan Plateau (TP) during the monsoon season. However, the pathway of the WV into the plateau associated with passing a trough and its contribution to the WV budget over the TP are not clear. In this study, the...

1] Surface air temperature, observed in the eastern Nepal Himalayas, showed large intraseasonal and year-to-year variability during the nonmonsoon season. A significant negative correlation was found in the monthly outgoing longwave radiation (OLR) between the area over the Himalayas and tropical areas between 80 and 150°E, which was confirmed by i...

Mountain weather changes in the Nepal Himalaya were intensively examined during the 2003 monsoon onset using in situ datasets, observed by multiple automatic weather stations (AWS) distributed across the Coordinated Enhanced Observing Period (CEOP) Himalaya reference site at locations with significant differences in altitude. Onset of monsoon rainf...

プロ野球球場として有名な千葉マリンスタジアム（千葉県千葉市）では他球場に比べて強風が頻発する．本研究では，千葉アメダスデータを解析し，暖候期に卓越する強風の原因は，関東以北に位置する低気圧や寒冷前線通過時に吹き込む南西風が，粗度の小さい東京湾上から直接千葉市沿岸に侵入するためである事を特定した．また，現 地観測により，海側から吹き込む風系は千葉アメダスと幕張で良く一致している事を確認した．次に，スタジアムのようなドーナッツ型の建築物周辺で発生する気流系の特徴を，大型風洞を利用した実験により明らかにした．作成したスタジアム模型の内部には明瞭な逆流が発生し，順流との境界およびスタジアム後面で乱れの大きな領域が 発生した．逆流域の範囲は模型前方の粗度や屋根の高さに依存していた．現地観測により，スタ...

Surface conditions in the non-mountainous areas of the central Tibetan Plateau were measured in a field survey in February 2004, and water balance parameters such as precipitation, sublimation, and water equivalent of snow cover were examined through the 2003/2004 winter by in situ automated measurements. Snow cover was shallow and coexisted with s...

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Causes of high photochemical oxidant at Nagahama city, located in the O-mi basin, were examined by using surface meteorological data from the 1992-2001 warm seasons. Long-range transportation of photochemical oxidants from Osaka, Kyoto and Fukui prefecture was not detected in cases where the weather was favorable. There was a possibility of transpo...

The characteristics of atmospheric circulations in Asia causing snowfalls over the central Tibetan Plateau (TP) were investigated during the nonmonsoon season. During 1994–2004, a clear pattern of a barotropic pressure anomaly was found over northeast Asia by means of composite analysis. NCEP reanalysis data and METEOSAT images were examined for sn...

Land-atmosphere interactions on the Tibetan Plateau are important because of their influence on energy and water cycles on both regional and global scales. Flux variance and eddy covariance methods were used to measure turbulent fluxes of heat, water vapor, and momentum over a Tibetan shortgrass prairie during the Global Energy and Water Cycle Expe...

[1] Land-atmosphere interactions on the Tibetan Plateau are important because of their influence on energy and water cycles on both regional and global scales. Flux variance and eddy covariance methods were used to measure turbulent fluxes of heat, water vapor, and momentum over a Tibetan shortgrass prairie during the Global Energy and Water Cycle...

The energy and water cycle over the Tibetan Plateau play an important role in the Asian monsoon system, which in turn is a major component of both the energy and water cycles of the global climate system. The intensive observation period and long-term observation of the GEWEX (global energy and water cycle experiment) Asian monsoon experiment on th...

The soundings, precipitation and radar data obtained from IOP of GAME-TIBET in the summer of 1998 are used to analyze the diurnal variations of precipitation and thermodynamic variables CAPE, LCL and relationships between precipitation and thermodynamic variables in monsoon season. The diurnal variations of precipitation are obvious. Maximum precip...

The energy and water cycle over the Tibetan Plateau play an important role in the Asian monsoon system, which in turn is a major component of both the energy and water cycles of the global climate system. The intensive observation period and long-term observation of the GEWEX (global energy and water cycle experiment) Asian monsoon experiment on th...

ネパールヒマラヤ及びチベット高原における近年の気候変化の実態を解説し,ヒマラヤでの気象観測の現状を紹介した.Shrestha et al.(1999), Liu and Chen(2000)らの研究によれば,同地域の地上気温には明らかに昇温傾向がみとめられ,特に高所・寒侯期ほど顕著である.一方,降水量の長期傾向は明らかではなく,大きな年々変動が存在する.1990年代以降にヒマラヤにおける自動気象観測が多数実施されるようになり,山岳気象の年々変動の様相が明らかにされつつある.

There is a need to compare and understand the characteristics of the land surface models used in the GAME (GEWEX Asian Monsoon Experiment) project with a common forcing data in order to integrate the various products of the project. We successfully drove the JMA-SiB, CCSR/NIES-LAND, MATSIRO and TOHOKU models, using the GAME/Tibet POP97 data (during...

In order to reveal the characteristics of convective clouds over the Tibetan Plateau, we carried out Doppler radar observations of the clouds in the suburbs of Naqu city (4500 m ASL), which is located in the central part of the Tibetan Plateau, from 27 May to 19 September 1998, during the intensive observation period of the GEWEX Asian Monsoon Expe...

This study analyzed the temporal and spatial scales, types, and intensity of precipitation with their temporal variability by using the precipitation data, intensively observed as part of the GAME-Tibet international project, at the Naqu basin (4500-5000 m) in the Tibetan Plateau from was to September, 1998. The monsoon period at the basin was defi...

During the GAME-Tibet Intensive Observation Period (IOP), the precipitation radar (PR) of the Tropical Rainfall Measuring Mission (TRMM) satellite detected a diurnal cycle of rainfall in Tibet. Much rainfall was brought both by convection in the daytime and by stratiform precipitation over a wide rain area in the evening and night. Two case studies...

Precipitation distribution around the Tibetan Plateau was examined by using satellite data of the Geostationary Meteorological Satellite Infrared channel (GMS/IR) and Special Sensor Microwave/Imager (SSM/I). These data were compared with observed precipitation and a product of Xie and Arkin (1997), in 1993 monsoon season. Three kinds of algorithms...

Precipitation in the monsoon season on the Tibetan Plateau occurs as rain or snow depending on the elevation and temperature conditions. Point measurements of precipitation may not describe the accurate spatial distribution if systematic-error corrections of precipitation measurement are not applied. Precipitation data at 5 points intensively obser...

Three major teleconnection patterns prevailing at 500hPa height, e. g., North Atlantic Oscillation (NAO), Pacific-North American (PNA) and Western Pacific (WP) patterns, are investigated in the northern Winter season associated with cyclone tracks and precipitation patterns. Cyclone position and tracks, objectively analyzed using NCAR Sea Level Pre...

Temperature and humidity fields in the low-level atmosphere around cyclones, which are assumed to differ for each individual cyclone, were objectively analyzed through a year on the hemispheric scale to detect their representative spatial patterns. Geographical and seasonal characteristics for the appearance of cyclones as related to these patterns...

A statistical study was carried out to clarify the relations between the change of AMeDAS hourly precipitation distribution and the topography in different spatial scales. A weighted-averaging interpolation scheme was applied to filter the isohyetal map. The weighting factor was taken as a function of three different radii (R=0.25°, 0.5°and0.75°)....

Thesis--University of Tsukuba, D.Sc.(A), no. 876, 1991. 3. 25

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