摘要
应用地面观测站、ERA5再分析资料和高分辨率的WRF模式分析了一次美国博尔德(Boulder)的强下坡风事件,此次强下坡风暴爆发的机制是高空急流带断裂导致动量下传到背风坡山脚处。进一步分析表明,强下坡风的爆发与天气尺度系统高压脊过境及局地的背风坡重力波有关。在焚风的作用下,背风坡持续变暖导致重力波加强并转竖,侵蚀对流层顶的急流带,最终导致急流带断裂,高空动量下传至地面,强下坡风暴在背风坡爆发。
This study uses ground station observations,ERA5 reanalysis datas and a high-resolution WRF model simulation to analyze a downslope windstorm event in Boulder,United States.It is believed that the mechanism of this downslope windstorm outbreak is the downward transfer of momentum to the foot of the leeward slope caused by the rupture of the high-altitude jet belt.Further analysis shows that the outbreak of the downslope windstorm is related to the passage of synoptic scale high-pressure ridges and local leeward slope gravity waves.Under the influence of the foehn,continuous warming on the leeward slope causes gravity waves to strengthen and turn vertically,eroding the top of the troposphere's jet zone and ultimately leading to the rupture of the jet with high-altitude momentum transferred to the ground,as a result,the downslope windstorm erupted on the leeward slope.
作者
余静梅
胡非
汤胜茗
YU Jingmei;HU Fei;TANG Shengming(Shanghai Typhoon Institute,China Meteorological Administration,Shanghai 200030,China;State Key Laboratory of Atmospheric boundary layer Physics and Atmospheric Chemistry,Chinese Academy of Sciences,Beijing 100029,China)
出处
《气象学报》
CAS
CSCD
北大核心
2024年第1期68-79,共12页
Acta Meteorologica Sinica
基金
国家重点研发计划项目(2021YFC3000804)。
关键词
强下坡风
地形重力波
高空急流
动量下传
焚风
Downslope windstorm
Orographic gravity waves
High-level jet
Momentum downward transmission
Foehn
