Kouichi Nishimura
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View article: Parameterizing Snow Sublimation in Conditions of Drifting and Blowing Snow
Parameterizing Snow Sublimation in Conditions of Drifting and Blowing Snow Open
Snow transport favors strong sublimation and may therefore have an important effect on the surface mass balance of polar and high‐mountain regions. Recently, small‐scale models such as large‐eddy simulation (LES) with Lagrangian snow parti…
View article: Using Arctic field data and remote sensing BrO data to constrain blowing snow sea salt aerosol production parameterizations
Using Arctic field data and remote sensing BrO data to constrain blowing snow sea salt aerosol production parameterizations Open
Field evidence has confirmed a new sea salt aerosol (SSA) source on sea ice, which may significantly affect polar boundary layer chemistry and polar winter climate. While the SSA production rate from blowing snow has been previously parame…
View article: Direct observation of Arctic Sea salt aerosol production from blowing snow and modeling over a changing sea ice environment
Direct observation of Arctic Sea salt aerosol production from blowing snow and modeling over a changing sea ice environment Open
In the polar regions, there is significant model bias in the number concentrations and seasonality of sea salt aerosol (SSA) due to the lack of understanding of aerosol sources associated with sea ice, which is hampering accurate climate f…
View article: Quantitative Evaluation of Probabilistic Hazard Mapping With Polynomial Chaos Quadrature and Its Practical Application
Quantitative Evaluation of Probabilistic Hazard Mapping With Polynomial Chaos Quadrature and Its Practical Application Open
Snow avalanches pose a significant threat to settlements and their inhabitants. Consequently, hazard maps that delineate avalanche runout areas serve as valuable tools for mitigating their destructive impact. Dynamic models have been used …
View article: Elucidation of spatiotemporal structures from high-resolution blowing-snow observations
Elucidation of spatiotemporal structures from high-resolution blowing-snow observations Open
Systematic observations were conducted to investigate the spatiotemporal structures of blowing snow. Along a line perpendicular to the dominant wind direction on the lee side of a flat field, 15 snow particle counters (SPCs) and ultrasonic…
View article: Quantitative evaluation of probabilistic hazard mapping with polynomial chaos quadrature and its practical application
Quantitative evaluation of probabilistic hazard mapping with polynomial chaos quadrature and its practical application Open
Snow avalanches pose a significant threat to settlements and their inhabitants. Consequently, hazard maps are a valuable tool for mitigating their impact. Dynamic models have been used to visualize areas affected by avalanches; however, th…
View article: Parameterizing Snow Sublimation in Conditions of Drifting and Blowing Snow
Parameterizing Snow Sublimation in Conditions of Drifting and Blowing Snow Open
Snow transport favors strong sublimation and may therefore have an important effect on the surface mass balance of polar and high-mountain regions. Recently, small-scale models such as large-eddy simulation (LES) with Lagrangian snow parti…
View article: Research on avalanches caused by stability of snow cornices developed by blowing snow
Research on avalanches caused by stability of snow cornices developed by blowing snow Open
Our research is aimed at improving the prediction accuracy of avalanches caused by the stability of snow cornices developed by blowing snow in the Niseko region, one of Japan's international ski resorts. For this purpose, several studies w…
View article: Co-creation with local governments and ski resorts to generate scientific information that contributes to ski resort avalanche safety management
Co-creation with local governments and ski resorts to generate scientific information that contributes to ski resort avalanche safety management Open
In the Niseko area in Hokkaido, Japan, a unique set of rules -the "Niseko Rules"- control the opening and closing of gates to allow off-course skiing according to the avalanche danger level. In recent years, the need for scientific evidenc…
View article: Avalanche hazard mapping in Langtang, Nepal
Avalanche hazard mapping in Langtang, Nepal Open
The 2015 Gorkha earthquake in Nepal triggered a large avalanche in Langtang, covering the village with avalanche debris and causing severe damage. The analysis of this disaster was conducted using an avalanche dynamics simulation, which es…
View article: Reply on RC2
Reply on RC2 Open
Abstract. Systematic observations were conducted to investigate the spatio-temporal structures of blowing snow. Along a line perpendicular to the dominant wind direction on the leeside of a flat field, fifteen Snow Particle Counters (SPCs)…
View article: Reply on RC1
Reply on RC1 Open
Abstract. Systematic observations were conducted to investigate the spatio-temporal structures of blowing snow. Along a line perpendicular to the dominant wind direction on the leeside of a flat field, fifteen Snow Particle Counters (SPCs)…
View article: Comment on egusphere-2023-1845
Comment on egusphere-2023-1845 Open
Abstract. Systematic observations were conducted to investigate the spatio-temporal structures of blowing snow. Along a line perpendicular to the dominant wind direction on the leeside of a flat field, fifteen Snow Particle Counters (SPCs)…
View article: Elucidation of Spatiotemporal structures from high-resolution blowing snow observations
Elucidation of Spatiotemporal structures from high-resolution blowing snow observations Open
Systematic observations were conducted to investigate the spatio-temporal structures of blowing snow. Along a line perpendicular to the dominant wind direction on the leeside of a flat field, fifteen Snow Particle Counters (SPCs) and Ultra…
View article: Sea salt aerosol and ice nucleating particles (INP) in the Central Arctic during winter/spring – a discussion of a source from blowing snow above sea ice
Sea salt aerosol and ice nucleating particles (INP) in the Central Arctic during winter/spring – a discussion of a source from blowing snow above sea ice Open
Arctic clouds are poorly represented in climate models partly due to a lack of understanding of their source and nucleating capability of natural aerosol in the high Arctic. Recent field campaigns provided evidence of a source of sea salt …
View article: Numerical simulation of snow avalanches using a continuum body model considering development and decrescence processes
Numerical simulation of snow avalanches using a continuum body model considering development and decrescence processes Open
固液混相流である土石流・泥流を一流体連続体モデルとして扱った数値シミュレーションモデルの物性値を雪崩の値に置き換え，固気混相流である雪崩の発達・減衰過程を考慮した数値シミュレーションモデルを開発した．また，開発した雪崩の数値シミュレーションモデルを2020年2月に北海道のピンネシリ岳及び2019年3月に栃木県の茶臼岳で発生した雪崩に適用し，雪崩の流動現象の再現を試みた．その結果，ピンネシリ岳の雪崩の堆積域は，堆積場所，堆積域の大きさなど，現地の堆積域と近い値となった．また，…
View article: Relation between mean and instantaneous values of snow-drift flux under drifting snow
Relation between mean and instantaneous values of snow-drift flux under drifting snow Open
吹雪は,風により雪が空気中を輸送される現象であり,乱流による気流の変動に伴い,その性状が,時間・空間的に大きく変動する.そのため,吹雪の特徴量に関しては,定常的な性状だけでなく,乱流変動に伴うばらつきなど非定常的な性状の把握も重要である.本研究では,浮遊層の乱流変動とそれに伴う飛雪流量の変動や稀に発生する大きな飛雪流量の現象を把握することを目的として,北海道弟子屈町の雪原で吹雪のタワー観測を実施し,1.0,1.5,3.0,7.0 mの4高度の風速及び飛雪流量の時系列データを…
View article: Hysteresis and Surface Shear Stresses During Snow-Particle Aeolian Transportation
Hysteresis and Surface Shear Stresses During Snow-Particle Aeolian Transportation Open
Surface shear stresses produced by wind and particle collision play a key role in aerodynamic entrainment and splash processes. The fluid shear stress at the surface during aeolian transport has been researched for decades; however, the eq…
View article: Calculation of Snowdrift Distribution over Complex Topography to Improve the Accuracy of Snow Avalanche Warning Systems
Calculation of Snowdrift Distribution over Complex Topography to Improve the Accuracy of Snow Avalanche Warning Systems Open
We introduce a new procedure to evaluate the snowdrift distribution over complex topography and improve the accuracy of snow avalanche warning systems. We select the Niseko region, Japan, as the target area, and first obtain the wind distr…
View article: Perspectives on Snow Avalanche Dynamics Research
Perspectives on Snow Avalanche Dynamics Research Open
As an introduction for non-specialists to the Special Issue on snow avalanche dynamics, this paper first outlines how understanding the dynamics of snow avalanches can contribute to reducing risk for settlements and infrastructure. The mai…
View article: Techniques of blowing snow measurements
Techniques of blowing snow measurements Open
雪面上を吹き渡る風によって雪粒子が舞い上げられ移動する吹雪は,極地や山岳地,氷河氷床上の水・エネルギー循環や質量収支から道路や鉄道,建築分野における雪害に至るまで,様々な分野に深く関連する雪氷現象である.各々の分野において吹雪の現象そのものや影響を評価する目的で,長年にわたり,様々な計測や観測,調査が試みられてきた.本稿では,吹雪量や空間密度などの基礎的な計測から,防災・建設分野等の応用分野における調査方法等,吹雪に関する計測,調査方法を解説する.
View article: Application of an Inertia Dependent Flow Friction Model to Snow Avalanches: Exploration of the Model Using a Ping-Pong Ball Experiment
Application of an Inertia Dependent Flow Friction Model to Snow Avalanches: Exploration of the Model Using a Ping-Pong Ball Experiment Open
Snow avalanches are catastrophic phenomena because of their destructive power. Therefore, it is very important to forecast the affected area of snow avalanches using numerical simulations. In our study, we focus on applying a numerical mod…
View article: Seismic localization and dynamical characterization of snow avalanches and slush flows of Mt. Fuji, Japan
Seismic localization and dynamical characterization of snow avalanches and slush flows of Mt. Fuji, Japan Open
<p>Snow avalanches and slush flows are often released at the stratovolcano of Mt. Fuji, which is the highest mountain of Japan (3776 m a.s.l.). These flows represent a major natural hazard as they may attain run-out distances up to 4…
View article: First direct observation of sea salt aerosol production from blowing snow above sea ice
First direct observation of sea salt aerosol production from blowing snow above sea ice Open
Two consecutive cruises in the Weddell Sea, Antarctica, in winter 2013 provided the first direct observations of sea salt aerosol (SSA) production from blowing snow above sea ice, thereby validating a model hypothesis to account for winter…