Comparative Study on Fine Characteristics of Surface Wind Field in Winter and Early Spring over Yanqing Complex Terrain during Beijing Winter Olympics

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  • 1. Institute of Urban MeteorologyChina Meteorological AdministrationBeijing 100089China
    2. Ocean University of ChinaQingdao 266100ShandongChina
    3. Beijing Meteorological Data CenterBeijing 100089China
    4. Urban Meteorological Key Open LaboratoryChina Meteorological AdministrationBeijing 100089China
    5. Beijing Urban Meteorological Engineering Research CenterBeijing 100089China

Online published: 2024-10-22

Abstract

Wind is one of the most important meteorological conditions in previous Winter Olympicsand it is the primary factor that affects the mountain events for Beijing Winter Olympics. Understanding the fine distribution law of wind can provide important theoretical basis for track constructionwind forecast and prevention measures. Using hourly observation data from surface automatic weather stations at different altitudes in Yanqing mountain area of Beijing Winter Olympics from December 2017 to March 2022this study investigated the characteristics of local wind field during winter and early springMarParalympics periodunder complex terrainfocusing on comparing the frequency of wind speeds and directionsas well as the diurnal and seasonal variations. Firstlyall stations were grouped into four categories using the K-Means clustering algorithmand Groups 1 to 4 represent the low-elevation Yangqing suburb areathe northeastern foothills transition areathe southwest‐ ern transition area and the high-elevation mountain top arearespectively. Subsequentlyfine-grained characteristic analysis was conducted on each group separately. Results show that:(1The frequency of strong winds is closely related to the altitudewith higher altitudes generally having a higher frequency of strong winds. In Groups 1~2altitude below 1000 m),the frequency of light winds≤3. 3 m·s-1exceeds 80%while the propor-tion of strong winds≥10. 7 m·s-1is 0%. In Group 3above 1000 m),the frequency of light winds decreases to below 75%and strong winds occasionally occur for less than 1%. In Group 4above 1800 m),there is a significant shift in the wind speed frequency distributionwith the frequency of strong winds increasing to above 10%which is much higher during winter compared to early spring.2There are significant local variations in the distribution characteristics of wind directions. Group 4 is primarily dominated by large-scale winter monsoonal circulationresulting in a prevailing northwesterly windwith rare concurrence of other wind directions. Groups 1~ 3 are influenced by a combination of large-scale circulationvalley wind circulation and underlying surface conditionsleading to different frequencies for each wind direction.3The diurnal variation exhibits contrasting characteristics between high and low elevations. Groups 1~3 show lower wind speeds at night and higher wind speeds during the daywhile Group 4 shows a reserved pattern and an obvious small wind “window period” in midday. Groups 1~3 exhibit distinct daily transitions in wind directionoccurring after sunrise and sunsetwhere‐ as Group 4 does not show any diurnal change.4From a seasonal perspectivethere are significant local differences between early spring and winter. Compared to winterGroup 2 exhibits a daytime wind speed increase in early springand Group 3 exhibits a nighttime decreasewhile Group 4 exhibits a significant decrease in wind speeds throughout the day. Wind directions in early spring are relatively more variablewith an evident increase in northeasterly winds in Group 1a delay of about 3 hours in the transition of valley wind circulation in Group 2and an increase in southwesterly winds in Groups 3~4. This study contributes to a deeper comprehension of the fine-scale spatiotemporal patterns of near-surface local wind fields within complex terrainsand can offer crucial background clues for Winter Olympics and small-scale mountainous meteorological monitoring and forecasting.

Cite this article

XU Jingfeng, SONG Linye, CHEN Jing, YANG Lu, CHEN Mingxuan, HAN Lei . Comparative Study on Fine Characteristics of Surface Wind Field in Winter and Early Spring over Yanqing Complex Terrain during Beijing Winter Olympics[J]. Plateau Meteorology, 0 : 1 . DOI: 10. 7522/j. issn. 1000-0534. 2024. 00071

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