Observational Studies of Low Altitude Wind Shear (LAWS) formed in the Lee of Mountains

スポンサーリンク

概要

• 論文の詳細を見る

• The purpose of this study is to further our understanding of LAWS occurring in the lee of mountains through an observational investigation of the formation processes. The location of the study is Hanamaki Airport, situated in a basin in the Tohoku Region, Japan, where there is many reports of LAWS. A statistical analysis, based on LAWS reports submitted by flight pilots, and surface wind data observed at the airport, revealed the importance of changes in wind direction, as well as wind speed when an aircraft encounters LAWS. Thus, the standard deviation of the horizontal wind vector is defined as a WSI (Wind Shear Index) to evaluate the occurrence of severe LAWS. A case study using upper wind data in the boundary layer, recorded by commercial aircraft flying through severe LAWS systems, pointed out the importance of both a sudden change in wind direction and a descending current, especially close to the ground. To clarify the fine structure and formation process of these wind characteristics, a six-month observation of the boundary layer winds, using a Doppler sodar installed at the airport, was conducted from December, 1996. A WSI analysis was applied to Doppler sodar observations and revealed the following three significant factors when a severe LAWS system is formed: 1) A strong westerly wind in the middle or upper boundary layer, causing a high WSI current, is observed; 2) The process in which a high WSI peak reaches from the boundary layer down to the ground; 3) and, A descending current is present close to the ground after the high WSI peak touches down.

• 社団法人日本気象学会の論文
• 2001-02-25

著者

• Kikuchi Katsuhiro

  Division of Environmental Structure, Graduate School of Environmental Science, Hokkaido University

• Mori Shuichi

  Division Of Earth And Planetary Sciences Graduate School Of Science Hokkaido University:(present Aff

• UYEDA Hiroshi

  Division of Earth and Planetary Sciences, Graduate School of Science, Hokkaido University

• Kikuchi Katsuhiro

  Division Of Earth And Planetary Sciences Graduate School Of Science Hokkaido University

• Uyeda Hiroshi

  Division Of Earth And Planetary Sciences Graduate School Of Science Hokkaido University

• Kikuchi Katsuhiro

  Division Of Earth And Planetary Sciences Graduate School Of Science Hokkaido University:(present Affiliation)faculty Of Bioresource Sciences Akita Prefectural University

関連論文

• On the Atmospheric Aerosol Particles in Relation to the Pressure Patterns in Winter Season, Sapporo, Japan
• Internal and Meso-γ Scale Structures of Baiu Frontal Rainbands Observed at Shigaraki, Shiga Prefecture by using a Dual-Polarization Dropper Radar
• Doppler Radar Observations of Orographic Effects of Isolated Echoes during the Baiu Season at Nagasaki Prefecture, on July 14 and 15, 1988
• Dual-Doppler Radar Observations on Factors Causing Differences in the Structure of Snow Clouds during Winter Monsoon Surges
• In Situ Growth Experiments on "Gohei Twins" Snow Crystals Observed at Inuvik in Arctic Canada
• Relationship between Ice Nuclei and Snowfalls Observed in the Arctic Regions
• STUDIES ON WATER VAPOR, AEROSOL AND SNOW CRYSTALS IN THE ARCTIC (WANTS-ARCTIC; CANADA)
• ON THE SUPERCOOLED DRIZZLE OBSERVED AT INUVIK IN THE MID-WINTER SEASON (WANTS-ARCTIC; CANADA)
• ON THE SNOW CRYSTALS OF LOW TEMPERATURE TYPES
• On the formation of snow crystals of the "Gohei" type (abstract)
• OBSERVATIONS OF LIQUID WATER, WATER VAPOR, AND DOWNWARD FLUX OF INFRARED RADIATION IN THE ARCTIC REGION WITH A MICROWAVE RADIOMETER AND A PYRGEOMETER
• Roughness of Cloud Top Surfaces of Winter Stratocumulus Clouds over the Ocean : Preliminary Investigations on Cloud and Radiation
• Structures of Planetary Boundary Layers Observed by a Doppler Sodar in a Cold Season at Sapporo, Japan
• Airflow Circulations in the Precipitation Clouds over the Southeastern Slope of the Orofure Mountain Range, Hokkaido, Japan
• Two Case Studies of Heavy Rainfalls from the Stratiform and Convective Precipitation Clouds in the Orofure Mountain Range, Hokkaido, Japan
• A Case Study of Heavy Rainfalls from the Shallow Orographic Precipitating Clouds in the Orofure Mountain Range, Hokkaido, Japan
• Observational Studies of Low Altitude Wind Shear (LAWS) formed in the Lee of Mountains
• The Snow Crystals of "Double Gohei Twin Types"
• Time variations of the number concentrations of aerosol particles in west Greenland (abstract)

もっと見る 閉じる

スポンサーリンク